Publikationen VS: Bibliographie BibTeX
@inproceedings {INPROC-2021-01,
author = {David Hellmanns and Lucas Haug and Moritz Hildebrand and Frank D{\"u}rr and Stephan Kehrer and Ren{\'e} Hummen},
title = {{How to Optimize Joint Routing and Scheduling Models for TSN Using Integer Linear Programming}},
booktitle = {Proceedings of the 29th International Conference on Real-Time Networks and Systems},
editor = {ACM},
address = {Nantes},
publisher = {ACM (Online)},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {1--12},
type = {Konferenz-Beitrag},
month = {April},
year = {2021},
isbn = {10.1145/3453417.3453421},
keywords = {Time-Sensitive Networking, TSN, Scheduling, Routing, Integer Linear Programming, Optimization, Model, ILP},
language = {Englisch},
cr-category = {D.4.7 Operating Systems Organization and Design},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2021-01/INPROC-2021-01.pdf},
contact = {david.hellmanns@ipvs.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Reliable real-time communication is an essential technology for industrial
manufacturing but also other branches to transport mission-critical messages.
IEEE Time-Sensitive Networking (TSN) is a disruptive real-time communication
standard extending IEEE Ethernet with real-time mechanisms. One of the core
features of TSN is the Time-Aware Shaper (TAS) enabling TDMA-based scheduling
of streams within the network. TDMA has many advantages from the real-time
perspective. Foremost, stream isolation in the time dimension enables tight
delay and jitter bounds. Moreover, conformance to these bounds is proven by the
design of the TDMA schedule. However, calculating an optimal schedule is an
NP-hard problem. Therefore, various approaches to optimize the schedule
calculation are proposed, such as Integer Linear Programming (ILP).
Nevertheless, a systematic comparsion of the different optimization approaches
with respect to their performance is missing so far. To fill this gap, we first
provide a systematic classification of optimizations of ILP-based TSN
scheduling. To quantify the effects of such optimization approaches, we
introduce a base ILP and propose optimizations for the different categories.
Using the proposed optimization, we evaluate the performance with regard to
execution time and schedulability (number of solved schedules). Our results
show that the optimizations lead to strongly fluctuating results. Certain
intuitive optimizations can even lead to massive performance degradations.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2021-01&engl=0}
}
@inproceedings {INPROC-2020-36,
author = {Milan Tepic\&\#769; and Mohamed Abdelaal and Marc Weber and Kurt Rothermel},
title = {{AutoSec: Multidimensional Timing-Based Anomaly Detection for Automotive Cybersecurity}},
booktitle = {Proceedings of the 26th IEEE International Conference on Embedded and Real-Time Computing Systems and Applications (RTCSA’20), August 2020},
publisher = {IEEE},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {1--10},
type = {Konferenz-Beitrag},
month = {August},
year = {2020},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2020-36/INPROC-2020-36.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Nowadays, autonomous driving and driver assistance applications are being
developed at an accelerated pace. This rapid growth is primarily driven by the
potential of such smart applications to significantly improve safety on public
roads and offer new possibilities for modern transportation concepts. Such
indispensable applications typically require wireless connectivity between the
vehicles and their surroundings, i.e. roadside infrastructure and cloud
services. Nevertheless, such connectivity to external networks exposes the
internal systems of individual vehicles to threats from remotely-launched
attacks. In this realm, it is highly crucial to identify any misbehavior of the
software components which might occur owing to either these threats or even
software/hardware malfunctioning.
In this paper, we introduce $\backslash$PaperAcronym, a host-based anomaly detection
algorithm which relies on observing four timing parameters of the executed
software components to accurately detect malicious behavior on the operating
system level. To this end, $\backslash$PaperAcronym formulates the task of detecting
anomalistic executions as a clustering problem. Specifically, $\backslash$PaperAcronym
devises a hybrid clustering algorithm for grouping a set of collected timing
traces resulted from executing the legitimate code. During the runtime,
$\backslash$PaperAcronym simply classifies a certain execution as an anomaly, if its
timing parameters are distant enough from the boundaries of the predefined
clusters. To show the effectiveness of $\backslash$PaperAcronym, we collected timing
traces from a testbed composed of a set of real and virtual control units
communicating over a CAN bus. We show that using our proposed $\backslash$PaperAcronym,
compared to baseline methods, we can identify up to 21$\backslash$\% less false positives
and 18$\backslash$\% less false negatives.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2020-36&engl=0}
}
@inproceedings {INPROC-2020-29,
author = {Ahmad Slo and Sukanya Bhowmik and Kurt Rothermel},
title = {{hSPICE: State-Aware Event Shedding in Complex Event Processing}},
booktitle = {Proceedings of the 14th ACM International Conference on Distributed and Event-based Systems (DEBS '20), July 13--17, 2020, Virtual Event, QC, Canada.},
publisher = {ACM},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {1--12},
type = {Konferenz-Beitrag},
month = {Juli},
year = {2020},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2020-29/INPROC-2020-29.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {In complex event processing (CEP), load shedding is performed to maintain a
given latency bound during overload situations when there is a limitation on
resources. However, shedding load implies degradation in the quality of results
(QoR). Therefore, it is crucial to perform load shedding in a way that has the
lowest impact on QoR. Researchers, in the CEP domain, propose to drop either
events or partial matches (PMs) in overload cases. They assign utilities to
events or PMs by considering either the importance of events or the importance
of PMs but not both together. In this paper, we propose a load shedding
approach for CEP systems that combines these approaches by assigning a utility
to an event by considering both the event importance and the importance of PMs.
We adopt a probabilistic model that uses the type and position of an event in a
window and the state of a PM to assign a utility to an event corresponding to
each PM. We, also, propose an approach to predict a utility threshold that is
used to drop the required amount of events to maintain a given latency bound.
By extensive evaluations on two real-world datasets and several representative
queries, we show that, in the majority of cases, our load shedding approach
outperforms state-of-the-art load shedding approaches, w.r.t. QoR.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2020-29&engl=0}
}
@inproceedings {INPROC-2020-28,
author = {Jonathan Falk and Frank D{\"u}rr and Kurt Rothermel},
title = {{Time-Triggered Traffic Planning for Data Networks with Conflict Graphs}},
booktitle = {26th IEEE Real-Time and Embedded Technology and Applications Symposium (RTAS 2020)},
address = {Sydney, Australia},
publisher = {IEEE},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
type = {Konferenz-Beitrag},
month = {April},
year = {2020},
keywords = {Real-Time; Traffic-Planning; Time-Triggered},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2020-28/INPROC-2020-28.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Traffic planning is the key enabler of time-triggered real-time communication
in distributed systems, and it is known to be notoriously hard. Current
approaches predominantly tackle the problem in the domain of the traffic
planning problem, e.g., by formulating constraints on the transmission
schedules for individual data streams, or the links used by the data streams.
This results in a high degree of coupling of the configuration of an individual
data stream and the global (network-wide) traffic configuration with
detrimental effects on the scalability and runtime of the planning phase.
In contrast, we present a configuration-conflict graph based approach, which
solves the original traffic planning problem by searching an independent vertex
set in the conflict graph. We show how to derive the configuration-conflict
graph, and discuss the conceptual advantages of this approach. To show the
practical advantages of the conflict-graph based traffic planning approach we
additionally present a proof-of-concept implementation and evaluate it against
a reference ILP-based implementation. In our evaluations, our proof-of-concept
implementation of the conflict-graph based approach outperforms the reference
ILP and is more memory efficient, making it a promising alternative to current
constraint-based traffic planning approaches.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2020-28&engl=0}
}
@inproceedings {INPROC-2020-05,
author = {Ben William Carabelli and Frank D{\"u}rr and Kurt Rothermel},
title = {{SCRaM -- State-Consistent Replication Management for Networked Control Systems}},
booktitle = {11th IEEE/ACM International Conference on Cyber-Physical Systems (ICCPS)},
address = {Sydney, NSW, Australia},
publisher = {IEEE},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
type = {Konferenz-Beitrag},
month = {April},
year = {2020},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems,
C.4 Performance of Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2020-05/INPROC-2020-05.pdf},
contact = {Ben Carabelli ben.carabelli@ipvs.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Networked control systems (NCS) consist of sensors and actuators that are
connected to a controller through a packet-switched network in a feedback loop
to control physical systems in diverse application areas such as industry,
automotive, or power infrastructure. The control of critical real-time systems
places strong requirements on the latency and reliability of both the
communication network and the controller. In this paper, we consider the
problem of increasing the reliability of an NCS subject to crash failures and
message loss by replicating the controller component. Previous replication
schemes for real-time systems have focused on ensuring that no conflicting
values are sent to the actuators by different replicas. Since this property,
which we call output consistency, only refers to the values within one time
step, it is insufficient for reasoning about the formal conditions under which
a group of replicated controllers behaves equivalent to a non-replicated
controller. Therefore, we propose the stronger state consistency property,
which ensures that the sequence of values produced by the replicated controller
exhibits the same dynamical behaviour as a non-replicated controller. Moreover,
we present SCRaM, a protocol for replicating generic periodically sampled
controllers that satisfies both of these consistency requirements. To
demonstrate the effectiveness of our approach, we evaluated it experimentally
for the control of a cart-driven inverted pendulum.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2020-05&engl=0}
}
@inproceedings {INPROC-2020-02,
author = {David Hellmanns and Jonathan Falk and Alexander Glavackij and Ren{\'e} Hummen and Stephan Kehrer and Frank D{\"u}rr},
title = {{On the Performance of Stream-based, Class-based Time-aware Shaping and Frame Preemption in TSN}},
booktitle = {Proceedings of 2020 IEEE International Conference on Industrial Technology (ICIT), Buenos Aires, Argentinia, February 26–28, 2020},
address = {Buenos Aires},
publisher = {IEEE Xplore},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
pages = {1--6},
type = {Konferenz-Beitrag},
month = {Februar},
year = {2020},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2020-02/INPROC-2020-02.pdf},
contact = {david.hellmanns@ipvs.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {Time-sensitive Networking (TSN) is an evolving group of IEEE standards for
deterministic real-time communication making standard Ethernet technology
applicable to safety-critical application domains such as manufacturing or
automotive systems. TSN includes several mechanisms influencing the timely
forwarding of traffic, in particular, a time-triggered scheduling mechanism
called time-aware shaper (TAS) and frame preemption to reduce the blocking time
of high-priority traffic by low-priority traffic. Although these mechanisms
have been standardized and products implementing them begin to enter the
market, it is still hard for practitioners to select and apply suitable
mechanisms fitting the problem at hand. For instance, TAS schedules can be
calculated for individual streams or classes of traffic, and frame preemption
with strict priority scheduling (w/o TAS) might seem to be an option in
networks with extremely high data rates. In this paper, we make a first step
towards assisting practitioners in making an informed decision when choosing
between stream-based TAS, class-based TAS, and frame preemption by comparing
these mechanisms in selected scenarios using our TSN network simulation tool
NeSTiNg. Moreover, to facilitate the application of class-based TAS, we derive
a formula for calculating class-based TAS configuration.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2020-02&engl=0}
}
@inproceedings {INPROC-2020-01,
author = {Mohamed Abdelaal and Mustafa Karadeniz and Frank Duerr and Kurt Rothermel},
title = {{liteNDN: QoS-Aware Packet Forwarding and Caching for Named Data Networks}},
booktitle = {Proceedings of the IEEE Consumer Communications and Networking Conference (CCNC)},
address = {Las Vegas, USA},
publisher = {IEEE},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {1--9},
type = {Konferenz-Beitrag},
month = {Januar},
year = {2020},
keywords = {Named Data Networking; Forwarding Strategy; Caching Policy; Quality of Service},
language = {Englisch},
cr-category = {C.2.2 Network Protocols},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2020-01/INPROC-2020-01.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Recently, named data networking (NDN) has been introduced to connect the world
of computing devices via naming data instead of their containers. Through this
strategic change, NDN brings several new features to network communication,
including in-network caching, multipath forwarding, built-in multicast, and
data security. Despite these unique features of NDN networking, there exist
plenty of opportunities for continuing developments, especially with packet
forwarding and caching. In this context, we introduce liteNDN, a novel
forwarding and caching strategy for NDN networks. liteNDN comprises a
cooperative forwarding strategy through which NDN routers share their
knowledge, i.e. data names and interfaces, to optimize their packet forwarding
decisions. Subsequently, liteNDN leverages that knowledge to estimate the
probability of each downstream path to swiftly retrieve the requested data.
Additionally, liteNDN exploits heuristics, such as routing costs and data
significance, to make proper decisions about caching normal as well as
segmented packets. The proposed approach has been extensively evaluated in
terms of the data retrieval latency, network utilization, and the cache hit
rate. The results showed that liteNDN, compared to conventional NDN forwarding
and caching strategies, achieves much less latency while reducing the
unnecessary traffic and caching activities.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2020-01&engl=0}
}
@inproceedings {INPROC-2019-45,
author = {Otto Bibartiu and Frank D{\"u}rr and Kurt Rothermel and Beate Ottenw{\"a}lder and Andreas Grau},
title = {{Towards Scalable k-out-of-n Models for Assessing the Reliability of Large-scale Function-as-a-Service Systems with Bayesian Networks}},
booktitle = {2019 IEEE 12th International Conference on Cloud Computing (CLOUD)},
editor = {IEEE},
address = {Milan, Italy},
publisher = {Online},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {1--3},
type = {Konferenz-Beitrag},
month = {Juli},
year = {2019},
isbn = {10.1109/CLOUD.2019.00095},
keywords = {Bayesian networks, k-out-of-n gates, scalable structures},
language = {Englisch},
cr-category = {B.8.1 Reliability, Testing, and Fault-Tolerance},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2019-45/INPROC-2019-45.pdf,
https://ieeexplore.ieee.org/document/8814557/},
contact = {otto.bibartiu@ipvs.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Typically, Function-as-a-Service (FaaS) involves state-less replication with
very large numbers of instances. The reliability of such services can be
evaluated using Bayesian Networks and k-out-of-n models. However, existing
k-out-of-n models do not scale to the larger number of hosts of FaaS services.
Therefore, we propose a scalable k-out-of-n model in this paper with the same
semantics as the standard k-out-of-n voting gates in fault trees, enabling the
reliability analysis of FaaS services.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2019-45&engl=0}
}
@inproceedings {INPROC-2019-27,
author = {Mohamed Abdelaal and Mochamad Dandy and Marwan Abdelgawad and Frank Duerr and Kurt Rothermel},
title = {{GaaS: Adaptive Cross-Platform Gateway for IoT Applications}},
booktitle = {Proceedings of the 16th IEEE International Conference on Mobile Ad-Hoc and Smart Systems (EEE MASS)},
address = {Monterey, California, USA},
publisher = {IEEE},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {1--10},
type = {Konferenz-Beitrag},
month = {November},
year = {2019},
keywords = {Internet of Things; Mobile Gateways; Opportunistic Data Collection; Priority-Based Scheduling},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2019-27/INPROC-2019-27.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Internet of Things (IoT) is expanding at a rapid rate where it allows for
virtually endless opportunities and connections to take place. In general, IoT
opens the door to a myriad of applications but also to many challenges. One of
the major challenges is how to efficiently retrieve the sensory data from
{\^a}€œresources-limited{\^a}€ IoT devices. Such devices typically have a restricted
energy budget, which broadly hinders their direct connection to the Internet.
In this realm, modern mobile devices, e.g. smartphones, tablets, smartwatches,
have been harnessed to bridge between the low-power IoT devices and the
Internet. However, the current vision which mainly relies on designing siloed
gateways, i.e. a separate gateway/App for each IoT device, is certainly
impractical, especially with the rapid growth in the number of IoT devices.
Furthermore, energy efficiency of the smart mobile devices hosting the IoT
gateways has to be thoroughly considered.
To tackle these challenges, we introduce GaaS (Gateway as a Service), a
cross-platform gateway architecture for opportunistically retrieving sensory
data from the low-power IoT sensors. Through Bluetooth low energy radios, GaaS
is capable of simultaneously connecting to several nearby IoT sensors. To this
end, we devise two distinct priority-based scheduling algorithms, namely the
EP-WSM and FEP-AHP schedulers, which rank the detected IoT sensors, before
estimating the connection time for each IoT sensor. The intuition behind
ranking the IoT sensors is to improve the data retrieval rate from these
sensors together with reducing the energy overhead on the mobile devices.
Additionally, GaaS encompasses a self-adaptive engine to automatically balance
the trade-off between energy efficiency and data retrieval rate through
switching between schedulers according to the runtime dynamics. To demonstrate
the effectiveness of GaaS, we implemented an IoT testbed to evaluate the energy
consumption, the latency, and the data retrieval rate. The results show that
using GaaS, compared to siloed gateways, we can identify up to 18\% savings in
the consumed energy while requiring much less data retrieval time.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2019-27&engl=0}
}
@inproceedings {INPROC-2019-26,
author = {Ahmad Slo and Sukanya Bhowmik and Albert Flaig and Kurt Rothermel},
title = {{pSPICE: Partial Match Shedding for Complex Event Processing}},
booktitle = {Proceedings of the 2019 IEEE International Conference on Big Data (BigData '19); Los Angeles, CA, USA 9 - 12 December, 2019},
publisher = {IEEE},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {1--11},
type = {Konferenz-Beitrag},
month = {Dezember},
year = {2019},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2019-26/INPROC-2019-26.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Complex event processing (CEP) systems continuously process input event streams
to detect patterns. Over time, the input event rate might fluctuate and
overshoot the system{\^a}€™s capabilities. One way to reduce the overload on the
system is to use load shedding. In this paper, we propose a load shedding
strategy for CEP systems which drops a portion of the CEP operator{\^a}€™s internal
state (a.k.a. partial matches) to maintain a given latency bound. The crucial
question here is how many and which partial matches to drop so that a given
latency bound is maintained while minimizing the degradation in the quality of
results. In the stream processing domain, different load shedding strategies
have been proposed that mainly depend on the importance of individual tuples.
However, as CEP systems perform pattern detection, the importance of events is
also influenced by other events in the stream. Our load shedding strategy uses
Markov chain and Markov reward process to predict the utility/importance of
partial matches to determine the ones to be dropped. In addition, we represent
the utility in a way that minimizes the overhead of load shedding. Furthermore,
we provide algorithms to decide when to start dropping partial matches and how
many partial matches to drop. By extensively evaluating our approach on three
real-world datasets and several representative queries, we show that the
adverse impact of our load shedding strategy on the quality of results is
considerably less than the impact of state-of-the-art load shedding strategies.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2019-26&engl=0}
}
@inproceedings {INPROC-2019-25,
author = {Ahmad Slo and Sukanya Bhowmik and Kurt Rothermel},
title = {{eSPICE: Probabilistic Load Shedding from Input Event Streams in Complex Event Processing}},
booktitle = {Proceedings of Middleware '19: 20th International Middleware Conference (Middleware '19) Dec 08-13 2019. Davis, CA, USA . ACM, New York, NY, USA},
publisher = {ACM Press},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {1--13},
type = {Konferenz-Beitrag},
month = {Dezember},
year = {2019},
keywords = {Complex Event Processing; Stream Processing; Load Shedding; Approximate Computing; latency bound; QoS},
language = {Englisch},
cr-category = {H.3.4 Information Storage and Retrieval Systems and Software},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2019-25/INPROC-2019-25.pdf},
contact = {ahmad.slo@ipvs.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Complex event processing systems process the input event streams on-the-fly.
Since input event rate could overshoot the system{\^a}€™s capabilities and results
in violating a defined latency bound, load shedding is used to drop a portion
of the input event streams. The crucial question here is how many and which
events to drop so the defined latency bound is maintained and the degradation
in the quality of results is minimized. In stream processing domain, different
load shedding strategies have been proposed but they mainly depend on the
importance of individual tuples (events). However, as complex event processing
systems perform pattern detection, the importance of events is also influenced
by other events in the same pattern. In this paper, we propose a load shedding
framework called eSPICE for complex event processing systems. eSPICE depends on
building a probabilistic model that learns about the importance of events in a
window. The position of an event in a window and its type are used as features
to build the model. Further, we provide algorithms to decide when to start
dropping events and how many events to drop. Moreover, we extensively evaluate
the performance of eSPICE on two real-world datasets.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2019-25&engl=0}
}
@inproceedings {INPROC-2019-23,
author = {Jonathan Falk and Frank D{\"u}rr and Steffen Linsenmayer and Stefan Wildhagen and Carabelli Ben and Kurt Rothermel},
title = {{Optimal Routing and Scheduling of Complemental Flows in Converged Networks}},
booktitle = {Proceedings of the 27th International Conference on Real-Time Networks and Systems (RTNS 2019), November 6-8, 2019 -Toulouse/France},
publisher = {ACM},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
type = {Konferenz-Beitrag},
month = {November},
year = {2019},
doi = {10.1145/3356401.3356415},
keywords = {Routing Scheduling Complemental Flows},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2019-23/INPROC-2019-23.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Converged networks support applications with completely different (real-time)
requirements. The communication paradigms offered in converged networks are
predominantly treated as separate entities from the perspective of traffic
engineering, e.g., time-triggered traffic for closed-loop control systems,
shaped traffic for multimedia-streaming applications, and best-effort traffic
for non-time-critical IT applications. However, there are scenarios where
applications benefit from considering time-triggered messages and
non-time-triggered messages as complemental components of a single traffic
flow. These applications have the property that time-triggered transmissions
guarantee basic functionality (e.g., stability of a control system), and
additional non-time-triggered transmissions improve the application's
performance.
We present how to model these so-called complemental traffic flows for this
type of application using a traffic metric for the description of the
non-time-triggered traffic part. Furthermore, we show that complemental flows
are suitable for traffic engineering by presenting two different approaches for
the problem of optimized joint routing and scheduling in converged networks
with mixed integer linear programming.
In our evaluations, we use an exemplary min-max objective for the joint routing
and scheduling problem which yields an average reduction of the peak value of
the traffic metric by 20-30$\backslash$\% over constraint-based approaches.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2019-23&engl=0}
}
@inproceedings {INPROC-2019-22,
author = {Jonathan Falk and Frank D{\"u}rr and Kurt Rothermel},
title = {{Modeling Time-Triggered Service Intermittence In Network Calculus}},
booktitle = {Proceedings of the 27th International Conference on Real-Time Networks and Systems (RTNS 2019), November 6-8, 2019 -Toulouse/France},
publisher = {ACM},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
type = {Konferenz-Beitrag},
month = {November},
year = {2019},
doi = {10.1145/3356401.3356411},
keywords = {Real-time, Network Calculus Service Intermittence},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2019-22/INPROC-2019-22.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Network elements (e.g., switches), which intermit service, i.e., stop
forwarding and transmission of data according to a repeating schedule, can be
found in many real-time capable communication networks, e.g., communication
networks with TDMA, Ethernet with Time-aware Shapers or low-power wireless
networks. The behavior of those network elements depends on the (stationary)
properties of the network elements, their schedule, and the current time, as
well as the offered traffic load. If a networked real-time system generates
traffic flows which are not synchronized to the schedules of the network
elements, formal frameworks such as Network Calculus (NC) are highly valuable
to derive deterministic guarantees for the communication.
In this paper, we show the fundamental implications of modeling time-triggered
network elements with service intermittence in NC. We identify two archetypes
of network elements with intermittent service, and propose time-variant and
time-invariant approaches to derive service curve formulations to model them.
We evaluate the differences between time-variant and time-invariant service
curves with respect to the overestimation of worst-case backlog and worst-case
delay, and we identify schedule properties which influence the tightness of the
derived bounds.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2019-22&engl=0}
}
@inproceedings {INPROC-2019-21,
author = {Henriette R{\"o}ger and Sukanya Bhowmik and Kurt Rothermel},
title = {{Combining it all: Cost minimal and low-latency stream processing across distributed heterogeneous infrastructures}},
booktitle = {Proceedings of Middleware '19: 20th International Middleware Conference (Middleware '19) Dec 08-13 2019. Davis, CA, USA . ACM, New York, NY, USA},
publisher = {ACM Press},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {1--13},
type = {Konferenz-Beitrag},
month = {Dezember},
year = {2019},
isbn = {ISDB: 978-1-4503-7009-7/19/12},
doi = {10.1145/3361525.3361551},
language = {Deutsch},
cr-category = {C.2.4 Distributed Systems,
C.4 Performance of Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2019-21/INPROC-2019-21.pdf},
contact = {henriette.roeger@ipvs.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Control mechanisms of stream processing applications (SPAs) that ensure latency
bounds at minimal runtime cost mostly target a specific infrastructure, e.g.,
homogeneous nodes. With the growing popularity of the Internet of Things, fog,
and edge computing, SPAs are more often distributed on het- erogeneous
infrastructures, triggering the need for a holis- tic SPA-control that still
considers heterogeneity. We there- fore combine individual control mechanisms
via the latency- distribution problem that seeks to distribute latency budgets
to individually managed components of distributed SPAs for a lightweight yet
effective end-to-end control. To this end, we introduce a hierarchical control
architecture, give a formal definition of the latency-distribution problem, and
provide both an ILP formulation to find an optimal solution as well as a
heuristic approach, thereby enabling the combi- nation of individual control
mechanisms into one SPA while ensuring global cost minimality. Our evaluations
show that both solutions are effective{\^a}€”while the heuristic approach is only
slightly more costly than the optimal ILP solution, it significantly reduces
runtime and communication overhead.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2019-21&engl=0}
}
@inproceedings {INPROC-2019-04,
author = {Jonathan Falk and David Hellmanns and Ben Carabelli and Naresh Nayak and Frank D{\"u}rr and Stephan Kehrer and Kurt Rothermel},
title = {{NeSTiNg: Simulating IEEE Time-sensitive Networking (TSN) in OMNeT++}},
booktitle = {Proceedings of the 2019 International Conference on Networked Systems (NetSys)},
address = {Garching b. M{\"u}nchen, Germany},
publisher = {IEEE},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
type = {Konferenz-Beitrag},
month = {M{\"a}rz},
year = {2019},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2019-04/INPROC-2019-04.pdf,
https://gitlab.com/ipvs/nesting},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {IEEE 802.1 Time-sensitive Networking (TSN) enables real-time communication with
deterministically bounded network delay and jitter over standard IEEE 802.3
networks (``Ethernet''). In particular, TSN specifies a time-triggered scheduling
mechanism in IEEE Std 802.1Qbv implemented by switches to control when outgoing
queues get access to switch ports. Besides this time-triggered scheduling
mechanism, other scheduling mechanisms can be active in the network at the same
time including priority queuing and a credit-based shaper. Moreover, further
supporting mechanisms such as the possibility to interrupt frames already in
transmission (frame preemption) are specified by the TSN standards. Overall,
this leads to a complex network infrastructure transporting both, real-time and
non-real-time traffic in one converged network, making it hard to analyze the
behavior of converged networks.
To facilitate the analysis of TSN networks, we present TSN-specific extensions
to the popular OMNeT++/INET framework for network simulations in this paper
including, in particular, the time-triggered scheduling mechanism of IEEE Std
802.1Qbv. Besides the design of the TSN simulator, we present a
proof-of-concept implementation and exemplary evaluation of TSN networks.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2019-04&engl=0}
}
@inproceedings {INPROC-2019-01,
author = {Steffen Linsenmayer and Ben W. Carabelli and Frank D{\"u}rr and Jonathan Falk and Frank Allg{\"o}wer and Kurt Rothermel},
title = {{Integration of Communication Networks and Control Systems Using a Slotted Transmission Classification Model}},
booktitle = {Proceedings of the 16th IEEE Annual Consumer Communications \& Networking Conference (CCNC)},
address = {Las Vegas, NV, USA},
publisher = {IEEE},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
type = {Workshop-Beitrag},
month = {Januar},
year = {2019},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2019-01/INPROC-2019-01.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {In this paper, we present a communication abstraction for Networked Control
Systems that is characterized by a slotted transmission classification model.
We discuss, how such a model can be implemented over local area networks by
using IEEE Time Sensitive Networking methods. Furthermore, it is shown how
asymptotic stability can be analyzed for linear systems that communicate over
such a network. Based on the stability result, a controller design procedure is
derived that takes the information captured in the network model into account.
Further topics and related open problems that are implicated by the proposed
model are briefly discussed as an outlook.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2019-01&engl=0}
}
@inproceedings {INPROC-2018-55,
author = {Guilherme F. Lima and Ahmad Slo and Sukanya Bhowmik and Markus Endler and Kurt Rothermel},
title = {{Skipping Unused Events to Speed Up Rollback-Recovery in Distributed Data-Parallel CEP}},
booktitle = {Proceedings of 2018 IEEE/ACM 5th International Conference on Big Data Computing Applications and Technologies (BDCAT)},
publisher = {IEEE},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {1--10},
type = {Konferenz-Beitrag},
month = {Dezember},
year = {2018},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2018-55/INPROC-2018-55.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {We propose two extensions for a state-of-the-art method of rollback-recovery in
distributed CEP (complex event processing). In CEP, an operator network is used
to search for patterns in events streams. Sometimes these operators fail and
lose their state. Rollback-recovery is a method for dealing with such state
losses. The type of rollback-recovery we consider is upstream backup, where the
state of a failed operator is recovered by replaying to it the input events
that led it to that state. These events are kept in upstream operators{\^a}€™
memory buffers, which are trimmed continuously as the downstream operator
progresses. The first extension we propose saves memory and speeds up recovery
by avoiding to store and retransmit unnecessary events. The second extension
makes the base method of upstream backup compatible with data-parallel CEP,
allowing that the windows into which operators partition their input be
processed in parallel. We evaluated the proposed extensions through experiments
that showed a significant reduction in memory usage and recovery time at the
expense of a negligible processing overhead during normal operation.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2018-55&engl=0}
}
@inproceedings {INPROC-2018-46,
author = {Jonathan Falk and Frank D{\"u}rr and Kurt Rothermel},
title = {{Exploring Practical Limitations of Joint Routing and Scheduling for TSN with ILP}},
booktitle = {Proceedings of the 2018 IEEE 24th International Conference on Embedded and Real-Time Computing Systems and Applications (RTCSA 2018) Hakodate, Japan, 29-31 August 2018},
publisher = {IEEE},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {136--146},
type = {Konferenz-Beitrag},
month = {August},
year = {2018},
doi = {10.1109/RTCSA.2018.00025},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2018-46/INPROC-2018-46.pdf,
https://ieeexplore.ieee.org/document/8607243},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {IEEE 802.1Q networks with extensions for time-sensitive networking aim to
enable converged networks. Converged networks support hard-real time
communication services in addition to the currently supported services classes.
Real-time communication in these networks requires routes and schedules for the
real-time transmissions. We present a formulation in the integer linear
programming (ILP) framework which models the joint routing and scheduling
problem for flows of periodic real-time transmissions in converged TSN
networks. In the joint routing and scheduling problem, both routes and
schedules for real-time transmissions are computed in one step, i.e. we do not
schedule over predefined routes. We explore the practical limitations of this
approach by evaluating the runtime of problem instances with widely varying
parameters with a state-of-the-art ILP solver. The observed solver runtimes
indicate the qualitative impact of the number of real-time flows, the size of
the network, the transmission frequency of real-time transmissions, and the
network topology.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2018-46&engl=0}
}
@inproceedings {INPROC-2018-45,
author = {Christian Mayer and Ruben Mayer and Sukanya Bhowmik and Lukas Epple and Kurt Rothermel},
title = {{HYPE: Massive Hypergraph Partitioning with Neighborhood Expansion}},
booktitle = {Proceedings of the 2018 IEEE International Conference on Big Data (BigData '18); Seattle, WA, USA, December 10-13, 2018},
publisher = {IEEE},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {1--10},
type = {Konferenz-Beitrag},
month = {Dezember},
year = {2018},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2018-45/INPROC-2018-45.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Many important real-world applications---such as social networks or distributed
data bases---can be modeled as hypergraphs. In such a model, vertices represent
entities---such as users or data records---whereas hyperedges model a group
membership of the vertices---such as the authorship in a specific topic or the
membership of a data record in a specific replicated shard. To optimize such
applications, we need an efficient and effective solution to the NP-hard
balanced k-way hypergraph partitioning problem. However, existing hypergraph
partitioners that scale to very large graphs do not effectively exploit the
hypergraph structure when performing the partitioning decisions. We propose
HYPE, a hypergraph partitionier that exploits the neighborhood relations
between vertices in the hypergraph using an efficient implementation of
neighborhood expansion. HYPE improves partitioning quality by up to 95\% and
reduces runtime by up to 39\% compared to the state of the art.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2018-45&engl=0}
}
@inproceedings {INPROC-2018-30,
author = {Johannes K{\"a}ssinger and Mohamed Abdelaal and Fank D{\"u}rr and Kurt Rothermel},
title = {{GreenMap: Approximated Filtering towards Energy-Aware Crowdsensing for Indoor Mapping}},
booktitle = {Proceedings of the 2018 IEEE 15th International Conference on Mobile Ad-hoc and Sensor Systems (MASS2018)},
address = {Chengdu, China},
publisher = {IEEE},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {451--459},
type = {Konferenz-Beitrag},
month = {Oktober},
year = {2018},
doi = {10.1109/MASS.2018.00069},
keywords = {Crowdsensing; Mobile Sensing; Indoor; Pointcloud; Approximate Computing; Approximate Filtering},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2018-30/INPROC-2018-30.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Recently, mobile crowdsensing has become an appealing paradigm thanks to the
ubiquitous presence of powerful mobile devices. Indoor mapping, as an example
of crowdsensingdriven applications, is essential to provide many indoor
locationbased services, such as emergency response, security, and
tracking/navigation in large buildings. In this realm, 3D point clouds stand as
an optimal data type which can be crowdsensed—using currently-available mobile
devices, e.g. Google Tango, Microsoft Hololens and Apple ARKit—to generate
floor plans with different levels of detail, i.e. 2D and 3D mapping. However,
collecting such bulky data from ”resources-limited“ mobile devices can
significantly harm their energy efficiency. To overcome this challenge, we
introduce GreenMap, an energy-aware architectural framework for automatically
mapping the interior spaces using crowdsensed point clouds with the support of
structural information encoded in formal grammars. GreenMap reduces the energy
overhead through projecting the point clouds to several filtration steps on the
mobile devices. In this context, GreenMap leverages the potential of
approximate computing to reduce the computational cost of data filtering while
maintaining a satisfactory level of modeling accuracy. To this end, we propose
two approximation strategies, namely DyPR and SuFFUSION. To demonstrate the
effectiveness of GreenMap, we implemented a crowdsensing Android App to collect
3D point clouds from two different buildings. We show that GreenMap achieves
significant energy savings of up to 67.8\%, compared to the baseline methods,
while generating comparable floor plans.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2018-30&engl=0}
}
@inproceedings {INPROC-2018-29,
author = {Mohamed Abdelaal and Daniel Reichelt and Frank Duerr and Kurt Rothermel and Lavinia Runceanu and Susanne Becker and Fritsch Dieter},
title = {{ComNSense: Grammar-Driven Crowd-Sourcing of Point Clouds for Automatic Indoor Mapping}},
booktitle = {Proceedings of the 2018 ACM International Joint Conference on Pervasive and Ubiquitous Computing (UbiComp 2018), PACM IMWUT Issue 1, October 2018.},
address = {Singapore},
publisher = {ACM},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {1--26},
type = {Konferenz-Beitrag},
month = {Oktober},
year = {2018},
keywords = {Indoor Mapping; Crowdsensing; 3D Point Clouds; Energy Efficiency; Formal Grammars},
language = {Englisch},
cr-category = {C.3 Special-Purpose and Application-Based Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2018-29/INPROC-2018-29.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2018-29&engl=0}
}
@inproceedings {INPROC-2018-26,
author = {Zohaib Riaz and Frank D{\"u}rr and Kurt Rothermel},
title = {{Location Privacy and Utility in Geo-social: Survey and Research Challenges}},
booktitle = {Proceedings of the 16th Annual Conference on Privacy, Security and Trust (PST 2018), August 28-30, 2018, Belfast, Northern Ireland, United Kingdom.},
publisher = {IEEE Xplore},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {1--10},
type = {Konferenz-Beitrag},
month = {August},
year = {2018},
language = {Englisch},
cr-category = {K.4 Computers and Society},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2018-26/INPROC-2018-26.pdf},
contact = {zohaib.riaz@ipvs.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2018-26&engl=0}
}
@inproceedings {INPROC-2018-21,
author = {Saravana Murthy Palanisamy and Frank D{\"u}rr and Muhammad Adnan Tariq and Kurt Rothermel},
title = {{Preserving Privacy and Quality of Service in Complex Event Processing through Event Reordering}},
booktitle = {Conference Proceedings: Proceedings of the 12th ACM International Conference on Distributed and Event-Based Systems: DEBS2018 ; Hamilton, New Zealand, June 25-29, 2018},
address = {Hamilton, New Zealand},
publisher = {ACM},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
series = {Saravana Murthy Palanisamy},
pages = {40--51},
type = {Konferenz-Beitrag},
month = {Juni},
year = {2018},
isbn = {978-1-4503-5782-1},
language = {Englisch},
cr-category = {D.4.6 Operating Systems Security and Protection,
G.1.6 Numerical Analysis Optimization,
F.1.1 Models of Computation},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2018-21/INPROC-2018-21.pdf,
https://doi.org/10.1145/3210284.3210296},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2018-21&engl=0}
}
@inproceedings {INPROC-2018-16,
author = {Thomas Kohler and Ruben Mayer and Frank D{\"u}rr and Marius Maa{\ss} and Sukanya Bhowmik and Kurt Rothermel},
title = {{P4CEP: Towards In-Network Complex Event Processing}},
booktitle = {Proceedings of the ACM SIGCOMM 2018 Morning Workshop on In-Network Computing},
address = {Budapest, Hungary},
publisher = {ACM},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
series = {NetCompute'18},
pages = {0--5},
type = {Konferenz-Beitrag},
month = {August},
year = {2018},
doi = {10.1145/3229591.3229593},
isbn = {978-1-4503-5908-5/18/08},
keywords = {In-network Computing, Data Plane Programming, P4, Complex Event Processing (CEP)},
language = {Englisch},
cr-category = {C.2.1 Network Architecture and Design,
C.2.4 Distributed Systems,
C.2.3 Network Operations},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2018-16/INPROC-2018-16.pdf,
https://doi.org/10.1145/3229591.3229593},
contact = {thomas.kohler@ipvs.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {In-network computing using programmable networking hardware is a strong trend
in networking that promises to reduce latency and consumption of server
resources through offloading to network elements (programmable switches and
smart NICs). In particular, the data plane programming language P4 together
with powerful P4 networking hardware has spawned projects offloading services
into the network, e.g., consensus services or caching services. In this paper,
we present a novel case for in-network computing, namely, Complex Event
Processing (CEP). CEP processes streams of basic events, e.g., stemming from
networked sensors, into meaningful complex events. Traditionally, CEP
processing has been performed on servers or overlay networks. However, we argue
in this paper that CEP is a good candidate for in-network computing along the
communication path avoiding detouring streams to distant servers to minimize
communication latency while also exploiting processing capabilities of novel
networking hardware. We show that it is feasible to express CEP operations in
P4 and also present a tool to compile CEP operations, formulated in our P4CEP
rule specification language, to P4 code. Moreover, we identify challenges and
problems that we have encountered to show future research directions for
implementing full-fledged in-network CEP systems.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2018-16&engl=0}
}
@inproceedings {INPROC-2018-15,
author = {Christoph Stach and Sascha Alpers and Stefanie Betz and Frank D{\"u}rr and Andreas Fritsch and Kai Mindermann and Saravana Murthy Palanisamy and Gunther Schiefer and Manuela Wagner and Bernhard Mitschang and Andreas Oberweis and Stefan Wagner},
title = {{The AVARE PATRON: A Holistic Privacy Approach for the Internet of Things}},
booktitle = {Proceedings of the 15th International Conference on Security and Cryptography (SECRYPT '18)},
publisher = {INSTICC Press},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {1--8},
type = {Konferenz-Beitrag},
month = {Juli},
year = {2018},
keywords = {Privacy; IoT Apps; Smart Things; Stream Processing; Privacy Preferences Elicitation \& Veri\&\#64257; cation},
language = {Englisch},
cr-category = {K.4.1 Computers and Society Public Policy Issues,
D.4.6 Operating Systems Security and Protection},
contact = {Senden Sie eine E-Mail an Christoph.Stach@ipvs.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Anwendersoftware;
Universit{\"a}t Stuttgart, Institut f{\"u}r Softwaretechnologie, Software Engineering;
Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Applications for the Internet of Things are becoming increasingly popular. Due
to the large amount of available context data, such applications can be used
effectively in many domains. By interlinking these data and analyzing them, it
is possible to gather a lot of knowledge about a user. Therefore, these
applications pose a threat to privacy. In this paper, we illustrate this threat
by looking at a real-world application scenario. Current state of the art
focuses on privacy mechanisms either for Smart Things or for big data
processing systems. However, our studies show that for a comprehensive privacy
protection a holistic view on these applications is required. Therefore, we
describe how to combine two promising privacy approaches from both categories,
namely AVARE and PATRON. Evaluation results confirm the thereby achieved
synergy effects.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2018-15&engl=0}
}
@inproceedings {INPROC-2018-04,
author = {Christoph Stach and Frank D{\"u}rr and Kai Mindermann and Saravana Murthy Palanisamy and Stefan Wagner},
title = {{How a Pattern-based Privacy System Contributes to Improve Context Recognition}},
booktitle = {Proceedings of the 2018 IEEE International Conference on Pervasive Computing and Communications Workshops (CoMoRea)},
publisher = {IEEE Computer Society},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {1--6},
type = {Workshop-Beitrag},
month = {M{\"a}rz},
year = {2018},
keywords = {privacy; access control; pattern concealing; stream processing; complex event processing; databases},
language = {Englisch},
cr-category = {K.4.1 Computers and Society Public Policy Issues,
D.4.6 Operating Systems Security and Protection},
contact = {Senden Sie eine E-Mail an Christoph.Stach@ipvs.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Anwendersoftware;
Universit{\"a}t Stuttgart, Institut f{\"u}r Softwaretechnologie, Software Engineering;
Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {As Smart Devices have access to a lot of user-preferential data, they come in
handy in any situation. Although such data - as well as the knowledge which can
be derived from it - is highly beneficial as apps are able to adapt their
services appropriate to the respective context, it also poses a privacy threat.
Thus, a lot of research work is done regarding privacy. Yet, all approaches
obfuscate certain attributes which has a negative impact on context recognition
and thus service quality. Therefore, we introduce a novel access control
mechanism called PATRON. The basic idea is to control access to information
patterns. For instance, a person suffering from diabetes might not want to
reveal his or her unhealthy eating habit, which can be derived from the pattern
``rising blood sugar level'' -$>$ ``adding bread units''. Such a pattern which must
not be discoverable by some parties (e.g., insurance companies) is called
private pattern whereas a pattern which improves an app's service quality is
labeled as public pattern. PATRON employs different techniques to conceal
private patterns and, in case of available alternatives, selects the one with
the least negative impact on service quality, such that the recognition of
public patterns is supported as good as possible.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2018-04&engl=0}
}
@inproceedings {INPROC-2017-72,
author = {Ruben Mayer and Christian Mayer and Larissa Laich},
title = {{The TensorFlow Partitioning and Scheduling Problem: It’s the Critical Path!}},
booktitle = {Proceedings of DIDL'17: Workshop on Distributed Infrastructures for Deep Learning (DIDL'17)},
publisher = {ACM},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {1--6},
type = {Workshop-Beitrag},
month = {Dezember},
year = {2017},
keywords = {TensorFlow; partitioning; scheduling; critical path},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2017-72/INPROC-2017-72.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2017-72&engl=0}
}
@inproceedings {INPROC-2017-69,
author = {Mohamed Abdelaal and Mohammad Qaid and Frank Duerr and Kurt Rothermel},
title = {{iSense: Energy-Aware Crowd-Sensing Framework}},
booktitle = {Proceedings of the 36th IEEE International Performance Computing and Communications Conference (IPCCC'17), San Diego, California, USA, December 2017},
publisher = {IEEE},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {1--9},
type = {Konferenz-Beitrag},
month = {Dezember},
year = {2017},
keywords = {Crowd-sensing; Energy Efficiency; Positioning; Compressed Sensing},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2017-69/INPROC-2017-69.pdf},
contact = {mohamed.abdelaal@ipvs.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2017-69&engl=0}
}
@inproceedings {INPROC-2017-58,
author = {Mohamed Abdelaal and Frank Duerr and Kurt Rothermel and Susanne Becker and Dieter Fritsch},
title = {{GraMap: QoS-Aware Indoor Mapping Through Crowd-Sensing Point Clouds with Grammar Support}},
booktitle = {Proceedings of the 14th EAI International Conference on Mobile and Ubiquitous Systems: Computing, Networking and Services (MobiQuitous'17). Melbourne, VIC, Australia, November 7-10, 2017},
publisher = {ACM},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {1--10},
type = {Konferenz-Beitrag},
month = {November},
year = {2017},
isbn = {https://doi.org/10.1145/3144457.314443},
keywords = {Indoor Mapping; 3D Point Clouds; Energy Efficiency; Formal Grammars},
language = {Englisch},
cr-category = {C.3 Special-Purpose and Application-Based Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2017-58/INPROC-2017-58.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2017-58&engl=0}
}
@inproceedings {INPROC-2017-55,
author = {Thomas Kohler and Frank D{\"u}rr and Christian B{\"a}umlisberger and Kurt Rothermel},
title = {{InFEP - Lightweight Virtualization of Distributed Control on White-box Networking Hardware}},
booktitle = {2017 International Workshop on Management of SDN and NFV Systems (ManSDNNFV2017)},
editor = {IFIP/IEEE},
address = {Tokyo, Japan},
publisher = {IEEE},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {1--6},
type = {Konferenz-Beitrag},
month = {November},
year = {2017},
doi = {10.23919/CNSM.2017.8256045},
keywords = {Software-defined Networking; Control Plane Distribution; Virtualization},
language = {Englisch},
cr-category = {C.2.1 Network Architecture and Design,
C.2.4 Distributed Systems,
C.2.3 Network Operations},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2017-55/INPROC-2017-55.pdf,
https://doi.org/10.23919/CNSM.2017.8256045},
contact = {thomas.kohler@ipvs.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Recent developments in networking hardware and software-defined networking have
enabled full distribution of network control to reduce control latency and
increase reliability. However, both, hardware and software of current white-box
networking hardware are highly heterogeneous, which limits the deployment and
operation of switch-local control applications. Furthermore, switch-local
control raises yet unconsidered security concerns. In this paper, we present
our concept of in-forward-element processing, which leverages the open access
to the control plane of white-box networking hardware to deploy control logic
directly onto switches. We combine local control applications with lightweight
virtualization to cope with networking hardware heterogeneity and to achieve
required isolation properties and ease of management. Beyond distributed
network control, we show this scheme is also beneficial for implementing
switch-local virtual network functions (NFV), processing packets. Highlighting
the practicability of the concepts, we provide an overview of the current
white-box networking hardware and software landscape and their compatibility
with lightweight virtualization technologies. To this end, we perform an
empirical evaluation of NOS-virtualization combinations on such hardware and
compare the results with respect to incurring virtualization overhead.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2017-55&engl=0}
}
@inproceedings {INPROC-2017-52,
author = {David Richard Sch{\"a}fer and Kurt Rothermel and Muhammad Adnan Tariq},
title = {{Exploring the Search Space between Active and Passive Workflow Replication}},
booktitle = {Proceedings of the 10th IEEE International Conference on Service-Oriented Computing and Applications (SOCA), Kanazawa, Japan, November 22-25, 2017},
publisher = {IEEE},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {1--8},
type = {Konferenz-Beitrag},
month = {November},
year = {2017},
keywords = {SOA; availability; workflows; replication},
language = {Deutsch},
cr-category = {C.2.4 Distributed Systems,
C.4 Performance of Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2017-52/INPROC-2017-52.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2017-52&engl=0}
}
@inproceedings {INPROC-2017-51,
author = {Thomas Bach and Muhammad Adnan Tariq and Ruben Mayer and Kurt Rothermel},
title = {{Knowledge is at the Edge! How to Search in Distributed Machine Learning Models}},
booktitle = {OTM 2017 Conferences},
publisher = {Springer International Publishing},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {1--19},
type = {Konferenz-Beitrag},
month = {Oktober},
year = {2017},
doi = {10.1007/978-3-319-69462-7_27},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2017-51/INPROC-2017-51.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2017-51&engl=0}
}
@inproceedings {INPROC-2017-50,
author = {Naresh Ganesh Nayak and Frank D{\"u}rr and Kurt Rothermel},
title = {{Routing Algorithms for IEEE802.1Qbv Networks}},
booktitle = {In the 15th International Workshop on Real-Time Networks, RTN-2017},
publisher = {ACM},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {1--6},
type = {Konferenz-Beitrag},
month = {Juni},
year = {2017},
language = {Englisch},
cr-category = {C.2.1 Network Architecture and Design,
C.2.3 Network Operations},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2017-50/INPROC-2017-50.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2017-50&engl=0}
}
@inproceedings {INPROC-2017-46,
author = {Zohaib Riaz and Frank D{\"u}rr and Kurt Rothermel},
title = {{Understanding Vulnerabilities of Location Privacy Mechanisms against Mobility Prediction Attacks}},
booktitle = {Proceedings of the 14th EAI International Conference on Mobile and Ubiquitous Systems: Computing, Networking and Services, Melbourne, VIC, Australia, November 7–10, 2017 (MobiQuitous’17)},
publisher = {ACM},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {1--10},
type = {Konferenz-Beitrag},
month = {September},
year = {2017},
isbn = {ACM ISBN: 978-1-4503-5368-7/17/11, DOI:10.1145/3144457.314450544505},
keywords = {location privacy; attack algorithms; semantic location information; mobility prediction; hidden Markov models},
language = {Englisch},
cr-category = {C.2.0 Computer-Communication Networks, General,
D.2 Software Engineering,
K.4.1 Computers and Society Public Policy Issues,
G.3 Probability and Statistics},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2017-46/INPROC-2017-46.pdf},
contact = {zohaib.riaz@ipvs.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2017-46&engl=0}
}
@inproceedings {INPROC-2017-43,
author = {Ruben Mayer and Ahmad Slo and Muhammad Adnan Tariq and Kurt Rothermel and Manuel Gr{\"a}ber and Umakishore Ramachandran},
title = {{SPECTRE: Supporting Consumption Policies in Window-Based Parallel Complex Event Processing}},
booktitle = {Proceedings of Middleware ’17, Las Vegas, NV, USA, December 11–15, 2017},
publisher = {ACM},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {1--13},
type = {Konferenz-Beitrag},
month = {Dezember},
year = {2017},
doi = {10.1145/3135974.3135983},
language = {Deutsch},
cr-category = {C.2.4 Distributed Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2017-43/INPROC-2017-43.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Distributed Complex Event Processing (DCEP) is a paradigm to infer the
occurrence of complex situations in the surrounding world from basic events
like sensor readings. In doing so, DCEP operators detect event patterns on
their incoming event streams. To yield high operator throughput, data
parallelization frameworks divide the incoming event streams of an operator
into overlapping windows that are processed in parallel by a number of operator
instances. In doing so, the basic assumption is that the different windows can
be processed independently from each other. However, consumption policies
enforce that events can only be part of one pattern instance; then, they are
consumed, i.e., removed from further pattern detection. That implies that the
constituent events of a pattern instance detected in one window are excluded
from all other windows as well, which breaks the data parallelism between
different windows. In this paper, we tackle this problem by means of
speculation: Based on the likelihood of an event's consumption in a window,
subsequent windows may speculatively suppress that event. We propose the
SPECTRE framework for speculative processing of multiple dependent windows in
parallel. Our evaluations show an up to linear scalability of SPECTRE with the
number of CPU cores.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2017-43&engl=0}
}
@inproceedings {INPROC-2017-36,
author = {Christian Mayer and Ruben Mayer and Majd Abdo},
title = {{StreamLearner: Distributed Incremental Machine Learning on Event Streams: Grand Challenge}},
booktitle = {Proceedings of the 11th ACM International Conference on Distributed and Event-based Systems},
publisher = {ACM},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {298--303},
type = {Konferenz-Beitrag},
month = {Juni},
year = {2017},
doi = {10.1145/3093742.3095103},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2017-36/INPROC-2017-36.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2017-36&engl=0}
}
@inproceedings {INPROC-2017-33,
author = {Ruben Mayer and Muhammad Adnan Tariq and Kurt Rothermel},
title = {{Minimizing Communication Overhead in Window-Based Parallel Complex Event Processing}},
booktitle = {Proceedings of the 11th ACM International Conference on Distributed and Event-based Systems},
publisher = {ACM},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {54--65},
type = {Konferenz-Beitrag},
month = {Juni},
year = {2017},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2017-33/INPROC-2017-33.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2017-33&engl=0}
}
@inproceedings {INPROC-2017-32,
author = {Christoph Stach and Frank D{\"u}rr and Kai Mindermann and Saravana Murthy Palanisamy and Muhammad Adnan Tariq and Bernhard Mitschang and Stefan Wagner},
title = {{PATRON - Datenschutz in Datenstromverarbeitungssystemen}},
booktitle = {Informatik 2017: Digitale Kulturen, Tagungsband der 47. Jahrestagung der Gesellschaft f{\"u}r Informatik e.V. (GI), 25.09. - 29.09.2017, Technische Universit{\"a}t Chemnitz},
publisher = {Gesellschaft f{\"u}r Informatik e.V. (GI)},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
series = {LNI},
pages = {1--12},
type = {Workshop-Beitrag},
month = {September},
year = {2017},
keywords = {Datenschutz; Zugriffskontrolle; Datenstr{\"o}me; Internet der Dinge; Privatheit; Sensoren},
language = {Deutsch},
cr-category = {K.4.1 Computers and Society Public Policy Issues,
D.4.6 Operating Systems Security and Protection},
contact = {Senden Sie eine E-Mail an Christoph.Stach@ipvs.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Anwendersoftware;
Universit{\"a}t Stuttgart, Institut f{\"u}r Softwaretechnologie, Software Engineering;
Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Angetrieben durch die stetig voranschreitende Digitalisierung gewinnt das
Internet der Dinge (engl. IoT) immer mehr an Bedeutung. Im IoT werden
technische Ger{\"a}te mit unterschiedlichen Sensoren ausgestattet und miteinander
vernetzt. Dadurch werden neuartige Anwendungen beispielsweise im Bereich
E-Health erm{\"o}glicht, in denen Sensordaten miteinander kombiniert und so in
h{\"o}herwertige Informationen umgewandelt werden. Die von diesen Anwendungen
abgeleiteten Informationen verraten viel {\"u}ber den Nutzer und m{\"u}ssen daher
besonders gesch{\"u}tzt werden. H{\"a}ufig hat der Nutzer allerdings keine Kontrolle
{\"u}ber die Verarbeitung seiner Daten, ganz davon zu schweigen, dass er das Ausma{\ss}
und die Art der daraus ableitbaren Informationen nicht ermessen kann.
In diesem Artikel stellen wir daher einen neuartigen Kontrollmechanismus vor,
der private Informationen im IoT sch{\"u}tzt. Anstelle von abstrakten
Datenschutzregeln f{\"u}r einzelne Sensoren definiert der Nutzer Muster, die es zu
sch{\"u}tzen gilt. Ein Muster kann beispielsweise eine Kombination aus Messwerten
sein, die auf eine bestimmte Krankheit schlie{\ss}en lassen. Der Nutzer definiert
die zu verheimlichenden Informationen nat{\"u}rlichsprachlich, und ein
Dom{\"a}nenexperte setzt diese in formale Regeln um. Sind diese Regeln zu
restriktiv, so kann die Anwendung ihre angedachte Funktionalit{\"a}t nicht
erbringen. Daher muss bez{\"u}glich der Servicequalit{\"a}t ein Kompromiss zwischen
gew{\"u}nschter Privatheit und ben{\"o}tigter Funktionalit{\"a}t gefunden werden.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2017-32&engl=0}
}
@inproceedings {INPROC-2017-30,
author = {Sukanya Bhowmik and Muhammad Adnan Tariq and Alexander Balogh and Kurt Rothermel},
title = {{Addressing TCAM Limitations of Software-Defined Networks for Content-Based Routing}},
booktitle = {Proceedings of Distributed and Event- Based Systems, Barcelona, Spain, June 19-23, 2017 (DEBS ’17)},
publisher = {ACM},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {1--12},
type = {Konferenz-Beitrag},
month = {Juni},
year = {2017},
language = {Englisch},
cr-category = {C.2.1 Network Architecture and Design,
C.2.4 Distributed Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2017-30/INPROC-2017-30.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2017-30&engl=0}
}
@inproceedings {INPROC-2017-22,
author = {Thomas Kohler and Frank D{\"u}rr and Kurt Rothermel},
title = {{ZeroSDN: A Highly Flexible and Modular Architecture for Full-range Network Control Distribution}},
booktitle = {Proceedings of the 13th ACM/IEEE Symposium on Architectures for Networking and Communications Systems: ANCS'17, May 18-19, 2017, Beijing, China},
editor = {ACM/IEEE},
publisher = {Association for Computing Machinery (ACM) / Institute of Electrical and Electronics Engineers (IEEE)},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {1--13},
type = {Konferenz-Beitrag},
month = {Mai},
year = {2017},
keywords = {Software-defined Networking; OpenFlow; Control Plane Distribution; Publish/Subscribe; White-box Networking},
language = {Englisch},
cr-category = {C.2.1 Network Architecture and Design,
C.2.4 Distributed Systems,
C.2.3 Network Operations},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2017-22/INPROC-2017-22.pdf},
contact = {thomas.kohler@ipvs.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2017-22&engl=0}
}
@inproceedings {INPROC-2017-09,
author = {Ben William Carabelli and Rainer Blind and Frank D{\"u}rr and Kurt Rothermel},
title = {{State-dependent Priority Scheduling for Networked Control Systems}},
booktitle = {Proceedings of the 2017 American Control Conference (ACC)},
address = {Seattle, WA, USA},
publisher = {IEEE},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {1003--1010},
type = {Konferenz-Beitrag},
month = {Mai},
year = {2017},
doi = {10.23919/ACC.2017.7963084},
keywords = {cyber-physical systems; networked control systems; optimization; scheduling},
language = {Englisch},
cr-category = {C.2.1 Network Architecture and Design,
C.2.4 Distributed Systems,
G.1.6 Numerical Analysis Optimization},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2017-09/INPROC-2017-09.pdf,
http://ieeexplore.ieee.org/document/7963084/,
https://arxiv.org/abs/1703.08311},
contact = {ben.carabelli@ipvs.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Networked control systems (NCS) have attracted considerable attention in recent
years. While the stabilizability and optimal control of NCS for a given
communication system has already been studied extensively, the design of the
communication system for NCS has recently seen an increase in more thorough
investigation. In this paper, we address an optimal scheduling problem for a
set of NCS sharing a dedicated communication channel, providing performance
bounds and asymptotic stability. We derive a suboptimal scheduling policy with
dynamic state-based priorities calculated at the sensors, which are then used
for stateless priority queuing in the network, making it both scalable and
efficient to implement on routers or multi-layer switches. These properties are
beneficial towards leveraging existing IP networks for control, which will be a
crucial factor for the proliferation of wide-area NCS applications. By allowing
for an arbitrary number of concurrent transmissions, we are able to investigate
the relationship between available bandwidth, transmission rate, and delay. To
demonstrate the feasibility of our approach, we provide a proof-of-concept
implementation of the priority scheduler using real networking hardware.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2017-09&engl=0}
}
@inproceedings {INPROC-2017-07,
author = {Ruben Mayer and Harshit Gupta and Enrique Saurez and Umakishore Ramachandran},
title = {{The Fog Makes Sense: Enabling Social Sensing Services With Limited Internet Connectivity}},
booktitle = {Proceedings of the 2nd International Workshop on Social Sensing},
publisher = {Association for Computing Machinery (ACM)},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
series = {SocialSens '17},
pages = {1--6},
type = {Workshop-Beitrag},
month = {April},
year = {2017},
doi = {http://dx.doi.org/10.1145/3055601.3055614},
keywords = {Social Sensing; Fog Computing; Situation Awareness},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2017-07/INPROC-2017-07.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Social sensing services use humans as sensor carriers, sensor operators and
sensors themselves in order to provide situation-awareness to applications.
This promises to provide a multitude of benefits to the users, for example in
the management of natural disasters or in community empowerment. However,
current social sensing services depend on Internet connectivity since the
services are deployed on central Cloud platforms. In many circumstances,
Internet connectivity is constrained, for instance when a natural disaster
causes Internet outages or when people do not have Internet access due to
economical reasons. In this paper, we propose the emerging Fog Computing
infrastructure to become a key-enabler of social sensing services in situations
of constrained Internet connectivity. To this end, we develop a generic
architecture and API of Fog-enabled social sensing services. We exemplify the
usage of the proposed social sensing architecture on a number of concrete use
cases from two different scenarios.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2017-07&engl=0}
}
@inproceedings {INPROC-2017-03,
author = {Christoph Dibak and Frank D{\"u}rr and Kurt Rothermel},
title = {{Demo: Server-Assisted Interactive Mobile Simulations for Pervasive Applications}},
booktitle = {Proceedings of the 15th IEEE International Conference on Pervasive Computing and Communications (PerCom Demos)},
address = {Kona, Hawaii, USA},
publisher = {IEEE},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {1--3},
type = {Demonstration},
month = {M{\"a}rz},
year = {2017},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems,
G.1 Numerical Analysis},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2017-03/INPROC-2017-03.pdf},
contact = {Christoph Dibak christoph.dibak@ipvs.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Emerging augmented reality devices allow for visualizing results of numerical
simulations ubiquitously. This enables decision makers and engineers in the
field to make better decisions. However, computation of resource-intensive
simulation models on resource-poor and battery-powered mobile devices requires
to drastically reduce the quality of the simulation. We therefore proposed
approaches utilizing a remote server and the Reduced Basis Method (RBM) to
generate a reduced model of the simulation.
In our demo, we demonstrate the effectiveness of our approaches for mobile
simulations. Our demo consists of two devices, a mobile device and a server.
Both devices are connected via wireless network. The mobile device visualizes
the result of a complex computation. Parameters of the simulation are effected
by sensors of the mobile device. The user can choose between computing on the
mobile device, computing solely on the server, or computing using our approach.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2017-03&engl=0}
}
@inproceedings {INPROC-2017-02,
author = {Christoph Dibak and Andreas Schmidt and Frank D{\"u}rr and Bernard Haasdonk and Kurt Rothermel},
title = {{Server-Assisted Interactive Mobile Simulations for Pervasive Applications}},
booktitle = {Proceedings of the 15th IEEE International Conference on Pervasive Computing and Communications (PerCom)},
address = {Kona, Hawaii, USA},
publisher = {IEEE},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {1--10},
type = {Konferenz-Beitrag},
month = {M{\"a}rz},
year = {2017},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems,
G.1 Numerical Analysis},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2017-02/INPROC-2017-02.pdf},
contact = {Christoph Dibak christoph.dibak@ipvs.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Currently, various hardware and software companies are developing augmented
reality devices, most prominently Microsoft with its Hololens. Besides gaming,
such devices can be used for serious pervasive applications, like interactive
mobile simulations to support engineers in the field. Interactive simulations
have high demands on resources, which the mobile device alone is unable to
satisfy. Therefore, we propose a framework to support mobile simulations by
distributing the computation between mobile device and a remote server. For the
computation of parameter-dependent solutions of the simulation, we use the
reduced basis method, which allows to drastically reduce the computation time
and energy consumption. We present three approaches for the distributed
execution of the reduced basis method between mobile device and server.
Evaluations show that we can speed-up the numerical computation to over 131
times while using 73 times less energy compared to offloading everything to a
server.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2017-02&engl=0}
}
@inproceedings {INPROC-2016-41,
author = {Stephan Schnitzer and Simon Gansel and Frank D{\"u}rr and Kurt Rothermel},
title = {{Real-time scheduling for 3D GPU rendering}},
booktitle = {11th IEEE International Symposium on Industrial Embedded Systems (SIES)},
publisher = {IEEE},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {1--10},
type = {Konferenz-Beitrag},
month = {Mai},
year = {2016},
doi = {10.1109/SIES.2016.7509411},
keywords = {automobiles; graphical user interfaces; graphics processing units; rendering (computer graphics); 3D GPU rendering; GPU sharing; real-time GPU scheduling framework; real-time scheduling; automotive HMI; embedded systems},
language = {Englisch},
cr-category = {H.5.2 Information Interfaces and Presentation User Interfaces,
I.3.m Computer Graphics Miscellaneous},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2016-41/INPROC-2016-41.pdf,
http://dx.doi.org/10.1109/SIES.2016.7509411},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {3D graphical functions in cars enjoy growing popularity. For instance, analog
instruments of the instrument cluster are replaced by digital 3D displays as
shown by Mercedes-Benz in the F125 prototype car. The trend to use 3D
applications expands into two directions: towards more safety-relevant
applications such as the speedometer and towards third-party applications,
e.g., from an app store. In order to save cost, energy, and installation space,
all these applications should share a single GPU. GPU sharing brings up the
problem of providing real-time guarantees for rendering content of
time-sensitive applications like the speedometer. To solve this problem, we
present a real-time GPU scheduling framework which provides strong guarantees
for critical applications while still giving as much GPU resources to less
important applications as possible, thus ensuring a high GPU utilization. Since
current GPUs are not preemptible, we use the estimated execution time of each
GPU rendering job to make the scheduling decisions. Our evaluations show that
our scheduler guarantees given real-time constraints, while achieving a high
GPU utilization of 97\%. Moreover, scheduling is performed highly efficient in
real-time with less than 10 us latency.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2016-41&engl=0}
}
@inproceedings {INPROC-2016-34,
author = {Florian Berg and Frank D{\"u}rr and Kurt Rothermel},
title = {{Increasing the Efficiency of Code Offloading in n-tier Environments with Code Bubbling}},
booktitle = {Proceedings of the 13th Annual International Conference on Mobile and Ubiquitous Systems: Computing, Networking and Services},
publisher = {-},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
type = {Konferenz-Beitrag},
month = {November},
year = {2016},
isbn = {978-1-4503-4750-1/16/11},
doi = {dx.doi.org/10.1145/2994374.2994375},
keywords = {Mobile Cloud Computing; Multi-tier Code Offloading; Cyber Foraging; Code Bubbling; n-tier environment},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
contact = {Florian.Berg@ipvs.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Code offloading strives for increasing the energy efficiency and execution
speed of mobile applications on resource-constrained mobile devices. First
approaches considered only a code offloading between two (or three) tiers,
executing code either locally on the mobile device or remotely on a powerful
server in the vicinity or in a distant cloud. However, new execution
environments comprise multiple tiers, containing highly distributed
heterogeneous resources. We present in this paper our Code Bubbling Offload
System (CoBOS). CoBOS targets n-tier environments containing highly distributed
heterogeneous resources with different performance characteristics and cost
implications. In such n-tier environments, it is very costly for a
resource-constrained mobile device to gather a global view on available
resources. As a result, we propose the novel concept of code bubbling. Code
bubbling moves code dynamically and adaptively towards more powerful and more
distant tiers, enabling an efficient and scalable code offloading in n-tier
environments. Each tier makes autonomous decisions to execute code in the tier
or forward it further to the next tier. To support such a recursive escalation
of code along autonomous tiers, CoBOS offloads self-contained offload requests
that possess all of the required information for the processing. Our real-world
evaluation shows that CoBOS decreases the energy consumption by 77\% and the
execution time by 83\% for code offloading in n-tier environments.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2016-34&engl=0}
}
@inproceedings {INPROC-2016-32,
author = {Frank D{\"u}rr and Naresh Ganesh Nayak},
title = {{No-wait Packet Scheduling for IEEE Time-sensitive Networks (TSN)}},
booktitle = {24th International Conference on Real-Time Networks and Systems, RTNS-2016},
address = {Brest, France},
publisher = {ACM},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {1--10},
type = {Konferenz-Beitrag},
month = {Oktober},
year = {2016},
keywords = {Time-sensitive network, TSN, Real-time communication, Job shop scheduling problem, Tabu search, IEEE 802.1Qbv},
language = {Englisch},
cr-category = {C.2.1 Network Architecture and Design,
C.2.3 Network Operations},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2016-32/INPROC-2016-32.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {The IEEE Time-sensitive Networking (TSN) Task Group has recently standardized
enhancements for IEEE 802.3 networks for enabling it to transport
time-triggered traffic (aka scheduled traffic) providing them with stringent
bounds on network delay and jitter while also transporting best-effort traffic.
These enhancements primarily include dedicating one queue per port of the
switch for scheduled traffic along with a programmable gating mechanism that
dictates which of the queues are to be considered for transmission. While the
IEEE 802.1Qbv standards define these mechanisms to handle scheduled traffic, it
stops short of specifying algorithms to compute fine-grained link schedules for
the streams of scheduled traffic. Further, the mechanisms in TSN require
creation of so-called guard bands to isolate scheduled traffic from the
best-effort traffic. These guard bands may potentially result in bandwidth
wastage, and hence schedules with lower number of guard bands are preferred. In
this paper, we introduce the No-wait Packet Scheduling Problem (NWPSP) for
modelling the scheduling in IEEE Time-sensitive Networks and map it to the
No-wait Job-shop Scheduling Problem (NW-JSP), a well-known problem from the
field of operational research. In particular, we present a Tabu search
algorithm for efficient computing of schedules and a schedule compression
technique to reduce number of guard bands in schedule. Our evaluations show
that our Tabu search algorithm can compute near-optimal schedules for over 1500
flows and the subsequent schedule compression reduces the number of guard bands
on an average by 24\%.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2016-32&engl=0}
}
@inproceedings {INPROC-2016-31,
author = {Naresh Ganesh Nayak and Frank D{\"u}rr and Kurt Rothermel},
title = {{Time-sensitive Software-defined Network (TSSDN) for Real-time Applications}},
booktitle = {Proceedings of the 24th International Conference on Real-Time Networks and Systems, RTNS 2016},
address = {Brest, France},
publisher = {ACM},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {1--10},
type = {Konferenz-Beitrag},
month = {Oktober},
year = {2016},
language = {Deutsch},
cr-category = {C.2.1 Network Architecture and Design,
C.2.3 Network Operations},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2016-31/INPROC-2016-31.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Cyber-physical systems (CPS), like the ones used in industrial automation
systems, are highly time-sensitive applications demanding zero packet losses
along with stringent real-time guarantees like bounded latency and jitter from
the underlying network for communication. With the proliferation of IEEE 802.3
and IP networks, there is a desire to use these networks instead of the
currently used fieldbuses for time-sensitive applications. However, these
networking technologies, which originally were designed to provide best effort
communication services, lack mechanisms for providing real-time guarantees. In
this paper, we present Time-Sensitive Software-Defined Networks (TSSDN), which
provide real-time guarantees for the time-triggered traffic in time-sensitive
systems while also transporting non-time-sensitive traffic. TSSDN provides
these guarantees by bounding the non-deterministic queuing delays for
time-sensitive traffic. To this end, it exploits the logical centralization
paradigm of software-defined networking to compute a transmission schedule for
time-sensitive traffic initiated by the end systems based on a global view. In
particular, we present various Integer Linear Program (ILP) formulations that
solve the combined problem of routing and scheduling time-triggered traffic.
Moreover, we show that end systems can comply with a given schedule with high
precision using user-space packet processing frameworks. Our evaluations show
that TSSDN has deterministic end-to-end delays ($<$= 14 us on our benchmark
topology) with low and bounded jitter ($<$= 7 us).},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2016-31&engl=0}
}
@inproceedings {INPROC-2016-18,
author = {Sukanya Bhowmik and Muhammad Adnan Tariq and Jonas Grunert and Kurt Rothermel},
title = {{Bandwidth-Efficient Content-Based Routing on Software-Defined Networks}},
booktitle = {Proceedings of the ACM International Conference on Distributed and Event-based Systems (DEBS 2016); Irvine, California, US, June 20-24, 2016},
publisher = {IEEE},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {1--8},
type = {Konferenz-Beitrag},
month = {Juni},
year = {2016},
language = {Englisch},
cr-category = {C.2.1 Network Architecture and Design,
C.2.4 Distributed Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2016-18/INPROC-2016-18.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {With the vision of Internet of Things gaining popularity at a global level,
efficient publish/subscribe middleware for communication within and across
datacenters is extremely desirable. In this respect, the very popular
Software-defined Networking (SDN), which enables publish/subscribe middleware
to perform line-rate filtering of events directly on hardware, can prove to be
very useful. While deploying content filters directly on switches of a
software-defined network allows optimized paths, high throughput rates, and low
end-to-end latency, it suffers from certain inherent limitations w.r.t. no. of
bits available on hardware switches to represent these filters. Such a
limitation affects expressiveness of filters, resulting in unnecessary traffic
in the network.
In this paper, we explore various techniques to represent content filters
expressively while being limited by hardware. We implement and evaluate
techniques that i) use workload, in terms of events and subscriptions, to
represent content, and ii) efficiently select attributes to reduce redundancy
in content. Moreover, these techniques complement each other and can be
combined together to further enhance performance. Our detailed performance
evaluations show the potential of these techniques in reducing unnecessary
traffic when subjected to different workloads.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2016-18&engl=0}
}
@inproceedings {INPROC-2016-17,
author = {Ruben Mayer and Christian Mayer and Muhammad Adnan Tariq and Kurt Rothermel},
title = {{GraphCEP - Real-time Data Analytics Using Parallel Complex Event and Graph Processing}},
booktitle = {Proceedings of the 10th ACM International Conference on Distributed Event-Based Systems, DEBS'16},
publisher = {ACM},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {1--8},
type = {Konferenz-Beitrag},
month = {Juni},
year = {2016},
doi = {10.1145/2933267.2933509},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2016-17/INPROC-2016-17.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {In recent years, the proliferation of highly dynamic graph-structured data
streams fueled the demand for real-time data analytics. For instance, detecting
recent trends in social networks enables new applications in areas such as
disaster detection, business analytics or health-care. Parallel Complex Event
Processing has evolved as the paradigm of choice to analyze data streams in a
timely manner, where the incoming data streams are split and processed
independently by parallel operator instances. However, the degree of
parallelism is limited by the feasibility of splitting the data streams into
independent parts such that correctness of event processing is still ensured.
In this paper, we overcome this limitation for graph-structured data by further
parallelizing individual operator instances using modern graph processing
systems. These systems partition the graph data and execute graph algorithms in
a highly parallel fashion, for instance using cloud resources. To this end, we
propose a novel graph-based Complex Event Processing system GraphCEP and
evaluate its performance in the setting of two case studies from the DEBS Grand
Challenge 2016.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2016-17&engl=0}
}
@inproceedings {INPROC-2016-16,
author = {Sukanya Bhowmik and Muhammad Adnan Tariq and Lobna Hegazy and Kurt Rothermel},
title = {{Hybrid Content-based Routing Using Network and Application Layer Filtering}},
booktitle = {Proceedings of the 36th IEEE International Conference on Distributed Computing Systems (ICDCS 2016), Nara, Japan, June 27-30, 2016},
publisher = {IEEE},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
type = {Konferenz-Beitrag},
month = {Juni},
year = {2016},
keywords = {Content-based Routing; Publish/Subscribe; Software-defined Networking; Network Virtualization; Hybrid Routing},
language = {Englisch},
cr-category = {C.2.1 Network Architecture and Design,
C.2.4 Distributed Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2016-16/INPROC-2016-16.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Over the past few decades, content-based publish/subscribe has been primarily
implemented as an overlay network of software brokers. Even though such systems
provide the possibility of bandwidth efficient expressive filtering in
software, they cannot match up to the performance (in terms of end-to-end
latency and throughput) of communication protocols implemented on the network
layer. To exploit network layer performance benefits, recently, content-based
publish/subscribe was realized using the capabilities of Software-defined
Networking (SDN). While SDN allows line-rate forwarding of events by content
filters directly installed on switches, it suffers from inherent hardware
limitations (w.r.t. flow table size, limited availability of bits in header
fields) that adversely impact expressiveness of these filters, resulting in
unnecessary network traffic.
In this paper, we strike a balance between purely application-layer-based and
purely network-layer-based publish/subscribe implementations by realizing the
first hybrid content-based middleware that enables filtering of events in both
layers. Moreover, we provide different selection algorithms with varying
degrees of complexity to determine the events to be filtered at each layer such
that unnecessary network traffic can be minimized while also considering delay
requirements of the middleware. Our hybrid middleware offers full flexibility
to configure it according to the performance requirements of the system. We
provide a detailed performance evaluation of the proposed selection algorithms
to determine their impact on the performance of the designed hybrid middleware
which we further compare to state-of-the art solutions.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2016-16&engl=0}
}
@inproceedings {INPROC-2016-15,
author = {David Richard Sch{\"a}fer and Andreas Wei{\ss} and Muhammad Adnan Tariq and Vasilios Andrikopoulos and Santiago G{\'o}mez S{\'a}ez and Lukas Krawczyk and Kurt Rothermel},
title = {{HAWKS: A System for Highly Available Executions of Workflows}},
booktitle = {Proceedings of the 13th IEEE International Conference on Services Computing: SCC'16; San Francisco, California, USA, June 27-July 2, 2016},
publisher = {IEEE},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {130--137},
type = {Konferenz-Beitrag},
month = {Juni},
year = {2016},
doi = {10.1109/SCC.2016.24},
keywords = {SOA; workflows; availability; replication; performance},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems,
C.4 Performance of Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2016-15/INPROC-2016-15.pdf,
http://dx.doi.org/10.1109/SCC.2016.24},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Architektur von Anwendungssystemen;
Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {The workflow technology is the de facto standard for managing business
processes. Today, workflows are even used for automating interactions and
collaborations between business partners, e.g., for enabling just-in-time
production. Every workflow that is part of such a collaboration needs to be
highly available. Otherwise, the business operations, e.g., the production,
might be hindered or even stopped. Since today's business partners are
scattered across the globe, the workflows are executed in a highly distributed
and heterogeneous environment. Those environments are, however, failure-prone
and, thus, providing availability is not trivial. In this work, we improve
availability by replicating workflow executions, while ensuring that the
outcome is the same as in a non-replicated execution. For making workflow
replication easily usable with current workflow technology, we derive the
requirements for modeling a workflow replication system. Then, we propose the
HAWKS system, which adheres to the previously specified requirements and is
compatible with current technology. We implement a proof-of-concept in the
open-source workflow execution engine Apache ODE for demonstrating this
compatibility. Finally, we extensively evaluate the impact of using HAWKS in
terms of performance and availability in the presence of failures.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2016-15&engl=0}
}
@inproceedings {INPROC-2016-13,
author = {Christian Mayer and Muhammad Adnan Tariq and Chen Li and Kurt Rothermel},
title = {{GrapH: Heterogeneity-Aware Graph Computation with Adaptive Partitioning}},
booktitle = {Proceedings of the 2016 IEEE 36th International Conference on Distributed Computing Systems (ICDCS)},
publisher = {IEEE},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {118--128},
type = {Konferenz-Beitrag},
month = {Juni},
year = {2016},
doi = {10.1109/ICDCS.2016.92},
issn = {1063-6927},
keywords = {cloud computing; data analysis; GrapH; GraphX; PowerGraph; Pregel; adaptive edge migration strategy; adaptive partitioning; data access locality; data analytics; diverse vertex traffic; expensive network links; graph vertices; graph-structured data; heterogeneity-aware graph computation; heterogeneous network; specialized graph partitioning algorithms; suboptimal partitioning decisions; vertex-centric graph processing; vertex-cut graph partitioning; Automata; Computational modeling; Data analysis; Distributed databases; Heuristic algorithms; Mirrors; Partitioning algorithms},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2016-13/INPROC-2016-13.pdf,
http://dx.doi.org/10.1109/ICDCS.2016.92},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Vertex-centric graph processing systems such as Pregel, PowerGraph, or GraphX
recently gained popularity due to their superior performance of data analytics
on graph-structured data. These systems exploit the graph structure to improve
data access locality during computation, making use of specialized graph
partitioning algorithms. Recent partitioning techniques assume a uniform and
constant amount of data exchanged between graph vertices (i.e., uniform vertex
traffic) and homogeneous underlying network costs. However, in real-world
scenarios vertex traffic and network costs are heterogeneous. This leads to
suboptimal partitioning decisions and inefficient graph processing. To this
end, we designed GrapH, the first graph processing system using vertex-cut
graph partitioning that considers both, diverse vertex traffic and
heterogeneous network, to minimize overall communication costs. The main idea
is to avoid frequent communication over expensive network links using an
adaptive edge migration strategy. Our evaluations show an improvement of 60\% in
communication costs compared to state-of-the-art partitioning approaches.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2016-13&engl=0}
}
@inproceedings {INPROC-2016-11,
author = {Zohaib Riaz and Frank D{\"u}rr and Kurt Rothermel},
title = {{On the Privacy of Frequently Visited User Locations}},
booktitle = {Proceedings of the Seventeenth International Conference on Mobile Data Management: MDM'16; Porto, Portugal, June 13-16, 2016},
address = {Porto, Portugal},
publisher = {IEEE Computer Society},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {1--10},
type = {Konferenz-Beitrag},
month = {Juni},
year = {2016},
keywords = {Location Privacy, Location-based Applications, Semantic Locations, Visit-Frequency, Frequent locations, Geo-social networking, Location Servers, Non-trusted systems},
language = {Englisch},
cr-category = {K.4.1 Computers and Society Public Policy Issues,
C.2.4 Distributed Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2016-11/INPROC-2016-11.pdf},
contact = {zohaib.riaz@ipvs.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {With the fast adoption of location-enabled devices, Location-based Applications
(LBAs) have become widely popular. While LBAs enable highly useful concepts
such as geo-social networking, their use also raises serious privacy concerns
as it involves sharing of location data with non-trusted third parties. In this
respect, we propose an approach that protects the frequently visited locations
of users, e.g., a bar, against inferences from longterm monitoring of their
location data. Such inferences equate a privacy leak as they reveal a user{\^a}€™s
personal behavior and interests to possibly malicious non-trusted parties.
To this end, we first present a study of a dataset of location check-ins to
show the existence of this threat among users of LBAs. We then propose our
approach to protect visit-frequency of the users to different locations by
distributing their location data among multiple third-party Location Servers.
This distribution not only serves to avoid a single point of failure for
privacy in our system, it also allows the users to control which LBA accesses
what information about them. We also describe a number of possible attacks
against our privacy approach and evaluate them on real-data from the check-ins
dataset. Our results show that our approach can effectively hide the frequent
locations while supporting good quality-of-service for the LBAs.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2016-11&engl=0}
}
@inproceedings {INPROC-2015-59,
author = {Simon Gansel and Stephan Schnitzer and Ahmad Gilbeau-Hammoud and Viktor Friesen and Frank D{\"u}rr and Kurt Rothermel and Christian Maih{\"o}fer and Ulrich Kr{\"a}mer},
title = {{Context-aware Access Control in Novel Automotive HMI Systems}},
booktitle = {Proceedings of 11th International Conference on Information Systems Security, ICISS 2015, Kolkata, India},
editor = {Sushil Jajodia and Chandan Mazumdar},
publisher = {Springer International Publishing},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {118--138},
type = {Konferenz-Beitrag},
month = {Dezember},
year = {2015},
isbn = {10.1007/978-3-319-26961-0_8},
language = {Englisch},
cr-category = {D.4.6 Operating Systems Security and Protection},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2015-59/INPROC-2015-59.pdf,
http://link.springer.com/chapter/10.1007%2F978-3-319-26961-0_8},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {The growing relevance of vehicular applications like media player, navigation
system, or speedometer using graphical presentation has lead to an increasing
number of displays in modern cars. This effectuates the desire for flexible
sharing of all the available displays between several applications. However,
automotive requirements include many regulations to avoid driver distraction to
ensure safety. To allow for safe sharing of the available screen surface
between the many safety-critical and non-safety-critical applications, adequate
access control systems are required. We use the notion of $\backslash$emph{contexts} to
dynamically determine, which application is allowed to access which display
area. A context can be derived from vehicle sensors (e.g., the current speed),
or be an application-specific state (e.g., which menu item is selected). We
propose an access control model that is inherently aware of the context of the
car and the applications. It provides delegation of access rights to display
areas by applications. We implemented a proof-of-concept implementation that
demonstrates the feasibility of our concept and evaluated the latency
introduced by access control. Our results show that the delay reacting on
dynamic context changes is small enough for automotive scenarios.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2015-59&engl=0}
}
@inproceedings {INPROC-2015-54,
author = {Simon Gansel and Stephan Schnitzer and Riccardo Cecolin and Frank D{\"u}rr and Kurt Rothermel and Christian Maih{\"o}fer},
title = {{Efficient Compositing Strategies for Automotive HMI Systems}},
booktitle = {10th IEEE International Symposium on Industrial Embedded Systems (SIES), Siegen, Germany, 2015},
address = {Siegen},
publisher = {IEEE},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {1--10},
type = {Konferenz-Beitrag},
month = {Juni},
year = {2015},
doi = {10.1109/SIES.2015.7185036},
keywords = {CPU execution time; automotive HMI systems; automotive embedded platforms; cache-hybrid compositing; graphical functions; off-screen buffers; power consumption; vehicular applications},
language = {Englisch},
cr-category = {D.4.9 Systems Programs and Utilities,
H.5.2 Information Interfaces and Presentation User Interfaces,
I.3.6 Computer Graphics Methodology and Techniques},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2015-54/INPROC-2015-54.pdf,
http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=7185036&isnumber=7185026},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {The relevance of graphical functions in vehicular applications has increased
significantly during the last years. Modern cars are equipped with multiple
displays used by different applications such as speedometer, navigation system,
or media players. The rendered output of the applications is stored in
so-called off-screen buffers and then bitblitted to the screen buffer at the
respective window sizes and positions. To guarantee the visibility of the
potentially overlapping windows, the compositing has to match the z-order of
the windows. To this end, two common compositing strategies Tile compositing
and Full compositing are used, each having performance issues depending on how
windows overlap. Since automotive embedded platforms are restricted in power
consumption, installation space, and hardware cost, their performance is
limited which effectuates the need for highly efficient bitblitting. In order
to increase the performance in compositing the windows, we propose Hybrid
Compositing which predicts the required bitblitting time and chooses the most
efficient strategy for each pair of overlapping windows. Using various
scenarios we show that our approach is faster than the other strategies. In
addition, we propose CacheHybrid Compositing which reduces the CPU execution
time of our approach by up to 66 \%. In case of an automotive scenario we show
that our optimized approach saves up to 51 \% bitblitting time compared to
existing approaches.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2015-54&engl=0}
}
@inproceedings {INPROC-2015-49,
author = {Thomas Kohler and Frank D{\"u}rr and Kurt Rothermel},
title = {{Update Consistency in Software-defined Networking based Multicast Networks}},
booktitle = {Proceedings of the 2015 IEEE Conference on Network Function Virtualization and Software Defined Networks (NFV-SDN), San Francisco, USA, November 18-21, 2015},
address = {San Francisco, USA},
publisher = {IEEE Computer Society},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {177--183},
type = {Konferenz-Beitrag},
month = {September},
year = {2015},
doi = {10.1109/NFV-SDN.2015.7387424},
keywords = {Software-defined Networking; Multicast communication; Computer network management; Concurrency Control},
language = {Englisch},
cr-category = {C.2.1 Network Architecture and Design,
C.2.3 Network Operations,
C.2.4 Distributed Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2015-49/INPROC-2015-49.pdf,
http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=7387424},
contact = {thomas.kohler@ipvs.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {When applying updates on distributed network elements with SDN, intra-update
states may violate desired network properties, such as drop- and loop-freeness.
Current stateless approaches cannot guarantee the constancy of arbitrary
network invariants (correctness) in general, yet update procedures guaranteeing
certain invariants do exist. In this paper, we investigate on update
consistency for the case of multicast routing and show that there is no correct
update procedure w.r.t. both drop- and duplicate-freeness. We show that certain
updates of multicast routes inherently raise a concurrency issue, which
necessarily results in the occurrence of either drops or duplicates.
Furthermore, we present a generic update procedure for multicast routing
updates that identifies concurrency-relevant update steps. This procedure
allows for the selection of an update strategy, such that either drops or
duplicates are avoided. These effects can severely degrade network performance
or quality of experience. To investigate the implications of drops and
duplicates, we evaluate their frequencies and impact for wide-area network
scenarios both, analytically and empirically, through direct measurement in the
data plane under update.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2015-49&engl=0}
}
@inproceedings {INPROC-2015-48,
author = {Florian Berg and Frank D{\"u}rr and Kurt Rothermel},
title = {{Increasing the Efficiency of Code Offloading through Remote-side Caching}},
booktitle = {Proceedings of the IEEE 11th International Conference on Wireless and Mobile Computing, Networking and Communications: WiMob'15; Abu-Dhabi, United Arab Emirates (UAE), October 19-21, 2015},
publisher = {IEEE Computer Society},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {573--580},
type = {Konferenz-Beitrag},
month = {Oktober},
year = {2015},
doi = {10.1109/WiMOB.2015.7348013},
keywords = {Mobile Cloud Computing; Code Offloading; Distributed Execution; Data Replication; Function Caching},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
ee = {http://dx.doi.org/10.1109/WiMOB.2015.7348013},
contact = {Florian.Berg@ipvs.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {End users execute today on their smart phones different kinds of mobile
applications like calendar apps or high-end mobile games, differing in local
resource usage. Utilizing local resources of a smart phone heavily, like
playing high-end mobile games, drains its limited energy resource in few hours.
To prevent the limited energy resource from a quick exhaustion, smart phones
benefit from executing resource-intensive application parts on a remote server
in the cloud (code offloading). During the remote execution on the remote
server, a smart phone waits in idle mode until it receives a result. However,
code offloading introduces computation and communication overhead, which
decreases the energy efficiency and induces monetary cost. For instance,
sending or receiving execution state information to or from a remote server
consumes energy. Moreover, executing code on a remote server instance in a
commercial cloud causes monetary cost. To keep consumed energy and monetary
cost low, we present in this paper the concept of remote-side caching for code
offloading, which increases the efficiency of code offloading. The remote-side
cache serves as a collective storage of results for already executed
application parts on remote servers, avoiding the repeated execution of
previously run application parts. The smart phone queries the remote-side cache
for corresponding results of resource-intensive application parts. In case of a
cache hit, the smart phone gets immediately a result and continues the
application execution. Otherwise, it migrates the application part and waits
for a result of the remote execution. We show in our evaluation that the use of
a remote-side cache decreases energy consumption and monetary cost for mobile
applications by up to 97\% and 99\%, respectively.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2015-48&engl=0}
}
@inproceedings {INPROC-2015-42,
author = {Thomas Bach and Muhammad Adnan Tariq and Christian Mayer and Kurt Rothermel},
title = {{Utilizing the Hive Mind - How to Manage Knowledge in Fully Distributed Environments}},
booktitle = {OTM 2015 Conferences},
address = {Rhodos},
publisher = {Springer Verlag},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {1--18},
type = {Konferenz-Beitrag},
month = {Oktober},
year = {2015},
keywords = {Knowledge retrieval; Distributed knowledge; Confidence-based indexing; Indexing; Query routing; Knowledge},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2015-42/INPROC-2015-42.pdf},
contact = {thomas.bach@ipvs.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {By 2020, the Internet of Things will consist of 26 Billion connected devices.
All these devices will be collecting an innumerable amount of raw observations,
for example, GPS positions or communication patterns. In order to benefit from
this enormous amount of information, machine learning algorithms are used to
derive knowledge from the gathered observations. This benefit can be increased
further, if the devices are enabled to collaborate by sharing gathered
knowledge. In a massively distributed environment, this is not an easy task, as
the knowledge on each device can be very heterogeneous and based on a different
amount of observations in diverse contexts. In this paper, we propose two
strategies to route a query for specific knowledge to a device that can answer
it with high confidence. To that end, we developed a confidence metric that
takes the number and variance of the observations of a device into account. Our
routing strategies are based on local routing tables that can either be learned
from previous queries over time or actively maintained by interchanging
knowledge models. We evaluated both routing strategies on real world and
synthetic data. Our evaluations show that the knowledge retrieved by the
presented approaches is up to 96.7 \% as accurate as the global optimum.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2015-42&engl=0}
}
@inproceedings {INPROC-2015-41,
author = {Naresh Ganesh Nayak and Frank D{\"u}rr and Kurt Rothermel},
title = {{Software-defined Environment for Reconfigurable Manufacturing Systems}},
booktitle = {Proceedings of the 5th International Conference on Internet of Things (IoT 2015)},
address = {Seoul, South Korea},
publisher = {IEEE},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
type = {Konferenz-Beitrag},
month = {Oktober},
year = {2015},
keywords = {Time-sensitive networks; Industry 4.0; Quality of service; Genetic Algorithm; Software-defined networks},
language = {Englisch},
cr-category = {C.2.1 Network Architecture and Design,
C.2.3 Network Operations},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2015-41/INPROC-2015-41.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Conventional manufacturing systems like assembly lines cannot handle the
constantly changing requirements of a modern-day manufacturer, which are driven
by volatile market demands. In a bid to satisfy such requirements, modern
manufacturing systems, comprising innumerable cyber-physical systems (CPS), aim
to be reconfigurable. CPS implement production processes through an ICT
infrastructure networked with sensors and actuators embedded in the shop floor.
Reconfigurability, in context of manufacturing systems, must include the entire
system of networked components and hence requires a flexible ICT
infrastructure. Providing flexible ICT infrastructures, often, comes at the
cost of diluted quality of service (QoS) guarantees. This, however, is not an
option for manufacturing systems, most of which require strict QoS guarantees
to function correctly. To overcome this obstacle, we propose a new
software-defined environment (SDE) for reconfigurable manufacturing systems
with real-time properties in this paper. Software-defined environment is an
emerging technology that provides flexible ICT infrastructures modifiable using
software. Our contributions include an SDE-based system architecture for
dynamically configuring the underlying infrastructure for a manufacturing
system. In particular, we focus on configuring the network for the
time-sensitive communication flows essential for realising CPS. Moreover, we
propose a pair of routing algorithms to calculate routes for these flows while
configuring the network.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2015-41&engl=0}
}
@inproceedings {INPROC-2015-36,
author = {Christoph Dibak and Frank D{\"u}rr and Kurt Rothermel},
title = {{Numerical Analysis of Complex Physical Systems on Networked Mobile Devices}},
booktitle = {Proceedings of the 12th IEEE International Conference on Mobile Ad hoc and Sensor Systems (MASS 2015); Dallas, USA, October 19-22 2015},
address = {Dallas},
publisher = {IEEE},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {1--9},
type = {Konferenz-Beitrag},
month = {Oktober},
year = {2015},
keywords = {mobile cloud computing; numerical applications; mobile cyber-physical systems; augmented reality},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems,
C.4 Performance of Systems,
G.1.0 Numerical Analysis General},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2015-36/INPROC-2015-36.pdf},
contact = {Christoph Dibak christoph.dibak@ipvs.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Recently, a new class of mobile applications has appeared that takes into
account the behavior of physical phenomenon. Prominent examples of such
applications include augmented reality applications visualizing physical
processes on a mobile device or mobile cyber-physical systems like autonomous
vehicles or robots. Typically, these applications need to solve partial
differential equations (PDE) to simulate the behavior of a physical system.
There are two basic strategies to numerically solve these PDEs: (1) offload all
computations to a remote server; (2) solve the PDE on the resource-constrained
mobile device. However, both strategies have severe drawbacks. Offloading will
fail if the mobile device is disconnected, and resource constraints require to
reduce the quality of the solution.
Therefore, we propose a new approach for mobile simulations using a hybrid
strategy that is robust to communication failures and can still benefit from
powerful server resources. The basic idea of this approach is to dynamically
decide on the placement of the PDE solver based on a prediction of the wireless
link availability using Markov Chains. Our tests based on measurement in real
cellular networks and real mobile devices show that this approach is able to
keep deadline constraints in more than 61 \% of the cases compared to a pure
offloading approach, while saving up to 74 \% of energy compared to a simplified
approach.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2015-36&engl=0}
}
@inproceedings {INPROC-2015-22,
author = {Sukanya Bhowmik and Muhammad Adnan Tariq and Boris Koldehofe and Andre Kutzleb and Kurt Rothermel},
title = {{Distributed Control Plane for Software-defined Networks: A Case Study Using Event-based Middleware}},
booktitle = {Proceedings of the 9th International Conference on Distributed Event-based Systems, Oslo, Norway, June 29 - July 3, 2015},
publisher = {ACM},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {1--12},
type = {Konferenz-Beitrag},
month = {Juni},
year = {2015},
isbn = {http://doi.acm.org/10.1145/2675743.2771835},
language = {Englisch},
cr-category = {C.2.1 Network Architecture and Design,
C.2.4 Distributed Systems,
D.2.11 Software Engineering Software Architectures},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2015-22/INPROC-2015-22.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Realizing a communication middleware in a software-defined network can leverage
significant performance gains in terms of latency, throughput and bandwidth
efficiency. For example, filtering operations in an event-based middleware can
be performed highly efficiently in the TCAM memory of switches enabling
line-rate forwarding of events. A key challenge in a software-defined network,
however, is to ensure high responsiveness of the control plane to dynamically
changing communication interactions. In this paper, we propose a methodology
for both vertical and horizontal scaling of the distributed control plane that
is capable of improving the responsiveness by enabling concurrent network
updates in the presence of high dynamics while ensuring consistent changes to
the data plane of a communication middleware. In contrast to existing scaling
approaches that aim for a general-purpose distributed control plane, our
approach uses knowledge of the application semantics that is already available
in the design of the data plane of a communication middleware, e.g.
subscriptions and advertisements in an event-based middleware. By proposing a
methodology for an application-aware control distribution, we show, in the
context of PLEROMA, an event-based middleware, that application-awareness is
significantly beneficial in avoiding the synchronization bottlenecks for
ensuring consistency in the presence of concurrent network updates and thus
greatly improves the responsiveness of the control plane.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2015-22&engl=0}
}
@inproceedings {INPROC-2015-06,
author = {Zohaib Riaz and Frank D{\"u}rr and Kurt Rothermel},
title = {{Optimized Location Update Protocols for Secure and Efficient Position Sharing}},
booktitle = {Proceedings of the 2nd International Conference on Networked Systems: NetSys 2015; Cottbus, Germany, March 9-13, 2015},
publisher = {IEEE Computer Society},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {1--8},
type = {Konferenz-Beitrag},
month = {M{\"a}rz},
year = {2015},
language = {Englisch},
cr-category = {C.2.0 Computer-Communication Networks, General,
K.4.1 Computers and Society Public Policy Issues},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2015-06/INPROC-2015-06.pdf},
contact = {zohaib.riaz@ipvs.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Abstract{\^a}€”Although location-based applications have seen fast growth in the
last decade due to pervasive adoption of GPS enabled mobile devices, their use
raises privacy concerns. To mitigate these concerns, a number of approaches
have been proposed in literature, many of which rely on a trusted party to
regulate user privacy. However, trusted parties are known to be prone to data
breaches [1]. Consequently, a novel solution, called Position Sharing, was
proposed in [2] to secure location privacy in fully non-trusted systems. In
Position Sharing, obfuscated position shares of the actual user location are
distributed among several location servers, each from a different provider,
such that there is no single point of failure if the servers get breached.
While Position Sharing can exhibit useful properties such as graceful
degradation of privacy, it incurs significant communication overhead as
position shares are sent to several location servers instead of one.
To this end, we propose a set of location update protocols to minimize the
communication overhead of Position Sharing while maintaining the privacy
guarantees that it originally provided. As we consider the scenario of frequent
location updates, i.e., movement trajectories, our protocols additionally add
protection against an attack based on spatio-temporal correlation in published
locations. By evaluating on a set of real-world GPS traces, we show that our
protocols can reduce the communication overhead by 75\% while significantly
improving the security guarantees of the original Position Sharing algorithm.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2015-06&engl=0}
}
@inproceedings {INPROC-2015-05,
author = {Thomas Bach and Muhammad Adnan Tariq and Boris Koldehofe and Kurt Rothermel},
title = {{A Cost Efficient Scheduling Strategy to Guarantee Probabilistic Workflow Deadlines}},
booktitle = {Proceedings of the International Conference on Networked Systems},
address = {Cottbus, Germany},
publisher = {IEEE Computer Society},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {1--8},
type = {Konferenz-Beitrag},
month = {M{\"a}rz},
year = {2015},
keywords = {robust workflow execution; parallel service execution; service execution},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2015-05/INPROC-2015-05.pdf},
contact = {thomas.bach@ipvs.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Today, workflows are widely used to model business processes. A recent trend is
to use them to model applications in heterogeneous, large-scale distributed
systems. In such systems, many, possibly mobile, providers offer independent
and interchangeable services that can be used to satisfy the different
activities of a workflow. Due to varying server loads, failures, and changing
network characteristics, the response time of these services is highly
volatile. Thus, it is hard to ensure the timely and reliable execution of
workflows depending on such services. A common approach is to invoke several
services in parallel to increase the probability of success. This, however, can
easily lead to overprovisioning and high cost when needlessly invoked services
have to be compensated. In this paper, we investigate the search space between
parallel and sequential invocation of services. We propose to invoke
independent services staggered over time to ensure timely workflow execution at
minimal cost. Evaluations show that our approach reduces the execution cost by
up to 85 \% while it guarantees to fulfill activity deadlines with 99.9 \%
probability.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2015-05&engl=0}
}
@inproceedings {INPROC-2014-95,
author = {Simon Gansel and Stephan Schnitzer and Ahmad Gilbeau-Hammoud and Viktor Friesen and Frank D{\"u}rr and Kurt Rothermel and Christian Maih{\"o}fer},
title = {{An access control concept for novel automotive HMI systems}},
booktitle = {Proceedings of the 19th ACM symposium on Access control models and technologies, 2014, London, Ontario, Canada.},
publisher = {ACM},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {17--28},
type = {Konferenz-Beitrag},
month = {Juni},
year = {2014},
isbn = {978-1-4503-2939-2},
doi = {10.1145/2613087.2613104},
keywords = {Access Control; State-based Model; Automotive; Windows},
language = {Englisch},
cr-category = {D.4.6 Operating Systems Security and Protection,
H.5.2 Information Interfaces and Presentation User Interfaces},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2014-95/INPROC-2014-95.pdf,
http://dl.acm.org/citation.cfm?id=2613104},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {The relevance of graphical functions in vehicular applications has increased
significantly during the few last years. Modern cars are equipped with multiple
displays used by different applications such as speedometer or navigation
system. However, so far applications are restricted to using dedicated
displays. In order to increase flexibility, the requirement of sharing displays
between applications has emerged. Sharing displays leads to safety and security
concerns since safety-critical applications as the dashboard warning lights
share the same displays with uncritical or untrusted applications like the
navigation system or third-party applications. To guarantee the safe and secure
sharing of displays, we present a formal model for defining and controlling the
access to display areas in this paper. We prove the validity of this model, and
present a proof-of-concept implementation to demonstrate the feasibility of our
concept.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2014-95&engl=0}
}
@inproceedings {INPROC-2014-94,
author = {Stephan Schnitzer and Simon Gansel and Frank D{\"u}rr and Kurt Rothermel},
title = {{Concepts for execution time prediction of 3D GPU rendering}},
booktitle = {9th IEEE International Symposium on Industrial Embedded Systems (SIES), 2014, pp.160-169, 18-20 June 2014},
publisher = {IEEE},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {160--169},
type = {Konferenz-Beitrag},
month = {Juni},
year = {2014},
isbn = {10.1109/SIES.2014.6871200},
keywords = {3D-rendering; GPU-scheduling; embedded systems; execution time prediction; real-time},
language = {Englisch},
cr-category = {H.5.2 Information Interfaces and Presentation User Interfaces,
I.3.m Computer Graphics Miscellaneous},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2014-94/INPROC-2014-94.pdf,
http://dx.doi.org/10.1109/SIES.2014.6871200},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {The relevance of graphical functions in vehicular applications has increased
significantly during the last years. Modern cars are equipped with multiple
displays used by different applications such as speedometer, navigation system,
or media players. The recent trend towards hardware consolidation to reduce
hardware cost, installation space, and energy consumption, causes graphical 3D
applications of different safety-criticality to share a single GPU. This
requires effective real-time GPU scheduling concepts to ensure safety and
isolation for 3D rendering. Since current GPUs are not preemptible, a
deadline-based scheduler must know the GPU execution time of GPU commands in
advance. In this work, we present a novel framework to measure and predict the
execution time of GPU commands using OpenGL ES 2.0. We present prediction
models for the main GPU commands relevant for 3D rendering, namely, FLUSH,
CLEAR, and DRAW. For the DRAW command we propose to use the 3D bounding box of
the rendered model and apply the vertex shader projection to heuristically
estimate the number of fragments rendered. We finally present the
implementation and evaluation of our framework, which demonstrates its
feasibility and shows that good prediction accuracy can be achieved. In our
evaluation using realistic scenarios the absolute prediction error of the DRAW
command did not exceed 260 µs.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2014-94&engl=0}
}
@inproceedings {INPROC-2014-78,
author = {Florian Berg and Frank D{\"u}rr and Kurt Rothermel},
title = {{Optimal Predictive Code Offloading}},
booktitle = {Proceedings of the 11th International Conference on Mobile and Ubiquitous Systems: Computing, Networking and Services},
publisher = {IEEE Computer Society},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {1--10},
type = {Konferenz-Beitrag},
month = {Dezember},
year = {2014},
doi = {10.4108/icst.mobiquitous.2014.258023},
keywords = {Code Offloading; Markov chain; Link quality},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
ee = {http://dl.acm.org/citation.cfm?id=2692985},
contact = {Florian.Berg@ipvs.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Modern mobile devices like smart phones and tablets are equipped with powerful
processing and memory resources, enabling resource-intensive mobile
applications such as high-end mobile games. The main limitation, however,
remains the energy resource. To improve the energy efficiency, code offloading
has been proposed, which offloads code to remote servers and transfers the
results back to the mobile device. Although several approaches have shown that
code offloading improves energy efficiency significantly in general, they
largely neglect the adverse effects of network disconnections. Therefore, we
have proposed the concept of preemptive code offloading to improve energy
efficiency also under link failures. It transmits so-called safe-points between
server and mobile device during remote execution, enabling the re-use of
partial remote results after link failures. In this paper, we improve our basic
preemptive code offloading approach by optimizing the time when to generate and
transmit safe-points to minimize the communication overhead and maximize energy
efficiency. To find the optimal safe-point schedule, we use a predictive
approach that predicts the mobile link quality in order to send safe-points
before network disconnections. Moreover, we consider additional deadline
constraints for code execution to ensure a minimal responsiveness of offloaded
applications despite link failures. Our evaluation results show that energy
efficiency can be improved significantly using our predictive offloading
approach.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2014-78&engl=0}
}
@inproceedings {INPROC-2014-74,
author = {Ruben Mayer and Boris Koldehofe and Kurt Rothermel},
title = {{Meeting Predictable Buffer Limits in the Parallel Execution of Event Processing Operators}},
booktitle = {Proceedings of the 2014 IEEE International Conference on Big Data, BigData '14},
publisher = {IEEE},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {402--411},
type = {Konferenz-Beitrag},
month = {Oktober},
year = {2014},
keywords = {Complex Event Processing, Stream Processing, Data Parallelization, Self-Adaptation, Quality of Service},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems,
C.4 Performance of Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2014-74/INPROC-2014-74.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Complex Event Processing (CEP) systems enable applications to react to
live-situations by detecting event patterns (complex events) in data streams.
With the increasing number of data sources and the increasing volume at which
data is produced, parallelization of event detection is becoming of tremendous
importance to limit the time events need to be buffered before they actually
can be processed by an event detector—named event processing operator. In this
paper, we propose a pattern-sensitive partitioning model for data streams that
is capable of achieving a high degree of parallelism for event patterns which
formerly could only be consistently detected in a sequential manner or at a low
parallelization degree. Moreover, we propose methods to dynamically adapt the
parallelization degree to limit the buffering imposed on event detection in the
presence of dynamic changes to the workload. Extensive evaluations of the
system behavior show that the proposed partitioning model allows for a high
degree of parallelism and that the proposed adaptation methods are able to meet
the buffering level for event detection under high and dynamic workloads.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2014-74&engl=0}
}
@inproceedings {INPROC-2014-67,
author = {Muhammad Adnan Tariq and Boris Koldehofe and Sukanya Bhowmik and Kurt Rothermel},
title = {{PLEROMA: A SDN-based High Performance Publish/Subscribe Middleware}},
booktitle = {To appear in Proceedings of the ACM/IFIP/USENIX Middleware Conference},
publisher = {ACM press.},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
type = {Konferenz-Beitrag},
month = {Dezember},
year = {2014},
doi = {10.1145/2663165.2663338},
keywords = {Content-based Routing, Publish/Subscribe, Software-defined Networking, Network Virtualization},
language = {Englisch},
cr-category = {C.2.1 Network Architecture and Design,
C.2.4 Distributed Systems,
D.2.11 Software Engineering Software Architectures},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2014-67/INPROC-2014-67.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {With the increasing popularity of Software-defined networks (SDN), TCAM memory
of switches can be directly accessed by a publish/subscribe middleware to
perform filtering operations at low latency. This way two important
requirements for a publish/subscribe middleware can be fulfilled: namely
bandwidth efficiency and line-rate performance in forwarding messages between
producers and consumers. Nevertheless, it is challenging to sustain line-rate
performance in the presence of dynamic changes in the interest of producers and
consumers. In this paper, we propose and evaluate the PLEROMA middleware to
realize publish/subscribe at line-rate and bandwidth efficiently in SDN.
PLEROMA offers methods to efficiently reconfigure a deployed topology in the
presence of dynamic subscriptions and advertisements. Furthermore, PLEROMA
ensures interoperability and independent reconfiguration of multiple controlled
SDN networks.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2014-67&engl=0}
}
@inproceedings {INPROC-2014-57,
author = {David Richard Sch{\"a}fer and Santiago G{\'o}mez S{\'a}ez and Thomas Bach and Vasilios Andrikopoulos and Muhammad Adnan Tariq},
title = {{Towards Ensuring High Availability in Collective Adaptive Systems}},
booktitle = {Proceedings of the First International Workshop of Business Processes in Collective Adaptive Systems: BPCAS'14; Eindhoven, Netherlands, September 8, 2014},
publisher = {Springer},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
type = {Workshop-Beitrag},
month = {September},
year = {2014},
keywords = {workflows; high availability; service discovery; process fragment injection},
language = {Englisch},
cr-category = {D.2.0 Software Engineering General,
D.2.11 Software Engineering Software Architectures,
D.2.12 Software Engineering Interoperability,
C.2.4 Distributed Systems,
C.4 Performance of Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2014-57/INPROC-2014-57.pdf},
contact = {david.schaefer@ipvs.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Architektur von Anwendungssystemen;
Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Collective Adaptive Systems support the interaction and adaptation of virtual
and physical entities towards achieving common objectives. For these systems,
several challenges at the modeling, provisioning, and execution phases arise.
In this position paper, we define the necessary underpinning concepts and
identify requirements towards ensuring high availability in such systems. More
specifically, based on a scenario from the EU Project ALLOW Ensembles, we
identify the necessary requirements and derive an architectural approach that
aims at ensuring high availability by combining active workflow replication,
service selection, and dynamic compensation techniques.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2014-57&engl=0}
}
@inproceedings {INPROC-2014-55,
author = {Thomas Kohler and Jan-Philipp Stegh{\"o}fer and D{\'\i}dac Busquets and Jeremy Pitt},
title = {{The Value of Fairness: Trade-offs in Repeated Dynamic Resource Allocation}},
booktitle = {Proceedings of the 2014 IEEE Eighth International Conference on Self-Adaptive and Self-Organizing Systems (SASO 2014), London, UK},
publisher = {IEEE Computer Society},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {1--10},
type = {Konferenz-Beitrag},
month = {September},
year = {2014},
doi = {10.1109/SASO.2014.12},
isbn = {978-1-4799-5367-7},
keywords = {artificial intelligence; distributive justice; electronic institution; fairness; multi-agent system; allocation},
language = {Englisch},
cr-category = {I.2.11 Distributed Artificial Intelligence},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2014-55/INPROC-2014-55.pdf,
http://dx.doi.org/10.1109/SASO.2014.12},
contact = {thomas.kohler@ipvs.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Resource allocation problems are an important part of many distributed
autonomous systems. In sensor networks, they determine which nodes get to use
the communication links, in SmartGrid applications they decree which electric
vehicle batteries are loaded, and in autonomous power management they select
which generators produce the power required to satisfy the overall load. These
cases have been considered in the literature before under the aspect of demand
satisfaction: how well can distributed algorithms with local knowledge
approximate the best allocation. A factor that has been ignored, however, is
fairness: how fair is the resource allocation and - in extension - the
distribution of revenue, wear, or recovery time.
In this paper, we bring together previously disjoint approaches on dynamic
distributed resource allocation and on fairness in electronic institutions. We
show that fair allocations based on Ostrom's principles and on Rescher's canons
of distributive justice create value in repeated resource allocations. We apply
the scheme to solve the multi-objective problem of distributing load to
generators fairly based on demands made by the individual generators. Our
evaluation shows that a fair distribution increases satisfaction of the
individual agents while reducing the hazard of optimising the problem in the
short-term at the cost of long-term robustness and stability.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2014-55&engl=0}
}
@inproceedings {INPROC-2014-54,
author = {Christoph Dibak and Boris Koldehofe},
title = {{Towards Quality-aware Simulations on Mobile Devices}},
booktitle = {Proceedings of the 44. Jahrestagung der Gesellschaft f{\"u}r Informatik e.V. (GI) (Informatik 2014)},
publisher = {Gesellschaft f{\"u}r Informatik (GI)},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
series = {Lecture Notes in Informatics (LNI)},
type = {Workshop-Beitrag},
month = {September},
year = {2014},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems,
G.1.8 Partial Differential Equations},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2014-54/INPROC-2014-54.pdf,
http://www.gi.de/service/publikationen/lni},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Numerical simulations are import for analyzing Big Data and realizing
applications in the Internet of Things. Running numerical simulations on mobile
devices makes analyzing and reasoning about Big Data ubiquitous. However,
mobile devices are limited in energy and compute resources, and connectivity to
a dedicated infrastructure like a cloud cannot always be assured. Therefore, we
propose to run the simulation on a distributed environment consisting of a
mobile device and the cloud. This environment has a number of constraints for
compute and network resources that need to be considered for providing
simulation results in time and with high quality. In this paper we propose an
architecture for mobile simulations and list challenges for realizing them.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2014-54&engl=0}
}
@inproceedings {INPROC-2014-32,
author = {Florian Berg and Frank D{\"u}rr and Kurt Rothermel},
title = {{Increasing the Efficiency and Responsiveness of Mobile Applications with Preemptable Code Offloading}},
booktitle = {Proceedings of the 3rd IEEE International Conference on Mobile Services: MS'14; Anchorage, Alaska, USA, June 27 - July 2, 2014},
publisher = {IEEE Computer Society},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {76--83},
type = {Konferenz-Beitrag},
month = {Juni},
year = {2014},
doi = {10.1109/MobServ.2014.20},
keywords = {Distributed Systems, Code Offloading, Safe-points, Mobile Cloud Computing, Efficiency, Responsiveness},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2014-32/INPROC-2014-32.pdf,
http://dx.doi.org/10.1109/MobServ.2014.20},
contact = {Florian.Berg@ipvs.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Mobile applications are getting more and more sophisticated and demanding.
Although the processing, memory, and storage resources of mobile devices are
constantly increasing to enable such resource-demanding mobile applications,
battery capacity is still the main limiting factor. To solve this problem,
mobile code offloading approaches can be used to offload parts of a mobile
application to remote servers and utilize the resources of cloud services. In
this paper, we propose a novel code offloading approach that makes code
offloading robust against communication link failures, which are still a major
problem of mobile systems. To this end, we propose preemptable code offloading.
It allows for interrupting the offloading process and continuing the remote
execution locally after a link failure, without abandoning the complete result
calculated remotely so far. The basic idea of our approach is to create
safe-points of the remote execution and transmit these intermediate results
back to the mobile device. After a link failure, the mobile device can now
continue execution from the last transmitted safe-point. Although safe-points
induce communication and energy overhead, our evaluations show that using an
optimized safe-point schedule this overhead quickly pays off under link
failures. Besides reducing the overall energy consumption significantly,
responsiveness also benefits from safe-points by meeting given execution
deadlines after link failures.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2014-32&engl=0}
}
@inproceedings {INPROC-2014-31,
author = {Beate Ottenw{\"a}lder and Boris Koldehofe and Kurt Rothermel and Kirak Hong and Umakishore Ramachandran},
title = {{RECEP: Selection-based Reuse for Distributed Complex Event Processing}},
booktitle = {Proceedings of the 8th ACM International Conference on Distributed Event-Based Systems (DEBS 2014)},
publisher = {ACM},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {59--70},
type = {Konferenz-Beitrag},
month = {Mai},
year = {2014},
doi = {10.1145/2611286.2611297},
keywords = {mobility; complex event processing; query optimization},
language = {Englisch},
cr-category = {C.2.1 Network Architecture and Design,
C.2.4 Distributed Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2014-31/INPROC-2014-31.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {An appealing use case of complex event processing (CEP) systems is for mobile
users to react in real-time to events in their environment, e.g., to the
occurrence of a dangerous situation such as an accident. Maintaining mobile CEP
systems is highly resource intensive since in many cases events need to be
detected in a consumer-centric manner to ensure low latency event detection and
high quality of results. In this paper we propose the RECEP system to increase
the scalability of mobile CEP systems. In the presence of mobile users with
partially overlapping interest, the RECEP system offers methods to efficiently
reuse computations and this way reduces the resource requirements of mobile
CEP. Since reuse of computations happens with respect to well defined quality
metrics, RECEP can be easily tailored to specific mobile applications and
maximize the resource savings for their desired quality in terms of precision
and recall of the processed events from the user's environment.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2014-31&engl=0}
}
@inproceedings {INPROC-2014-29,
author = {David Richard Sch{\"a}fer and Thomas Bach and Muhammad Adnan Tariq and Kurt Rothermel},
title = {{Increasing Availability of Workflows Executing in a Pervasive Environment}},
booktitle = {Proceedings of the 2014 IEEE International Conference on Services Computing},
address = {Anchorage, AK, USA},
publisher = {IEEE Computer Society},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {717--724},
type = {Konferenz-Beitrag},
month = {Juni},
year = {2014},
doi = {10.1109/SCC.2014.98},
isbn = {978-1-4799-5066-9/14},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems,
C.4 Performance of Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2014-29/INPROC-2014-29.pdf,
http://dx.doi.org/10.1109/SCC.2014.98},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Workflows have gained enormous importance to organize and manage business
processes. With the recent advent of smartphones and mobile applications,
traditional business process management is shifting. Now, long-running business
processes (workflows) have to be executed in large-scale distributed and
pervasive environments. Due to the heterogeneity and high dynamicity of such
environments, they are vulnerable to frequent communication and device failures
and, thus, impose new requirements on the execution of workflows. To increase
the availability, we concurrently executed restructured replicas of workflows
on multiple nodes. We developed techniques to generate differently structured
replicas and propose a metric that identifies the set of replicas that ensures
the highest availability during execution. Finally, we presented a distributed
algorithm to coordinate and synchronize the concurrent execution of the
identified replicas while maintaining the original workflow semantics. Our
methods approximately double the availability during execution, while our
generation techniques produce almost optimal replicas over a hundred times
faster.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2014-29&engl=0}
}
@inproceedings {INPROC-2014-26,
author = {Andreas Benzing and Boris Koldehofe and Kurt Rothermel},
title = {{Bandwidth-Minimized Distribution of Measurements in Global Sensor Networks}},
booktitle = {In Proceedings of the 14th IFIP International Conference on Distributed Applications and Interoperable Systems (DAIS 2014)},
publisher = {Springer-Verlag},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
series = {Lecture Notes in Computer Science},
volume = {8460},
pages = {156--170},
type = {Konferenz-Beitrag},
month = {Juni},
year = {2014},
doi = {10.1007/978-3-662-43352-2_13},
keywords = {Data Streams; Global Sensor Networks; Optimization},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2014-26/INPROC-2014-26.pdf,
http://link.springer.com/chapter/10.1007/978-3-662-43352-2_13},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Global sensor networks (GSN) allow applications to integrate huge amounts of
data using real-time streams from virtually anywhere. Queries to a GSN offer
many degrees of freedom, e.g. the resolution and the geographic origin of data,
and scaling optimization of data streams to many applications is highly
challenging. Existing solutions hence either limit the flexibility with
additional constraints or ignore the characteristics of sensor streams where
data points are produced synchronously. In this paper, we present a new
approach to bandwidth-minimized distribution of real-time sensor streams in a
GSN. Using a distributed index structure, we partition queries for bandwidth
management and quickly identify overlapping queries. Based on this information,
our relay strategy determines an optimized distribution structure which
minimizes traffic while being adaptive to changing conditions. Simulations show
that total traffic and user perceived delay can be reduced by more than 50\%.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2014-26&engl=0}
}
@inproceedings {INPROC-2014-03,
author = {Damian Philipp and Patrick Baier and Christoph Dibak and Frank D{\"u}rr and Kurt Rothermel and Susanne Becker and Michael Peter and Dieter Fritsch},
title = {{MapGENIE: Grammar-enhanced Indoor Map Construction from Crowd-sourced Data}},
booktitle = {Proceedings of the 12th IEEE International Conference on Pervasive Computing and Communications (PerCom 2014)},
address = {Budapest, Hungary},
publisher = {IEEE Computer Society Conference Publishing Services},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {139--147},
type = {Konferenz-Beitrag},
month = {M{\"a}rz},
year = {2014},
doi = {10.1109/PerCom.2014.6813954},
keywords = {Public Sensing; Opportunistic Sensing; Indoor Mapping; Map Reconstruction; IMU; Grammar},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2014-03/INPROC-2014-03.pdf,
http://dx.doi.org/10.1109/PerCom.2014.6813954},
contact = {damian.philipp@ipvs.uni-stuttgart.de patrick.baier@ipvs.uni-stuttgart.de christoph.dibak@ipvs.uni-stuttgart.de frank.duerr@ipvs.uni-stuttgart.de susanne.becker@ifp.uni-stuttgart.de michael.peter@ifp.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {While location-based services are already well established in outdoor
scenarios, they are still not available in indoor environments. The reason for
this can be found in two open problems: First, there is still no off-the-shelf
indoor positioning system for mobile devices and, second, indoor maps are not
publicly available for most buildings. While there is an extensive body of work
on the first problem, the efficient creation of indoor maps remains an open
challenge.
We tackle the indoor mapping challenge in our MapGENIE approach that
automatically derives indoor maps from traces collected by pedestrians moving
around in a building. Since the trace data is collected in the background from
the pedestrians' mobile devices, MapGENIE avoids the labor-intensive task of
traditional indoor map creation and increases the efficiency of indoor mapping.
To enhance the map building process, MapGENIE leverages exterior information
about the building and uses grammars to encode structural information about the
building. Hence, in contrast to existing work, our approach works without any
user interaction and only needs a small amount of traces to derive the indoor
map of a building. To demonstrate the performance of MapGENIE, we implemented
our system using Android and a foot-mounted IMU to collect traces from
volunteers. We show that using our grammar approach, compared to a purely
trace-based approach we can identify up to four times as many rooms in a
building while at the same time achieving a consistently lower error in the
size of detected rooms.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2014-03&engl=0}
}
@inproceedings {INPROC-2013-67,
author = {Simon Gansel and Stephan Schnitzer and Frank D{\"u}rr and Kurt Rothermel and Christian Maih{\"o}fer},
title = {{Towards Virtualization Concepts for Novel Automotive HMI Systems}},
booktitle = {Proceedings of 4th IFIP TC 10 International Embedded Systems Symposium, IESS 2013, Paderborn, Germany, June 17-19, 2013.},
publisher = {Springer Berlin Heidelberg},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
series = {Embedded Systems: Design, Analysis and Verification},
volume = {403},
pages = {193--204},
type = {Konferenz-Beitrag},
month = {Juni},
year = {2013},
isbn = {978-3-642-38853-8},
isbn = {10.1007/978-3-642-38853-8_18},
keywords = {Virtualization; Automotive HMI},
language = {Englisch},
cr-category = {H.5.2 Information Interfaces and Presentation User Interfaces,
J.7 Computers in Other Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2013-67/INPROC-2013-67.pdf,
http://link.springer.com/chapter/10.1007%2F978-3-642-38853-8_18},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Many innovations in the automotive industry are based on electronics and
software, which has led to a steady increase of electronic control units (ECU)
in cars. This brought up serious scalability and complexity issues in terms of
cost, installation space, and energy consumption. In order to tackle these
problems, there is a strong interest to consolidate ECUs using virtualization
technologies. However, current efforts largely neglect legal constraints and
certification issues and the resulting technical requirements.
In this paper, we focus on the consolidation of graphics hardware through
virtualization, which received a lot of interest in the car industry due to the
growing relevance of HMI systems such as head unit and instrument cluster in
modern cars. First, we investigate relevant ISO standards and legal
requirements and derive seven technical requirements for a virtualized
automotive HMI system. Based on these requirements, we present the concept for
a Virtualized Automotive Graphics System (VAGS) that allows for the
consolidation of mixed-criticality graphics ECUs.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2013-67&engl=0}
}
@inproceedings {INPROC-2013-62,
author = {Kirak Hong and Beate Ottenw{\"a}lder and Umakishore Ramachandran},
title = {{Scalable Spatio-temporal Analysis on Distributed Camera Networks}},
booktitle = {Proceedings of the 7th International Symposium on Intelligent Distributed Computing (IDC 2013)},
publisher = {Springer International Publishing},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
series = {Studies in Computational Intelligence},
volume = {511},
pages = {131--140},
type = {Konferenz-Beitrag},
month = {September},
year = {2013},
doi = {10.1007/978-3-319-01571-2_16},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2013-62/INPROC-2013-62.pdf,
http://link.springer.com/chapter/10.1007/978-3-319-01571-2_16},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Technological advances and the low cost of sensors enable the deployment of
large-scale camera networks in airports and metropolises. A well-known
technique, called spatio-temporal analysis, enables detecting anomalies such as
an individual entering into a restricted area without permission.
Spatio-temporal analysis requires a large amount of system resources to infer
locations of occupants in real-time. In particular, state update becomes a
bottleneck due to computation and communication overhead to update possibly
large application state. In this paper we propose a system design and
mechanisms for scalable spatio-temporal analysis. We present a distributed
system architecture including smart cameras and distributed worker nodes in the
cloud to enable real-time spatio-temporal analysis on large-scale camera
networks. Furthermore we propose and implement a couple of selective update
mechanisms to further improve scalability of our system by reducing the
communication cost for state update.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2013-62&engl=0}
}
@inproceedings {INPROC-2013-59,
author = {Marius Wernke and Frank D{\"u}rr and Kurt Rothermel},
title = {{Protecting Movement Trajectories through Fragmentation}},
booktitle = {Proceedings of the Tenth Annual International Conference on Mobile and Ubiquitous Systems: Computing, Networking and Services (MobiQuitous '13)},
address = {Tokyo, Japan},
publisher = {ICST},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {1--12},
type = {Konferenz-Beitrag},
month = {Dezember},
year = {2013},
keywords = {Location based applications; position sharing; privacy},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2013-59/INPROC-2013-59.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Location-based applications (LBAs) like geo-social networks, points of interest
finders, and real-time traffic monitoring applications have entered people's
daily life. Advanced LBAs rely on location services (LSs) managing movement
trajectories of multiple users in a scalable fashion. However, exposing
trajectory information raises user privacy concerns, in particular if LSs are
non-trusted. For instance, an attacker compromising an LS can use the retrieved
user trajectory for stalking, mugging, or to trace user movement. To limit the
misuse of trajectory data, we present a new approach for the secure management
of trajectories on non-trusted servers. Instead of providing the complete
trajectory of a user to a single LS, we split up the trajectory into a set of
fragments and distribute the fragments among LSs of different providers. By
distributing fragments, we avoid a single point of failure in case of
compromised LSs, while different LBAs can still reconstruct the trajectory
based on user-defined access rights.
In our evaluation, we show the effectiveness of our approach by using real
world trajectories and realistic attackers using map knowledge and statistical
information to predict and reconstruct the user's movement.
Location management, fragmentation, trajectories, privacy},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2013-59&engl=0}
}
@inproceedings {INPROC-2013-57,
author = {Susanne Becker and Michael Peter and Dieter Fritsch and Damian Philipp and Patrick Baier and Christoph Dibak},
title = {{Combined grammar for the modeling of building interiors}},
booktitle = {ISPRS Annals of the Photogrammetry, Remote Sensing and Spatial Information Sciences},
address = {Kapstadt, S{\"u}dafrika},
publisher = {International Society for Photogrammetry and Remote Sensing},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
series = {ISPRS Acquisition and Modelling of Indoor and Enclosed Environments},
volume = {II-4/W1},
pages = {1--6},
type = {Konferenz-Beitrag},
month = {Dezember},
year = {2013},
keywords = {Public Sensing; Opportunistic Sensing; Smartphone; Indoor; Mapping},
language = {Deutsch},
cr-category = {J.5 Arts and Humanities,
C.2.4 Distributed Systems},
contact = {Susanne Becker susanne.becker@ifp.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {As spatial grammars have proven successful and efficient to deliver LoD3
models, the next challenge is their extension to indoor applications, leading
to LoD4 models. Therefore, a combined indoor grammar for the automatic
generation of indoor models from erroneous and incomplete observation data is
presented. In building interiors where inaccurate observation data is
available, the grammar can be used to make the reconstruction process robust,
and verify the reconstructed geometries. In unobserved building interiors, the
grammar can generate hypotheses about possible indoor geometries matching the
style of the rest of the building. The grammar combines concepts from L-systems
and split grammars. It is designed in such way that it can be derived from
observation data fully automatically. Thus, manual predefinitions of the
grammar rules usually required to tune the grammar to a specific building
style, become obsolete. The potential benefit of using our grammar as support
for indoor modeling is evaluated based on an example where the grammar has been
applied to automatically generate an indoor model from erroneous and incomplete
traces gathered by foot-mounted MEMS/IMU positioning systems.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2013-57&engl=0}
}
@inproceedings {INPROC-2013-52,
author = {Damian Philipp and Jaroslaw Stachowiak and Frank D{\"u}rr and Kurt Rothermel},
title = {{Model-Driven Public Sensing in Sparse Networks}},
booktitle = {Proceedings of the 10th International Conference on Mobile and Ubiquitous Systems: Computing, Networking and Services},
publisher = {Springer},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
series = {LNCS},
pages = {1--12},
type = {Konferenz-Beitrag},
month = {Dezember},
year = {2013},
keywords = {model-driven; energy optimization; public sensing; opportunistic sensing; adaptive algorithm; mobility},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2013-52/INPROC-2013-52.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Public Sensing (PS) is a recent trend for building large-scale sensor data
acquisition systems using commodity smartphones. Limiting the energy drain on
participating devices is a major challenge for PS, as otherwise people will
stop sharing their resources with the PS system. Existing solutions for
limiting the energy drain through model-driven optimizations are limited to
dense networks where there is a high probability for every point of interest to
be covered by a smartphone. In this work, we present an adaptive model-driven
PS system that deals with both dense and sparse networks. Our evaluations show
that this approach improves data quality by up to 41 percentage points while
enabling the system to run with a greatly reduced number of participating
smartphones. Furthermore, we can save up to 81\% of energy for communication and
sensing while providing data matching an error bound of 1°C up to 96\% of the
time.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2013-52&engl=0}
}
@inproceedings {INPROC-2013-51,
author = {Marius Wernke and Frank D{\"u}rr and Kurt Rothermel},
title = {{Speed Protection Algorithms for Privacy-aware Location Management}},
booktitle = {Proceedings of the IEEE 9th International Conference on Wireless and Mobile Computing, Networking and Communications (WiMob 2013).},
address = {Lyon, France},
publisher = {IEEE Xplore},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {355--362},
type = {Konferenz-Beitrag},
month = {Oktober},
year = {2013},
keywords = {Location-based applications; location-based services; speed protection; movement trajectory; location management; location privacy},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2013-51/INPROC-2013-51.pdf,
www.ieeexplore.ieee.org,
www.PriLoc.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Nowadays, millions of users share their complete movement trajectory online
when using real-time traffic monitoring applications, pay-as-you-drive
insurances, or when sharing their last road trip with friends. However, many
users still hesitate to use location-based applications as they are not willing
to reveal, for instance, their driving behavior or the occurrence of a speeding
violation.
Therefore, we present novel speed protection algorithms protecting users from
revealing a violation of given speed limits when using location-based
applications. Our algorithms support time-based and distance-based position
updates. To protect positions indicating a speeding violation, we either adjust
temporal information by delaying position updates or adjust their spatial
information. We evaluate our algorithms by using real world traces and show
that the protected movement trajectory of the user is of high quality even
after removing speeding violations.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2013-51&engl=0}
}
@inproceedings {INPROC-2013-35,
author = {Patrick Baier and Frank D{\"u}rr and Kurt Rothermel},
title = {{Efficient Distribution of Sensing Queries in Public Sensing Systems}},
booktitle = {Proceedings of the 10th IEEE International Conference on Mobile Ad-hoc and Sensor Systems (MASS 2013)},
publisher = {IEEE Computer Society},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {1--9},
type = {Konferenz-Beitrag},
month = {Oktober},
year = {2013},
language = {Deutsch},
cr-category = {C.2 Computer-Communication Networks},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2013-35/INPROC-2013-35.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {The advent of mobile phones paved the way for a new paradigm for gathering
sensor data termed Public Sensing (PS). PS uses built-in sensors of mobile
devices to opportunistically gather sensor data. For instance, the microphones
of a crowd of mobile phones can be used to capture sound samples, which can be
used to construct a city noise map.
A great challenge of PS is to reduce the energy consumption of mobile devices
since otherwise users might not be willing to participate. One crucial part in
the overall power consumption is the energy required for the communication
between the mobile devices and the infrastructure. In particular, the
communication required for sending sensing queries to mobile devices has been
largely neglected in the related work so far.
Therefore, in this paper, we address the problem of minimizing communication
costs for the distribution of sensing queries. While existing systems simply
broadcast sensing queries to all devices, we use a selective strategy by
addressing only a subset of devices. In order not to negatively affect the
quality of sensing w.r.t. completeness, this subset is carefully chosen based
on a probabilistic sensing model that defines the probability of mobile devices
to successfully perform a given sensing query.
Our evaluations show that with our optimized sensing query distribution, the
energy consumption can be reduced by more than 70\% without significantly
reducing the quality of sensing.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2013-35&engl=0}
}
@inproceedings {INPROC-2013-33,
author = {Patrick Baier and Frank D{\"u}rr and Kurt Rothermel},
title = {{Opportunistic Position Update Protocols for Mobile Devices}},
booktitle = {Proceedings of the International Joint Conference on Pervasive and Ubiquitous Computing (UbiComp 2013)},
publisher = {ACM},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {1--9},
type = {Konferenz-Beitrag},
month = {September},
year = {2013},
language = {Englisch},
cr-category = {C.2 Computer-Communication Networks},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2013-33/INPROC-2013-33.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Many location-based applications such as geo-social networks rely on location
services storing mobile object positions. To update positions on location
servers, position update protocols are used. On the one hand, these protocols
decide when an update has to be sent to ensure a certain quality of position
information. On the other hand, they try to minimize the energy consumption of
the mobile device by reducing communication to a minimum.
In this paper, we show how to improve the energy efficiency of different update
protocols by taking the energy characteristics of the mobile network interface
into account. In particular, we show that the energy consumption can be reduced
on average by 70\% using an opportunistic update strategy sending position
updates together with messages of other applications. We present a Markov model
to predict the arrival of messages and an online optimization algorithm
calculating an optimized schedule to send position updates.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2013-33&engl=0}
}
@inproceedings {INPROC-2013-31,
author = {Kirak Hong and David Lillethun and Umakishore Ramachandran and Beate Ottenw{\"a}lder and Boris Koldehofe},
title = {{Mobile Fog: A Programming Model for Large-Scale Applications on the Internet of Things}},
booktitle = {Proceedings of the 2nd MCC Workshop on Mobile Cloud Computing},
address = {Hong Kong, China},
publisher = {ACM Press},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {15--20},
type = {Konferenz-Beitrag},
month = {August},
year = {2013},
doi = {10.1145/2491266.2491270},
keywords = {fog computing; cloud computing; programming model; Internet of Things; future Internet applications; situation awareness applications},
language = {Englisch},
cr-category = {C.2.1 Network Architecture and Design,
C.2.4 Distributed Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2013-31/INPROC-2013-31.pdf,
http://doi.acm.org/10.1145/2491266.2491270},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {The ubiquitous deployment of mobile and sensor devices is creating a new
environment, namely the Internet of Things(IoT), that enables a wide range of
future Internet applications. In this work, we present Mobile Fog, a high level
programming model for future Internet applications that are geospatially
distributed, large-scale, and latency-sensitive. We analyze use cases for the
programming model with camera network and connected vehicle applications to
show the efficacy of Mobile Fog We also evaluate application performance
through simulation.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2013-31&engl=0}
}
@inproceedings {INPROC-2013-29,
author = {Kirak Hong and David Lillethun and Umakishore Ramachandran and Beate Ottenw{\"a}lder and Boris Koldehofe},
title = {{Opportunistic Spatio-temporal Event Processing for Mobile Situation Awareness}},
booktitle = {Proceedings of the 7th ACM International Conference on Distributed Event-Based Systems (DEBS)},
address = {Arlington, Texas, USA},
publisher = {ACM Press},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {195--206},
type = {Konferenz-Beitrag},
month = {Juni},
year = {2013},
doi = {10.1145/2488222.2488266},
keywords = {mobility; complex event processing; situation awareness},
language = {Englisch},
cr-category = {C.2.1 Network Architecture and Design,
C.2.4 Distributed Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2013-29/INPROC-2013-29.pdf,
http://doi.acm.org/10.1145/2488222.2488266},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {With the proliferation of mobile devices and sensors, mobile situation
awareness is becoming an important class of applications. The key requirement
of this class of applications is low-latency processing of events stemming from
sensordata in order to provide timely situational information to mobile
users.To satisfy the latency requirement, we propose a spatio-temporal event
processing system that uses prediction-based continuous query handling. Our
system predicts future query regions for moving consumers and starts processing
events early so that the live situational information is available when the
consumer reaches the future location. In contrast to existing systems, our
system provides timely information about a consumer's current position by
hiding computation latency for processing recent events. To evaluate our
system, we measure the quality of results and timeliness of live situational
information with various query parameters. Our evaluation shows that we can
achieve highly meaningful query results with near-zero latency in most cases.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2013-29&engl=0}
}
@inproceedings {INPROC-2013-28,
author = {Beate Ottenw{\"a}lder and Boris Koldehofe and Kurt Rothermel and Umakishore Ramachandran},
title = {{MigCEP: Operator Migration for Mobility Driven Distributed Complex Event Processing}},
booktitle = {Proceedings of the 7th ACM International Conference on Distributed Event-Based Systems (DEBS)},
address = {Arlington, Texas, USA},
publisher = {ACM Press},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {183--194},
type = {Konferenz-Beitrag},
month = {Juni},
year = {2013},
doi = {10.1145/2488222.2488265},
keywords = {complex event processing; migration; mobility},
language = {Englisch},
cr-category = {C.2.1 Network Architecture and Design,
C.2.4 Distributed Systems,
E.1 Data Structures},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2013-28/INPROC-2013-28.pdf,
http://doi.acm.org/10.1145/2488222.2488265},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {A recent trend in communication networks --- sometimes referred to as fog
computing --- offers to execute computational tasks close to the access points
of the networks. This enables real-time applications, like mobile Complex Event
Processing (CEP), to significantly reduce end-to-end latencies and bandwidth
usage. Most work studying the placement of operators in such an environment
completely disregards the migration costs. However, the mobility of users
requires frequent migration of operators, together with possibly large state
information, to meet latency restrictions and save bandwidth in the
infrastructure.
This paper presents a placement and migration method for providers of
infrastructures that incorporate cloud and fog resources. It ensures
application-defined end-to-end latency restrictions and reduces the network
utilization by planning the migration ahead of time. Furthermore, we present
how the application knowledge of the CEP system can be used to improve current
live migration techniques for Virtual Machines to reduce the required bandwidth
during the migration. Our evaluations show that we safe up to 49\% of the
network utilization with perfect knowledge about a users mobility pattern and
up to 27\% of the network utilization when considering the uncertainty of those
patterns.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2013-28&engl=0}
}
@inproceedings {INPROC-2013-27,
author = {Boris Koldehofe and Frank D{\"u}rr and Muhammad Adnan Tariq},
title = {{Event-based Systems Meet Software-defined Networking}},
booktitle = {Proceedings of the 7th ACM International Conference on Distributed Event-Based Systems (DEBS)},
publisher = {ACM},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
pages = {271--280},
type = {Konferenz-Beitrag},
month = {Juni},
year = {2013},
doi = {10.1145/2488222.2488270},
keywords = {Software-defined Networking, Event-based Systems, Content-based Routing, Publish/Subscribe, Network Virtualization},
language = {Englisch},
cr-category = {C.2.1 Network Architecture and Design,
C.2.4 Distributed Systems,
D.2.11 Software Engineering Software Architectures},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2013-27/INPROC-2013-27.pdf,
http://dx.doi.org/10.1145/2488222.2488270},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {Software-defined networking (SDN) is a recent development in the area of
communication networks with tremendous support by key players building the next
generation of computer hardware and software. This development will have
significant impact on how communication middleware---in particular, future
distributed event-based systems---can be designed. While currently the
communication middleware has no possibility to directly influence the
properties of its underlying communication channels on the network layer, SDN
enables communication middleware to control and flexibly adapt the forwarding
of communication flows in the underlying network. In addition to the immediate
implication to local area networks such as data center networks, campus
networks, or company networks, novel trends like network virtualization may
even support Internet-wide distributed applications to benefit from SDN in the
future. This paper gives an introduction on how to utilize SDN-concepts for
improving the performance of event-based middleware and to test their behavior.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2013-27&engl=0}
}
@inproceedings {INPROC-2013-26,
author = {Boris Koldehofe and Ruben Mayer and Umakishore Ramachandran and Kurt Rothermel and Marco V{\"o}lz},
title = {{Rollback-Recovery without Checkpoints in Distributed Event Processing Systems}},
booktitle = {Proceedings of the 7th ACM International Conference on Distributed Event-Based Systems (DEBS)},
publisher = {ACM},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {27--38},
type = {Konferenz-Beitrag},
month = {Juni},
year = {2013},
doi = {10.1145/2488222.2488259},
keywords = {Reliability; Recovery; Complex Event Processing},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems,
C.4 Performance of Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2013-26/INPROC-2013-26.pdf,
http://dx.doi.org/10.1145/2488222.2488259},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Reliability is of critical importance to many applications involving
distributed event processing systems. Especially the use of stateful operators
makes it challenging to provide efficient recovery from failures and to ensure
consistent event streams. Even during failure-free execution, state-of-the-art
methods for achieving reliability incur significant overhead at run-time
concerning computational resources, event traffic, and event detection time.
This paper proposes a novel method for rollback-recovery that allows for
recovery from multiple simultaneous operator failures, but eliminates the need
for persistent checkpoints. Thereby, the operator state is preserved in
savepoints at points in time when its execution solely depends on the state of
incoming event streams which are reproducible by predecessor operators. We
propose an expressive event processing model to determine savepoints and
algorithms for their coordination in a distributed operator network.
Evaluations show that very low overhead at failure-free execution in comparison
to other approaches is achieved.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2013-26&engl=0}
}
@inproceedings {INPROC-2013-23,
author = {Muhammad Adnan Tariq and Boris Koldehofe and Kurt Rothermel},
title = {{Efficient content-based routing with network topology inference}},
booktitle = {Proceedings of the 7th ACM International Conference on Distributed Event-Based Systems (DEBS)},
address = {Arlington, Texas, USA},
publisher = {ACM},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {51--62},
type = {Konferenz-Beitrag},
month = {Juni},
year = {2013},
doi = {10.1145/2488222.2488262},
keywords = {QoS; quality of service; network inference; underlay awareness; delay; bandwidth; content-based; publish/subscribe; event-based},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2013-23/INPROC-2013-23.pdf,
http://doi.acm.org/10.1145/2488222.2488262},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Content-based publish/subscribe has gained high popularity for large-scale
dissemination of dynamic content. Yet it is highly challenging to enable
communication-efficient dissemination of content in such systems, especially in
the absence of a broker infrastructure. This paper presents a novel approach
that exploits the knowledge of event traffic, user subscriptions and topology
of the underlying physical network to perform efficient routing in a
publish/subscribe system. In particular, mechanisms are developed to discover
the underlay topology among subscribers and publishers in a distributed manner.
The information of the topology and the proximity between the subscribers to
receive similar events is then used to construct a routing overlay with low
communication cost. Our evaluations show that for internet-like topologies the
proposed inference mechanisms are capable of modeling an underlay in an
efficient and accurate manner. Furthermore, the approach yields a significant
reduction in routing cost in comparison to the state of the art.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2013-23&engl=0}
}
@inproceedings {INPROC-2013-22,
author = {Frank D{\"u}rr},
title = {{Improving the Efficiency of Cloud Infrastructures with Elastic Tandem Machines}},
booktitle = {Proceedings of the 6th International Conference on Cloud Computing (Cloud 2013)},
address = {Santa Clara, CA, USA},
publisher = {IEEE Computer Society},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {1--8},
type = {Konferenz-Beitrag},
month = {Juni},
year = {2013},
keywords = {cloud computing; infrastructure as a service; efficiency; energy, elasticity; scaling; system on a chip; software-defined networking; green computing},
language = {Englisch},
cr-category = {C.2.3 Network Operations,
C.2.4 Distributed Systems,
C.2.1 Network Architecture and Design,
C.4 Performance of Systems,
C.5 Computer System Implementation,
H.3.4 Information Storage and Retrieval Systems and Software},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2013-22/INPROC-2013-22.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {In this paper, we propose a concept for improving the energy efficiency and
resource utilization of cloud infrastructures by combining the benefits of
heterogeneous machine instances. The basic idea is to integrate low-power
system on a chip (SoC) machines and high-power virtual machine instances into
so-called Elastic Tandem Machine Instances (ETMI). The low-power machine serves
low load and is always running to ensure the availability of the ETMI. When
load rises, the ETMI scales up automatically by starting the high-power
instance and handing over traffic to it. For the non-disruptive transition from
low-power to high-power machines and vice versa, we present a handover
mechanism based on software-defined networking technologies. Our evaluations
show the applicability of low-power SoC machines to serve low load efficiently
as well as the desired scalability properties of ETMIs.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2013-22&engl=0}
}
@inproceedings {INPROC-2013-04,
author = {Damian Philipp and Jaroslaw Stachowiak and Patrick Alt and Frank D{\"u}rr and Kurt Rothermel},
title = {{DrOPS: Model-Driven Optimization for Public Sensing Systems}},
booktitle = {2013 IEEE International Conference on Pervasive Computing and Communications (PerCom 2013)},
address = {San Diego, CA, USA},
publisher = {IEEE Computer Society},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {185--192},
type = {Konferenz-Beitrag},
month = {M{\"a}rz},
year = {2013},
doi = {10.1109/PerCom.2013.6526731},
keywords = {Data acquisition; Distributed computing; Wireless sensor networks; Public Sensing; Opportunistic Sensing; Smartphone; Model-Driven Data Acquisition; Quality aware; Adaptive, autonomic and context-aware computing; Energy-efficient and green pervasive computing; Innovative pervasive computing applications; Pervasive opportunistic communications and applications; Participatory, opportunistic and social sensing; Sensors and RFID in pervasive systems; Smart devices and intelligent environments},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2013-04/INPROC-2013-04.pdf,
http://www.comnsense.de,
http://dx.doi.org/10.1109/PerCom.2013.6526731},
contact = {Damian Philipp damian.philipp@ipvs.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {The proliferation of modern smartphones has given rise to Public Sensing, a new
paradigm for data acquisition systems utilizing smartphones of mobile
participants. In this paper, we present DrOPS, a system for improving the
efficiency of data acquisition in Public Sensing systems. DrOPS utilizes a
model-driven approach, where the number of required readings from mobile
smartphones is reduced by inferring readings from the model. Furthermore, the
model can be used to infer readings for positions where no sensor is available.
The model is directly constructed from the observed phenomenon in an online
fashion. Using such models together with a client-specified quality bound, we
can significantly reduce the effort for data acquisition while still reporting
data of required quality to the client. To this effect, we develop a set of
online learning and control algorithms to create and validate the model of the
observed phenomenon and present a sensing task execution system utilizing our
algorithms in this paper. Our evaluations show that we obtain models in a
matter of just hours or even minutes. Using the model-driven approach for
optimizing the data acquisition, we can save up to 80\% of energy for
communication and provide inferred temperature readings for uncovered positions
matching an error-bound of 1°C up to 100\% of the time.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2013-04&engl=0}
}
@inproceedings {INPROC-2013-01,
author = {Bj{\"o}rn Schilling and Boris Koldehofe and Kurt Rothermel and Umakishore Ramachandran},
title = {{Access Policy Consolidation for Complex Event Processing}},
booktitle = {IEEE Conference on Networked Systems (NetSys)},
publisher = {IEEE},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {92--101},
type = {Konferenz-Beitrag},
month = {M{\"a}rz},
year = {2013},
doi = {10.1109/NetSys.2013.18},
keywords = {Event processing; Complex event processing; CEP; Security; Access Control; Bayesian network},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2013-01/INPROC-2013-01.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {In distributed complex event processing, event streams are processed over a
chain of subsequent operators. For large-scale applications like a logistic
chain these operators may be hosted by different entities and thus are spread
over different security domains. Current approaches for complex event
processing cannot preserve the privacy of an operator’s incoming event streams.
An adversary may infer the original input stream from its legally received
event streams.
In this paper we present a fine-grained access management for complex event
processing. We show how to enforce privacy of events throughout the chain of
dependent operators by specifying appropriate access policies and proposing an
algorithm for policy consolidation. Furthermore, we introduce the calculation
of obfuscation achieved in a correlation step. This allows us to ignore access
requirements once a sufficient obfuscation level has been achieved, the
proposed algorithms is capable to reduce the required overhead in the
enforcement of access policies. We prove correctness and evaluate the cost in
establishing policy consolidation.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2013-01&engl=0}
}
@inproceedings {INPROC-2012-49,
author = {Marius Wernke and Frank D{\"u}rr and Kurt Rothermel},
title = {{Efficient Position Sharing for Location Privacy using Binary Space Partitioning}},
booktitle = {Proceedings of the Ninth Annual International Conference on Mobile and Ubiquitous Systems: Computing, Networking and Services (MobiQuitous '12)},
address = {Beijing, People's Republic of China},
publisher = {ICST},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {1--12},
type = {Konferenz-Beitrag},
month = {Dezember},
year = {2012},
keywords = {Position Sharing; Location Privacy; Location Based Applications; Privacy},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2012-49/INPROC-2012-49.pdf,
http://www.priloc.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Millions of users use location-based applications (LBAs) to share their
positions with friends, request information from points of interest finders, or
get notifications from event finders, etc. Such LBAs are typically based on
location servers (LSs) managing mobile object positions in a scalable fashion.
However, storing precise user positions on LSs raises privacy concerns, in
particular, if LS providers are non-trusted. To solve this problem, we present
PShare-BSP, a novel approach for the secure management of private user
positions on non-trusted LSs. PShare-BSP splits up precise user positions into
position shares and distributes them to different LSs of different providers.
Thus, a compromised provider only reveals user positions with degraded
precision. Nevertheless, LBAs can combine several shares from different LSs to
increase their precision.
PShare-BSP improves on our previous position sharing approaches: It uses a
deterministic share generation approach based on binary space partitioning to
avoid probabilistic attacks based, for instance, on Monte Carlo simulations.
Moreover, it significantly decreases the computational complexity and increases
the efficiency by reducing the update costs for succeeding position updates.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2012-49&engl=0}
}
@inproceedings {INPROC-2012-41,
author = {Boris Koldehofe and Frank D{\"u}rr and Muhammad Adnan Tariq and Kurt Rothermel},
title = {{The Power of Software-defined Networking: Line-rate Content-based Routing Using OpenFlow}},
booktitle = {Proceedings of the 7th MW4NG Workshop of the 13th International Middleware Conference},
publisher = {ACM},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {1--6},
type = {Workshop-Beitrag},
month = {Dezember},
year = {2012},
doi = {10.1145/2405178.2405181},
keywords = {Content-Based Routing; Publish/Subscribe; Software Defined Networking; SDN; Network Virtualization},
language = {Englisch},
cr-category = {C.2.1 Network Architecture and Design,
C.2.4 Distributed Systems,
D.2.11 Software Engineering Software Architectures},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2012-41/INPROC-2012-41.pdf,
http://doi.acm.org/10.1145/2405178.2405181},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {A lot of research effort has been invested to support efficient content-based
routing. Nevertheless, practitioners often fall back to far less expressive
communication paradigms like multicast groups. The benefits of content-based
routing in minimizing bandwidth consumption are often rendered useless by
simpler communication paradigms that rely on line-rate processing of data
packets at the switches of the network providers. Contrary content-based
routing protocols face the inherent overhead in matching the content of events
against subscriptions leading to far lower throughput rates and higher
end-to-end delays. However, recent trends in networking such as software
defined networking in combination with network virtualization have tremendous
potential to change the picture. In our opinion this will significantly
increase acceptance of sophisticated middleware like content-based routing in
the future. To support our claims we outline in this paper a reference
architecture that may be used to build middleware for Future Internet
applications. Furthermore, we provide a solution for realizing content-based
routing at line-rate relying on this reference architecture and illustrate
research problems that need to be addressed.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2012-41&engl=0}
}
@inproceedings {INPROC-2012-40,
author = {Stephan Schnitzer and Hugo Miranda and Boris Koldehofe},
title = {{Content Routing Algorithms to Support Publish/Subscribe in Mobile Ad Hoc Networks}},
booktitle = {Proceedings of the 5th IEEE Workshop on Architectures, Services and Applications for the Next Generation Internet},
publisher = {IEEE Computer Society},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {1--8},
type = {Workshop-Beitrag},
month = {Oktober},
year = {2012},
keywords = {MANET; TPSR; Ad Hoc; Wireless Routing},
language = {Deutsch},
cr-category = {H.3.4 Information Storage and Retrieval Systems and Software,
C.2.1 Network Architecture and Design,
C.2.2 Network Protocols},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2012-40/INPROC-2012-40.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Mobile Ad Hoc Networks (MANETs) allow communication between moving nodes
without using infrastructure like access points, stationary routers or GPS.
This offers new communication opportunities, especially in challenging
environments. To communicate in MANETs we often need routing functionality,
which usually provides unicast-based best effort packet delivery.
Publish/Subscribe (Pub/Sub) is a well known and powerful paradigm that provides
higher expressiveness than unicast routing. It decouples senders from receivers
and allows information exchange between network nodes that offer certain data
(called publishers) and nodes that declare their interest in data of some
pattern (called subscribers). Especially in MANET applications, Pub/Sub
provides useful functionality to support realistic scenarios and novel
applications. This paper proposes a new algorithm called TPSR, tailored to
efficiently support Pub/Sub in MANETs. It is based mainly on two principles: i)
it uses the dissemination of subscriptions to create source routes; and ii) it
uses the signal strength messages are received with, to optimize routes in
terms of striking a good balance between long routes and fragile routes.
Simulations based on ns-2 demonstrate its performance, in comparison with
flooding and unicast-based solutions.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2012-40&engl=0}
}
@inproceedings {INPROC-2012-34,
author = {Klaus Herrmann and Daniel Fischer and Damian Philipp},
title = {{Resource Management for Public Sensing}},
booktitle = {Activity Context Representation: Techniques and Languages},
editor = {Workshop Chair Lokendra Shastri},
address = {Toronto, Canada},
publisher = {Online},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {32--39},
type = {Workshop-Beitrag},
month = {Juli},
year = {2012},
keywords = {Resource Management; Public Sensing; Ad-Hoc Routing},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2012-34/INPROC-2012-34.pdf,
http://activitycontext.org/wp-content/uploads/2012/07/AAAI12_W12-05_TechnicalReport_ActivityContextRepresentation.pdf},
contact = {klaus.herrmann@ipvs.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Public sensing is a new research area in the fields of wireless sensor networks
and mobile computing. It leverages the mobile sensors and system resources
readily available in mobile phones to execute sensing tasks. In order to plan,
execute and adapt large-scale sensing tasks, applications need to query for the
available resources, e.g. the density of certain sensors. We investigate how
such information can be provided, and we propose a resource manager for public
sensing. Our primary goal is to minimize the energy consumed by the mobile
devices to make public sensing feasible without disturbing users. We propose a
cluster-based protocol for collecting local views of the resource state using
local ad-hoc communication since this is much more energy-efficient than
long-range (e.g. cellular) communication. We compare our solution to a standard
approach where mobile devices communicate their resource states using the
cellular phone network. We show that 65\% of the energy is saved and the
communication load on the infrastructure is reduced by 90\% while an average
delivery ratio of 93\% is retained.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2012-34&engl=0}
}
@inproceedings {INPROC-2012-30,
author = {Ben W. Carabelli and Andreas Benzing and Georg Seyboth and Rainer Blind and Mathias B{\"u}rger and Frank D{\"u}rr and Boris Koldehofe and Kurt Rothermel and Frank Allg{\"o}wer},
title = {{Exact Convex Formulations of Network-Oriented Optimal Operator Placement}},
booktitle = {Proceedings of the 51st IEEE Conference on Decision and Control (CDC2012)},
publisher = {IEEE},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {3777--3782},
type = {Konferenz-Beitrag},
month = {Dezember},
year = {2012},
doi = {10.1109/CDC.2012.6426790},
keywords = {Optimization; Computer networks; Sensor networks},
language = {Englisch},
cr-category = {G.1.6 Numerical Analysis Optimization},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2012-30/INPROC-2012-30.pdf,
http://dx.doi.org/10.1109/CDC.2012.6426790},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Data processing tasks are increasingly spread across the internet to account
for the spatially distributed nature of many data sources. In order to use
network resources efficiently, subtasks need to be distributed in the network
so data can be filtered close to the data sources. Previous approaches to this
operator placement problem relied on various heuristics to constrain the
complexity of the problem. In this paper, we propose two generic integer
constrained problem formulations: a topology aware version which provides a
placement including the specific network links as well as an end-to-end delay
aware version which relies on the routing capabilities of the network. A linear
programming relaxation for both versions is provided which allows exact and
efficient solution using common solvers.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2012-30&engl=0}
}
@inproceedings {INPROC-2012-26,
author = {Patrick Baier and Frank D{\"u}rr and Kurt Rothermel},
title = {{TOMP: Opportunistic Traffic Offloading Using Movement Predictions}},
booktitle = {Proceedings of the 37th IEEE Conference on Local Computer Networks (LCN)},
address = {Clearwater},
publisher = {IEEE Computer Society},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {1--8},
type = {Konferenz-Beitrag},
month = {Oktober},
year = {2012},
language = {Englisch},
cr-category = {C.2 Computer-Communication Networks},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2012-26/INPROC-2012-26.pdf,
http://www.comnsense.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Recent forecasts predict that the amount of cellular data traffic will
significantly increase within the next few years. The reason for this trend is
on the one hand the high growth rate of mobile Internet users and on the other
hand the growing popularity of high bandwidth streaming applications. Given the
fact that cellular networks (e.g. UMTS) have only limited capacity, the
existing network infrastructure will soon reach its limits. As a result, the
concept of traffic offloading attracts more and more attention in research
since it aims at the reduction of cellular traffic by shifting it to local-area
networks like Wifi. Within the last few years, some first approaches for
automatically offloading cellular traffic were proposed. These approaches
either assume the wide availability of publicly accessible Wifi networks or
knowledge about social relations of mobile users. However, these assumptions
are usually not fulfilled. To face this issue, we developed the TOMP system.
TOMP implements a system to distribute data from the infrastructure to a set of
mobile devices by partly shifting traffic from the cellular network to the
level of inter-device communication. In contrast to the prevailing approaches,
TOMP does not rely on open Wifi networks and only uses information about the
position and speed of mobile device. By using predictions about the future
movement of mobile users, TOMP determines devices that are most suitable
targets for traffic offloading. In this paper we show by simulation that TOMP
can save up to 40\% of cellular messages in comparison to a typical cellular
network.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2012-26&engl=0}
}
@inproceedings {INPROC-2012-20,
author = {Boris Koldehofe and Beate Ottenw{\"a}lder and Kurt Rothermel and Umakishore Ramachandran},
title = {{Moving Range Queries in Distributed Complex Event Processing}},
booktitle = {Proceedings of the 6th ACM International Conference on Distributed Event-Based Systems (DEBS).},
address = {Berlin},
publisher = {ACM},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {201--212},
type = {Konferenz-Beitrag},
month = {Juli},
year = {2012},
doi = {10.1145/2335484.2335507},
keywords = {Complex Event Processing; Event-based systems; Moving range queries},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2012-20/INPROC-2012-20.pdf,
http://doi.acm.org/10.1145/2335484.2335507},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Up to now correlations in complex event processing (CEP) systems are detected
by a well defined set of operators whose configuration is determined ahead of
deployment time. Although CEP operators involve location specific attributes,
state of the art systems are heavily constraint in detecting situations where
the interest in a situation changes dependent on the consumer's location, e.g.,
with the movement of mobile devices. This paper adopts the concept of range
queries to CEP systems. We propose a mobility-aware event delivery semantic and
present a corresponding execution model that accounts for mobility driven
selection of primary event streams to the CEP system. By utilizing the
properties of this execution model we derive an algorithm that establishes low
cost and coordinated reconfiguration of CEP operators in a distributed system.
The algorithm minimizes the amount of information that needs to be streamed
between operators and avoids additional delays as a result of a reconfiguration
of CEP operators. We present an analysis of the algorithm's properties and
evaluate the efficiency of the proposed reconfiguration algorithm.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2012-20&engl=0}
}
@inproceedings {INPROC-2012-17,
author = {Muhammad Adnan Tariq and Boris Koldehofe and Gerald. G Koch and Kurt Rothermel},
title = {{Distributed spectral cluster management: A method for building dynamic publish/subscribe systems}},
booktitle = {Proceedings of the 6th ACM International Conference on Distributed Event-Based Systems (DEBS)},
address = {Berlin, Germany},
publisher = {ACM},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {213--224},
type = {Konferenz-Beitrag},
month = {Juli},
year = {2012},
doi = {10.1145/2335484.2335508},
keywords = {Content-based; Publish/Subscribe; Broker-less; Spectral clustering; P2P; Event-based},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2012-17/INPROC-2012-17.pdf,
http://doi.acm.org/10.1145/2335484.2335508},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {In recent years peer-to-peer (P2P) networking has gained high popularity for
large-scale content distribution. Prominent systems expect a large user base
with rather diversified demands. Yet it is highly challenging to achieve
scalability without sacrificing the expressiveness of queries in such systems.
This paper proposes distributed spectral cluster management, an approach which
adapts the techniques from spectral graph theory to work in distributed
settings. The proposed approach is applied to content-based publish/subscribe
to i) significantly reduce the cost for event dissemination by clustering
subscribers exploiting the similarity of events, ii) preserve the
expressiveness of the subscription language, and iii) perform robustly in the
presence of workload variations. The evaluations analyze the accuracy of the
proposed distributed spectral mechanisms and show their effectiveness to
significantly reduce the efforts to disseminate events under many practical
workloads.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2012-17&engl=0}
}
@inproceedings {INPROC-2012-13,
author = {Stefan F{\"o}ll and Florian Berg and Klaus Herrmann and Kurt Rothermel},
title = {{A Predictive Protocol for Mobile Context Updates with Hard Energy Constraints}},
booktitle = {Proceedings of the 13th International Conference on Mobile Data Management (MDM 2012)},
address = {Bengaluru, India},
publisher = {IEEE Computer Society},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {125--130},
type = {Konferenz-Beitrag},
month = {Juli},
year = {2012},
doi = {10.1109/MDM.2012.11},
keywords = {mobile users; update protocols; discrete context; energy efficiency; context accuracy; contrained optimization problem, Markov decision process},
language = {Englisch},
cr-category = {C.2.1 Network Architecture and Design,
C.2.4 Distributed Systems},
ee = {http://dx.doi.org/10.1109/MDM.2012.11},
contact = {stefan.foell@ipvs.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {As mobile devices have become powerful sensor platforms, new applications have
emerged which continuously stream mobile user context (location, activities,
etc.). However, energy is a limited resource on battery-equipped mobile
devices. Especially frequent transmissions of context updates over
energy-expensive wireless channels drain the battery of mobile devices in an
uncontrolled manner. It is a fundamental algorithmic challenge to design
protocols such that users can control the energy consumption on mobile devices
while, at the same time, optimizing the quality of mobile applications. To
address this trade-off in the area of context update protocols, we propose a
novel protocol that maximizes the context accuracy perceived by a remote
consumer while guaranteeing that the consumed energy stays under a given limit.
Our update protocol exploits predictions about a user's future behaviour to
give priority to the most effective context updates. In our evaluation, we
apply our predictive update protocol to a real-world trace of user context and
show that the context accuracy is significantly increased compared to an update
protocol which operates without predictions under the same energy budget.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2012-13&engl=0}
}
@inproceedings {INPROC-2012-07,
author = {Pavel Skvortsov and Frank D{\"u}rr and Kurt Rothermel},
title = {{Map-aware Position Sharing for Location Privacy in Non-trusted Systems}},
booktitle = {Proceedings of the 10th International Conference on Pervasive Computing (Pervasive 2012)},
editor = {Lecture Notes in Computer Science},
address = {Newcastle, UK},
publisher = {Springer-Verlag},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {388--405},
type = {Konferenz-Beitrag},
month = {Juni},
year = {2012},
keywords = {location-based service; privacy; obfuscation; sharing; map-awareness},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems,
H.3.5 Online Information Services},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2012-07/INPROC-2012-07.pdf,
http://www.springerlink.com/content/w682352838637308/,
http://www.priloc.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Many current location-based applications (LBA) such as friend finder services
use information about the positions of mobile users. So-called location
services (LSs) have been proposed to manage these mobile user positions
efficiently. However, managing user positions raises privacy issues, in
particular, if the providers of LSs are only partially trusted. Therefore, the
concept of private position sharing for partially trusted systems was proposed
in the literature. The basic idea of position sharing is to split the precise
user position into a set of position shares of well-defined limited precision
and distribute these shares among LSs of different providers. The main
contributions of this paper are two extended position sharing approaches that
improve the basic position sharing approach in two ways: Firstly, we reduce the
predictability of share generation that allows an attacker to gain further
information from a sub-set of shares to further increase the position
precision. Secondly, we present a position sharing algorithm for constrained
movement scenarios whereas the existing approach was tailored to open space
environments. However, open space approaches are vulnerable to map-based
attacks. Therefore, we present a share generation algorithm that takes map
knowledge into account.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2012-07&engl=0}
}
@inproceedings {INPROC-2012-06,
author = {Marius Wernke and Frank D{\"u}rr and Kurt Rothermel},
title = {{PShare: Position Sharing for Location Privacy based on Multi-Secret Sharing}},
booktitle = {Proceedings of the 10th IEEE International Conference on Pervasive Computing and Communications (PerCom 2012)},
address = {Lugano, Switzerland},
publisher = {IEEE Computer Society},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {153--161},
type = {Konferenz-Beitrag},
month = {M{\"a}rz},
year = {2012},
keywords = {Location-based applications; privacy; position sharing; location management},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems,
H.3.5 Online Information Services},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2012-06/INPROC-2012-06.pdf,
http://www.priloc.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Location-based applications such as Facebook Places, Foursquare, or Loopt
attract millions of users by implementing point of interest finders, friend
finders, geosocial networking, etc. Typically, these applications act as
clients to a location service such as Google Latitude or Yahoo Fire Eagle,
which manage mobile object positions and ensure the scalability to provide
various clients with mobile object positions.
However, exposing precise user positions raises user privacy concerns,
especially if location service providers are not fully trusted, and private
position information could be lost, leaked, stolen, etc. To enable the secure
management of private user positions on non-trusted location servers (LSs), we
present novel position sharing approaches based on the concept of multi-secret
sharing. Our approaches split up a precise user position into position shares,
which are distributed to different LSs of different providers such that a
compromised provider only reveals user positions with degraded precision. On
the other hand, clients can combine several shares queried from different LSs
to increase their provided precision without the need to store precise
information at a single LS.
We propose two position sharing approaches: PShare-SLM is the first position
sharing approach presented so far for symbolic location models. For geometric
location models, we present PShare-GLM, which improves existing geometric
position sharing approaches[DSR11] by considering continuous position updates
and by increasing the robustness against various attacks.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2012-06&engl=0}
}
@inproceedings {INPROC-2012-03,
author = {Stefan F{\"o}ll and Klaus Herrmann and Kurt Rothermel},
title = {{Energy-efficient Update Protocols for Mobile User Context}},
booktitle = {Proceedings of the 26th IEEE International Conference on Advanced Information Networking and Applications (AINA-2012)},
address = {Fukoka, Japan},
publisher = {IEEE},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {1--8},
type = {Konferenz-Beitrag},
month = {M{\"a}rz},
year = {2012},
keywords = {mobile users; update protocols; discrete context; energy efficiency; context accuracy},
language = {Englisch},
cr-category = {C.2.2 Network Protocols,
C.2.4 Distributed Systems},
contact = {stefan.foell@ipvs.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Nowadays, rich information about the context of mobile users is directly
captured on the users' mobile phones in real-time. Especially, discrete context
(e.g., the user's activity) has become highly interesting for many applications
since it provides an intuitive and human-understandable description of the
user's current state. However, while sensing is executed locally on the mobile
device, changes of user context need to be distributed from the device to a
large number of interested consumers, e.g., the friends in an online social
network. This produces a large overhead for the continuous transmission of
context updates and represents a serious challenge for the limited energy
budget of battery-equipped mobile devices. In this paper, we propose different
strategies for energy-efficient context updates. We present a number of update
protocols that are characterized by an inherent trade-off between quality of
context and message overhead. To this end, we investigate update criteria that
allow consumers of context information to express their tolerance towards the
inaccurateness of received context, and we propose update protocols that
exploit this tolerance to save updates and, thus, energy. In our evaluation we
analyse our update protocols based on a real-world trace of user activities and
show that applications can save more than 80\% of the messages when tolerating a
minor degradation of the context quality only.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2012-03&engl=0}
}
@inproceedings {INPROC-2012-01,
author = {Patrick Baier and Frank D{\"u}rr and Kurt Rothermel},
title = {{PSense: Reducing Energy Consumption in Public Sensing Systems}},
booktitle = {Proceedings of the 26th IEEE International Conference on Advanced Information Networking and Applications (AINA-2012)},
publisher = {IEEE},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {136--143},
type = {Konferenz-Beitrag},
month = {M{\"a}rz},
year = {2012},
doi = {10.1109/AINA.2012.33},
keywords = {ad-hoc; mobile; public sensing},
language = {Englisch},
cr-category = {C.2 Computer-Communication Networks},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2012-01/INPROC-2012-01.pdf,
http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=6184863&isnumber=6184848,
http://www.comnsense.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Utilizing peoples' mobile devices for gathering sensor data has attracted a lot
of attention within the last few years. As a result, a great variety of systems
for sensing environmental phenomena like temperature or noise have been
proposed. However, most of these systems do not take into account that mobile
devices have only limited energy resources. For instance, an often assumed
prerequisite is that mobile devices are always aware of their position. Given
the fact that a position fix is a very energy consuming operation, continuous
positioning would quickly drain a device's battery. Since the owners of the
mobile devices will not tolerate a significant reduction of the devices'
battery lifetime, such an approach is not suitable. To address this issue we
present PSense, a flexible system for efficiently gathering sensor data with
mobile devices. By avoiding unnecessary position fixes, PSense reduces the
energy consumption of mobile devices by up to 70\% compared to existing mobile
sensing approaches. This is achieved by introducing an adaptive positioning
mechanism and by utilizing energy efficient short-range communication to
exchange position related information.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2012-01&engl=0}
}
@inproceedings {INPROC-2011-84,
author = {Stamatia Rizou and Frank D{\"u}rr and Kurt Rothermel},
title = {{Fulfilling End-to-End Latency Constraints in Large-scale Streaming Environments}},
booktitle = {Proceedings of the 30th IEEE International Performance Computing and Communications Conference: IPCCC'11},
publisher = {IEEE Xplore},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
pages = {1--8},
type = {Konferenz-Beitrag},
month = {November},
year = {2011},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems,
C.2.2 Network Protocols,
C.2.3 Network Operations},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2011-84/INPROC-2011-84.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {The on-line processing of high volume data streams is a prerequisite for many
modern applications relying on real-time data such as global sensor networks or
multimedia streaming. In order to achieve efficient data processing and
scalability w.r.t. the number of distributed data sources and applications,
in-network processing of data streams in an overlay network of data processing
operators has been proposed. For such stream processing overlay networks, the
placement of operators onto physical hosts plays an important role for the
resulting quality of service—in particular, the endto- end latency—and network
load. To this end, we present an enhanced placement algorithm that minimizes
the network load put onto the system by a stream processing task under
userdefined delay constraints in this paper. Our algorithm finds first the
optimal solution in terms of network load and then degrades this solution to
find a constrained optimum. In order to reduce the overhead of the placement
algorithm, we included mechanisms to reduce the search space in terms of hosts
that are considered during operator placement. Our evaluations show that this
approach leads to an operator placement of high quality solution while inducing
communication overhead proportional only to a small percentage of the total
hosts.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2011-84&engl=0}
}
@inproceedings {INPROC-2011-76,
author = {Hannes Wolf and Klaus Herrmann and Kurt Rothermel},
title = {{FlexCon – Robust Context Handling in Human-Oriented Pervasive Flows}},
booktitle = {On the Move to Meaningful Internet Systems: OTM 2011 Confederated International Conferences: CoopIS, DOA-SVI, and ODBASE 2011, Hersonissos, Crete, Greece, October 17-21, 2011, Proceedings, Part I},
editor = {Robert Meersman and Tharam Dillon and Pilar Herrero and Akhil Kumar and Manfred Reichert and Li Qing and Beng-Chin Ooi and Ernesto Damiani and Douglas C. Schmidt and Jules White White and Manfred Hauswirth and Pascal Hitzler and Mukesh Mohania},
address = {Berlin/Heidelberg},
publisher = {Springer Berlin Heidelberg},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
series = {Lecture Notes in Computer Science},
volume = {7044},
pages = {236--255},
type = {Konferenz-Beitrag},
month = {Oktober},
year = {2011},
issn = {1611-3349},
doi = {10.1007/978-3-642-25109-2_16},
language = {Englisch},
cr-category = {H.4.1 Office Automation,
G.3 Probability and Statistics},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2011-76/INPROC-2011-76.pdf,
http://www.springerlink.com/content/2245482r612336ln/},
contact = {wolfhs@ipvs.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Workflows are increasingly becoming a universal means for driving and
coordinating complex processes, not only in the business world but also in
areas like pervasive computing. Pervasive flows run in parallel with the
user{\^a}€™s real-world actions and are synchronized using automatically collected
context information about her current activities (context events). Respective
workflows cannot be rigidly defined since the user needs to retain her
flexibility and must not be obstructed by the workflow. However, if the order
of activities is not defined until the activities are actually executed,
correctly assigning the uncertain context events becomes a major challenge. We
propose FlexCon {\^a}€“ a novel event assignment approach for such human-oriented
workflows that is based on hybrid workflow models and Dynamic Bayesian
Networks. FlexCon exploits the dependency between context events to provide
more accurate information as to which events need to be consumed by which
workflow activities. Our evaluations show that FlexCon improves the event
accuracy on average by 54\% and the number of successful completed flows on
average by 88\%. Thus, FlexCon represents a major step towards unobtrusive
pervasive applications.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2011-76&engl=0}
}
@inproceedings {INPROC-2011-74,
author = {Patrick Baier and Harald Weinschrott and Frank D{\"u}rr},
title = {{Effiziente automatisierte Erstellung von Stra{\ss}enkarten}},
booktitle = {7.GI/ITG KuVS-Fachgespr{\"a}ch. Ortsbezogene Anwendungen und Dienste.},
editor = {Roth J{\"o}rg K{\"u}pper Axel},
address = {Berlin},
publisher = {Logos Verlag Berlin GmbH},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {85--92},
type = {Konferenz-Beitrag},
month = {September},
year = {2011},
isbn = {978-3-8325-2935-2},
language = {Deutsch},
cr-category = {C.2.1 Network Architecture and Design,
C.2.2 Network Protocols,
C.2.3 Network Operations,
C.2.4 Distributed Systems,
E.1 Data Structures},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2011-74/INPROC-2011-74.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Das relativ junge Paradigma des Urban Sensing erm{\"o}glicht die kosteng{\"u}nstige
Bereitstellung von Sensordaten, welche in diesem Umfang bisher nicht zug{\"a}nglich
waren. Ein potentieller Verwendungszweck dieser Daten liegt im Bereich der
Kartografie, indem von Mobilger{\"a}ten erfasste GPS-Daten genutzt werden, um
Stra{\ss}enkarten automatisch zu erstellen. Dadurch kann eine Ersparnis
hinsichtlich Aufwand und Kosten, im Vergleich zu konventionellen Methoden der
Kartenerstellung, erzielt werden. Diese Arbeit stellt einen solchen Ansatz zur
effizienten, automatisierten Erstellung von Stra{\ss}enkarten mithilfe von
GPS-Sensordaten vor. Diese Daten werden dabei automatisch von Personen
gesammelt, die ihre Mobilger{\"a}te wie gewohnt mit sich f{\"u}hren, zus{\"a}tzlich aber
auf ihren allt{\"a}glichen Wegen GPS-Positionsinformationen erfassen, welche sie
einem zentralen System zur Verf{\"u}gung stellen. Dies geschieht automatisch, ohne
dass eine Interaktion dieser Personen n{\"o}tig ist. Im Gegenzug soll der
Ressourcenverbrauch der teilnehmenden Mobilger{\"a}te m{\"o}glichst minimiert werden.
Daher koordiniert der in dieser Arbeit vorgestellte Ansatz die Erfassung der
GPS-Daten so, dass die Mobilger{\"a}te diese m{\"o}glichst nur dann erfassen, wenn sie
sich in einem Gebiet befinden, welches bis zu diesem Zeitpunkt noch nicht
ausreichend kartografisch erfasst wurde. Um diese gezielte Koordination der
Mobilger{\"a}te zu erm{\"o}glichen, werden im Rahmen dieser Arbeit Qualit{\"a}tsmetriken
f{\"u}r Geodaten vorgestellt, welche den erfassten Stra{\ss}en quantitative Gr{\"o}{\ss}en
zuordnen, um so einen Vergleich dieser Daten zu erm{\"o}glichen.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2011-74&engl=0}
}
@inproceedings {INPROC-2011-73,
author = {Damian Philipp and Frank D{\"u}rr and Kurt Rothermel},
title = {{A Sensor Network Abstraction for Flexible Public Sensing Systems}},
booktitle = {Proceedings of the 8th IEEE International Conference on Mobile Ad-Hoc and Sensor Systems: MASS'11; Valencia, Spain, October 17-22, 2011},
editor = {IEEE Computer Society Conference Publishing Services},
address = {Valencia},
publisher = {IEEE Computer Society Conference Publishing Services},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
series = {IEEE Computer Society Order Number},
volume = {E4469},
pages = {460--469},
type = {Konferenz-Beitrag},
month = {Oktober},
year = {2011},
doi = {10.1109/MASS.2011.52},
isbn = {978-0-7695-4469-4/11},
keywords = {Public Sensing; Sensor Networks; Smartphone},
language = {Englisch},
cr-category = {C.2.1 Network Architecture and Design,
C.2.4 Distributed Systems,
C.2.5 Local and Wide-Area Networks,
C.5.3 Microcomputers},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2011-73/INPROC-2011-73.pdf,
http://dx.doi.org/10.1109/MASS.2011.52,
http://www.comnsense.de},
contact = {damian.philipp@ipvs.uni-stuttgart.de, frank.duerr@ipvs.uni-stuttgart.de, kurt.rothermel@ipvs.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Public Sensing is a new paradigm for developing large-scale sensor networks at
low cost by utilizing mobile phones that are already surrounding us in our
everyday lives. In this paper we present a sensor network abstraction layer for
creating flexible public sensing systems that can execute arbitrary queries. To
this effect we develop several algorithms to select mobile nodes for executing
a query. These algorithms allow a user to define a trade-off between quality
and efficiency of query execution by choosing an appropriate algorithm. Our
evaluations show that we can achieve a 99$\backslash$\% increase in efficiency with the
most efficient approaches and only about 10$\backslash$\% decrease in result quality under
worst conditions.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2011-73&engl=0}
}
@inproceedings {INPROC-2011-70,
author = {Hannes Wolf and Jonas Palauro and Klaus Herrmann},
title = {{Fuzzy Event Assignment for Robust Context-Aware Workflows}},
booktitle = {Proceedings of The Fourth International Conference on Dependability (DEPEND 2011)},
editor = {IARIA},
address = {Nice/Saint Laurent du Var, France},
publisher = {IARIA},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {37--42},
type = {Konferenz-Beitrag},
month = {August},
year = {2011},
isbn = {978-1-61208-149-6},
keywords = {context-aware workflows, dependable event assignment, fuzzy logic},
language = {Englisch},
cr-category = {H.4.1 Office Automation,
I.2.3 Deduction and Theorem Proving},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2011-70/INPROC-2011-70.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {The dependability of any kind of context-aware pervasive system inherently
relies on the ability to detect and recognize context events robustly. However,
due to the inaccuracy of real-world sensors the accurate recognition and
handling of context information is a fundamental problem leading to ambiguities
and inconsistent behavior of applications. Adaptable Pervasive Flows (APF) are
a novel workflow-based programming paradigm for pervasive applications. An APF
encodes the temporal dependencies of a user’s tasks. We propose a Fuzzy Event
Assignment (FEvA) algorithm that exploits this flow-knowledge to significantly
improve the robustness of context-aware pervasive applications by resolving the
ambiguities inherent to the context data. Our experiments show that FEvA
reaches an event assignment accuracy of 78\% to 97\% and improves the performance
of dealing with false positive, out-of-order events, and missed context
information.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2011-70&engl=0}
}
@inproceedings {INPROC-2011-61,
author = {Lars Geiger and Frank D{\"u}rr and Kurt Rothermel},
title = {{Adaptive Routing in a Contextcast Overlay Network}},
booktitle = {Proceedings of the IEEE 7th International Conference on Wireless and Mobile Computing, Networking and Communications (WiMob 2011)},
publisher = {IEEE Xplore},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
pages = {1--8},
type = {Konferenz-Beitrag},
month = {Oktober},
year = {2011},
doi = {10.1109/WiMOB.2011.6085340},
language = {Englisch},
cr-category = {C.2.1 Network Architecture and Design,
C.2.2 Network Protocols,
C.2.4 Distributed Systems,
C.2.6 Internetworking},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2011-61/INPROC-2011-61.pdf,
http://dx.doi.org/10.1109/WiMOB.2011.6085340},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Context-based communication allows for the dissemination of messages to mobile
users with a specified context, i.e., at a location and with certain attribute
values. This enables, e.g., a message to students on campus attending a certain
class, with information about a study group for an upcoming exam. An overlay
network of context-aware routers efficiently disseminate the messages to all
matching receivers. Directed forwarding of such messages requires that the
routers maintain knowledge about the contexts of connected users. Global
knowledge, i.e., each router knowing about every user, scales poorly, though,
because of the necessary updates.
To overcome this challenge, a router can selectively propagate context
information that actually allows its neighbors to prune a message distribution
tree. In this paper, we present an approach to adaptively propagate only those
user contexts that offer a reduction in overall system load. The algorithm
automatically and locally adapts to the observed messages and user contexts on
each node.
Our solution significantly improves the scalability of the system by reducing
the overall load by almost 50\%.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2011-61&engl=0}
}
@inproceedings {INPROC-2011-59,
author = {Bilal Hameed and Jorge Minguez and Michael W{\"o}rner and Philip Hollstein and Sema Zor and Stefan Silcher and Frank D{\"u}rr and Kurt Rothermel},
title = {{The Smart Real-Time Factory as a Product Service System}},
booktitle = {3rd CIRP International Conference on Industrial Product Service Systems},
address = {Braunschweig, Germany},
publisher = {IRP},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {1--6},
type = {Konferenz-Beitrag},
month = {Januar},
year = {2011},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {In modern manufacturing landscape, companies are increasingly relying on
product service systems i.e. bundling of products and services together in
order to gain a competitive edge. In this article we present the Smart
Real-Time Factory, a smart digital manufacturing environment that can transform
the process of production into an informational service for the customers. The
different components of the smart factory are discussed at length along with a
discussion of the different services that can be offered by the smart factory.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2011-59&engl=0}
}
@inproceedings {INPROC-2011-51,
author = {Patrick Baier and Harald Weinschrott and Frank D{\"u}rr and Kurt Rothermel},
title = {{MapCorrect: Automatic Correction and Validation of Road Maps Using Public Sensing}},
booktitle = {36th Annual IEEE Conference on Local Computer Networks (LCN 2011)},
address = {Bonn, Germany},
publisher = {IEEE Computer Society},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {1--8},
type = {Konferenz-Beitrag},
month = {Oktober},
year = {2011},
keywords = {ad-hoc; mobile; public sensing},
language = {Englisch},
cr-category = {C.2 Computer-Communication Networks},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2011-51/INPROC-2011-51.pdf,
http://www.comnsense.de},
contact = {patrick.baier@ipvs.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {With the increasing proliferation of small and cheap GPS receivers, a new way
of generating road maps could be witnessed over the last few years.
Participatory mapping approaches like OpenStreetMap, for instance, introduced a
way to generate road maps collaboratively from scratch. Nevertheless, one of
the main problems of these maps is their unknown quality in terms of accuracy.
To address this issue, we propose MapCorrect: An automatic map correction and
validation system. MapCorrect automatically collects GPS traces from people's
mobile devices to correct a given road map and validate it. Since the
collection of GPS data raises concerns about the energy consumption of the
participating mobile devices, we tackle this issue by introducing a selective
sensing mechanism. Furthermore, we show by simulation that using this approach
up to 50\% of energy on the mobile phones can be saved while not impairing the
map correction and validation process at all.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2011-51&engl=0}
}
@inproceedings {INPROC-2011-49,
author = {Stefan F{\"o}ll and Klaus Herrmann and Kurt Rothermel},
title = {{PreCon - Expressive Context Prediction using Stochastic Model Checking}},
booktitle = {Proceedings of the 8th International Conference on Ubiquitous Intelligence and Computing (UIC 2011)},
address = {Banff, Canada},
publisher = {Springer-Verlag},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
series = {Lecture Notes in Computer Science},
pages = {1--15},
type = {Konferenz-Beitrag},
month = {September},
year = {2011},
keywords = {Context Prediction, Semi-Markov Model, Stochastic Model Checking, Temporal Logic},
language = {Deutsch},
cr-category = {G.3 Probability and Statistics,
I.2.6 Artificial Intelligence Learning,
I.6.4 Model Validation and Analysis},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2011-49/INPROC-2011-49.pdf,
http://www.springerlink.com/content/xv8821301mh22473/},
contact = {stefan.foell@ipvs.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Ubiquitous systems need to determine the context of humans to deliver the right
services at the right time. As the needs of humans are often coupled to their
future context, the ability to predict relevant changes in a user's context is
a key factor for providing intelligence and proactivity. Current context
prediction systems only allow applications to query for the next user context
(e.g. the user's next location). This severely limits the benefit of context
prediction since these approaches cannot answer more expressive time-dependent
queries (e.g. will the user enter location X within the next 10 minutes?).
Neither can they handle predictions of multi-dimensional context (e.g. activity
and location). We propose PreCon, a new approach to predicting
multi-dimensional context. PreCon improves query expressiveness, providing
clear formal semantics by applying stochastic model checking methods. PreCon is
composed of three major parts: a stochastic model to represent context changes,
an expressive temporal-logic query language, and stochastic algorithms for
predicting context. In our evaluations, we apply PreCon to real context traces
from the domain of healthcare and analyse the performance using well-known
metrics from information retrieval. We show that PreCon reaches an F-score
(combined precision and recall) of about 0.9 which indicates a very good
performance.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2011-49&engl=0}
}
@inproceedings {INPROC-2011-44,
author = {Marco V{\"o}lz and Boris Koldehofe and Kurt Rothermel},
title = {{Supporting Strong Reliability for Distributed Complex Event Processing Systems}},
booktitle = {Proceedings of 13th IEEE International Conference on High Performance Computing and Communications (HPCC-2011)},
publisher = {IEEE Computer Society Press},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {477--486},
type = {Konferenz-Beitrag},
month = {September},
year = {2011},
doi = {10.1109/HPCC.2011.69},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2011-44/INPROC-2011-44.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Many application classes such as monitoring applications, involve processing a
massive amount of data from a possibly huge number of data sources. Complex
Event Processing (CEP) has evolved as the paradigm of choice to determine
meaningful situations (complex events) by performing stepwise correlation over
event streams. To keep up with the high scalability demands of growing input
streams, recent approaches distribute event correlation over several
correlation nodes. However, the distribution of event correlation severely
limits the reliability of a CEP system. Already a failure of a single
correlation node impacts the correctness of the final correlation result.
Increasing the availability by a naive application of established replication
principles introduces new problems in the context of CEP. In particular,
ensuring the lossless delivery of events and the detection of duplicate events
before processing them is a challenging task. In this paper, we illustrate the
importance of a strong reliability semantics for CEP in the context of a
monitoring application in a distributed production environment. Strong
reliability ensures each complex event is detected and delivered exactly once
to each application entity. We present a replication scheme which ensures
strong reliability in an asynchronous system model and can be applied to an
arbitrary distributed CEP system. The algorithm tolerates f simultaneous
failures by introducing f additional replicas for each correlation node. We
prove correctness as well as evaluate the overhead introduced by the algorithm.
Results show, that the overhead scales linearly with the number of deployed
replicas and the node failure rate.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2011-44&engl=0}
}
@inproceedings {INPROC-2011-43,
author = {Bj{\"o}rn Schilling and Boris Koldehofe and Kurt Rothermel},
title = {{Efficient and Distributed Rule Placement in Heavy Constraint-Driven Event Systems}},
booktitle = {Proceedings of the 13th IEEE International Conference on High Performance Computing and Communications (HPCC-2011)},
publisher = {IEEE},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {355--364},
type = {Konferenz-Beitrag},
month = {September},
year = {2011},
doi = {10.1109/HPCC.2011.53},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2011-43/INPROC-2011-43.pdf,
http://dx.doi.org/10.1109/HPCC.2011.53},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Complex Event Processing (CEP) is of increasing importance in many industrial
applications to integrate a huge number of events in a scalable manner. A core
challenge towards scalable CEP is to efficiently distribute the rules which
define how correlations between events can be detected within an event
processing network. Furthermore, migration of rules is essential to adapt to
changing conditions. While recently significant effort has been spent on
optimizing CEP with respect to dedicated optimization goals, such as minimizing
latency and bandwidth usage, there remains a fundamental gap in supporting
requirements that emerge from deploying CEP over heterogeneous and independent
processing environments. Heterogeneity typically imposes many constraints on
the placement of rules, which increases the complexity of the underlying
optimization problem and cannot be handled efficiently by existing solutions.
In this paper we examine the distributed placement, migration and optimization
of rules in the context of the constraint optimization problem to minimize
network usage. We propose and evaluate a placement algorithm that efficiently
finds valid solutions in scenarios where the solution space is heavily
restricted by constraints. The algorithm operates in a decentralized way and is
adaptive to dynamic changes of processing nodes, rules, and load
characteristics of the event processing network. The optimization algorithm
adopts techniques from simulated annealing to avoid local minima. Furthermore,
the proposed rule migration policies resolve invalid placements quickly and
therefore ensure high availability. The evaluations show that the proposed
algorithm is able to efficiently find near optimum solutions within heavy
constraint-driven network conditions.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2011-43&engl=0}
}
@inproceedings {INPROC-2011-31,
author = {Daniel Fischer and Stefan F{\"o}ll and Klaus Herrmann and Kurt Rothermel},
title = {{Energy-efficient Workflow Distribution}},
booktitle = {Proceedings of the Fifth International Conference on Communication System Software and Middleware(COMSWARE 2011)},
address = {Verona, Italy},
publisher = {ACM},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {1--8},
type = {Konferenz-Beitrag},
month = {Juli},
year = {2011},
keywords = {Workflow distribution; Energy efficiency; Minimum Cut},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems,
H.4 Information Systems Applications},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2011-31/INPROC-2011-31.pdf,
http://doi.acm.org/10.1145/2016551.2016553},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Pervasive computing and business process modeling are joining forces, as mobile
human users shall be seamlessly integrated into business processes. This
current trend gains momentum. In respective scenarios, humans use mobile
devices and wireless communication technology to interact with electronic
workflows that are entirely running in some powerful back-end infrastructure.
However, the high degree of interaction between humans and their workflows
causes a high communication overhead, which consumes a significant amount of
energy on the mobile devices. This incurs a negative impact on the usability
and on the efficiency of the overall business process due to rapidly drained
batteries and the resulting short life-times of the devices and applications.
We present an approach based on the well-known minimum-cut algorithm for
reducing the costly data transmissions during workflow execution by
distributing parts of a workflow to the users' devices. Our main motivation is
to reduce the energy consumption on the mobile devices and, thus, avoid
situations in which batteries are drained in the field, rendering the usage of
mobile devices more efficient. We prove that our algorithm finds the optimal
solution for a given network and a workflow. Our evaluations show that our
approach decreases the energy consumed on mobile devices by 32-37\% compared to
an approach where the entire workflow is executed in a central infrastructure.
Thus, if mobile devices are primarily used for executing workflows (as seen in
application domains like logistics and health care), one third of the energy
can be saved. This either means that devices have to be charged less
frequently, leading to less distraction in the business process, or that mobile
device specifications can be lowered. Significant cost reductions result in
both cases.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2011-31&engl=0}
}
@inproceedings {INPROC-2011-30,
author = {Andreas Benzing and Boris Koldehofe and Kurt Rothermel},
title = {{Efficient Support for Multi-Resolution Queries in Global Sensor Networks}},
booktitle = {Proceedings of the Fifth International Conference on COMmunication System softWAre and middlewaRE: COMSWARE 2011},
publisher = {ACM},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {1--12},
type = {Konferenz-Beitrag},
month = {Juli},
year = {2011},
doi = {10.1145/2016551.2016562},
keywords = {DSPS, global sensor network, indexing, query processing},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2011-30/INPROC-2011-30.pdf,
http://dl.acm.org/authorize?6553117},
contact = {andreas.benzing@ipvs.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Stream processing has evolved as a paradigm for efficiently sharing and
integrating a massive amount of data into applications. However, the
integration of globally dispersed sensor data imposes challenges in the
effective utilization of the IT infrastructure that forms the global sensor
network. Especially, simulations require the integration of sensor streams at
widely differing spatial and temporal resolutions. For current stream
processing solutions it is necessary to generate a separate data stream for
each requested resolution. Therefore, these systems will suffer from high
redundancy in data streams, wasting a significant amount of bandwidth and
limiting their scalability.
This paper presents a new approach to scalable distributed stream processing of
data which stems from globally dispersed sensor networks. The approach supports
applications in establishing continuous queries for sensor data at different
resolutions and ensures efficient bandwidth usage of the data distribution
network. Unlike existing work in the context of video stream processing which
provides multiple resolutions by establishing separate channels for each
resolution, this paper presents a stream processing system that can efficiently
split/combine data streams in order to decrease/increase their resolution
without loss in data precision. In addition the system provides mechanisms for
load balancing of sensor data streams that allow efficient utilization of the
bandwidth of the global sensor network.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2011-30&engl=0}
}
@inproceedings {INPROC-2011-22,
author = {Andreas Grau and Klaus Herrmann and Kurt Rothermel},
title = {{NETbalance: Reducing the Runtime of Network Emulation using Live Migration}},
booktitle = {Proceedings of the 20th International Conference on Computer Communication Networks (ICCCN'11)},
address = {Maui, HI, USA},
publisher = {IEEE Computer Society},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {1--6},
type = {Konferenz-Beitrag},
month = {August},
year = {2011},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2011-22/INPROC-2011-22.pdf,
http://dx.doi.org/10.1109/ICCCN.2011.6005793},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Network emulation is an efficient method for evaluating distributed
applications and communication protocols by combining the benefits of real
world experiments and network simulation. The process of network emulation
involves the execution of connected instances of the software under test
(called virtual nodes) in a controlled environment. In previous work, we
introduced an approach to minimize the runtime of network emulation experiments
based on prior known average resource requirements of virtual nodes.
In this paper, we introduce NETbalance, a novel approach to runtime reduction
for experiments with unknown or varying resource requirements. NETbalance
migrates virtual nodes during an experiment to distribute the load evenly
across the physical nodes, avoiding overloaded nodes and exploiting the idle
resources on underloaded nodes for speeding up the experiment execution. We
make the following contributions: First, we present an emulation architecture
for efficiently supporting live migration of virtual nodes. Second, we propose
a cost model for determining the runtime reduction achieved through the
migration. Third, we introduce an algorithm for calculating placements that
minimize the experiment runtime. Our evaluations of the NETbalance prototype
show, that it is able to reduce the experiment runtime by up to 70\%.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2011-22&engl=0}
}
@inproceedings {INPROC-2011-19,
author = {Christian Hiesinger and Daniel Fischer and Stefan F{\"o}ll and Herrmann Klaus and Kurt Rothermel},
title = {{Minimizing Human Interaction Time in Workflows}},
booktitle = {Proceedings of the Sixth International Conference on Internet and Web Applications and Services (ICIW 2011)},
address = {St. Maarten, the Netherlands Antilles},
publisher = {IARIA},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {22--28},
type = {Konferenz-Beitrag},
month = {M{\"a}rz},
year = {2011},
keywords = {Workflow distribution; human interaction; pervasive workflows},
language = {Englisch},
cr-category = {D.2.4 Software Engineering Software/Program Verification,
H.4 Information Systems Applications},
contact = {christian.hiesinger@ipvs.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Many business scenarios require humans to interact with workflows. To support
humans as unobtrusively as possible in the execution of their activities, it is
important to keep the interaction time experienced by humans as low as
possible. The time required for such interactions is influenced by two factors:
First, by the runtime of the services that are used by a workflow during an
interaction. Second, by the time required to transfer data between workflow
servers and services that may be distributed in a global network. We propose an
algorithm that computes a suitable distribution of a workflow in such a
network. The goal of our algorithm is to minimize the time required for
interactions between a human and a workflow. Current approaches in the domain
of workflow optimization pay little attention towards optimizing a workflow to
increase the usability for humans. We show the feasibility of our approach by
comparing our algorithm with two non-distributed approaches and a distributed
approach which is based on a greedy algorithm and show that our algorithm
outperforms these approaches.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2011-19&engl=0}
}
@inproceedings {INPROC-2011-11,
author = {Frank D{\"u}rr and Pavel Skvortsov and Kurt Rothermel},
title = {{Position Sharing for Location Privacy in Non-trusted Systems}},
booktitle = {Proceedings of the 9th IEEE International Conference on Pervasive Computing and Communications (PerCom 2011)},
address = {Seattle, USA},
publisher = {IEEE Computer Society},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {189--196},
type = {Konferenz-Beitrag},
month = {M{\"a}rz},
year = {2011},
doi = {10.1109/PERCOM.2011.5767584},
keywords = {location-based service; privacy; obfuscation; sharing; location management},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems,
H.3.5 Online Information Services},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2011-11/INPROC-2011-11.pdf,
http://dx.doi.org/10.1109/PERCOM.2011.5767584,
http://www.priloc.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Many novel location-based services (LBS) such as a friend finder service
require knowledge about the positions of mobile users. Usually, location
services are used to manage these positions, and for providing basic
functionality like spatial range queries or spatial events to the LBS.
Managing and using the positions of mobile users raises privacy issues, in
particular, if the providers of LBS and location services are only partially
trusted. Many different approaches for preserving a user's privacy have been
proposed in the literature, e.g. location obfuscation and the k-anonymity
concept. However, most of them are not suitable if both LBS and location
service providers are non-trusted. In contrast to these approaches, we present
a novel approach for the secure management of private position information in
partially trusted system environments. The main contribution in this paper is a
position sharing concept which allows for the distribution of position
information (shares) of strictly limited accuracy onto several location servers
of different providers. With this approach, a compromised server will only
reveal information of limited accuracy. Moreover, we will show how position
shares of coarse granularity from multiple location servers can be fused into
information of higher precision to satisfy the accuracy requirements of
different LBS.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2011-11&engl=0}
}
@inproceedings {INPROC-2011-10,
author = {Harald Weinschrott and Julian Weisser and Frank D{\"u}rr and Kurt Rothermel},
title = {{Participatory Sensing Algorithms for Mobile Object Discovery in Urban Areas}},
booktitle = {Proceedings of the 9th Annual IEEE International Conference on Pervasive Computing and Communications},
publisher = {IEEE Computer Society},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
pages = {128--135},
type = {Konferenz-Beitrag},
month = {M{\"a}rz},
year = {2011},
doi = {10.1109/PERCOM.2011.5767577},
language = {Englisch},
cr-category = {C.2 Computer-Communication Networks},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2011-10/INPROC-2011-10.pdf,
http://dx.doi.org/10.1109/PERCOM.2011.5767577,
http://www.comnsense.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {This paper introduces mechanisms for the automated detection of mobile objects
in urban areas. Widely available devices such as mobile phones with integrated
proximity sensors such as RFID readers or Bluetooth cooperatively perform
sensing operations to discover mobile objects. In this paper, we propose a
coverage metric for assessing the completeness of sensing that considers
spatial and temporal aspects. To maximize coverage while minimizing energy
consumption of mobile nodes, we propose both a centralized and a distributed
coordination algorithm for selecting nodes that need to sense. Moreover, we
present strategies that allow selected nodes to perform efficient sense
operations. By extensive simulations, we show that distributed coordination
achieves drastic energy savings of up to 63\%, while limiting the coverage loss
to 13\%. Moreover, we show that the centralized algorithm loses less than 1\%
coverage compared to the maximum possible coverage.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2011-10&engl=0}
}
@inproceedings {INPROC-2011-09,
author = {Umakishore Ramachandran and Liviu Iftode and Rajnish Kumar and Santosh Pande and Kurt Rothermel and Boris Koldehofe},
title = {{Large-scale Situational Awareness with Camera Networks and Multimodal Sensing}},
booktitle = {NSF Workshop on Pervasive Computing at Scale (PeCS)},
publisher = {online},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {1--2},
type = {Workshop-Beitrag},
month = {Januar},
year = {2011},
keywords = {Distributed Systems},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {This white paper raises the challenges and solution approaches for dealing with
large-scale media-rich infrastructures for addressing the needs of large-scale
sensor-based applications, often classified as situation awareness
applications, using smart surveillance as a canonical example.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2011-09&engl=0}
}
@inproceedings {INPROC-2011-08,
author = {Gerald G. Koch and Andreas Benzing and Christoph P. Mayer},
title = {{An Approach for Urban Sensing with Quality-Aware Situation Detection and Efficient Communication}},
booktitle = {Proceedings of the Workshops der wissenschaftlichen Konferenz Kommunikation in verteilten Systemen 2011 (WowKiVS 2011); Kiel, Germany, March 11th, 2011},
editor = {Horst Hellbr{\"u}ck and Norbert Luttenberger and Volker Turau},
publisher = {EASST},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
series = {Electronic Communications of the EASST},
pages = {1--10},
type = {Workshop-Beitrag},
month = {M{\"a}rz},
year = {2011},
issn = {1863-2122},
keywords = {Urban sensing; Internet of Things; Complex Event Processing; CEP; Delay Tolerant Network; DTN; Distributed Diagnostic Simulation},
language = {Englisch},
cr-category = {C.2.2 Network Protocols,
C.2.4 Distributed Systems,
I.6.3 Simulation and Modeling Applications},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2011-08/INPROC-2011-08.pdf},
contact = {gerald.koch@ipvs.uni-stuttgart.de andreas.benzing@ipvs.uni-stuttgart.de mayer@kit.edu},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Urban Sensing employs physical-world mining to create a digital model of the
physical world using a large number of sensors. Handling the large amount of
data generated by sensors is costly and requires energy-saving measures for
sensing and sensor data transmission. Such schemes often affect data quality
and message delay. However, the detection of real-world situations using
Complex Event Processing on sensor data has to be dependable and timely and
requires precise data. In this position paper, we propose an approach to
integrate the contradicting optimization goals of energy-efficient wireless
sensor networks and dependable situation detection. It separates the system
into the following tiers: First, to support energy-efficiency and allow sparse,
unconnected sensor networks, we exploit the mobility of people through Delay
Tolerant Networking for collecting sensor data. This frees sensor nodes from
energy-expensive routing. Second, we employ Diagnostic Simulation which
provides data that is complete, precise and in time and therefore supports
quality-aware situation detection.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2011-08&engl=0}
}
@inproceedings {INPROC-2010-81,
author = {Ralph Lange and Frank D{\"u}rr and Kurt Rothermel},
title = {{Indexing Source Descriptions based on Defined Classes}},
booktitle = {Proceedings of the 14th International Database Engineering and Applications Symposium (IDEAS '10). Montreal, QC, Canada. August 2010},
publisher = {ACM},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
pages = {245--256},
type = {Konferenz-Beitrag},
month = {August},
year = {2010},
keywords = {heterogeneous information systems; source descriptions; indexing of source descriptions; defined classes; tree-based index structure},
language = {Englisch},
cr-category = {H.2.5 Heterogeneous Databases,
H.3.3 Information Search and Retrieval},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2010-81/INPROC-2010-81.pdf,
http://doi.acm.org/10.1145/1866480.1866514},
contact = {ralph.lange@ipvs.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Scaling heterogeneous information systems (HIS) to thousands of sources poses
particular challenges to source discovery. It requires a powerful formalism for
describing the contents of the sources in a concise manner and for formulating
compatible queries as well as a suitable structure for indexing and retrieving
the source descriptions efficiently.
We propose an extended logic-based description formalism for large-scale HIS
with structured sources and a shared ontology. The formalism refines existing
approaches that describe the sources by constraints on the attribute value
ranges in several ways: It allows for complex, nested descriptions based on
defined classes. It supports alternative descriptions to express that a source
may be discovered by different combinations of constraints. Finally, it allows
to adjust between positive matching, similar to keyword-based discovery, and
negative matching, as used in existing logic-based approaches.
We further propose the SDC-Tree for indexing such source descriptions. To allow
for efficient discovery, the SDC-Tree features multidimensional indexing
capabilities for the different attributes and the IS-A hierarchy of the shared
ontology, but also incorporates the existence or absence of constraints. For
this purpose, it supports three different types of node split operations which
exploit the expressiveness of the description formalism. Therefore, we also
propose a generic split algorithm which can be used with arbitrary ontologies.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2010-81&engl=0}
}
@inproceedings {INPROC-2010-80,
author = {Hannes Wolf and Klaus Herrmann and Kurt Rothermel},
title = {{Robustness in Context-Aware Mobile Computing}},
booktitle = {IEEE International Conference on Wireless and Mobile Computing, Networking and Communications (WiMob'2010)},
address = {Niagara Falls, Canada},
publisher = {IEEE Communications Society},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {46--53},
type = {Konferenz-Beitrag},
month = {Oktober},
year = {2010},
doi = {10.1109/WIMOB.2010.5645026},
language = {Englisch},
cr-category = {H.4.1 Office Automation,
I.5.1 Pattern Recognition Models},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2010-80/INPROC-2010-80.pdf,
http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=5645026},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {High level context recognition and situation detection are an enabling
technologies for unobtrusive mobile computing systems. Significant progress has
been made in processing and managing context information, leading to
sophisticated frameworks, middlewares, and algorithms. Despite great
improvements, context aware systems still require a significantly increased
recognition accuracy for high-level context information on uncertain sensor
data to enable the robust execution of context-aware applications. Recently
Adaptable Pervasive Workflows (APF)s have been presented as innovative
programming paradigm for mobile context-aware applications. We propose a novel
Flow Context System (FlowCon) that builds upon APFs. FlowCon uses structural
information from the APF to increase accuracy of uncertain high-level context
information up to 49$\backslash$\%. This way we make an important step to enable robust
execution of mobile context-aware applications.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2010-80&engl=0}
}
@inproceedings {INPROC-2010-78,
author = {A. Bucchiarone and A. Marconi and M. Pistore and S. F{\"o}ll and K. Herrmann and C. Hiesinger and S. Marinovic},
title = {{An Overall Process for Self-Adaptive Pervasive Systems}},
booktitle = {Proceedings of the Second International Conference on Adaptive and Self-adaptive Systems and Applications : ADAPTIVE 2010 ; Lisbon, Portugal, November 21-26, 2010},
publisher = {Elsevier},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {1--6},
type = {Konferenz-Beitrag},
month = {November},
year = {2010},
language = {Deutsch},
cr-category = {D.2.9 Software Engineering Management,
D.2.11 Software Engineering Software Architectures},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Self-adaptive pervasive systems often implement adaptation in a centralised
manner, where one component holds all the necessary knowledge to identify when
and how the system needs to adapt. In self-adaptive pervasive systems, composed
of autonomous components with different authorities (such as security,
distribution, etc.), this approach cannot be implemented as composing a
centralised knowledge is not feasible and it also obstructs the system's
ability to dynamically change its components. A simple alternative would be to
allow each component to adapt independently but this can quickly give rise to
conflicts, race conditions and oscillations between multiple independent
adaptations. To avoid these problems, we propose to coordinate individual
adaptations so that each component's adaptation goals are satisfied. Each
component proposes an adaptation which is reviewed by other components who may
propose their own adaptations that they may need to do. This continues until a
complete adaptation plan is agreed upon. In cases where certain individual
adaptations conflict with some components' goals, components are instructed to
seek alternative proposals. The Adaptation Manager component is in charge of
the negotiation process and it also has the authority to resolve certain
conflicts between adaptations. Our approach is evaluated in the context of
pervasive workflow systems where the failure probability and execution times
are assessed.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2010-78&engl=0}
}
@inproceedings {INPROC-2010-71,
author = {Bilal Hameed and Imran Ahmed Khan and Frank D{\"u}rr and Kurt Rothermel},
title = {{An RFID Based Consistency Management Framework for Production Monitoring In a Smart Real-Time Factory}},
booktitle = {Proceedings of 2010 Internet of Things Conference (To Appear).},
address = {Tokyo, Japan},
publisher = {IEEE},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {1--8},
type = {Konferenz-Beitrag},
month = {November},
year = {2010},
language = {Englisch},
cr-category = {C.2 Computer-Communication Networks,
C.2.1 Network Architecture and Design},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {The use of RFID devices for real-time production monitoring in modern factories
is impeded by the inherent unreliability of RFID devices. In this paper we
present a consistency stack that conceptually divides the different consistency
issues in production monitoring into separate layers. In addition to this we
have built a consistency management framework to ensure consistent real-time
production monitoring, using unreliable RFID devices. In detail, we deal with
the problem of detecting object sequences by a set of unreliable RFID readers
that are installed along production lines. We propose a probabilistic sequence
detection algorithm that assigns probabilities to objects detected by RFID
devices and provides probabilistic guarantees regarding the real-time sequences
of objects on the production lines.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2010-71&engl=0}
}
@inproceedings {INPROC-2010-69,
author = {Andreas Benzing and Boris Koldehofe and Marco V{\"o}lz and Kurt Rothermel},
title = {{Multilevel Predictions for the Aggregation of Data in Global Sensor Networks}},
booktitle = {Proceedings of the 14th IEEE/ACM International Symposium on Distributed Simulation and Real Time Applications},
publisher = {IEEE},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {169--178},
type = {Konferenz-Beitrag},
month = {Oktober},
year = {2010},
keywords = {Global Sensor Networks; Distributed Stream Processing; Predictors},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2010-69/INPROC-2010-69.pdf,
http://ieeexplore.ieee.org/search/srchabstract.jsp?tp=&arnumber=5636734},
contact = {andreas.benzing@ipvs.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Real-time simulations are one challenging application domain that is expected
to introduce high requirements to global sensor applications. Besides having
hard constraints on latency bounds at which data needs to be processed,
simulation applications will impose high requirements with respect to available
bandwidth. Predictors, originally introduced in the domain of wireless sensor
networks for energy saving, are one appealing solution to provide real-time
estimates and at the same time significantly reduce the data rates. While in
the setting of wireless sensor networks many prediction models have been
analyzed, their behavior and use is unclear when applied to distributed data
streams where aggregation results are typically processed over multilevel
hierarchies.
In the context of weather simulations, we propose a distributed R-Tree-based
aggregation algorithm that allows for efficient reuse of aggregate queries. In
the setting of real temperature readings taken from weather stations during one
month, we study the trade-off between updates of the prediction model and the
precision of the predicted values. Our evaluations indicate that even in
situations where complex prediction models are expected to perform best, simple
prediction models give higher benefits with respect to saving bandwidth while
providing similar data accuracy.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2010-69&engl=0}
}
@inproceedings {INPROC-2010-65,
author = {Daniel Fischer and Klaus Herrmann and Kurt Rothermel},
title = {{GeSoMo - A General Social Mobility Model for Delay Tolerant Networks}},
booktitle = {Proceedings of the 7th IEEE International Conference on Mobile Ad-hoc and Sensor Systems (MASS '10)},
publisher = {IEEE},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {1--9},
type = {Konferenz-Beitrag},
month = {November},
year = {2010},
language = {Deutsch},
cr-category = {C.2.1 Network Architecture and Design,
C.4 Performance of Systems,
I.6.0 Simulation and Modeling General},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Simulation is a fundamental means for evaluating mobile applications based on
ad-hoc networks. This has led to the design of a large number of mobility
models for simulating realistic user movement under physical constraints
(obstacles, acceleration, inertia etc.). In recent years, the new breed of
social mobility models (SMMs) has risen. These SMMs model the $\backslash$emph{social
aspects of human mobility}, i.e. which users meet, when and how often. Such
information is indispensable for the simulation of a wide range of
socially-aware communication protocols mostly based on delay-tolerant networks,
including opportunistic ad-hoc routing and data dissemination systems. Each SMM
needs a model of the relations between a set of relevant people (called social
network model -- SNM) in order to simulate their mobility. Existing SMMs lack
flexibility since each of them is implicitly restricted to a specific,
simplifying SNM.
We present GeSoMo, a new SMM that separates the core mobility model from the
structural description of the social network underlying the simulation. This
simple and elegant design principle gives GeSoMo generalizing power: Arbitrary
existing and future SNMs can be used without changing GeSoMo itself. Our
evaluation results show that GeSoMo produces simulations that are coherent with
a broad range of empirical data describing real-world human social behavior and
mobility.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2010-65&engl=0}
}
@inproceedings {INPROC-2010-63,
author = {Harald Weinschrott and Frank D{\"u}rr and Kurt Rothermel},
title = {{StreamShaper: Coordination Algorithms for Participatory Mobile Urban Sensing}},
booktitle = {Proceedings of the 7th IEEE International Conference on Mobile Ad-hoc and Sensor Systems (MASS'10)},
address = {San Francisco, CA, USA},
publisher = {IEEE},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
pages = {1--10},
type = {Konferenz-Beitrag},
month = {November},
year = {2010},
language = {Englisch},
cr-category = {C.2 Computer-Communication Networks},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2010-63/INPROC-2010-63.pdf,
http://www.comnsense.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {In this paper we introduce mechanisms for automated mapping of urban areas that
provide a virtual sensor abstraction to the applications. We envision a
participatory system that exploits widely available devices as mobile phones to
cooperatively read environmental conditions as air quality or noise pollution,
and map these measurements to stationary virtual sensors. We propose spatial
and temporal coverage metrics for measuring the quality of acquired sensor data
that reflect the conditions of urban areas and the uncontrolled movement of
nodes. To achieve quality requirements and efficiency in terms of energy
consumption, this paper presents two algorithms for coordinating sensing. The
first is based on a central control instance, which assigns sensing tasks to
mobile nodes based on movement predictions. The second algorithm is based on
coordination of mobile nodes in an ad-hoc network. By extensive simulations, we
show that these algorithms achieve a high quality of readings, which is about
95\% of the maximum possible. Moreover, the algorithms achieve a very high
energy efficiency allowing for drastic savings compared to uncoordinated
sensing.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2010-63&engl=0}
}
@inproceedings {INPROC-2010-60,
author = {Faraz Memon and Frank D{\"u}rr and Kurt Rothermel},
title = {{Index Recommendation Tool for Optimized Information Discovery Over Distributed Hash Tables}},
booktitle = {Proceedings of the 35th International Conference on Local Computer Networks (LCN '10)},
address = {Dever, CO, USA},
publisher = {IEEE Computer Society},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {1--8},
type = {Konferenz-Beitrag},
month = {Oktober},
year = {2010},
language = {Englisch},
cr-category = {C.2.1 Network Architecture and Design,
E.1 Data Structures,
E.2 Data Storage Representations,
H.3.1 Content Analysis and Indexing},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2010-60/INPROC-2010-60.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Peer-to-peer (P2P) networks allow for efficient information discovery in
large-scale distributed systems. Although point queries are well supported by
current P2P systems -- in particular systems based on distributed hash tables
(DHTs) --, providing efficient support for more complex queries remains a
challenge. Our research focuses on the efficient support for multi-attribute
range (MAR) queries over DHT-based information discovery systems.
Traditionally, the support for MAR queries over DHTs has been provided either
by creating an individual index for each data attribute or by creating a single
index using the combination of all data attributes. In contrast to these
approaches, we propose to create a set of indices over selected attribute
combinations. In order to limit the overhead induced by index maintenance, the
total number of created indices has to be limited. Thus, the resulting problem
is to create a limited number of indices such that the overall system
performance is optimal for MAR queries. In this paper, we propose an index
recommendation tool that implements heuristic solutions to this NP-hard
problem. Our evaluations show that these heuristics lead to a close-to-optimal
system performance for MAR queries.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2010-60&engl=0}
}
@inproceedings {INPROC-2010-57,
author = {Stamatia Rizou and Frank D{\"u}rr and Kurt Rothermel},
title = {{Providing QoS Guarantees for Large-Scale Operator Networks}},
booktitle = {Proceedings of the 12th IEEE International Conference on High Performance Computing and Communications},
address = {Melbourne, VIC, Australia},
publisher = {IEEE Computer Society Press},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
pages = {337--345},
type = {Konferenz-Beitrag},
month = {September},
year = {2010},
doi = {10.1109/HPCC.2010.53},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2010-57/INPROC-2010-57.pdf,
http://dx.doi.org/10.1109/HPCC.2010.53},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Application areas like global sensor networks and data stream processing
involve the on-line processing of large amounts of data in an overlay network
of operators on top of the Internet infrastructure. Trying to fulfill QoS
guarantees in such networks is a challenging task that should be realized under
the requirement for optimal usage of common resources in the network. Therefore
in this paper, we formalize a constrained optimization problem for the
placement of operators in an overlay network which strives for satisfying user
QoS constraints subject to latency, while minimizing the network load induced
by the deployment of the operators in the network. Since the initial problem is
NP-hard, we solve at a first step the problem in an intermediate continuous
latency space and then we map the continuous solution to its discrete variant.
Our evaluations provide an analysis about the inherent interdepedence between
the two metrics, network usage and latency, subject to this paper and
furthermore shows that our algorithm achieves a good balance between the user
requirements and the usage of the network resources.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2010-57&engl=0}
}
@inproceedings {INPROC-2010-56,
author = {Stamatia Rizou and Frank D{\"u}rr and Kurt Rothermel},
title = {{Solving the Multi-operator Placement Problem in Large-Scale Operator Networks}},
booktitle = {Proceedings of the 19th International Conference on Computer Communication Networks},
address = {Zurich, Switzerland},
publisher = {IEEE Communications Society},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
pages = {1--6},
type = {Konferenz-Beitrag},
month = {August},
year = {2010},
doi = {10.1109/ICCCN.2010.5560127},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2010-56/INPROC-2010-56.pdf,
http://dx.doi.org/10.1109/ICCCN.2010.5560127},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Processing streams of data in an overlay network of operators distributed over
a wide-area network is a common idea shared by different applications such as
distributed event correlation systems and large-scale sensor networks. In order
to utilize network resources efficiently and allow for the parallel deployment
of a large number of large-scale operator networks, suitable placement
algorithms are vital that place operators on physical nodes. In this paper, we
present a distributed placement algorithm that minimizes the bandwidth-delay
product of data streams between operators of the network in order to reduce the
induced network load. Since the fundamental optimization problem is NP-hard, we
propose a heuristic solution. First, we calculate an optimal solution in an
intermediate continuous search space, called latency space. Subsequently the
continuous solution is mapped to the physical network. Our evaluations show
that this algorithm reduces the resulting network load significantly compared
to state of the art algorithms and achieves results close to the optimum.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2010-56&engl=0}
}
@inproceedings {INPROC-2010-46,
author = {Stefan F{\"o}ll and Klaus Herrmann and Christian Hiesinger},
title = {{Flow-Based Context Prediction}},
booktitle = {Proceedings of the 7th International Conference on Pervasive Services (ICPS 2010), Berlin, Germany, July 13-15, 2010},
publisher = {ACM},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {1--1},
type = {Konferenz-Beitrag},
month = {Juli},
year = {2010},
keywords = {Context prediction, Markov model, workflows, context awareness, probabilistic user behaviour},
language = {Englisch},
cr-category = {G.3 Probability and Statistics,
I.2.6 Artificial Intelligence Learning},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2010-46/INPROC-2010-46.pdf},
contact = {stefan.foell@ipvs.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Context prediction has been recognized as an enabler for proactive pervasive
services that anticipate future situations already ahead of time. Traditional
context predictors are limited by their agnostic view on the targeted
application domain when analysing context histories of past user behaviour.
Awareness about the processes in which an entity is involved can provide rich
information to foresee future context changes more accurately. We present an
approach for context prediction in pervasive environments that are
characterized by context-aware workflows. In order to benefit from the explicit
knowledge about human behaviour in these environments, we devise a context
predictor that learns the relationship of context changes with the flow of
activities performed by humans. This relationship is encoded as a probabilistic
state transition system that can be explored to determine the most likely paths
of future context occurrences. Our evaluation shows that our enhanced predictor
is able to extract patterns from context histories that are inaccessible to
history-only predictors and significantly improves the prediction accuracy.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2010-46&engl=0}
}
@inproceedings {INPROC-2010-43,
author = {Stamatia Rizou and Kai H{\"a}ussermann and Frank D{\"u}rr and Nazario Cipriani and Kurt Rothermel},
title = {{A system for distributed context reasoning.}},
booktitle = {Proceedings of ICAS’10: International Conference on Autonomous and Autonomic Systems},
publisher = {IEEE Computer Society Conference Publishing Services},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
pages = {84--89},
type = {Konferenz-Beitrag},
month = {M{\"a}rz},
year = {2010},
isbn = {978-0-7695-3970-6},
doi = {10.1109/ICAS.2010.21},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2010-43/INPROC-2010-43.pdf,
http://dx.doi.org/10.1109/ICAS.2010.21},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme;
Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Anwendersoftware},
abstract = {Context aware systems use context information to adapt their behaviour
accordingly. In order to derive high level context information from low level
context, such as sensor values, context reasoning methods that correlate
observable context information, are necessary. Several context reasoning
mechanisms have been proposed in the literature. Usually these mechanisms are
centralized, leading to suboptimal utilization of network resources and poor
system performance in case of large-scale scenarios. Therefore to increase the
scalability of context reasoning systems the development of methods that
distribute the reasoning process is necessary. Existing distributed approaches
are method specific and do not provide a generic formalization for distributed
reasoning. In this paper we introduce a novel system which enables distributed
context reasoning in a generic way that is independent of the reasoning
algorithm.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2010-43&engl=0}
}
@inproceedings {INPROC-2010-38,
author = {Gerald G. Koch and M. Adnan Tariq and Boris Koldehofe and Kurt Rothermel},
title = {{Event processing for large-scale distributed games}},
booktitle = {Proceedings of the 4th International Conference on Distributed Event-Based Systems (DEBS'10)},
publisher = {ACM},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {103--104},
type = {Konferenz-Beitrag},
month = {Juli},
year = {2010},
doi = {http://doi.acm.org/10.1145/1827418.1827440},
isbn = {978-1-60558-927-5},
keywords = {Cordies; SpoVNet; CEP},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2010-38/INPROC-2010-38.pdf,
http://doi.acm.org/10.1145/1827418.1827440},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Novel peer-to-peer-based multiplayer online games are instantiated in an ad-hoc
manner without the support of dedicated infrastructure and maintain their state
in a distributed manner. Although their employed communication paradigms
provide efficient access to sections of distributed state, such communication
fails if the participants need to access large subsets of the application state
in order to detect high-level situations. We propose a demonstration that shows
how multiplayer online games can benefit from using publish/subscribe
communication and complex event processing alongside their traditional
communication paradigm.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2010-38&engl=0}
}
@inproceedings {INPROC-2010-32,
author = {Lars Geiger and Frank D{\"u}rr and Kurt Rothermel},
title = {{Aggregation of User Contexts in Context-based Communication}},
booktitle = {Proceedings of the 6th Euro-NF Conference on Next Generation Internet (NGI 2010)},
address = {Paris},
publisher = {IEEE Xplore},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
pages = {1--8},
type = {Konferenz-Beitrag},
month = {Juni},
year = {2010},
language = {Englisch},
cr-category = {C.2.1 Network Architecture and Design,
C.2.2 Network Protocols,
C.2.4 Distributed Systems,
C.2.6 Internetworking},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2010-32/INPROC-2010-32.pdf,
http://dx.doi.org/10.1109/NGI.2010.5534466},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {A context-based communication system enables the indirect addressing and
routing of messages according to the users' contexts. This provides, for
example, the means to send a message to all students on campus who attend a
certain class, with information about an upcoming exam. However, for a targeted
forwarding of messages towards users, the routers need information about the
context of connected users. Global knowledge, i.e., each router knowing about
every user, is not scalable, though, because of the necessary update messages
to keep this information up-to-date.
To address this challenge, a router can aggregate similar contexts and only
provide such an aggregated view to neighboring routers. In this paper, we
present an approach to aggregate similar contexts, based on a similarity
measure for user contexts. The algorithm can be adjusted according to the
observed messages and user contexts in the system by specifying a similarity
threshold to determine when contexts are aggregated.
The aggregation of user contexts improves the scalability of our approach by
significantly reducing the load of context updates by up to 30\%, depending on
the usage of the system. This improvement comes at the cost of a negligible
increase in false positive messages due to the loss of information used for
forwarding messages.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2010-32&engl=0}
}
@inproceedings {INPROC-2010-31,
author = {Muhammad Adnan Tariq and Gerald Georg Koch and Boris Koldehofe and Imran Khan and Kurt Rothermel},
title = {{Dynamic publish/subscribe to meet subscriber-defined delay and bandwidth constraints}},
booktitle = {The Sixteenth International Conference on Parallel Computing (Euro-Par 2010)},
publisher = {Springer},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {458--470},
type = {Konferenz-Beitrag},
month = {August},
year = {2010},
keywords = {Content-based; P2P; Event-based; Bandwidth; End-to-end Delay; Spatial indexing; QoS},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2010-31/INPROC-2010-31.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Current distributed publish/subscribe systems assume that all participants have
similar QoS requirements and equally contribute to the system’s resources.
However, in many real-world applications, the message delay tolerance of
individual peers may differ widely. Disseminating messages according to
individual delay requirements not only allows for the satisfaction of
user-specific needs but also significantly improves the utilization of the
resources in a publish/subscribe system. In this paper, we propose a
peer-to-peer-based approach to satisfy the individual delay requirements of
subscribers in the presence of bandwidth constraints. Our approach allows
subscribers to dynamically adjust the granularity of their subscriptions
according to their bandwidth constraints and delay requirements. Subscribers
maintain the publish/subscribe overlay in a decentralized manner by
establishing connections to peers that provide messages meeting exactly their
subscription granularity and complying to their delay requirements. Evaluations
show that for practical workloads, the proposed system scales up to a large
number of subscribers and performs robustly in a very dynamic setting.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2010-31&engl=0}
}
@inproceedings {INPROC-2010-30,
author = {Andreas Grau and Klaus Herrmann and Kurt Rothermel},
title = {{NETplace: Efficient Runtime Minimization of Network Emulation Experiments}},
booktitle = {Proceeding of the International Symposium on Performance Evaluation of Computer and Telecommunication Systems (SPECTS'10) [Best Paper Award]},
address = {Ottawa, Canada},
publisher = {IEEE Communications Society},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {265--272},
type = {Konferenz-Beitrag},
month = {Juli},
year = {2010},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2010-30/INPROC-2010-30.pdf,
http://www.ipvs.uni-stuttgart.de/abteilungen/vs/abteilung/mitarbeiter/andreas.grau_infos/spects10bestpaper.jpg,
http://ieeexplore.ieee.org/xpls/abs_all.jsp?arnumber=5589304},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Network emulation is an efficient method for evaluating distributed
applications and communication protocols by combining the benefits of real
world experiments and network simulation. The process of network emulation
involves execution of thousands of connected virtual nodes running the software
under test in a controlled environment. Along with the quality of the
experiment results, the runtime of network experiments strongly influences the
convenience of users and operators of emulation testbeds. The goal of this
paper is, therefore, to minimize the experiment runtime of network emulations.
In order to achieve this goal, we make the following contributions in this
paper: First, we present a highly scalable emulation architecture to
efficiently support network emulation testbeds with multicore CPUs. Second, we
propose a detailed and generic cost model for the communication costs of
emulation testbeds. Third, we present an efficient placement strategy
(NETplace) to assign virtual nodes to physical nodes of the testbed while
minimizing the runtime of network experiments. Therefore, we combine graph
partitioning and greedy approaches. Our evaluations show that our placement
strategy outperforms existing methods by reducing the experiment runtime up to
64\%.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2010-30&engl=0}
}
@inproceedings {INPROC-2010-24,
author = {Muhammad Adnan Tariq and Boris Koldehofe and Ala Altaweel and Kurt Rothermel},
title = {{Providing basic security mechanisms in broker-less publish/subscribe systems}},
booktitle = {Proceedings of the 4th International Conference on Distributed Event-Based Systems (DEBS'10), 2010},
publisher = {ACM},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {38--49},
type = {Konferenz-Beitrag},
month = {Juli},
year = {2010},
keywords = {Content-based; P2P; Broker-less; Security; Identity-based encryption; IBE; Attribute-based encryption; Clustering},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2010-24/INPROC-2010-24.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {The provisioning of basic security mechanisms such as authentication and
confidentiality is highly challenging in a content-based publish/subscribe
system. Authentication of publishers and subscribers is difficult to achieve
due to the loose coupling of publishers and subscribers. Similarly,
confidentiality of events and subscriptions conflicts with contentbased
routing. In particular, content-based approaches in broker-less environments do
not address confidentiality at all. This paper presents a novel approach to
provide confidentiality and authentication in a broker-less content-based
publish-subscribe system. By adapting the pairing-based cryptography mechanisms
to the needs of publish/subscribe authentication of publisher and subscriber as
well as confidentiality of events is ensured. Furthermore, an algorithm to
cluster subscribers according to their subscriptions preserves a weak notion of
subscription confidentiality. Our approach provides fine grained key management
and the cost for encryption, decryption and routing is in the order of
subscribed attributes. Moreover, the simulation results verify that supporting
security is affordable with respect to the cost for overlay construction and
event dissemination latencies, thus preserving scalability of the system.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2010-24&engl=0}
}
@inproceedings {INPROC-2010-22,
author = {Bj{\"o}rn Schilling and Boris Koldehofe and Udo Pletat and Kurt Rothermel},
title = {{Distributed Heterogeneous Event Processing: Enhancing Scalability and Interoperability of CEP in an Industrial Context}},
booktitle = {Proceedings of the 4th ACM International Conference on Distributed Event-Based Systems (DEBS); Cambridge, United Kingdom, July 12-15, 2010},
publisher = {ACM},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {150--159},
type = {Konferenz-Beitrag},
month = {Juli},
year = {2010},
isbn = {1827418.1827453},
language = {Deutsch},
cr-category = {C.2.1 Network Architecture and Design,
C.2.4 Distributed Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2010-22/INPROC-2010-22.pdf,
http://portal.acm.org/citation.cfm?doid=1827418.1827453},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Although a significant amount of research has investigated the benefits of
distributed CEP in terms of scalability and extensibility, there is an ongoing
reluctance in deploying distributed CEP in an industrial context. In this paper
we present the DHEP system developed together with the IBM laboratory in
B{\"o}blingen. It addresses some of the key problems in increasing the acceptance
of distributed CEP, for example supporting interoperability between
heterogeneous event processing systems. We present the concepts behind the DHEP
system and show how those concepts help to achieve scalable and extensible
event processing in an industrial context. Moreover, we verify in an evaluation
study that the additional cost imposed by the DHEP system is moderate and
'affordable' for the benefits provided.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2010-22&engl=0}
}
@inproceedings {INPROC-2010-21,
author = {Gerald Georg Koch and Boris Koldehofe and Kurt Rothermel},
title = {{Cordies: Expressive event correlation in distributed systems}},
booktitle = {Proceedings of the 4th International Conference on Distributed Event-Based Systems (DEBS'10)},
publisher = {ACM},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {26--37},
type = {Konferenz-Beitrag},
month = {Juli},
year = {2010},
isbn = {978-1-60558-927-5},
doi = {10.1145/1827418.1827424},
keywords = {Cordies; distributed complex event processing; restriction graph; correlation description},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2010-21/INPROC-2010-21.pdf,
http://doi.acm.org/10.1145/1827418.1827424},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Complex Event Processing (CEP) is the method of choice for the observation of
system states and situations by means of events. A number of systems have been
introduced that provide CEP in selected environments. Some are restricted to
centralised systems, or to system with synchronous communication, or to a
limited space of event relations that are defined in advance. Many modern
systems, though, are inherently distributed and asynchronous, and require a
more powerful CEP. We present Cordies, a distributed system for the detection
of correlated events that is designed for the operation in large-scale,
heterogeneous networks and adapts dynamically to changing network conditions.
With its expressive language to describe event relations, it is suitable for
environments where neither the event space nor the situations of interest are
predefined but are constantly adapted.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2010-21&engl=0}
}
@inproceedings {INPROC-2010-18,
author = {Andreas Benzing and Boris Koldehofe and Kurt Rothermel},
title = {{Distributed Diagnostic Simulations for the Smart Grid}},
booktitle = {Accepted Poster at the 1st International Conference on Energy-Efficient Computing and Networking: E-Energy 2010},
publisher = {Online},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {1--3},
type = {Konferenz-Beitrag},
month = {April},
year = {2010},
keywords = {Diagnostic Simulation; Global Sensor Grid},
language = {Deutsch},
cr-category = {C.2.4 Distributed Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2010-18/INPROC-2010-18.pdf},
contact = {andreas.benzing@ipvs.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Energy efficiency is usually achieved by reducing the energy consumption as far
as possible. With the growing amount of renewable energy sources, energy
efficient usage also has to consider what kind of and when power is consumed.
By matching the availability of electrical power with the current demands, the
amount of unused energy and therefore overall energy production can be reduced.
The so called smart grid aims to provide this matching with a broad deployment
of smart meters to acquire the current demand. However, current approaches to
the smart grid cannot handle the huge amount of sensors and energy sources
involved in a scalable way. Most data acquisition systems focus on the lookup
and reading of single sensors and therefore do not fit the requirements of a
large scale power grid simulation. We propose a Global Sensor Grid (GSG) which
provides consumers with data preprocessed to their needs instead of delivering
raw sensor data. With this decoupling from the actual sensors, multiple
consumers can benefit from improvements in data acquisition and avoidance of
the redundant processing of data by each consumer. By integrating so-called
diagnostic simulations into the GSG, gaps in sensor coverage can be filled with
higher precision than normal interpolation.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2010-18&engl=0}
}
@inproceedings {INPROC-2010-17,
author = {Frank D{\"u}rr and Harald Weinschrott and Kurt Rothermel},
title = {{Geocast Routing of Symbolically Addressed Messages in Wireless Mesh Networks}},
booktitle = {Proceedings of the 8th IEEE International Conference on Pervasive Computing and Communications Workshops (PerCom Workshops '10)},
address = {Mannheim, Germany},
publisher = {IEEE Computer Society},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
pages = {552--557},
type = {Workshop-Beitrag},
month = {M{\"a}rz},
year = {2010},
language = {Englisch},
cr-category = {C.2.2 Network Protocols},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2010-17/INPROC-2010-17.pdf,
http://dx.doi.org/10.1109/PERCOMW.2010.5470499},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Geocast protocols can be used to send messages to all receivers in a geographic
target area. In this paper we present geocast routing algorithms for Wireless
Mesh Networks that are tailored to symbolic addressing using symbolic location
names like floor or room numbers. Since in particular indoors no geometric
information is available, our algorithms use symbolic location models to derive
directional information for routing. Moreover, we show how to integrate
geometric and symbolic geographic routing algorithms into a hybrid routing
approach which is applicable to larger areas consisting of symbolically and
geometrically defined locations.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2010-17&engl=0}
}
@inproceedings {INPROC-2010-16,
author = {Harald Weinschrott and Frank D{\"u}rr and Kurt Rothermel},
title = {{Symbolic Routing for Location-based Services in Wireless Mesh Networks}},
booktitle = {Proceedings of the IEEE 24nd International Conference on Advanced Information Networking and Applications},
publisher = {IEEE Computer Society},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
pages = {1--8},
type = {Konferenz-Beitrag},
month = {April},
year = {2010},
language = {Englisch},
cr-category = {C.2.2 Network Protocols},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2010-16/INPROC-2010-16.pdf,
http://dx.doi.org/10.1109/AINA.2010.71},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Wireless Mesh Networks are cost-efficient medium-scale networks that have the
potential to serve as an infrastructure for advanced location-based services.
As a basis for these services we present a routing algorithm that allows to
address intuitive symbolic coordinates. This algorithm is based on a
proactively maintained geographic routing structure that mimics the structure
of a symbolic location model. Message forwarding is done greedily along short
paths defined by a symbolic location model and if this fails, through an
hierarchical overlay network built by selected mesh routers. We show how a
geocast communication mechanism that allows to send messages to all hosts
within a specific location can be implemented with this routing algorithm. In
extensive evaluations we show that a low proactive routing overhead allows to
achieve high message delivery rates even in case of mobility. Moreover, we show
that the paths achieved are only 25\% longer than the theoretic optimal paths
for a wide range of simulation settings.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2010-16&engl=0}
}
@inproceedings {INPROC-2010-15,
author = {Ralph Lange and Frank D{\"u}rr and Kurt Rothermel},
title = {{Efficient Tracking of Moving Objects using Generic Remote Trajectory Simplification (Demo Paper)}},
booktitle = {Proceedings of the 8th IEEE International Conference on Pervasive Computing and Communications Workshops (PerCom Workshops '10). Mannheim, Germany. March 2010},
publisher = {IEEE Computer Society},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
pages = {829--831},
type = {Workshop-Beitrag},
month = {M{\"a}rz},
year = {2010},
keywords = {Remote trajectory simplification; tracking; dead reckoning; moving objects database; MOD; line simplification},
language = {Englisch},
cr-category = {H.2.8 Database Applications},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2010-15/INPROC-2010-15.pdf,
http://dx.doi.org/10.1109/PERCOMW.2010.5470553},
contact = {ralph.lange@ipvs.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Position information of moving objects plays a vital role in many pervasive
applications. Therefore, moving objects databases (MODs), which can manage
trajectory data of a number objects, are used in many pervasive systems. A
crucial problem with MODs is how to efficiently track a remote object's
trajectory in real-time, i.e. how to continuously report the sensed trajectory
data to the MOD with minimal effort. For this purpose, we present a
prototypical implementation of the Generic Remote Trajectory Simplification
(GRTS) protocol, which optimizes storage consumption, processing, and
communication costs. Our prototypical system includes a fully functional MOD as
well as map-based mobile applications for subnotebooks and smartphones to
illustrate the functioning of GRTS.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2010-15&engl=0}
}
@inproceedings {INPROC-2010-118,
author = {Frank D{\"u}rr and Marius Wernke and Pavel Skvortsov and Kurt Rothermel},
title = {{Towards a Position Sharing Approach for Location-based Services}},
booktitle = {Proceedings of the W3C Workshop on Privacy for Advanced Web APIs},
publisher = {Online},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {1--3},
type = {Workshop-Beitrag},
month = {Juli},
year = {2010},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems,
H.3.5 Online Information Services},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2010-118/INPROC-2010-118.pdf,
http://www.w3.org/2010/api-privacy-ws/papers/privacy-ws-16.pdf,
http://www.priloc.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {In partially-trusted system environments like the WWW, the management of
private user positions is a great challenge. On the one hand, location-based
services of different partially-trusted providers have to be provided with
position information. On the other hand, location servers, which are
responsible for the management of user positions, might as well be operated by
only partially-trusted providers. Therefore, in order to protect his privacy, a
user might only want to store position information of limited precision on
location servers, and also provide location-based services with position
information of limited precision.
In this position paper, we sketch a novel position sharing approach that
enables the user to tightly control the precision of position information
stored on servers and provided to location-based services. This approach is
based on the idea of distributing position information among a set of servers
of different providers such that a compromised server only reveals information
of strictly limited precision.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2010-118&engl=0}
}
@inproceedings {INPROC-2010-116,
author = {Faraz Memon and Daniel Tiebler and Frank D{\"u}rr and Kurt Rothermel},
title = {{Optimized Information Discovery using Self-adapting Indices over Distributed Hash Tables}},
booktitle = {Proceedings of 29th International Performance Computing and Communications Conference (IPCCC'10)},
address = {Albuquerque, New Mexico, USA},
publisher = {IEEE},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {1--9},
type = {Konferenz-Beitrag},
month = {Dezember},
year = {2010},
language = {Englisch},
cr-category = {C.2.1 Network Architecture and Design,
E.1 Data Structures,
E.2 Data Storage Representations,
H.3.1 Content Analysis and Indexing},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2010-116/INPROC-2010-116.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Distributed Hash Table (DHT)-based peer-to-peer information discovery systems
have emerged as highly scalable systems for information storage and discovery
in massively distributed networks. Originally DHTs supported only point
queries. However, recently they have been extended to support more complex
queries, such as multi-attribute range (MAR) queries. Generally, the support
for MAR queries over DHTs has been provided either by creating an individual
index for each data attribute or by creating a single index using the
combination of all data attributes. In contrast to these approaches, we propose
to create and modify indices using the attribute combinations that dynamically
appear in MAR queries in the system.
In this paper, we present an adaptive information discovery system that adapts
the set of indices according to the dynamic set of MAR queries in the system.
The main contribution of this paper is a four-phase scalable index adaptation
process. Our evaluations show that the adaptive information discovery system
continuously optimizes the overall system performance for MAR queries.
Moreover, compared to a non-adaptive system, the adaptive information discovery
system shows several orders of magnitude improved performance.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2010-116&engl=0}
}
@inproceedings {INPROC-2010-06,
author = {Stephan Schuhmann and Klaus Herrmann and Kurt Rothermel},
title = {{Efficient Resource-Aware Hybrid Configuration of Distributed Pervasive Applications}},
booktitle = {Proceedings of the 8th International Conference on Pervasive Computing (Pervasive 2010); Helsinki, Finland, May 17-20, 2010},
publisher = {Springer-Verlag},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
series = {Lecture Notes in Computer Science},
volume = {6030},
pages = {373--390},
type = {Konferenz-Beitrag},
month = {Mai},
year = {2010},
keywords = {Adaptivity; Components; Distributed Application Configuration; Heterogeneous Environments; Middleware; Pervasive Applications},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2010-06/INPROC-2010-06.pdf,
http://www.springerlink.com/content/x6607vl0w9753683/},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {As the size and complexity of Pervasive Computing environments increases,
configuration and adaptation of distributed applications gains importance.
These tasks require automated system support, since users must not be
distracted by the (re-)composition of applications. In homogeneous ad hoc
scenarios, relying on decentralized configuration schemes is obviously
mandatory, while centralized approaches may help to reduce latencies in weakly
heterogeneous infrastructure-based environments. However, in case of strongly
heterogeneous pervasive environments including several resource-rich and
resource-weak devices, both approaches may lead to suboptimal results
concerning configuration latencies: While the resource-weak devices represent
bottlenecks for decentralized configuration, the centralized approach faces the
problem of not utilizing parallelism. Instead, a hybrid approach that involves
only the subset of resource-rich devices is capable of rendering configuration
and adaptation processes more efficiently. In this paper, we present such a
resource-aware hybrid scheme that effectively reduces the time required for
configuration processes. This is accomplished by a balanced-load clustering
scheme that exploits the computational power of resource-rich devices, while
avoiding bottlenecks in (re-)configurations. We present real-world evaluations
which confirm that our approach reduces configuration latencies in
heterogeneous environments by more than 30 \% compared to totally centralized
and totally decentralized approaches. This is an important step towards
seamless application configuration.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2010-06&engl=0}
}
@inproceedings {INPROC-2009-86,
author = {Matthias Grossmann and Nicola H{\"o}nle and Carlos L{\"u}bbe and Harald Weinschrott},
title = {{An Abstract Processing Model for the Quality of Context Data}},
booktitle = {Proceedings of the 1st International Workshop on Quality of Context},
publisher = {Springer},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
pages = {132--143},
type = {Workshop-Beitrag},
month = {Juni},
year = {2009},
keywords = {uncertainty; inconsistency; trust; processing model},
language = {Englisch},
cr-category = {H.2.8 Database Applications},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2009-86/INPROC-2009-86.pdf,
http://dx.doi.org/10.1007/978-3-642-04559-2_12},
contact = {Matthias.Grossmann@ipvs.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme;
Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Anwendersoftware},
abstract = {Data quality can be relevant to many applications. Especially applications
coping with sensor data cannot take a single sensor value for granted. Because
of technical and physical restrictions each sensor reading is associated with
an uncertainty. To improve quality, an application can combine data values from
different sensors or, more generally, data providers. But as different data
providers may have diverse opinions about a certain real world phenomenon,
another issue arises: inconsistency. When handling data from different data
providers, the application needs to consider their trustworthiness. This
naturally introduces a third aspect of quality: trust. In this paper we propose
a novel processing model integrating the three aspects of quality: uncertainty,
inconsistency and trust.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2009-86&engl=0}
}
@inproceedings {INPROC-2009-79,
author = {Hannes Wolf and Klaus Herrmann and Kurt Rothermel},
title = {{Modeling Dynamic Context Awareness for Situated Workflows}},
booktitle = {OTM 2009 Workshops},
editor = {R Meersman and P Herrero and T Dillon},
address = {Berlin, Heidelberg},
publisher = {Springer Verlag},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
series = {Lecture Notes in Computer Science},
volume = {5872},
pages = {98--107},
type = {Workshop-Beitrag},
month = {November},
year = {2009},
language = {Deutsch},
cr-category = {H.4.1 Office Automation,
H.3.3 Information Search and Retrieval},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2009-79/INPROC-2009-79.pdf,
http://www.springerlink.com/content/r6783472331327u4},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {A major challenge for pervasive computing is to support continuous adaptation
of applications to the behavior of the user. Recent research has adopted
classical workflows as alternative programming paradigm for pervasive
applications and approaches for context aware workflow models have been
presented. However the current approaches suffer from the low flexibility of
classical workflow models. We present a solution that allows attaching
workflows to real-world objects and defining relevant context dynamically in
relation to those objects. The benefits are a dynamic, yet simple modeling of
context constraints and events in pervasive workflows and a greatly reduced
amount of context information that must be provided to the workflow.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2009-79&engl=0}
}
@inproceedings {INPROC-2009-71,
author = {Davide Frey and Rachid Guerraoui and Anne-Marie Kermarrec and Boris Koldehofe and Martin Mogensen and Maxime Monod and Vivien Qu{\'e}ma},
title = {{Heterogeneous Gossip}},
booktitle = {Proceedings of the 10th ACM/IFIP/USENIX International Conference on Middleware},
publisher = {Springer},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {42--61},
type = {Konferenz-Beitrag},
month = {November},
year = {2009},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
ee = {http://delivery.acm.org/10.1145/1660000/1656984/a3-frey.pdf?key1=1656984&key2=2295269621&coll=GUIDE&dl=ACM&CFID=83635975&CFTOKEN=34871073},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Gossip-based information dissemination protocols are considered easy to deploy,
scalable and resilient to network dynamics. Load-balancing is inherent in these
protocols as the dissemination work is evenly spread among all nodes. Yet,
large-scale distributed systems are usually heterogeneous with respect to
network capabilities such as bandwidth. In practice, a blind load-balancing
strategy might significantly hamper the performance of the gossip
dissemination. This paper presents HEAP, HEterogeneity-Aware gossip Protocol,
where nodes dynamically adapt their contribution to the gossip dissemination
according to their bandwidth capabilities. Using a continuous, itself
gossip-based, approximation of relative bandwidth capabilities, HEAP
dynamically leverages the most capable nodes by increasing their fanout, while
decreasing by the same proportion that of less capable nodes. HEAP preserves
the simple and proactive (churn adaptation) nature of gossip, while
significantly improving its effectiveness. We extensively evaluate HEAP in the
context of a video streaming application on a testbed of 270 PlanetLab nodes.
Our results show that HEAP significantly improves the quality of the streaming
over standard homogeneous gossip protocols, especially when the stream rate is
close to the average available bandwidth.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2009-71&engl=0}
}
@inproceedings {INPROC-2009-66,
author = {Lars Geiger and Ronald Schertle and Frank D{\"u}rr and Kurt Rothermel},
title = {{Temporal Addressing for Mobile Context-Aware Communication}},
booktitle = {Proceedings of the Sixth Annual International Conference on Mobile and Ubiquitous Systems: Computing, Networking and Services (MobiQuitous '09), Toronto, ON, Canada, July 13-16, 2009},
publisher = {ICST},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
pages = {1--10},
type = {Konferenz-Beitrag},
month = {Juni},
year = {2009},
language = {Englisch},
cr-category = {C.2.1 Network Architecture and Design,
C.2.2 Network Protocols,
C.2.4 Distributed Systems,
C.2.6 Internetworking},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2009-66/INPROC-2009-66.pdf,
http://www.ieeexplore.ieee.org/xpls/abs_all.jsp?arnumber=5326393},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Mobile clients in context-aware systems benefit from the indirect addressing of
users via their context (contextcast), such as addressing messages to all users
in downtown Toronto whose age is below 35. There is, however, almost no support
for a temporal decoupling in such a contextcast system, i.e., the addressing of
users that were or will be in a certain context in the past or future,
respectively. This could for instance be used to distribute the minutes of a
meeting to all people who attended the meeting in room 1.138, 3 days ago,
between 1 and 3 pm.
To enable a context-aware communication system to address messages with
temporal relations, especially those contexts in the past, the system needs to
manage information about user context histories. This poses the risk that the
system can be abused to profile users, which would most probably hinder
acceptance. Therefore, privacy aspects need to be considered in the core design
of such a system. We present an extension to our earlier work, which allows a
temporal decoupling of messages and users and requires very little additional
overhead to manage historic context information. The solution includes
mechanisms to efficiently disseminate messages to both users with past and
future contexts, while effectively preventing user profiling through the use of
virtual identities.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2009-66&engl=0}
}
@inproceedings {INPROC-2009-51,
author = {Ralph Lange and Harald Weinschrott and Lars Geiger and Andre Blessing and Frank D{\"u}rr and Kurt Rothermel and Hinrich Sch{\"u}tze},
title = {{On a Generic Uncertainty Model for Position Information}},
booktitle = {Proceedings of the 1st International Workshop on Quality of Context},
publisher = {Springer},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
pages = {1--12},
type = {Workshop-Beitrag},
month = {Juni},
year = {2009},
keywords = {data uncertainty; position information; position accuracy; spatial queries},
language = {Englisch},
cr-category = {H.2.8 Database Applications},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2009-51/INPROC-2009-51.pdf,
http://www.springerlink.com/content/85450711831008k0/},
contact = {ralph.lange@ipvs.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Maschinelle Sprachverarbeitung;
Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Position information of moving as well as stationary objects is generally
subject to uncertainties due to inherent measuring errors of positioning
technologies, explicit tolerances of position update protocols, and
approximations by interpolation algorithms. There exist a variety of approaches
for specifying these uncertainties by mathematical uncertainty models such as
tolerance regions or the Dilution of Precision (DOP) values of GPS. In this
paper we propose a principled generic uncertainty model that integrates the
different approaches and derive a comprehensive query interface for processing
spatial queries on uncertain position information of different sources based on
this model. Finally, we show how to implement our approach with prevalent
existing uncertainty models.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2009-51&engl=0}
}
@inproceedings {INPROC-2009-48,
author = {Hanna Eberle and Stefan F{\"o}ll and Klaus Herrmann and Frank Leymann and Annapaola Marconi and Tobias Unger and Hannes Wolf},
title = {{Enforcement from the Inside: Improving Quality of Business in Process Management}},
booktitle = {2009 IEEE International Conference on Web Services (ICWS 2009)},
address = {Los Alamitos, CA, USA},
publisher = {IEEE Computer Society},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {405--412},
type = {Konferenz-Beitrag},
month = {Juli},
year = {2009},
doi = {10.1109/ICWS.2009.82},
isbn = {978-0-7695-3709-2},
keywords = {Business Process Management; BPM; BPEL; Enforcement},
language = {Englisch},
cr-category = {H.4.1 Office Automation},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2009-48/INPROC-2009-48.pdf,
http://ieeexplore.ieee.org/search/wrapper.jsp?arnumber=5175850,
http://www2.computer.org/portal/web/csdl/doi/10.1109/ICWS.2009.82},
contact = {unger@iaas.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Architektur von Anwendungssystemen;
Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {In this paper we introduce a new modeling tool for constraint handling in the
area of workflow technology. The constraint handlers can be used to improve the
quality of business processes but without changing already existing business
logic. Todays workflow languages provide no possibility to model constraints
and the actions in case the constraints get violated explicitly. Fault and
event handling mechanisms to react to events not expected in normal executions
are only provided by the BPEL language. Using BPEL as workflow language we
integrate the constraint handling extension without changing any existing
semantics in a smart way. In our approach we use this fault and event handling
mechanisms to extend the BPEL language with a constraint handling mechanism. By
integrating this constraint handling tool into the BPEL language we provide an
approach for quality driven process modeling with the BPEL language.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2009-48&engl=0}
}
@inproceedings {INPROC-2009-44,
author = {Andreas Grau and Klaus Herrmann and Kurt Rothermel},
title = {{Efficient and Scalable Network Emulation using Adaptive Virtual Time}},
booktitle = {Proceedings of the 18th International Conference on Computer Communications and Networks (ICCCN 2009)},
publisher = {IEEE Communications Society},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {1--6},
type = {Konferenz-Beitrag},
month = {August},
year = {2009},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2009-44/INPROC-2009-44.pdf,
http://dx.doi.org/10.1109/ICCCN.2009.5235306},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Performance analysis and functionality testing are major parts of developing
distributed software systems. Since the number of communicating software
instances heavily influences the behavior of distributed applications and
communication protocols, evaluation scenarios have to consider a large number
of nodes. Network emulation provides an infrastructure for running these
experiments using real prototype implementations in a controllable and
realistic environment. Large-scale experiments, however, have a high resource
consumption which often exceeds available physical testbed resources. Time
dilation allows for reducing the resource demands of a scenario at the expense
of the experiment's runtime. However, current approaches only consider a
constant time dilation factor, which wastes a lot of resources in case of
scenarios with varying load.
We propose a framework for adaptive time virtualization that significantly
reduces the runtime of experiments by improving resource utilization in network
emulation testbeds. In this framework, resource demands are monitored and the
time dilation factor is dynamically adapted to the required level. Our
evaluation shows that adaptive virtual time in combination with our lightweight
node virtualization architecture allows us to increase the possible scenario
sizes by more than an order of magnitude and, at the same time, ensure unbiased
emulation results. This represents an important contribution to making network
emulation systems highly scalable.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2009-44&engl=0}
}
@inproceedings {INPROC-2009-42,
author = {Faraz Memon and Daniel Tiebler and Frank D{\"u}rr and Kurt Rothermel and Marco Tomsu and Peter Domschitz},
title = {{Scalable Spatial Information Discovery over Distributed Hash Tables}},
booktitle = {Procs. of 4th International Conference on COMmunication System softWAre and middlewaRE (COMSWARE'09), Dublin, Ireland, June 2009. ACM.},
publisher = {ACM},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {1--12},
type = {Konferenz-Beitrag},
month = {Juni},
year = {2009},
language = {Englisch},
cr-category = {C.2.1 Network Architecture and Design,
H.3.3 Information Search and Retrieval},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2009-42/INPROC-2009-42.pdf,
http://doi.acm.org/10.1145/1621890.1621892},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {In this paper, we present a Peer-to-Peer (P2P) spatial information discovery
system that enables spatial range queries over Distributed Hash Tables (DHTs).
Our system utilizes a less-distorting octahedral map projection in contrast to
the quadrilateral projections used by majority of the previously proposed
systems, to represent the spatial information. We also introduce a
Space-Filling Curve (SFC)-based data placement strategy that reduces the
probability of data hot-spots in the network. Moreover, we show that our system
achieves scalable resolution of location-based range queries by utilizing a
tree-based query optimization algorithm. Compared to the basic query resolution
algorithm, the query optimization algorithm reduces the average number of
parallel messages used to resolve a query, by a factor of 96\%.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2009-42&engl=0}
}
@inproceedings {INPROC-2009-36,
author = {S{\'e}rgio Alves and Boris Koldehofe and Hugo Miranda and Francois Taiani},
title = {{Design of a Backup Network for Catastrophe Scenarios}},
booktitle = {Proceedings of the ACM International Workshop on Advanced Topics in Mobile Computing for Emergency Management: Communication and Computing Platforms (MCEM)},
publisher = {ACM Press},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
pages = {613--617},
type = {Workshop-Beitrag},
month = {Juni},
year = {2009},
doi = {10.1145/1582379.1582512},
language = {Englisch},
cr-category = {C.2.1 Network Architecture and Design,
C.2.4 Distributed Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {Communication networks play a fundamental role in the response to a massive
catastrophe, like an earthquake or a large-scale terrorist attack to a major
urban area. In such situations, command centres must be able to rely on a fully
operational communication network, for example to learn about on-going
situations and allocate and guide the rescue teams. Communication is
bidirectional: once in the field, these teams will feed the command centre with
a more accurate view of the situation, contributing to the efficient allocation
of the resources. Failures in this network, even if localised to some of the
regions affected by the catastrophe, can have costs both monetary and in human
lives. In this position paper, we propose the creation of a redundant,
best-effort, emergency communication network that could serve to mitigate
localised failures using off-the-shelf widespread technology. We give an
overview of an architecture for a backup network, highlight the possible
advantage of such an architecture to disaster management and discuss challenges
that need to be overcome in realizing it.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2009-36&engl=0}
}
@inproceedings {INPROC-2009-32,
author = {Lars Geiger and Frank D{\"u}rr and Kurt Rothermel},
title = {{On Contextcast: A Context-aware Communication Mechanism}},
booktitle = {IEEE International Conference on Communications, 2009. ICC '09.},
publisher = {IEEE Communications Society},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
pages = {1--6},
type = {Konferenz-Beitrag},
month = {Juni},
year = {2009},
language = {Englisch},
cr-category = {C.2.1 Network Architecture and Design,
C.2.2 Network Protocols,
C.2.4 Distributed Systems,
C.2.6 Internetworking},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2009-32/INPROC-2009-32.pdf,
http://dx.doi.org/10.1109/ICC.2009.5199239},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {The dissemination of messages according to clients' contexts (i.e., location
and other attributes) opens up new possibilities in context-aware systems.
While geocast or content-based publish/subscribe forward messages according to
client location or attributes, respectively, neither uses a combination of the
two. In this paper, we present this new communication paradigm and the
challenges it poses. We also extend concepts from publish/subscribe networks to
efficiently deal with highly dynamic user location to lower update rates by
approximating the user's location. This reduces update rates by between 25\% and
90\%, depending on the granularity of the approximation.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2009-32&engl=0}
}
@inproceedings {INPROC-2009-24,
author = {Harald Weinschrott and Frank D{\"u}rr and Kurt Rothermel},
title = {{Efficient Capturing of Environmental Data with Mobile RFID Readers}},
booktitle = {Proceedings of the 10th International Conference on Mobile Data Management (MDM'09); Taipei, Taiwan, Mai 18-20, 2009},
address = {Taipei, Taiwan},
publisher = {IEEE Computer Society Conference Publishing Services},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
pages = {1--10},
type = {Konferenz-Beitrag},
month = {Mai},
year = {2009},
keywords = {ad-hoc; mobile; RFID-sensor; urban sensing},
language = {Englisch},
cr-category = {C.2 Computer-Communication Networks},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2009-24/INPROC-2009-24.pdf,
http://doi.ieeecomputersociety.org/10.1109/MDM.2009.15,
http://www.comnsense.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {In this paper we introduce a novel scenario for environmental sensing based on
the combination of simple and cheap RFID-based sensors and mobile devices like
mobile phones with integrated RFID readers. We envision a system, where the
mobile nodes cooperatively read sensors installed in the environment as they
pass by and transmit the data to a server infrastructure. To achieve quality
requirements on the one hand, and on the other hand efficiency in terms of
communication cost and energy consumption, this paper presents several
algorithms for coordinating update operations. Mobile nodes form an ad-hoc
network for the cooperative management of requested update times to meet the
desired update interval and to avoid redundant sensor reading and collisions
during read operations. Besides this decentralized coordination algorithm, we
also show a complementary algorithm that exploits infrastructure based
coordination. By extensive simulations we show that our algorithms achieve a
high quality of sensor updates where nearly 100\% of the possible updates are
performed. Moreover, the algorithms achieve a very high energy efficiency
allowing for several hundred hours of operation assuming a typical battery of a
mobile phone.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2009-24&engl=0}
}
@inproceedings {INPROC-2009-141,
author = {Andreas Grau and Klaus Herrmann and Kurt Rothermel},
title = {{Exploiting Emulation Testbeds for Security Experiments}},
booktitle = {Proceedings of the Workshop on Experimental platforms for Internet resilience, security and stability research (invited paper)},
address = {Br{\"u}ssel},
publisher = {JRC European Commission},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {1--2},
type = {Workshop-Beitrag},
month = {Juni},
year = {2009},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2009-141/INPROC-2009-141.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Security, resilience and stability test are an important step to protect the
information and communication-based digital society. Experimental platforms
allow researchers to evaluate todays and tomorrows internet architectures,
protocols and applications. However, selecting the most adequate platform is
difficult. In this paper we first present a common used approach based on real
world testbeds. We identify a couple of problem coming around with this
approach and show how emulation-based testbeds can avoids them. Finally we
present an hybrid approach to combine the benefits of both systems to provide a
scalable, repeatable, controllable, flexible and secure experimental platform.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2009-141&engl=0}
}
@inproceedings {INPROC-2009-07,
author = {Ralph Lange and Nazario Cipriani and Lars Geiger and Matthias Gro{\ss}mann and Harald Weinschrott and Andreas Brodt and Matthias Wieland and Stamatia Rizou and Kurt Rothermel},
title = {{Making the World Wide Space Happen: New Challenges for the Nexus Context Platform}},
booktitle = {Proceedings of the 7th Annual IEEE International Conference on Pervasive Computing and Communications (PerCom '09). Galveston, TX, USA. March 2009},
publisher = {IEEE Computer Society},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
pages = {1--4},
type = {Konferenz-Beitrag},
month = {M{\"a}rz},
year = {2009},
keywords = {Nexus; context; mobile context-aware applications; context-awareness; context management; World Wide Space; stream-processing; situation recognition; reasoning; workflows; quality of context},
language = {Englisch},
cr-category = {H.2.8 Database Applications,
H.3.4 Information Storage and Retrieval Systems and Software,
H.3.5 Online Information Services},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2009-07/INPROC-2009-07.pdf,
http://www.nexus.uni-stuttgart.de/,
http://dx.doi.org/10.1109/PERCOM.2009.4912782},
contact = {ralph.lange@ipvs.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme;
Universit{\"a}t Stuttgart, Institut f{\"u}r Architektur von Anwendungssystemen;
Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Anwendersoftware},
abstract = {Context-aware applications rely on models of the physical world. Within the
Nexus project, we envision a World Wide Space which provides the conceptual and
technological framework for integrating and sharing such context models in an
open, global platform of context providers. In our ongoing research we tackle
important challenges in such a platform including distributed processing of
streamed context data, situation recognition by distributed reasoning,
efficient management of context data histories, and quality of context
information. In this paper we discuss our approach to cope with these
challenges and present an extended Nexus architecture.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2009-07&engl=0}
}
@inproceedings {INPROC-2009-06,
author = {Ralph Lange and Tobias Farrell and Frank D{\"u}rr and Kurt Rothermel},
title = {{Remote Real-Time Trajectory Simplification}},
booktitle = {Proceedings of the 7th Annual IEEE International Conference on Pervasive Computing and Communications (PerCom '09). Galveston, TX, USA. March 2009},
publisher = {IEEE Computer Society},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
pages = {1--10},
type = {Konferenz-Beitrag},
month = {M{\"a}rz},
year = {2009},
keywords = {Remote trajectory simplification; tracking; dead reckoning; moving objects database; MOD; line simplification},
language = {Englisch},
cr-category = {H.2.8 Database Applications},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2009-06/INPROC-2009-06.pdf,
http://dx.doi.org/10.1109/PERCOM.2009.4912767},
contact = {ralph.lange@ipvs.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Moving objects databases (MODs) have been proposed for managing trajectory
data, an important kind of information for pervasive applications. To save
storage capacity, a MOD generally stores simplified trajectories only. A
simplified trajectory approximates the actual trajectory of the mobile object
according to a certain accuracy bound. In order to minimize the costs of
communicating position information between mobile object and MOD, the
trajectory simplification should be performed by the mobile object. To assure
that the MOD always has a valid simplified trajectory of the remote object, we
propose the generic remote trajectory simplification protocol (GRTS) allowing
for computing and managing a simplified trajectory in such a system in
real-time. We show how to combine GRTS with existing line simplification
algorithms for computing the simplified trajectory and analyze trade-offs
between the different algorithms. Our evaluations show that GRTS outperforms
the two existing approaches by a factor of two and more in terms of reduction
efficiency. Moreover, on average, the reduction efficiency of GRTS is only 12\%
worse compared to optimal offline simplification.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2009-06&engl=0}
}
@inproceedings {INPROC-2009-04,
author = {Andreas Benzing and Klaus Herrmann and Boris Koldehofe and Kurt Rothermel},
title = {{Identifying the Challenges in Reducing Latency in GSN using Predictors}},
booktitle = {Workshops der Wissenschaftlichen Konferenz Kommunikation in Verteilten Systemen 2009 (WowKiVS 2009)},
editor = {Tiziana Margaria and Julia Padberg and Gabriele Taentzer},
address = {Kassel},
publisher = {EASST},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
series = {Electronic Communications of the EASST},
volume = {17},
pages = {1--6},
type = {Workshop-Beitrag},
month = {M{\"a}rz},
year = {2009},
issn = {1863-2122},
keywords = {Global Sensor Networks, Wireless Sensor Networks, Predictors},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2009-04/INPROC-2009-04.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Simulations based on real-time data continuously gathered from sensor networks
all over the world have received growing attention due to the increasing
availability of measured data. Furthermore, predictive techniques have been
employed in the realm of such networks to reduce communication for
energy-efficiency. However, research has focused on the high amounts of data
transferred rather than latency requirements posed by the applications. We
propose using predictors to supply data with low latency as required for
accurate simulations. This paper investigates requirements for a successful
combination of these concepts and discusses challenges that arise.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2009-04&engl=0}
}
@inproceedings {INPROC-2009-03,
author = {Adnan Tariq and Boris Koldehofe and Gerald Koch and Kurt Rothermel},
title = {{Providing Probabilistic Latency Bounds for Dynamic Publish/Subscribe Systems}},
booktitle = {Proceedings of the 16th ITG/GI Conference on Kommunikation in Verteilten Systemen 2009 (KiVS 2009)},
address = {Kassel, Germany},
publisher = {Springer},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
type = {Konferenz-Beitrag},
month = {Januar},
year = {2009},
doi = {10.1007/978-3-540-92666-5_13},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2009-03/INPROC-2009-03.pdf,
http://dx.doi.org/10.1007/978-3-540-92666-5_13},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {In the context of large decentralized many-to-many communication systems it is
impractical to provide realistic and hard bounds for certain QoS metrics
including latency bounds. Nevertheless, many applications can yield better
performance if such bounds hold with a given probability. In this paper we show
how probabilistic latency bounds can be applied in the context of
publish/subscribe. We present an algorithm for maintaining individual
probabilistic latency bounds in a highly dynamic environment for a large number
of subscribers. The algorithm consists of an adaptive dissemination algorithm
as well as a cluster partitioning scheme. Together they ensure i) adaptation to
the individual latency requirements of subscribers under dynamically changing
system properties, and ii) scalability by determining appropriate clusters
according to available publishers in the system.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2009-03&engl=0}
}
@inproceedings {INPROC-2008-98,
author = {Jos{\'e} Mocito and Briones-Garc{\'\i}a J. Alfonso and Boris Koldehofe and Hugo Miranda and Lu{\'\i}s Rodrigues},
title = {{Geographical distribution of subscriptions for Content-based Publish/Subscribe in MANETs}},
booktitle = {Proceedings of the Middleware'08 Companion},
address = {Leuven, Belgium},
publisher = {ACM},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
type = {Konferenz-Beitrag},
month = {Dezember},
year = {2008},
language = {Englisch},
cr-category = {C.2 Computer-Communication Networks},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Establishing content-based publish/subscribe in the resource constrained and
failure prone environment of Mobile Ad-Hoc Networks (MANETs) is a highly
challenging task. Movement of nodes and network partitioning can require
frequent and possibly expensive reorganizations of the publish/subscribe
system. Many approaches towards publish/subscribe in MANETs either rely
explicitly on location information, or are characterized by a high subscription
and publication overhead. In this paper we present preliminary research on how
geographical distribution of subscriptions may help to overcome some
shortcomings of both approaches.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2008-98&engl=0}
}
@inproceedings {INPROC-2008-90,
author = {Stephan Schuhmann and Lars V{\"o}lker},
title = {{Combining Passive Autoconfiguration and Anomaly-based Intrusion Detection in Ad-hoc Networks}},
booktitle = {Proceedings of the 8th International Workshop on Applications and Services in Wireless Networks (ASWN 2008); Kassel, Germany, October 9-10, 2008},
publisher = {IEEE},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {87--95},
type = {Workshop-Beitrag},
month = {Oktober},
year = {2008},
keywords = {MANET; Intrusion Detection; Anomalies; OLSR},
language = {Englisch},
cr-category = {C.2.0 Computer-Communication Networks, General,
C.2.2 Network Protocols},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2008-90/INPROC-2008-90.pdf,
http://dx.doi.org/10.1109/ASWN.2008.14},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Two essential services of Ad-hoc networks are IP address autoconfiguration and
intrusion detection systems. Since both autoconfiguration and intrusion
detection may base their decisions on routing protocol anomalies, their
interdependencies can cause problems. In this paper, we present our approach to
efficiently combine autoconfiguration and intrusion detection, and present our
enhancements in attack detection for an autoconfiguration system. We have
identified anomalies indicating specific attacks, implemented suitable anomaly
detectors, and evaluated our system. The results show that it is possible to
detect both the attacks and IP address conflicts in an efficient way.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2008-90&engl=0}
}
@inproceedings {INPROC-2008-84,
author = {Ralph Lange and Frank D{\"u}rr and Kurt Rothermel},
title = {{Scalable Processing of Trajectory-Based Queries in Space-Partitioned Moving Objects Databases}},
booktitle = {Proceedings of the 16th ACM SIGSPATIAL International Conference on Advances in Geographic Information Systems (ACM GIS 2008)},
address = {Irvine, CA, USA},
publisher = {ACM},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
pages = {1--10},
type = {Konferenz-Beitrag},
month = {November},
year = {2008},
keywords = {spatio-temporal indexing; moving objects database; MOD; trajectory-based query; distributed query processing},
language = {Englisch},
cr-category = {H.2.8 Database Applications},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2008-84/INPROC-2008-84.pdf,
http://doi.acm.org/10.1145/1463434.1463474},
contact = {ralph.lange@ipvs.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Space-partitioned Moving Objects Databases (SP-MODs) allow for the scalable,
distributed management of large sets of mobile objects' trajectories by
partitioning the trajectory data to a network of database servers. Processing a
spatio-temporal query q therefore requires efficiently routing q to the servers
storing the affected trajectory segments. With a coordinate-based query - like
a spatio-temporal range query - the relevant servers are directly determined by
the queried range. However, with trajectory-based queries - like retrieving the
distance covered by a certain object during a given time interval - the
relevant servers depend on actual movement of the queried object. Therefore,
efficient routing mechanisms for trajectory-based queries are an important
challenge in SP-MODs. In this paper, we present the Distributed Trajectory
Index (DTI) that allows for such efficient query routing by creating an overlay
network for each trajectory. We further present an enhanced index called DTI+S.
It accelerates the processing of queries on aggregates of dynamic attributes,
like the maximum speed during a time interval, by augmenting DTI with summaries
of trajectory segments. Our simulations with a network of 1000 database servers
show that DTI+S can reduce the overall processing time by more than 98\%.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2008-84&engl=0}
}
@inproceedings {INPROC-2008-83,
author = {Faraz Memon and Daniel Tiebler and Frank D{\"u}rr and Kurt Rothermel and Marco Tomsu and Peter Domschitz},
title = {{OID: Optimized Information Discovery using Space Filling Curves in P2P Overlay Networks}},
booktitle = {Proceedings of 14th International Conference on Parallel and Distributed Systems (ICPADS'08)},
publisher = {IEEE Computer Society},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {311--319},
type = {Konferenz-Beitrag},
month = {Dezember},
year = {2008},
isbn = {978-0-7695-3434-3},
language = {Englisch},
cr-category = {C.2.2 Network Protocols,
C.2.3 Network Operations,
C.2.4 Distributed Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2008-83/INPROC-2008-83.pdf,
http://dx.doi.org/10.1109/ICPADS.2008.57},
contact = {faraz.memon@ipvs.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {In this paper, we present the system design and evaluation of a Space-Filling
Curve (SFC)-based P2P information discovery system OID. The OID system uses
multiple SFCs to significantly optimize the performance of multi-attribute
range queries, particularly for applications with a large number of data
attributes where a single big SFC-based index is inefficient. The basic idea is
to have multiple SFCbased indices and select the best one to perform a query.
We also introduce two tree-based query optimizations that increase the
scalability of the system.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2008-83&engl=0}
}
@inproceedings {INPROC-2008-70,
author = {Stephan Schuhmann and Klaus Herrmann and Kurt Rothermel},
title = {{A Framework for Adapting the Distribution of Automatic Application Configuration}},
booktitle = {Proceedings of the 2008 ACM International Conference on Pervasive Services (ICPS 2008), Sorrento, Italy, July 6-10, 2008},
publisher = {ACM},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {163--172},
type = {Konferenz-Beitrag},
month = {Juli},
year = {2008},
keywords = {Adaptivity; Components; Middleware; Pervasive Computing; Application Configuration},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems,
D.2.11 Software Engineering Software Architectures},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2008-70/INPROC-2008-70.pdf,
http://doi.acm.org/10.1145/1387269.1387297},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Numerous current research projects deal with the issue of automatic application
configuration in pervasive computing scenarios. While completely distributed
configuration is inevitable in infrastructure-less ad hoc scenarios, many
realistic pervasive application scenarios are located in heterogeneous
environments where additional computation power of resource-rich devices can be
utilized. However, most of the current projects either focus solely on smart
environments which rely on additional infrastructure devices, or they address
ad hoc environments and treat all involved devices as equal. This leads to
suboptimal results in case of present resource-rich devices, as their
additional computation power is not exploited. In this paper, we present a
framework that is based on clustering and allows the efficient and flexible
support of automatic application configuration both in infrastructure-based and
ad hoc environments. This is realized by a new concept called Virtual Container
that enables the local emulation of remote devices’ functionalities and
resources. In our evaluation results, we prove that this concept considerably
reduces configuration delays noticeable by the user.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2008-70&engl=0}
}
@inproceedings {INPROC-2008-69,
author = {Stephan Schuhmann and Klaus Herrmann and Kurt Rothermel and Jan Blumenthal and Dirk Timmermann},
title = {{Improved Weighted Centroid Localization in Smart Ubiquitous Environments}},
booktitle = {Proceedings of the Fifth International Conference on Ubiquitous Intelligence and Computing (UIC 2008), Oslo, Norway, June 23-25, 2008},
publisher = {Springer-Verlag},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
series = {Lecture Notes in Computer Science},
volume = {5061},
pages = {20--34},
type = {Konferenz-Beitrag},
month = {Juni},
year = {2008},
keywords = {Weighted Centroid Localization; WLAN; Ubiquitous Computing},
language = {Englisch},
cr-category = {C.2.1 Network Architecture and Design,
C.2.4 Distributed Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2008-69/INPROC-2008-69.pdf,
http://www.springerlink.com/content/l3l121u67r12445u},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Location-awareness is highly relevant subject in ubiquitous computing, as many
applications exploit location information to provide adequate services or adapt
to a changing physical environment. While GPS provides reliable outdoor
localization, indoor positioning systems present a bigger challenge. Many
indoor localization systems have been proposed. However, most of them rely on
customized hardware or presume some dedicated infrastructure. In this paper, we
focus on WLAN-based localization in smart ubiquitous environments. We propose
an improved scheme of the Weighted Centroid Localization (WCL) algorithm that
is robust and provides higher location accuracy than the original WCL
algorithm. The improvements are based on the use of dynamic weighting factors
that are solely dependent on the correlation of the Received Signal Strength
Indicators of the received beacon signals. Compared to the original WCL scheme,
our approach does not increase requirements to the environment. Real-world
experiments in a typical environment that we report on in this paper confirm
that the increased location accuracy determined in previous calculations is
reproducible in a realistic noisy environment. This provides a simple,
cost-efficient, and battery-conserving, but yet adequate technique for getting
the accurate location information of mobile devices.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2008-69&engl=0}
}
@inproceedings {INPROC-2008-68,
author = {Saukh Olga and Robert Sauter and Matthias Gauger and Pedro Jos{\'e} Marr{\'o}n and Kurt Rothermel},
title = {{On Boundary Recognition without Location Information in Wireless Sensor Networks}},
booktitle = {Proceedings of the 2008 International Conference on Information Processing in Sensor Networks (IPSN 2008)},
address = {Washington, DC, USA},
publisher = {IEEE Computer Society},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {207--218},
type = {Konferenz-Beitrag},
month = {April},
year = {2008},
isbn = {978-0-7695-3157-1},
doi = {http://dx.doi.org/10.1109/IPSN.2008.11},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2008-68&engl=0}
}
@inproceedings {INPROC-2008-67,
author = {Matthias Gauger and Olga Saukh and Marcus Handte and Pedro Jos{$\backslash$'e} Marr{$\backslash$'o}n and Andreas Heydlauff and Kurt Rothermel},
title = {{Sensor-based Clustering for Indoor Applications}},
booktitle = {Proceedings of the 5th IEEE Communications Society Conference on Sensor, Mesh and Ad Hoc Communications and Networks (SECON 2008)},
publisher = {IEEE Computer Society Press},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
type = {Konferenz-Beitrag},
month = {Juni},
year = {2008},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
contact = {gauger@cs.uni-bonn.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2008-67&engl=0}
}
@inproceedings {INPROC-2008-39,
author = {Jorge A. Briones and Boris Koldehofe and Kurt Rothermel},
title = {{SPINE: Publish/Subscribe for Wireless Mesh Networks through Self-Managed Intersecting Paths}},
booktitle = {Proceedings of the 8th International Conference on Innovative Internet Community Systems (I2CS 2008); Schoelcher, Martinique, June 16-18, 2008},
address = {Schoelcher, Martinique},
publisher = {online proceedings},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
type = {Konferenz-Beitrag},
month = {Juni},
year = {2008},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2008-39/INPROC-2008-39.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Application deployment on Wireless Mesh Networks (WMNs) is a challenging issue.
First it requires communication abstractions that allow for interoperation with
Internet applications and second the offered solution should be sensitive to
the available resources in the underlying network. Loosely coupled
communication abstractions, like publish/subscribe, promote interoperability,
but unfortunately are typically implemented at the application layer without
considering the available resources at the underlay imposing a significant
degradation of application performance in the setting of Wireless Mesh
Networks. In this paper we present SPINE, a content-based publish/subscribe
system, which considers the particular challenges of deploying
application-level services in Wireless Mesh Networks. SPINE is designed to
reduce the overhead which stems from both publications and reconfigurations, to
cope with the inherent capacity limitations on communication links as well as
with mobility of the wireless mesh-clients. We demonstrate the effectiveness of
SPINE by comparison with traditional approaches in implementing content-based
publish/subscribe.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2008-39&engl=0}
}
@inproceedings {INPROC-2008-37,
author = {Ralph Lange and Frank D{\"u}rr and Kurt Rothermel},
title = {{Online Trajectory Data Reduction using Connection-preserving Dead Reckoning}},
booktitle = {Proceedings of the Fifth Annual International Conference on Mobile and Ubiquitous Systems: Computing, Networking and Services: MobiQuitous '08; Dublin, Ireland, July 21-25, 2008},
publisher = {ICST},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
pages = {1--10},
type = {Konferenz-Beitrag},
month = {Juli},
year = {2008},
isbn = {978-963-9799-21-9},
keywords = {Online trajectory reduction; dead reckoning; MOD},
language = {Englisch},
cr-category = {H.2.8 Database Applications},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2008-37/INPROC-2008-37.pdf,
http://portal.acm.org/citation.cfm?id=1595044},
contact = {ralph.lange@ipvs.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Moving objects databases (MODs) store objects’ trajectories by spatiotemporal
polylines that approximate the actual movements given by sequences of sensed
positions. Determining such a polyline with as few vertices as possible under
the constraint that it does not deviate by more than a certain accuracy bound
epsilon from the sensed positions is an algorithmic problem known as trajectory
reduction.
A specific challenge is online trajectory reduction, i.e. continuous reduction
with position sensing in realtime. This particularly is required for moving
objects with embedded position sensors whose movements are tracked and stored
by a remote MOD.
In this paper, we present Connection-preserving Dead Reckoning (CDR), a new
approach for online trajectory reduction. It outperforms the existing
approaches by 30 to 50\%. CDR requires the moving objects to temporally store
some of the previously sensed positions. Although the storage consumption of
CDR generally is small, it is not bounded. We therefore further present CDRM
whose storage allocation and execution time per position fix can be adjusted
and limited. Even with very limited storage allocations of less than 1 kB CDRM
outperforms the existing approach by 20 to 40\%.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2008-37&engl=0}
}
@inproceedings {INPROC-2008-28,
author = {Paolo Costa and Daniela Gavidia and Boris Koldehofe and Hugo Miranda and Mirco Musolesi and Orian Riva},
title = {{When Cars Start Gossiping}},
booktitle = {Proceedings of the ACM EuroSys 2008 Affilated Workshops},
publisher = {ACM Press},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {1--4},
type = {Workshop-Beitrag},
month = {April},
year = {2008},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2008-28&engl=0}
}
@inproceedings {INPROC-2008-15,
author = {Dominique Dudkowski and Harald Weinschrott and Pedro Jos{\'e} Marr{\'o}n},
title = {{Design and Implementation of a Reference Model for Context Management in Mobile Ad-Hoc Networks}},
booktitle = {Proceedings of the International Workshop on Data Management for Wireless and Pervasive Communications (DMWPC2008); Gino-wan, Okinawa, Japan, March, 2008},
publisher = {IEEE},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
pages = {832--837},
type = {Konferenz-Beitrag},
month = {M{\"a}rz},
year = {2008},
keywords = {context; data management; MANET; reference model; hybrid system},
language = {Englisch},
cr-category = {C.2 Computer-Communication Networks},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2008-15/INPROC-2008-15.pdf,
http://www.computer.org/portal/web/csdl/doi/10.1109/WAINA.2008.72},
contact = {harald.weinschrott@ipvs.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {The fundamental paradigm of context-aware computing has lead to a diversity of
conceivable context-based applications. In order to support these applications,
efficient and scalable context management platforms have become utterly
important. In this paper we propose a layered reference model that encapsulates
suitable abstractions to tackle the complexity of context management in mobile
ad-hoc networks. For each layer, we outline strategies and mechanisms we have
developed to manage context information efficiently so that it can readily be
used by context-based services and applications in these networks. In addition,
we discuss refinements of the current model that we currently investigate,
which are related to data semantics such as context quality and expressive
location models, performance enhancement by adaptation, and aspects regarding
the integration of ad-hoc context management with infrastructure-based systems
leading to a hybrid system structure.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2008-15&engl=0}
}
@inproceedings {INPROC-2008-145,
author = {Matthias Gauger and Pedro Jos{\'e} Marr{\'o}n and Marcus Handte and Olga Saukh and Daniel Minder and Andreas Lachenmann and Kurt Rothermel},
title = {{Integrating Sensor Networks in Pervasive Computing Environments Using Symbolic Coordinates}},
booktitle = {Proceedings of the Third International Conference on Communication System Software and Middleware (COMSWARE 2008)},
publisher = {IEEE},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
pages = {1--10},
type = {Konferenz-Beitrag},
month = {Januar},
year = {2008},
keywords = {wireless sensor network; pervasive computing; routing; symbolic coordinates},
language = {Englisch},
cr-category = {C.3 Special-Purpose and Application-Based Systems,
C.2.2 Network Protocols},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2008-145/INPROC-2008-145.pdf,
http://ieeexplore.ieee.org/xpls/abs_all.jsp?arnumber=4554476},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Wireless sensor networks can monitor different types of physical phenomena and
are able to provide a diverse set of context data to interested clients.
Allowing mobile pervasive computing devices to access such data requires
solutions for routing messages between mobile devices and the static sensor
network. This paper presents a novel approach that addresses this problem with
the help of symbolic coordinates. It requires only a small amount of topology
information distributed in the network and allows mobile devices to send
messages to arbitrary areas. The routing task is split among the client nodes,
which specify a symbolic source route, and the sensor nodes that handle
node-to-node routing. The paper describes the algorithm, specific challenges
associated with its design and gives an extensive evaluation of the approach
and its properties, showing that the use of symbolic coordinates in these
environments is a viable alternative to more traditional types of routing.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2008-145&engl=0}
}
@inproceedings {INPROC-2008-14,
author = {Matthias Gauger and Daniel Minder and Pedro Jos{\'e} Marr{\'o}n and Arno Wacker and Andreas Lachenmann},
title = {{Prototyping Sensor-Actuator Networks for Home Automation}},
booktitle = {Proceedings of the 3rd Workshop on Real-World Wireless Sensor Networks (REALWSN 2008)},
publisher = {ACM},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
type = {Konferenz-Beitrag},
month = {April},
year = {2008},
keywords = {sensor-actuator networks; home automation; prototyping},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems,
B.4.1 Data Communications Devices},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Integrating actuators into sensor networks is often considered to be the next
logical step in the evolution of wireless sensor networks. However, few
practical examples of such sensor and actuator networks have been demonstrated
so far. In this paper, we present a prototype system that supports the easy
prototyping of such applications in the area of home automation. We demonstrate
the utility of this system with a simple light control application built on top
of it. We also report first experiences and insights gained with the help of
real-world experiments.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2008-14&engl=0}
}
@inproceedings {INPROC-2008-123,
author = {Matthias Gauger and Olga Saukh and Marcus Handte and Pedro Jos{\'e} Marr{\'o}n and Andreas Heydlauff and Kurt Rothermel},
title = {{Sensor-based Clustering for Indoor Applications}},
booktitle = {Proceedings of the European Conference on Wireless Sensor Networks (EWSN 2008), Poster/Demo session},
publisher = {Springer},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
type = {Workshop-Beitrag},
month = {September},
year = {2008},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {The lifetime requirements on wireless sensor networks often require the
redundant deployment of sensor nodes with appropriate management mechanisms
based on node clustering. Yet, existing clustering approaches do not take the
primary task of sensor networks into account: performing relevant measurements.
They usually form 'arbitrary' clusters, e.g., using connectivity information,
and thus, the resulting measurements are often of only limited use to the
applications. This problem can be avoided by considering application-specific
semantics. For indoor applications, the notion of a room provides a natural
unit of clustering since walls are constructed deliberately to ensure locality.
This paper shows that it is feasible to automatically create clusters that
reflect boundaries between rooms by analyzing the measurements of inexpensive,
broadly available sensors. The paper first analyzes the applicability of
statistical clustering methods and based on this analysis, it proposes and
evaluates a lightweight approach to determine clusters in real deployments.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2008-123&engl=0}
}
@inproceedings {INPROC-2008-122,
author = {Matthias Gauger and Olga Saukh and Marcus Handte and Pedro Jos{\'e} Marr{\'o}n and Andreas Heydlauff and Kurt Rothermel},
title = {{Sensor-based Clustering for Indoor Applications}},
booktitle = {Proceedings of the 5th IEEE Communications Society Conference on Sensor, Mesh and Ad Hoc Communications and Networks (SECON 2008)},
publisher = {IEEE Communications Society},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {478--486},
type = {Konferenz-Beitrag},
month = {Juni},
year = {2008},
isbn = {978-1-4244-1777-3},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2008-122/INPROC-2008-122.pdf,
http://ieeexplore.ieee.org/search/srchabstract.jsp?arnumber=4557787},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {The lifetime requirements on wireless sensor networks often require the
redundant deployment of sensor nodes with appropriate management mechanisms
based on node clustering. Yet, existing clustering approaches do not take the
primary task of sensor networks into account: performing relevant measurements.
They usually form 'arbitrary' clusters, e.g., using connectivity information,
and thus, the resulting measurements are often of only limited use to the
applications. This problem can be avoided by considering application-specific
semantics. For indoor applications, the notion of a room provides a natural
unit of clustering since walls are constructed deliberately to ensure locality.
This paper shows that it is feasible to automatically create clusters that
reflect boundaries between rooms by analyzing the measurements of inexpensive,
broadly available sensors. The paper first analyzes the applicability of
statistical clustering methods and based on this analysis, it proposes and
evaluates a lightweight approach to determine clusters in real deployments.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2008-122&engl=0}
}
@inproceedings {INPROC-2008-113,
author = {Frank D{\"u}rr and Kurt Rothermel},
title = {{Kommunikationsprotokolle zur Vermittlung kontextbezogener Informationen auf Basis r{\"a}umlicher Umgebungsmodelle}},
booktitle = {Proceedings of VDE-Kongress 2008 -- Zukunftstechnologien: Innovationen - M{\"a}rkte - Nachwuchs},
address = {Munich, Germany},
publisher = {VDE Verlag GmbH},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
pages = {1--6},
type = {Konferenz-Beitrag},
month = {November},
year = {2008},
isbn = {978-3-8007-3126-8},
keywords = {contextcast; geocast; Protokoll; protocol; kommunikation; communication; location-based; context-aware; ortsbezogen; kontextbezogen; Ort; Kontext; lokationsbasiert; service; Dienst},
language = {Deutsch},
cr-category = {C.2 Computer-Communication Networks},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2008-113/INPROC-2008-113.pdf,
http://www.vde-verlag.de/proceedings-en/453126101.html},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {In diesem Artikel stellen wir ein neuartiges kontextbezogenes
Kommunikationsparadigma namens Contextcast vor. Contextcast erm{\"o}glicht das
selektive Senden von Nachrichten an Teilnehmer mit einem bestimmten Kontext,
wobei der Kontext eines Teilnehmers beispielsweise durch seinen Aufenthaltsort,
seine Interessen oder seine Situation bestimmt ist. Typische Anwendungen f{\"u}r
Contextcast sind die gezielte Verteilung von Warnmeldungen,
Touristeninformationen oder Veranstaltungshinweise. Wir pr{\"a}sentieren zun{\"a}chst
Konzepte zur effizienten Vermittlung von ortsbezogenen Informationen (Geocast)
und diskutieren anschlie{\ss}end notwendige Erweiterungen f{\"u}r die effiziente
Realisierung der Contextcast-Kommunikation.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2008-113&engl=0}
}
@inproceedings {INPROC-2008-110,
author = {Frank D{\"u}rr and Jonas Palauro and Lars Geiger and Ralph Lange and Kurt Rothermel},
title = {{Ein kontextbezogener Instant-Messaging-Dienst auf Basis des XMPP-Protokolls}},
booktitle = {5. GI/ITG KuVS Fachgespr{\"a}ch Ortsbezogene Anwendungen und Dienste. N{\"u}rnberg. September 2008},
address = {N{\"u}rnberg},
publisher = {Georg-Simon-Ohm-Hochschule N{\"u}rnberg},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
series = {Sonderdruck Schriftenreihe der Georg-Simon-Ohm-Hochschule N{\"u}rnberg},
volume = {42},
pages = {23--28},
type = {Workshop-Beitrag},
month = {September},
year = {2008},
issn = {1867-5433},
keywords = {Nexus; Instant-Messaging; Kontextbezug; context-awareness; Contextcast; XMPP},
language = {Deutsch},
cr-category = {H.4.3 Information Systems Applications Communications Applications},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2008-110/INPROC-2008-110.pdf,
http://www.nexus.uni-stuttgart.de/,
http://www.wireless-earth.de/fg_lbs/meeting_5/meeting_5.html},
contact = {frank.duerr@ipvs.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Dieser Beitrag beschreibt die Verteilung kontextbezogener Informationen mittels
eines erweiterten Instant-Messaging-Dienstes. Dieser Dienst erm{\"o}glicht das
Senden von Nachrichten an alle Teilnehmer, die einen bestimmten Kontext
besitzen und sich z.B. an einem bestimmten Ort aufhalten oder bestimmte
Interessen besitzen. Als Basis dient das Extensible Messaging and Presence
Protokoll (XMPP) sowie ein XMPP-basierter Instant-Messaging-Dienst. Wir
beschreiben Protokoll- und Architekturerweiterungen f{\"u}r die Integration von
Kontextinformationen in das XMPP-Protokoll und die Server-Infrastruktur. Der
erweiterte Dienst unterst{\"u}tzt insbesondere die Server-seitige Filterung von
Nachrichten aufgrund von Kontextinformationen und erm{\"o}glicht dadurch die
effiziente Nachrichtenverteilung.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2008-110&engl=0}
}
@inproceedings {INPROC-2008-103,
author = {Manuel Gonzalo and Klaus Herrmann and Kurt Rothermel},
title = {{Self-Adaptive Load Balancing for Many-To-Many Communication in Wireless Sensor Networks}},
booktitle = {Proceedings of the 7th GI/ITG KuVS Fachgespr{\"a}ch ``Drahtlose Sensornetze''},
address = {Berlin},
publisher = {ACM},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {64--67},
type = {Workshop-Beitrag},
month = {September},
year = {2008},
keywords = {WSN; multisink; routing; many to many; load balancing},
language = {Englisch},
cr-category = {C.2.1 Network Architecture and Design},
contact = {manuel.gonzalo@ipvs.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {New scenarios in wireless sensor networks, where several independent sinks can
ask for different kinds of data, are currently emerging. Former algorithms that
route data to a centralized sink, are not appropriate for these scenarios.
First solutions for these multi-source to multi-sink scenarios simply create
independent trees for each source. As a result, some nodes become hot-spots,
since they are included in several trees, whereas nodes around them remain
unused. In this paper, we propose a new algorithm that balances the load evenly
in the network, extending the network lifetime, while still providing a small
delay in packet delivery. Based on the information of one-hop neighbors and the
number of hops to the sinks, the algorithm attempts to reduce both the delay
and the power consumption. We present the cost function used to select the next
hop(s) towards the sinks. The evaluation of the protocol demonstrates its
ability to fulfill its target.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2008-103&engl=0}
}
@inproceedings {INPROC-2008-102,
author = {Klaus Herrmann and Kurt Rothermel},
title = {{Developing user-responsive mobile applications}},
booktitle = {PerAda Magazine},
publisher = {Online},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
type = {Workshop-Beitrag},
month = {Oktober},
year = {2008},
isbn = {http://www.perada-magazine.eu/view.php?article=1270-2008-09-19&category=Mobile+Applications},
keywords = {ALLOW; pervasive adaptation; flow attachment; flow distribution; context-aware flows; horizontal adaptation; vertical adaptation},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2008-102/INPROC-2008-102.pdf,
http://www.perada-magazine.eu/view.php?article=1270-2008-09-19&category=%20Mobile+Applications},
contact = {Klaus.Herrmann@ipvs.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {A novel workflow-based approach may one day enable adaptive programs to
unobtrusively assist people with everyday tasks.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2008-102&engl=0}
}
@inproceedings {INPROC-2008-101,
author = {Klaus Herrmann and Kurt Rothermel and Gerd Kortuem and Dulay Naranker},
title = {{Adaptable Pervasive Flows - An Emerging Technology for Pervasive Adaptation}},
booktitle = {Proceedings of the Workshop on Pervasive Adaptation at the Second IEEE International Conference on Self-Adaptive and Self-Organizing Systems (SASO 2008)},
publisher = {IEEE Computer Society},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
type = {Workshop-Beitrag},
month = {Oktober},
year = {2008},
keywords = {ALLOW; pervasive computing; pervasive adaptation; flow distribution; flow attachment; context-aware flows; horizontal adaptation; vertical adaptation},
language = {Englisch},
cr-category = {C.2 Computer-Communication Networks},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2008-101/INPROC-2008-101.pdf,
http://dx.doi.org/10.1109/SASOW.2008.25},
contact = {Klaus.Herrmann@ipvs.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {The era of pervasive computing brings with it a grand challenge: Pervasive
applications must adapt to the dynamics entailed in human behavior and
constantly changing computing environments. In this paper, we propose Adaptable
Pervasive Flows as a novel technology that goes far beyond existing approaches
for adapting pervasive computing systems. APFs model applications in a fashion
similar to classical workflows while being situated in the real world. The
notable advantage of this is that applications as well as their environment can
be adapted proactively based on knowledge about future tasks. We introduce the
visions, concepts, and challenges of this emerging approach.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2008-101&engl=0}
}
@inproceedings {INPROC-2008-10,
author = {Stephan Schuhmann and Klaus Herrmann and Kurt Rothermel},
title = {{Direct Backtracking: An Advanced Adaptation Algorithm for Pervasive Applications}},
booktitle = {Proceedings of the 21st International Conference on Architecture of Computing Systems (ARCS 2008); Dresden, Germany, February 25-28, 2008},
editor = {Uwe et al. Brinkschulte},
address = {Berlin Heidelberg},
publisher = {Springer-Verlag},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
series = {Lecture Notes in Computer Science},
volume = {4934},
pages = {53--67},
type = {Konferenz-Beitrag},
month = {Februar},
year = {2008},
isbn = {978-3-540-78152-3},
keywords = {Pervasive Computing; Adaptation; Configuration; Backtracking; Pervasive Applications},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2008-10/INPROC-2008-10.pdf,
http://www.springerlink.com/content/167w160l00445832},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {The adaptation of pervasive applications is in the focus of many current
research projects. While decentralized adaptation is mandatory in
infrastructureless ad hoc scenarios, most realistic pervasive application
scenarios are situated in heterogeneous environments where additional
computation power of resource-rich devices can be exploited. Therefore, we
propose a hybrid approach to application configuration that applies centralized
as well as decentralized configuration as appropriate in the given environment.
In this paper we introduce the Direct Backtracking algorithm that represents an
efficient way for centralized configuration and adaptation of pervasive
applications in heterogeneous scenarios. In our evaluation, we show that
compared with other centralized algorithms, our algorithm significantly reduces
adaptation latency as it avoids unnecessary adaptations that arise in many
other backtracking algorithms, without significantly increasing memory waste.
This is achieved by introducing two mechanisms: 1. proactive backtracking
avoidance and 2. intelligent backtracking.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2008-10&engl=0}
}
@inproceedings {INPROC-2008-07,
author = {Andreas Grau and Steffen Maier and Klaus Herrmann and Kurt Rothermel},
title = {{Time Jails: A Hybrid Approach to Scalable Network Emulation}},
booktitle = {22nd ACM/IEEE/SCS Workshop on Principles of Advanced and Distributed Simulation (PADS 2008)},
publisher = {IEEE Computer Society; ACM},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {7--14},
type = {Workshop-Beitrag},
month = {Juni},
year = {2008},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2008-07/INPROC-2008-07.pdf,
http://dx.doi.org/10.1109/PADS.2008.19},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {It is essential to evaluate the performance of newly developed distributed
software and network protocols. Network emulation enables reproducible
evaluation of unmodified real implementations. Software built for distributed
systems, such as a large scale peer-to-peer system, requires evaluation
scenarios with thousands of communicating nodes. Two approaches for scaling
network emulation to such scenario sizes have been proposed in the literature:
node virtualization and time virtualization. Node virtualization allows
maximizing the utilization of standard hardware used for emulation experiments.
Time virtualization enables trading experiment duration for virtually increased
resources of the hardware. It stands to reason that a combination of those two
approaches may increase scalability even further. However, in existing
combinations, either node virtualization implies relatively high overhead or
time virtualization requires modifications of the test subject implementation.
In this paper, we present a novel hybrid approach called Time Virtualized
Emulation Environment (TVEE). It integrates node virtualization with low
overhead and time virtualization, which is transparent to the execution of test
subjects. We introduce virtual time based on epochs to enable better dynamic
hardware utilization during long lasting experiments. Additionally, a mechanism
similar to soft timers ensures an accurate reproduction of network properties
in the time virtualized emulation. Our evaluations show the accuracy and
scalability of time virtualized network emulation. Comparing TCP throughput,
TVEE outperforms other approaches using an event based virtual time by an order
of magnitude.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2008-07&engl=0}
}
@inproceedings {INPROC-2008-06,
author = {Gerald G. Koch and Boris Koldehofe and Kurt Rothermel},
title = {{Higher confidence in event correlation using uncertainty restrictions}},
booktitle = {28th IEEE International Conference on Distributed Computing Systems Workshops (ICDCSW'08); 2008},
publisher = {IEEE Computer Society},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {417--422},
type = {Workshop-Beitrag},
month = {Juni},
year = {2008},
issn = {1545-0678},
doi = {http://dx.doi.org/10.1109/ICDCS.Workshops.2008.22},
keywords = {event correlation, uncertainty restriction},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2008-06/INPROC-2008-06.pdf,
http://dx.doi.org/10.1109/ICDCS.Workshops.2008.22},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Distributed cooperative systems that use event notification for communication
can benefit from event correlation within the notification network. In the
presence of uncertain data, however, correlation results easily become
unreliable. The handling of uncertainty is therefore an important challenge for
event correlation in distributed event notification systems. In this paper, we
present a generic correlation model that is aware of uncertainty. We propose
uncertainty constraints that event correlation can take into account and show
how they can lead to higher confidence in the correlation result. We
demonstrate that the application of this model allows to obtain a qualitative
description of event correlation.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2008-06&engl=0}
}
@inproceedings {INPROC-2008-03,
author = {Frank D{\"u}rr and Kurt Rothermel},
title = {{An Adaptive Overlay Network for World-wide Geographic Messaging}},
booktitle = {Proceedings of the 22nd IEEE International Conference on Advanced Information Networking and Applications (AINA 2008); Gino-wan, Okinawa, Japan, March 25-28, 2008},
publisher = {IEEE},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
pages = {875--882},
type = {Konferenz-Beitrag},
month = {M{\"a}rz},
year = {2008},
keywords = {geocast; overlay network; communication; protocol; location-based service; geographic communication; networking; context; context-aware systems},
language = {Englisch},
cr-category = {C.2 Computer-Communication Networks},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2008-03/INPROC-2008-03.pdf,
http://dx.doi.org/10.1109/AINA.2008.67},
contact = {frank.duerr@ipvs.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {In this paper, we propose an overlay network supporting world-wide geographic
messaging. Our approach is based on hierarchical symbolic coordinates like
/usa/fl/miami/. Although hierarchical network topologies lend themselves to the
implementation of such overlay networks, they may lead to bottlenecks at the
root of the hierarchy, long message paths, and inefficient bandwidth
utilization. To avoid these problems, we propose an overlay network that adapts
its structure to the users' communication patterns by dynamically adding
shortcut`` links to the hierarchy leading to a routing mesh. We present an
algorithm that carefully selects shortcuts based on their utility to assure
short message paths on the one hand and to reduce the induced overhead on the
other hand. Through simulations we show that this approach decreases the
average path length significantly and reduces network load to about 50\%
compared to hierarchical routing.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2008-03&engl=0}
}
@inproceedings {INPROC-2007-84,
author = {Dominique Dudkowski and Pedro Jos{\'e} Marr{\'o}n and Kurt Rothermel},
title = {{Migration Policies for Location-Centric Data Storage in Mobile Ad-Hoc Networks}},
booktitle = {Proceedings of the 3rd International Conference on Mobile Ad-hoc and Sensor Networks (MSN'07); Beijing, China, December, 2007},
publisher = {Springer},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
pages = {197--208},
type = {Konferenz-Beitrag},
month = {Dezember},
year = {2007},
keywords = {location-centric; MANET; migration},
language = {Englisch},
cr-category = {C.2 Computer-Communication Networks},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Location-centric data storage is a fundamental paradigm for data management in
wireless ad-hoc networks. It guarantees that data is stored at network nodes
near specific geometric reference locations in the region where the network is
deployed. In mobile ad-hoc networks, maintaining spatial proximity between data
and its associated location requires explicit migration mechanisms in order to
``keep the data in place''. In this paper we propose comprehensive policies for
data migration that effectively maintain the spatial coherence of data given
the particular characteristics of mobile ad-hoc networks. Using extensive
simulations we show how the proposed policies outperform related migration
approaches over a wide range of system parameter settings, in particular, node
density, network dynamics, and migratable data size.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2007-84&engl=0}
}
@inproceedings {INPROC-2007-83,
author = {J{\"o}rg H{\"a}hner and Dominique Dudkowski and Pedro Jos{\'e} Marr{\'o}n and Kurt Rothermel},
title = {{Quantifying Network Partitioning in Mobile Ad Hoc Networks.}},
booktitle = {Proceedings of the 8th International Conference on Mobile Data Management (MDM 2007), Mannheim, Germany, May 2007},
publisher = {IEEE},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
pages = {174--181},
type = {Konferenz-Beitrag},
month = {Mai},
year = {2007},
language = {Englisch},
cr-category = {C.2 Computer-Communication Networks},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {The performance of distributed algorithms in mobile ad hoc networks is strongly
influenced by the connectivity of the network. In cases where the connectivity
is low, network partitioning occurs. The mobility and the density of network
nodes as well as the communication technology are fundamental properties that
have a large impact on partitioning. A detailed characterization of this
behavior helps to improve the performance of distributed algorithms.
In this paper we introduce a set of metrics that characterize partitioning in
mobile ad hoc networks. Based on an extensive simulation study we show the
impact of node mobility, density and transmission range on the proposed metrics
for a wide range of network scenarios.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2007-83&engl=0}
}
@inproceedings {INPROC-2007-73,
author = {Sebastien Baehni and Rachid Guerraoui and Boris Koldehofe and Maxime Monod},
title = {{Towards Fair Event Dissemination}},
booktitle = {Proceedings of the 27th IEEE International Conference on Distributed Computing Systems Workshops (ICDCSW'07)},
publisher = {IEEE Computer Society},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
type = {Konferenz-Beitrag},
month = {Juni},
year = {2007},
doi = {10.1109/ICDCSW.2007.83},
language = {Englisch},
cr-category = {C.2.2 Network Protocols,
C.2.4 Distributed Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2007-73/INPROC-2007-73.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Event dissemination in large scale dynamic systems is typically claimed to be
best achieved using decentralized peer-to-peer architectures. The rationale is
to have every participant in the system act both as a client (information
consumer) and as a server (information dissemination enabler), thus, precluding
specific brokers which would prevent scalability and fault-tolerance. We argue
that, for such decentralized architectures to be really meaningful,
participants should serve the system as much as they benefit from it. That is,
the system should be fair in the sense that the extend to which a participant
acts as a server should depend on the extend to which it has the opportunity to
act as a client. This is particularly crucial in selective information
dissemination schemes where clients are not all interested in the same
information. In this position paper, we discuss what a notion of fairness could
look like, explain why current architectures are not fair, and raise several
challenges towards achieving fairness.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2007-73&engl=0}
}
@inproceedings {INPROC-2007-57,
author = {The SpoVNet Consortium and Boris Koldehofe and Gerald Georg Koch},
title = {{SpoVNet: An Architecture for Supporting Future Internet Applications}},
booktitle = {Proc. 7th W{\"u}rzburg Workshop on IP: Joint EuroFGI and ITG Workshop on ``Visions of Future Generation Networks''},
address = {W{\"u}rzburg, Germany},
publisher = {-},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
type = {Workshop-Beitrag},
month = {Juli},
year = {2007},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2007-57/INPROC-2007-57.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {This talk presents an approach for providing Spontaneous Virtual Networks
(SpoVNets) that enable flexible, adaptive, and spontaneous provisioning of
application-oriented and network-oriented services on top of heterogeneous
networks. SpoVNets supply new and uniform communication abstractions for future
Internet applications so applications can make use of advanced services not
supported by today's Internet. We expect that many functions, which are
currently provided by SpoVNet on the application layer will become an integral
part of future networks. Thus, SpoVNet will transparently use advanced services
from the underlying network infrastructure as they become available (e.g.,
QoS-support in access networks or multicast in certain ISPs), enabling a
seamless transition from current to future genera-tion networks without
modifying the applications.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2007-57&engl=0}
}
@inproceedings {INPROC-2007-55,
author = {Klaus Herrmann},
title = {{Group Anti-Entropy - Achieving Eventual Consistency in Mobile Service Environments}},
booktitle = {Proceedings of the 8th IEEE International Conference on Mobile Data Management (MDM'07)},
publisher = {IEEE Computer Society Press},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
type = {Konferenz-Beitrag},
month = {Januar},
year = {2007},
keywords = {mobility, ambient services, data consistency, optimistic replication},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems,
H.2 Database Management},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2007-55/INPROC-2007-55.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Data consistency protocols are vital ingredients of mobile data management
systems. Notable research efforts have been spent to find adequate consistency
models for allowing mobile and nomadic users to share mutable data. Recently,
mobile Ambient Service infrastructures that pose somewhat different
requirements have entered the focus of attention. Such services are not as
loosely coupled as the afore-mentioned systems, but they still need flexible
consistency protocols that may adapt to the current dynamics in the system. We
propose an extension to the well-known anti-entropy protocol that makes use of
the nature of Ambient Service environments to allow for a flexible consistency
management among arbitrary groups of mobile service replicas. We will show that
our protocol can exploit the concept of group updates to increase its
efficiency in terms of bandwidth usage. Furthermore, we prove that it avoids
costly state transfers by means of a simple rule that limits the divergence
within the overall set of replicas. Finally, we introduce two simple tunable
parameters, and we present experimental results that show how they may be used
to shape the characteristics of the protocol.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2007-55&engl=0}
}
@inproceedings {INPROC-2007-54,
author = {Gero M{\"u}hl and Matthias Werner and Michael A. Jaeger and Klaus Herrmann and Helge Parzyjegla},
title = {{On the Definitions of Self-Managing and Self-Organizing Systems}},
booktitle = {KiVS 2007 Workshop: Selbstorganisierende, Adaptive, Kontextsensitive verteilte Systeme (SAKS 2007)},
address = {Bern, Switzerland},
publisher = {Springer-Verlag},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
series = {Informatik aktuell},
type = {Konferenz-Beitrag},
month = {M{\"a}rz},
year = {2007},
keywords = {self-organization, self-management, adaptivity, classification, formal model},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems,
F.1.1 Models of Computation},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2007-54/INPROC-2007-54.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {The management costs of software systems are becoming the dominating cost
factor in running IT infrastructures. The main driving force behind this
development is the ever-increasing system complexity which is becoming the
limiting factor for further development. The fact that human administrators get
more and more overstrained by management tasks has led to the idea of systems
that manage themselves, i.e., self-managing systems. Another concept that is
closely related to selfmanagement is self-organization. Self-organizing
software systems often build on bio- and nature-inspired approaches. However,
most publications on self-managing or self-organizing systems miss a clear
definition of these terms. Even worse, although self-management and
self-organization aim at similar goals, their relation still has not been
defined properly. In this paper, we approach these problems by introducing a
classification of systems that models self-organizing systems as a subclass of
selfmanaging systems. The classification builds upon a definition of adaptive
systems and introduces self-manageable, self-managing, and selforganizing
systems. Our proposal serves as a starting point for further discussions,
eventually leading to a better understanding of the terms self-organization and
self-management and their interrelationship.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2007-54&engl=0}
}
@inproceedings {INPROC-2007-53,
author = {Michael A. Jaeger and Helge Parzyjegla and Gero M{\"u}hl and Klaus Herrmann},
title = {{Self-Organizing Broker Topologies for Publish/Subscribe Systems}},
booktitle = {The 22nd Annual ACM Symposium on Applied Computing},
address = {Seoul, Korea},
publisher = {ACM Press},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {543--550},
type = {Konferenz-Beitrag},
month = {M{\"a}rz},
year = {2007},
keywords = {publish/subscribe, adaptable middleware, self-organization, overlay networks},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2007-53/INPROC-2007-53.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Distributed publish/subscribe systems are usually deployed on top of an overlay
network that enables complex routing strategies implemented in the application
layer. Up to now, only little effort has been spent on the design of the broker
overlay network assuming that it is either static or manually administered. As
publish/subscribe systems are increasingly targeted at dynamic environments
where client behavior and network characteristics vary over time, static
overlay networks lead to suboptimal performance. In this paper, we present a
self-organizing broker overlay infrastructure that adapts dynamically to
achieve a better efficiency on both, the application and the network layer.
This is obtained by taking network metrics as well as notification traffic into
account.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2007-53&engl=0}
}
@inproceedings {INPROC-2007-51,
author = {Klaus Herrmann},
title = {{Self-Organizing Replica Placement - A Case Study on Emergence}},
booktitle = {Proceedings of the first IEEE International Conference on Self-Adaptive and Self-Organizing Systems},
publisher = {IEEE Computer Society Press},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {13--22},
type = {Konferenz-Beitrag},
month = {Juli},
year = {2007},
keywords = {self-organization, emergence, replica placement, case study},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems,
H Information Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2007-51/INPROC-2007-51.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {The concept of self-organization is rapidly gaining importance in the area of
distributed computing systems. However, we still lack the necessary means for
engineering such system in a standardized way since their common properties are
rather abstract, and the mechanisms from which self-organization emerges are
too diverse. Therefore, it has become common practice to engineer computing
systems by taking inspirations from well-known case studies of biological
systems. However, the concepts found in such systems are in many cases only
partially transferable to the domain of distributed computing systems since
biological systems are subject to vastly different constraints compared to
those in a computing system. Our contributions in this paper are the following:
(i) We present a case study of a self-organizing software system that
originates from the domain of distributed computing systems. Therefore, its
concepts can be exploited in other distributed computing systems much more
directly. (ii) We give a detailed analysis of the emergent properties of the
system and the mechanisms by which they arise. (iii) We generalize the
mechanisms by which self-organization emerges in this system and present a
catalog of design questions that may help engineers in creating arbitrary
self-organizing systems.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2007-51&engl=0}
}
@inproceedings {INPROC-2007-50,
author = {Klaus Herrmann},
title = {{Self-Organizing Infrastructures for Ambient Services}},
booktitle = {Kommunikation in Verteilten Systemen (KiVS), 15. ITG/GI Fachtagung Kommunikation in Verteilten Systemen (KiVS 2007)},
publisher = {Springer-Verlag},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
series = {Informatik aktuell},
pages = {299--306},
type = {Konferenz-Beitrag},
month = {Januar},
year = {2007},
isbn = {3-540-69961-9},
keywords = {self-organization, middleware, data consistency, lookup service, mobile ad hoc networks, replica placement, wireless mesh networks},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2007-50/INPROC-2007-50.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {The vision of Ambient Intelligence (AmI) as a new paradigm for supporting the
mobile user in his daily activities is currently entering the focus of European
research efforts. A high degree of autonomy on the part of the supporting
software system is inherent to this vision of omnipresent and continuously
running services. However, adequate concepts for creating respective
infrastructures that may operate autonomously and in a self-organized fashion
are still largely unexplored. We propose the Ad hoc Service Grid (ASG) as a
dedicated AmI infrastructure that may be deployed in an ad hoc fashion at
arbitrary medium-sized locations (shopping malls, construction sites, trade
fairs, etc.). In this paper, we give an overview over our results thus far. We
focus on the problems of service placement, discovery and lookup, and data
consistency within an ASG environment and show how we have solved these
problems with new self-organizing and adaptive algorithms. These vital
functions are the basis for the realization of ASG systems and represent an
essential contribution to AmI research in general.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2007-50&engl=0}
}
@inproceedings {INPROC-2007-48,
author = {Marcus Handte and Klaus Herrmann and Gregor Schiele and Christian Becker and Kurt Rothermel},
title = {{Automatic Reactive Adaptation of Pervasive Applications}},
booktitle = {Proceedings of ICPS'07: IEEE International Conference on Pervasive Services},
publisher = {IEEE Computer Society Press},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {214--222},
type = {Konferenz-Beitrag},
month = {Juli},
year = {2007},
keywords = {adaptivity, components, mobility, optimization},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2007-48/INPROC-2007-48.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Pervasive Computing envisions seamless and distraction-free support for
everyday tasks through distributedapplications that leverage the resources of
the users' environment. Due to the mobility of users and devices, applications
need to adapt continuously to their changing execution environment. Therefore,
developers need a suitable framework in order to efficiently create adaptive
applications. In this paper, we present and evaluate our approach to adapting a
pervasive computing application to changes during its execution. This work is
based on the minimal component system PCOM and on an algorithm to fully
automate the initial configuration of a componentbased application which we
have presented in earlier work. The contribution of this paper is threefold.
First, we describe a number of modifications to the component model that are
required to enable fully automatic adaptation. Secondly, we propose a simple
yet powerful cost model to capture the complexity of specific adaptations.
Thirdly, we describe an online optimization heuristic that extends our
distributed configuration algorithm in order to choose to a low-cost
configuration whenever the current configuration of a pervasive application
requires adaptation.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2007-48&engl=0}
}
@inproceedings {INPROC-2007-46,
author = {Matthias Gauger and Pedro Jos{\'e} Marr{\'o}n and Daniel Kauker and Kurt Rothermel},
title = {{Low Overhead Assignment of Symbolic Coordinates in Sensor Networks}},
booktitle = {Proceedings of the IFIP First International Conference on Wireless Sensor and Actor Networks, WSAN'07},
editor = {Luis Orozco-Barbosa and Teresa Olivares and Rafael Casado and Aurelio Berm{\'u}dez},
publisher = {Springer},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {181--192},
type = {Konferenz-Beitrag},
month = {September},
year = {2007},
isbn = {978-0-387-74898-6},
language = {Englisch},
cr-category = {C.3 Special-Purpose and Application-Based Systems},
contact = {gauger@cs.uni-bonn.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Approximate information on the location of nodes in a sensor network is
essential to many types of sensor network applications and algorithms. In many
cases, using symbolic coordinates is an attractive alternative to the use of
geographic coordinates due to lower costs and lower requirements on the
available location information during coordinate assignment. In this paper, we
investigate different possible methods of assigning symbolic coordinates to
sensor nodes. We present a method based on broadcasting coordinate messaging
and filtering using sensor events. We show in the evaluation that this method
allows a reliable assignment of symbolic coordinates while only generating a
low overhead.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2007-46&engl=0}
}
@inproceedings {INPROC-2007-45,
author = {Daniel Minder and Pedro Jos{\'e} Marr{\'o}n and Andreas Lachenmann and Kurt Rothermel},
title = {{Coordinated group adaptation in sensor networks}},
booktitle = {6. Fachgespr{\"a}ch Sensornetzwerke},
publisher = {RWTH Aachen},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
series = {Technischer Bericht},
volume = {AIB 2007-11},
pages = {43--46},
type = {Konferenz-Beitrag},
month = {Juli},
year = {2007},
issn = {0935-3232},
keywords = {wireless sensor network; group adaptation; coordination},
language = {Englisch},
cr-category = {D.4.7 Operating Systems Organization and Design,
C.2.1 Network Architecture and Design,
C.2.3 Network Operations},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2007-45/INPROC-2007-45.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {In Wireless Sensor Networks, several algorithms are used to perform different
functionality, e.g. routing or clock synchronization. Each algorithm is
intended for specific network characteristics and user requirements. But the
acutal characteristics and requirements may change during system runtime.
TinyCubus and particularly its Tiny Data Managment Framework use adaptation to
solve this problem.
In this paper, we first explain the centralized adaptation process. Then, we
examine how this can be done localized in the network. Since coordination
between local adaptation decisions is found to be necessary, metrics for this
coordination and their dependencies are shown.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2007-45&engl=0}
}
@inproceedings {INPROC-2007-38,
author = {Lars Geiger and Frank D{\"u}rr},
title = {{Kontextbezogene Kommunikation}},
booktitle = {4. GI/ITG KuVS Fachgespr{\"a}ch Ortsbezogene Anwendungen und Dienste},
editor = {J{\"o}rg Roth and Axel K{\"u}pper and Claudia Linnhoff-Popien},
address = {M{\"u}nchen},
publisher = {Verlag Dr. Hut},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
pages = {22--26},
type = {Konferenz-Beitrag},
month = {September},
year = {2007},
isbn = {978-3-89963-591-1},
keywords = {Kontext; Kommunikation; Multicast; Nexus},
language = {Deutsch},
cr-category = {C.2.1 Network Architecture and Design,
C.2.2 Network Protocols,
C.2.4 Distributed Systems,
C.2.6 Internetworking},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2007-38/INPROC-2007-38.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Verbindet man die Position eines Benutzers mit weiteren Attributen wie
beispielsweise Typ, Alter oder Status zu seinem Kontext, so ergeben sich daraus
interessante neue Anwendungsm{\"o}glichkeiten. In diesem Artikel soll ein Verfahren
vorgestellt werden, wie ein solcher Kontext benutzt werden kann, um Nachrichten
an bestimmte Gruppen von Benutzern --- bestimmt durch ihren Kontext --- zu
versenden. Ein solcher Kommunikationsmechanismus k{\"o}nnte beispielsweise
eingesetzt werden, um Verkehrsnachrichten gezielt an alle Fahrzeuge innerhalb
eines bestimmten Gebietes und mit einer bestimmten Fahrtrichtung zu
{\"u}bermitteln.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2007-38&engl=0}
}
@inproceedings {INPROC-2007-35,
author = {Tobias Farrell and Reynold Cheng and Kurt Rothermel},
title = {{Energy-Efficient Monitoring of Mobile Objects with Uncertainty-Aware Tolerances}},
booktitle = {Proceedings of the 11th International Database Engineering and Applications Symposium (IDEAS 2007); Banff, Canada, September 6-8, 2007},
editor = {Bipin C. Desai and Ken Barker},
publisher = {IEEE Computer Society},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
pages = {129--140},
type = {Konferenz-Beitrag},
month = {September},
year = {2007},
isbn = {0-7695-2947-X},
doi = {10.1109/IDEAS.2007.4318097},
language = {Englisch},
cr-category = {C.2 Computer-Communication Networks},
ee = {http://ieeexplore.ieee.org/xpls/abs_all.jsp?isnumber=4318075&arnumber=4318097},
contact = {Tobias.Farrell@ipvs.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {In location-based services, continuous queries are often employed to monitor
the locations of mobile ob-jects that are determined by sensing devices like
GPS receivers. Due to limited battery resources, it is impor-tant for these
objects to acquire and report location data only if necessary. We study how
these energy-consuming operations can be reduced with a con-trolled impact on
query accuracy of continuous range queries (CRQs). Specifically, we develop
uncertainty-aware tolerances, which are user-defined error bounds that provide
correctness guarantees, with considera-tion of different sources of data
uncertainty: sensing uncertainty, sampling uncertainty, and communication
delay. Novel algorithms are developed to control carefully when an object
should acquire and update a location, while satisfying these tolerances.
Extensive simulations validate the effectiveness of our methods.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2007-35&engl=0}
}
@inproceedings {INPROC-2007-34,
author = {Tobias Farrell and Ralph Lange and Kurt Rothermel},
title = {{Energy-efficient Tracking of Mobile Objects with Early Distance-based Reporting}},
booktitle = {Proceedings of the Fourth Annual International Conference on Mobile and Ubiquitous Systems: Networking and Services (MobiQuitous 2007); Philadelphia, PA, USA, August 6-10, 2007},
publisher = {IEEE Press},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
type = {Konferenz-Beitrag},
month = {August},
year = {2007},
isbn = {1-4244-1025-8},
doi = {10.1109/MOBIQ.2007.4450984},
language = {Englisch},
cr-category = {C.2 Computer-Communication Networks},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2007-34/INPROC-2007-34.pdf,
http://www.ieeexplore.ieee.org/xpls/abs_all.jsp?isnumber=4450969&arnumber=4450984},
contact = {Tobias.Farrell@ipvs.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Many location-based systems rely on fine-grained tracking of mobile objects
that determine their own locations with sensing devices like GPS receivers. For
these objects, energy is a very valuable and limited resource. A distance-based
reporting protocol can be employed to reduce the energy they consume by sending
position updates. However, the energy required for position sensing has not
been considered in the past. In this paper, we study how the resulting energy
consumption from both sensing and update operations can be reduced for
distance-based reporting. We show that significant savings are achieved by
sending position updates earlier than actually required. For uniform movement,
we derive the minimal power consumption analytically. Subsequently, two novel
online heuristics are proposed that control the sending of position updates at
runtime. Their effectiveness is validated by extensive simulations.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2007-34&engl=0}
}
@inproceedings {INPROC-2007-15,
author = {Martin Saternus and Mirko Knoll and Frank D{\"u}rr and Torben Weis},
title = {{Symstry: Ein P2P-System f{\"u}r Ortsbezogene Anwendungen}},
booktitle = {Proceedings of 15. ITG/GI - Fachtagung (KiVS 2007)},
publisher = {VDE-Verlag},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
pages = {99--104},
type = {Konferenz-Beitrag},
month = {Februar},
year = {2007},
isbn = {ISBN 978-3-8007-2980-7},
keywords = {peer-to-peer; context-aware system},
language = {Deutsch},
cr-category = {H.3.3 Information Search and Retrieval},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2007-15&engl=0}
}
@inproceedings {INPROC-2007-14,
author = {Martin Saternus and Torben Weis and Mirko Knoll and Frank D{\"u}rr},
title = {{A Middleware for Context-Aware Applications and Services Based on Messenger Protocols}},
booktitle = {Proceedings of the Fifth Annual IEEE International Conference on Pervasive Computing and Communications Workshops (PerComW'07)},
publisher = {IEEE},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
pages = {467--471},
type = {Konferenz-Beitrag},
month = {M{\"a}rz},
year = {2007},
keywords = {context-aware application; middleware; user interface; messenger},
language = {Englisch},
cr-category = {D.2.6 Software Engineering Programming Environments,
H.5.0 Information Interfaces and Presentation General},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Nowadays most context-aware applications are independent proprietary pieces of
software. A general framework or middleware deployed in the field does not
exist; therefore the implementation of context-aware applications and services
assumes the development of the whole application stack for each application.
Along these development issues, deployment and privacy problems are to be
solved.
This imposes the following challenges concerning a middleware for context-aware
applications: (1) We need an architecture that allows to implement and deploy
services easily on the network. (2) We need a user interface that is
widespread, well known to users and allows to mange one’s privacy settings for
every single service transparently.
In this paper we describe our middleware’s architecture for context-aware
applications, based on messenger protocols.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2007-14&engl=0}
}
@inproceedings {INPROC-2007-133,
author = {Andreas Lachenmann and Pedro Jos{\'e} Marr{\'o}n and Daniel Minder and Kurt Rothermel},
title = {{Meeting Lifetime Goals with Energy Levels}},
booktitle = {Proceedings of the 5th ACM Conference on Embedded Networked Sensor Systems (SenSys 2007)},
publisher = {ACM},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
pages = {131--144},
type = {Konferenz-Beitrag},
month = {November},
year = {2007},
doi = {10.1145/1322263.1322277},
keywords = {wireless sensor network; energy; lifetime goal; programming abstraction},
language = {Englisch},
cr-category = {D.3.3 Programming Language Constructs and Features,
D.4.8 Operating Systems Performance},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2007-133/INPROC-2007-133.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {In this paper we present Levels, a programming abstraction for energy-aware
sensor network applications. Unlike most previous work it does not try to
maximize network lifetime but rather helps to meet user-defined lifetime goals
while maximizing application quality. Levels is targeted to applications where
there is no redundancy and no node should fail early.
With our programming abstraction the application developer defines so-called
energy levels. These energy levels form a stack and can be deactivated from top
to bottom if the lifetime goal cannot be met otherwise. Each code block within
an energy level contains information about its energy consumption, which can be
obtained from simulation tools without much effort. The runtime system then
uses the data about the energy consumption of the different levels to compute
an optimal level assignment for the time remaining. As we show in the
evaluation, applications using Levels can accurately meet given lifetime goals
and offer good application quality. In addition, the runtime overhead of our
system is almost negligible.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2007-133&engl=0}
}
@inproceedings {INPROC-2007-132,
author = {Daniel Minder and Andreas Grau and Pedro Jos{\'e} Marr{\'o}n},
title = {{On Group Formation for Self-Adaptation in Pervasive Systems}},
booktitle = {Proceedings of the First International Conference on Autonomic Computing and Communication Systems},
publisher = {ACM},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
pages = {1--10},
type = {Konferenz-Beitrag},
month = {Oktober},
year = {2007},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2007-132/INPROC-2007-132.pdf,
http://portal.acm.org/citation.cfm?doid=1365562.1365584},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Adaptation in Pervasive Computing normally focuses on services or on
application behaviour, but the consideration of lower level algorithms in this
process can lead to significant performance increase. To perform adaptation of
algorithms the concept of context normally used in Pervasive Computing has to
be extended. Based on the same context, group formation models are established
to group devices with similar relevant context to optimise the adaptation
process. In this paper, such group formation models are developed and
evaluated. We also draw general conclusions for adaptation.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2007-132&engl=0}
}
@inproceedings {INPROC-2007-13,
author = {Marcus Handte and Klaus Herrmann and Gregor Schiele and Christian Becker},
title = {{Supporting Pluggable Configuration Algorithms in PCOM}},
booktitle = {Perware Workshop at 5th IEEE International Conference on Pervasive Computing and Communications (PerCom)},
address = {New York, USA},
publisher = {IEEE},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {472--476},
type = {Konferenz-Beitrag},
month = {M{\"a}rz},
year = {2007},
language = {Englisch},
cr-category = {D.2.11 Software Engineering Software Architectures,
D.1.2 Automatic Programming},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2007-13/INPROC-2007-13.pdf,
http://dx.doi.org/10.1109/PERCOMW.2007.111},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Pervasive Computing envisions distributed applications that optimally leverage
the resources present in their ever-changing execution environment. To ease the
development of pervasive applications, we have created a pervasive component
system (PCOM). PCOM automates the configuration and runtime adaptation of a
component-based application using a builtin distributed configuration
algorithm. In this paper, we present an architectural extension that allows
switching between different algorithms. This enables PCOM to dynamically select
an algorithm that suits the computational resources present in an environment.
To validate the extended architecture, we compare the overheads of a
distributed and a centralized configuration algorithm in two different
environments.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2007-13&engl=0}
}
@inproceedings {INPROC-2007-12,
author = {Gregor Schiele and Marcus Handte and Christian Becker},
title = {{Good Manners for Pervasive Computing - An Approach Based on the Ambient Calculus}},
booktitle = {WIP Track at 5th IEEE International Conference on Pervasive Computing and Communications (PerCom)},
address = {New York, USA},
publisher = {IEEE},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {589--593},
type = {Konferenz-Beitrag},
month = {M{\"a}rz},
year = {2007},
language = {Englisch},
cr-category = {D.2.7 Software Engineering Distribution, Maintenance, and Enhancement},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {When people interact, they follow distinct rules that coordinate the order of
speech, who opens doors, whom and how to greet, and many things more. Such a
social codex depends on the milieu -- or ambience -- people are acting in.
People breaking the codex are either considered badly educated or foreigners to
the ambience -- sometimes even both. In Pervasive Computing a multitude of
applications is expected to populate our environment and to follow objects and
users throughout their daily journey. Consequently, we will need a new codex --
or manners -- for Pervasive Computing applications that controls the
interaction between applications. Such a codex will have to incorporate our
existing codices as well as technical aspects. In this work in progress paper
we present an approach to extend our prior work on Pervasive Computing system
support by specifying interdependencies of applications based on the ambient
calculus. This allows specifying and technically enforcing ``manners'' for
Pervasive Computing applications.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2007-12&engl=0}
}
@inproceedings {INPROC-2007-05,
author = {Steffen Maier and Andreas Grau and Harald Weinschrott and Kurt Rothermel},
title = {{Scalable Network Emulation: A Comparison of Virtual Routing and Virtual Machines}},
booktitle = {Proceedings of the IEEE Symposium on Computers and Communications (ISCC'07), Aveiro, Portugal, July 1-4},
publisher = {IEEE Computer Society},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {395--402},
type = {Konferenz-Beitrag},
month = {Juli},
year = {2007},
keywords = {network emulation; performance measurement; virtual machine; virtual routing},
language = {Englisch},
cr-category = {C.4 Performance of Systems,
D.4.4 Operating Systems Communications Management,
D.4.8 Operating Systems Performance,
I.6.3 Simulation and Modeling Applications},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2007-05/INPROC-2007-05.pdf,
http://dx.doi.org/10.1109/ISCC.2007.4381529},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Performance analysis is a necessary step during the development of distributed
applications and communication protocols. Network emulation testbeds provide
synthetic, configurable environments for comparative performance measurements
of real implementations. However, realistic scenarios require more
communicating nodes than usual testbeds are able to provide. In order to enable
scalable network emulation, various concepts for the virtualization of nodes
have been proposed. The overhead of virtualization strongly impacts the total
size of a scenario, that can be emulated on a given testbed. However, the
overhead of different virtualization approaches in the context of network
emulation has not been compared directly so far. In this paper, we present a
comparison of different virtual machine implementations (Xen, User Mode Linux)
and our own virtual routing approach (NET). We discuss qualitative evaluation
criteria and present a quantitative evaluation showing the efficiency of each
approach in a traditional wired infrastructure-based and in a wireless ad hoc
network emulation scenario. Our results give insights on which virtualization
approach is best suited for which kind of network emulation.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2007-05&engl=0}
}
@inproceedings {INPROC-2007-02,
author = {Andreas Lachenmann and Pedro Jos{\'e} Marr{\'o}n and Matthias Gauger and Daniel Minder and Olga Saukh and Kurt Rothermel},
title = {{Removing the Memory Limitations of Sensor Networks with Flash-Based Virtual Memory}},
booktitle = {Proceedings of the European Conference on Computer Systems (EuroSys 2007)},
publisher = {EuroSys},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
series = {Also published in ACM SIGOPS Operating Systems Review, vol. 41(3), 2007},
pages = {131--144},
type = {Konferenz-Beitrag},
month = {M{\"a}rz},
year = {2007},
language = {Englisch},
cr-category = {D.4.2 Storage Management,
D.3.4 Programming Languages Processors},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2007-02/INPROC-2007-02.pdf,
http://www.ipvs.uni-stuttgart.de/abteilungen/vs/forschung/projekte/tinycubus/start},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Virtual memory has been successfully used in different domains to extend the
amount of memory available to applications. We have adapted this mechanism to
sensor networks, where, traditionally, RAM is a severely constrained resource.
In this paper we show that the overhead of virtual memory can be significantly
reduced with compile-time optimizations to make it usable in practice, even
with the resource limitations present in sensor networks.
Our approach, ViMem, creates an efficient memory layout based on variable
access traces obtained from simulation tools. This layout is optimized to the
memory access patterns of the application and to the specific properties of the
sensor network hardware.
Our implementation is based on TinyOS. It includes a pre-compiler for nesC code
that translates virtual memory accesses into calls of ViMem’s runtime
component. ViMem uses flash memory as secondary storage. In order to evaluate
our system we have modified nontrivial existing applications to make use of
virtual memory. We show that its runtime overhead is small even for large data
sizes.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2007-02&engl=0}
}
@inproceedings {INPROC-2007-01,
author = {Andreas Lachenmann and Pedro Jos{\'e} Marr{\'o}n and Daniel Minder and Olga Saukh and Matthias Gauger and Kurt Rothermel},
title = {{Versatile Support for Efficient Neighborhood Data Sharing}},
booktitle = {Proceedings of the 4th European Conference on Wireless Sensor Networks (EWSN 2007)},
editor = {Koen Langendoen and Thiemo Voigt},
publisher = {Springer-Verlag},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
series = {Lecture Notes in Computer Science},
volume = {4373},
pages = {1--16},
type = {Konferenz-Beitrag},
month = {Januar},
year = {2007},
keywords = {wireless sensor networks; neighborhood data sharing; polite gossiping},
language = {Englisch},
cr-category = {C.2.2 Network Protocols,
C.3 Special-Purpose and Application-Based Systems,
D.3.3 Programming Language Constructs and Features},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2007-01/INPROC-2007-01.pdf,
http://www.ipvs.uni-stuttgart.de/abteilungen/vs/forschung/projekte/tinycubus/start,
http://dx.doi.org/10.1007/978-3-540-69830-2_1},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Many applications in wireless sensor networks rely on data from neighboring
nodes. However, the effort for developing efficient solutions for sharing data
in the neighborhood is often substantial. Therefore, we present a
general-purpose algorithm for this task that makes use of the broadcast nature
of radio transmission to reduce the number of packets. We have integrated this
algorithm into TinyXXL, a programming language extension for data exchange.
This combined system offers seamless support both for data exchange among the
components of a single node and for efficient neighborhood data sharing. We
show that compared to existing solutions, such as Hood, our approach further
reduces the work of the application developer and provides greater efficiency.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2007-01&engl=0}
}
@inproceedings {INPROC-2006-73,
author = {Stephan Urbanski and Marcus Handte and Gregor Schiele and Kurt Rothermel},
title = {{Experience using Processes for Pervasive Computing}},
booktitle = {Pervasive University Workshop at Informatik 2006},
editor = {GI},
publisher = {GI},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {1--5},
type = {Konferenz-Beitrag},
month = {Oktober},
year = {2006},
language = {Englisch},
cr-category = {D.2.11 Software Engineering Software Architectures},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Pervasive Computing envisions seamless computing support for users while
performing their everyday tasks. Many of these tasks are hard to capture by the
notion of a single application as their requirements on computing support vary
over time. To ease the development of applications for such tasks, we have
designed an application model for process-oriented pervasive applications,
called Sentient Processes, and a supporting middleware system implementing the
flow control for processes. In this paper, we show the capabilities of the
Sentient Process model to capture everyday user tasks by the example of a
process supporting a student in managing his classes during a term.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2006-73&engl=0}
}
@inproceedings {INPROC-2006-72,
author = {Stephan Urbanski and Christian Becker and Kurt Rothermel},
title = {{Sentient Processes - Process-based Applications in Pervasive Computing}},
booktitle = {WIP Track at 4th IEEE Conference on Pervasive Computing and Communications (PerCom)},
editor = {IEEE},
address = {Pisa, Italy},
publisher = {IEEE},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {1--4},
type = {Konferenz-Beitrag},
month = {M{\"a}rz},
year = {2006},
language = {Englisch},
cr-category = {D.2.3 Software Engineering Coding Tools and Techniques,
D.2.11 Software Engineering Software Architectures},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Users' tasks are typically a sequence of steps. Today, the goal of pervasive
computing applications - to support users in their tasks by using context
information - is only partially met as applications supported by current
infrastructures focus on individual steps instead of supporting the
coordination of the whole sequence. In this paper, we present an approach for
supporting multi-step user tasks by using a process-based application model,
called sentient processes. Along with the model, the paper introduces the
design of an execution engine for such processes.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2006-72&engl=0}
}
@inproceedings {INPROC-2006-62,
author = {Pedro Jos{\'e} Marr{\'o}n and Daniel Minder and Andreas Lachenmann and Olga Saukh and Matthias Gauger and Robert Sauter and Manuel Gonzalo},
title = {{Adaption and Cross-Layer Support for Sensor Networks}},
booktitle = {4. GMM-Workshop Energieautarke Sensorik},
publisher = {GMM},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
series = {Fachbericht},
volume = {51},
pages = {63--72},
type = {Konferenz-Beitrag},
month = {September},
year = {2006},
isbn = {3-8007-2987-3},
keywords = {wireless sensor networks; adaptation; cross-layer},
language = {Englisch},
cr-category = {D.4.7 Operating Systems Organization and Design,
C.2.1 Network Architecture and Design,
C.3 Special-Purpose and Application-Based Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {-},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2006-62&engl=0}
}
@inproceedings {INPROC-2006-61,
author = {Pedro Jos{\'e} Marr{\'o}n and Robert Sauter and Olga Saukh and Matthias Gauger and Kurt Rothermel},
title = {{Challenges of Complex Data Processing in Real World Sensor Network Deployments}},
booktitle = {Proceedings of the ACM Workshop on Real-World Wireless Sensor Networks (REALWSN 2006)},
address = {Uppsala, Sweden},
publisher = {ACM},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {43--47},
type = {Konferenz-Beitrag},
month = {Juni},
year = {2006},
keywords = {Sensor networks; data processing; challenges},
language = {Englisch},
cr-category = {H.3.4 Information Storage and Retrieval Systems and Software,
C.2.4 Distributed Systems,
C.3 Special-Purpose and Application-Based Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2006-61/INPROC-2006-61.pdf,
http://www.ipvs.uni-stuttgart.de/abteilungen/vs/forschung/projekte/tinycubus/start},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Long-term deployments of wireless sensor networks so far have been focused on
the periodic gathering of simple sensor readings. However, technological
advances allow working with more complex types of data that also create larger
data volumes. In this paper we use a real world engineering application to
identify a series of challenges related to complex data processing in sensor
networks. We present a classification of these challenges and outline a set of
preliminary solutions that we are currently in the process of developing for
our motivating application.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2006-61&engl=0}
}
@inproceedings {INPROC-2006-60,
author = {Matthias Gauger and Pedro Jos{\'e} Marr{\'o}n and Marcus Handte and Kurt Rothermel},
title = {{Routing in Sensor Networks based on Symbolic Coordinates}},
booktitle = {5. GI/ITG KuVS Fachgespr{\"a}ch ``Drahtlose Sensornetze''},
editor = {Pedro Marr{\'o}n},
address = {Stuttgart},
publisher = {Universit{\"a}t Stuttgart},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
series = {Technischer Bericht},
volume = {2006/07},
pages = {81--86},
type = {Konferenz-Beitrag},
month = {Juli},
year = {2006},
language = {Englisch},
cr-category = {C.2.3 Network Operations,
C.2.4 Distributed Systems,
C.3 Special-Purpose and Application-Based Systems},
contact = {Matthias.Gauger@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {The routing of messages between mobile nodes and a sensor network is an
important but challenging task. In this paper we present our approach for this
problem that is based on the use of symbolic coordinates and that divides the
task among client and sensor nodes.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2006-60&engl=0}
}
@inproceedings {INPROC-2006-55,
author = {Andreas Lachenmann and Pedro Jos{\'e} Marr{\'o}n and Kurt Rothermel},
title = {{Efficient Flash-based Virtual Memory for Sensor Networks}},
booktitle = {5. GI/ITG KuVS Fachgespr{\"a}ch ``Drahtlose Sensornetze''},
editor = {Pedro Jos{\'e} Marr{\'o}n},
publisher = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
series = {Technical Report},
volume = {2006/07},
pages = {27--31},
type = {Konferenz-Beitrag},
month = {Juli},
year = {2006},
keywords = {Virtual Memory; Wireless Sensor Networks; Flash Memory; Memory Layout},
language = {Englisch},
cr-category = {D.4.4 Operating Systems Communications Management,
D.3.4 Programming Languages Processors},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2006-55/INPROC-2006-55.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {In this paper we present a virtual memory system for sensor networks that uses
flash-memory to extend the amount of RAM available on each node. By analyzing
access traces from simulation tools it creates an efficient memory layout that
makes virtual memory viable despite the resource constraints typical for sensor
networks.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2006-55&engl=0}
}
@inproceedings {INPROC-2006-51,
author = {Frank D{\"u}rr and Kurt Rothermel},
title = {{An Overlay Network for Forwarding Symbolically Addressed Geocast Messages}},
booktitle = {Proceedings of the 15th International Conference on Computer Communications and Networks (ICCCN '06); Arlington, VA, October 9-11, 2006},
publisher = {IEEE},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
pages = {427--434},
type = {Konferenz-Beitrag},
month = {Oktober},
year = {2006},
isbn = {0-4244-0572-6},
keywords = {network protocols; communication protocols; geocast; location-based services},
language = {Englisch},
cr-category = {C.2 Computer-Communication Networks},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2006-51/INPROC-2006-51.pdf,
http://dx.doi.org/10.1109/ICCCN.2006.286314},
contact = {frank.duerr@ipvs.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Geocast, which allows for forwarding messages to hosts residing at specified
geographic areas, is a promising communication paradigm with a wide range of
applications. Geocast target areas can be specified either by geometric figures
or symbolic addresses, such as /usa/fl/miami/market-street.
In this paper, we present a novel geocast routing protocol for symbolically
addressed messages. Compared to geocast protocols based on geometric
information, our protocol can operate on simple symbolic location models, and
message forwarding does not require costly geometric operations. The proposed
protocol is based on an overlay network that is mapped to an IP-based network
infrastructure. The overlay network is structured in a hierarchical fashion, to
ensure a scalable global geocast service supporting also large target areas.
Although our protocol does not rely on a layer 3 multicast protocol, we also
show how to improve the performance of message forwarding by integrating a
light-weight layer 3 multicast protocol. Our evaluations of the protocol
underline the scalability of our approach and show good routing quality leading
to short message paths.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2006-51&engl=0}
}
@inproceedings {INPROC-2006-50,
author = {Andreas Lachenmann and Pedro Jos{\'e} Marr{\'o}n and Daniel Minder and Matthias Gauger and Olga Saukh and Kurt Rothermel},
title = {{TinyXXL: Language and Runtime Support for Cross-Layer Interactions}},
booktitle = {Proceedings of the Third Annual IEEE Communications Society Conference on Sensor, Mesh and Ad Hoc Communications and Networks (SECON 2006)},
publisher = {IEEE},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {178--187},
type = {Konferenz-Beitrag},
month = {September},
year = {2006},
isbn = {1-4244-0626-9},
keywords = {wireless sensor networks; cross-layer interactions; TinyXXL; data exchange; data sharing; parametrization},
language = {Englisch},
cr-category = {D.3.3 Programming Language Constructs and Features,
D.2.11 Software Engineering Software Architectures,
C.2.2 Network Protocols},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2006-50/INPROC-2006-50.pdf,
http://www.ipvs.uni-stuttgart.de/abteilungen/vs/forschung/projekte/tinycubus/start},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {In the area of wireless sensor networks, cross-layer interactions are often
preferred to strictly layered architectures. However, architectural properties
such as modularity and the reusability of components suffer from such
optimizations. In this paper we present TinyXXL that provides programming
abstractions for data exchange, a form of cross-layer interaction with a large
potential for optimizations. Our approach decouples components providing and
using data, and it allows for automatic optimizations of applications composed
of reusable components. Its runtime representation is efficient regarding
memory consumption and processing overhead.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2006-50&engl=0}
}
@inproceedings {INPROC-2006-46,
author = {Susanne B{\"u}rklen and Pedro Jos{\'e} Marr{\'o}n and Kurt Rothermel and Timo Pfahl},
title = {{Hoarding Location-Based Data Using Clustering}},
booktitle = {Proceedings of the 4-th ACM International Workshop on Mobility Management and Wireless Access Protocols (MobiWAC 2006); Torremolinos, Spain, Oct. 2, 2006},
publisher = {Sheridan Printing},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
pages = {1--1},
type = {Konferenz-Beitrag},
month = {Oktober},
year = {2006},
language = {Englisch},
cr-category = {H.3 Information Storage and Retrieval},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {The proliferation of mobile devices and the fact that high-bandwidth and
continuous connectivity is not available everywhere, has led to the creation of
hoarding algorithms that attempt to mitigate the problems related with
disconnected operation and with the operation in areas where bandwidth is
either scarce or expensive. In this paper, we present a hoarding scheme for
location-based data in semi-structured information spaces, such as the World
Wide Web, which relies on clustering of semantically related data items. We
show by means of experimental evaluation that our clustering-based approach
outperforms existing hoarding techniques that do not make use of clustering by
a factor of more than 2 in terms of hoard cache hit ratio.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2006-46&engl=0}
}
@inproceedings {INPROC-2006-43,
author = {J{\"o}rg H{\"a}hner and Pedro Jos{\'e} Marr{\'o}n and Kurt Rothermel},
title = {{Maintaining Update-Linearizability for Replicated Information in MANETs}},
booktitle = {Proceedings of the First International Conference on Communication System Software and Middleware (COMSWARE 2006); New Delhi, India, January 2006},
publisher = {IEEE},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
type = {Konferenz-Beitrag},
month = {Januar},
year = {2006},
keywords = {update consistency; MANET; dissemination; replication},
language = {Deutsch},
cr-category = {H.2 Database Management,
C.2 Computer-Communication Networks,
E.1 Data Structures},
contact = {joerg.haehner@ipvs.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {In the process of observing changes in our surroundings, the chronological
ordering of these observations plays a crucial role. The same holds for many
applications that employ sensors to gather information about their physical
environment in order to adapt to changes. In this paper, we present a data
replication algorithm for mobile ad hoc and sensor networks that guarantees
chronological ordering of update operations for information objects.
Information objects reflect the state of physical world objects and are updated
by devices equipped with appropriate sensors. Our algorithm allows for multiple
independent devices to update the same object and does not require synchronized
clocks. We describe the underlying consistency model called
update-linearizability and the design of the algorithm, and present simulations
that show its feasibility in practice.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2006-43&engl=0}
}
@inproceedings {INPROC-2006-42,
author = {Abdelmajid Khelil and Pedro Jos{\'e} Marr{\'o}n and Christian Becker and Kurt Rothermel},
title = {{Hypergossiping: A Generalized Broadcast Strategy for MANETs}},
booktitle = {Elsevier Ad Hoc Networks Journal},
publisher = {Elsevier},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
type = {Konferenz-Beitrag},
month = {August},
year = {2006},
keywords = {mobile ad hoc network (MANET); adaptive broadcast; network partitioning},
language = {Englisch},
cr-category = {C.2.1 Network Architecture and Design,
C.2.2 Network Protocols},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Broadcasting is a commonly used communication primitive needed by many
applications and protocols in mobile ad hoc networks (MANET). Unfortunately,
most broadcast solutions are tailored to one class of MANETs with respect to
node density and node mobility and are unlikely to operate well in other
classes. In this paper, we introduce hypergossiping, a novel adaptive broadcast
algorithm that combines two strategies. Hypergossiping uses adaptive gossiping
to efficiently distribute messages within single network partitions and
implements an efficient heuristic to distribute them across partitions.
Simulation results in ns-2 show that hypergossiping operates well for a broad
range of MANETs with respect to node densities, mobility levels and network
loads.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2006-42&engl=0}
}
@inproceedings {INPROC-2006-34,
author = {Abdelmajid Khelil},
title = {{Mobility-Aware Buffering for Delay-Tolerant Broadcasting in MANETs}},
booktitle = {to appear in Proceedings of The International Symposium on Performance Evaluation of Computer and Telecommunication Systems (SPECTS'06), Calgary, Canada, July, 2006},
address = {Calgary, Canada},
publisher = {n/a},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
pages = {0--1},
type = {Konferenz-Beitrag},
month = {Juli},
year = {2006},
keywords = {MANET, Delay-Tolerant Ad Hoc Networking, Broadcasting, Network Partitioning, Hypergossiping},
language = {Englisch},
cr-category = {C.2.1 Network Architecture and Design,
C.2.2 Network Protocols,
I.6.5 Model Development},
contact = {khelil.informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Mobility plays a major role in mobile ad hoc networks (MANETs), since it
stresses networking tasks such as routing on the one hand, but aids to increase
the network capacity and to overcome network partitioning on the other hand. To
benefit from node mobility, a new class of MANET protocols and applications are
designed to be delay-tolerant and mobility-aided. The main communication
paradigm here is store-and-forward. For delay-tolerant mobility-aided
networking, mobility on a large time-scale is a key feature. So far however, a
few work is done to adapt store-and-forward concepts to the large time-scale
mobility.
Our first step that simplifies the adaptation to node mobility, is a set of
novel mobility metrics. These metrics quantify the mobility on a large
time-scale and are based on the pair-wise contacts between mobile nodes. In
this paper, we show how to exploit these mobility metrics to design an
efficient buffering strategy for hypergossiping, a delay-tolerant
mobility-aided MANET broadcasting protocol. The novel buffering strategy
detects relevant mobility patterns at run-time, using contact-based mobility
metrics, and adapts the buffering decision to the detected mobility pattern.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2006-34&engl=0}
}
@inproceedings {INPROC-2006-29,
author = {Illya Stepanov and Kurt Rothermel},
title = {{Simulating Mobile Ad-Hoc Networks in City Scenarios}},
booktitle = {Proceedings of the 4th International Conference on Wired/Wireless Internet Communications (WWIC 2006), Bern, Switzerland, May 2006},
editor = {T. Braun and G. Carle and S. Fahmy and Y. Koucheryavy (Eds.)},
publisher = {Springer},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {1--12},
type = {Konferenz-Beitrag},
month = {Mai},
year = {2006},
isbn = {3-540-34023-8},
keywords = {Communication systems; mobile communication; modeling; simulation},
language = {Englisch},
cr-category = {C.2.1 Network Architecture and Design,
C.4 Performance of Systems,
I.6.3 Simulation and Modeling Applications},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2006-29/INPROC-2006-29.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Simulation tools are frequently used for performance evaluations of mobile
ad-hoc networks. Currently the tools poorly support urban scenarios, since they
do not take a spatial environment into account. In this paper, we describe a
platform for the modeling of city scenarios. We extend ns-2 with corresponding
mobility and wireless transmission models. By using its emulation facility, we
integrate unmodified applications and real implementations of network
protocols. We demonstrate the usefulness of the platform for performance
evaluations by modeling a mobile application in a simulated environment of
Stuttgart downtown. We show that it helps identifying application problems
before deployment.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2006-29&engl=0}
}
@inproceedings {INPROC-2006-27,
author = {Florian Bitzer and Dominique Dudkowski and Norbert Haala},
title = {{Investigation of Empirical Pedestrian Traces for Calibrating Microscopic Mobility Models}},
booktitle = {Proceedings of the International Symposium Networks for Mobility 2006, Stuttgart, Germany},
editor = {Wolfgang M{\"o}hlenbrink and Frank Englmann and Markus Friedrich and Ullrich Martin and Ulrich Hangleiter},
address = {Stuttgart},
publisher = {Eigenverlag},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
type = {Konferenz-Beitrag},
month = {Oktober},
year = {2006},
keywords = {pedestrian; microscopic; simulation; empirical data},
language = {Deutsch},
cr-category = {I.6.0 Simulation and Modeling General},
contact = {florian.bitzer@isv.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme;
Universit{\"a}t Stuttgart, Institut f{\"u}r Photogrammetrie (ifp);
Universit{\"a}t Stuttgart, Institut f{\"u}r Stra{\ss}en- und Verkehrswesen, Abteilung Stra{\ss}enplanung und Stra{\ss}enbau (ISV/SuS)},
abstract = {In the research field of microscopic simulation models for pedestrian mobility
substantial pro-gress was achieved in recent years. The ongoing strong growth
of computational power to-gether with new approaches founding on cellular
automata allows the microscopic simulation of large-scale scenarios like the
evacuation of whole soccer stadiums, as self-organization can be initiated by
using a relatively simple rule set. Recent developments at the Institute for
Road and Transportation Science will now ease the simulation of everyday
situations with multiple source-destination relations as they occur e.g. in
city centers, airport terminals and public transport interchange points.
Regardless of its level of detail, each mobility simulation model is in need of
comprehensive empirical data for validation and calibration purposes. Thereby
macroscopic mobility models, e.g. traffic assignment models, only need cross
sectional data like “vehicles per time seg-ment” for instance. Concerning
pedestrian mobility on the large scale, only macroscopic sur-veys like cordon
counting in a public transport system or traveler flow counting in an airport
terminal have been carried out up to now. However, the empirical data resulting
from these surveys is not suitable for calibrating and validating microscopic
simulation models for pedes-trian traffic, because they only deliver aggregated
traffic flow data. Therefore it was neces-sary to develop a new survey method
which allows the noninvasive recording and analysis of pedestrian traces. In
collaboration with the Institute of Transport Research of the German Aerospace
Center (DLR) a two-day video survey at the Campus Vaihingen of Universit{\"a}t
Stuttgart was carried out. By a network of four wide-angle cameras placed at
strategic viewpoints, a central area of the campus of about 20,000 sqm
incorporating the commuter railway station and the sur-rounding buildings was
recorded at a rate of five frames per second with a spatial resolution of
1024x786 pixels of each camera. In order to analyze the collected imagery of
some giga-bytes of raw data, solutions for several challenges had to be found.
First, suitable tie and control points for georeferencing of the respective
cameras had to be identified. This is re-quired to transform the pedestrians’
trajectories from the respective images to a common reference system. Second,
methods for deriving pedestrian trajectories from consecutive frames as well as
the distinction between pedestrians’ movements and the movement of all other
objects had to be improved. Third, unique tags had to be assigned to the
observed pe-destrians to trace them over the whole monitored area while they
are tracked by the different cameras. The resulting new and unique data set not
only consists of pedestrian traces with decided timestamps at each waypoint, it
also includes the resulting source-destination matrix on which the timestamp
for each pedestrian allows many kinds of statistical operations, e.g. the
computation of the average walking time and standard deviation on different
source-destination relations. The availability of these real traces will
finally enable extensive and high-quality calibration and validation operations
for microscopic simulation models. The dataset may even serve as input
information for simulation in the research field of communi-cation networks, in
particular, in mobile ad hoc networks. In the near future, the detailed
ex-amination of many other problems, such as counter flow, crossing behavior,
and path build-ing phenomena based on real microscopic mobility data will
become possible.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2006-27&engl=0}
}
@inproceedings {INPROC-2006-25,
author = {Susanne B{\"u}rklen and Pedro Jos{\'e} Marr{\'o}n and Kurt Rothermel},
title = {{Proactive Hoarding in Location-Based Systems}},
booktitle = {Proceedings of the Second Workshop on Context Awareness for Proactive Systems (CAPS 2006)},
publisher = {Springer-Verlag},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
pages = {1--11},
type = {Konferenz-Beitrag},
month = {Juni},
year = {2006},
keywords = {Hoarding; location-based systems},
language = {Englisch},
cr-category = {H.3 Information Storage and Retrieval},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {The proliferation of mobile devices and the fact that high-bandwidth
connectivity is not available everywhere, has led to the development of
hoarding algorithms. The aim of these algorithms is to select and prefetch
data, mobile users might access when they are weakly connected in the future.
The data is selected based on context information of users, such as their
location. In this paper, we present a hoarding approach for semi-structured
information items and introduce our Bounded Path Search algorithm (BPS) for the
computation of the hoard list. We show by means of experimental evaluation that
BPS outperforms existing hoarding techniques that use standard graph search
algorithms by a factor of 2.7 in terms of hoard cache hit ratio.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2006-25&engl=0}
}
@inproceedings {INPROC-2006-13,
author = {Tobias Drosdol and Dominique Dudkowski and Christian Becker and Kurt Rothermel},
title = {{Efficient Indexing of Symbolic Location Information}},
booktitle = {Proceedings of the Second Workshop on Context Awareness for Proactive Systems (CAPS 2006)},
address = {Kassel, Germany},
publisher = {---},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
type = {Konferenz-Beitrag},
month = {Juni},
year = {2006},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems,
E.2 Data Storage Representations,
H.3 Information Storage and Retrieval},
contact = {Tobias.Drosdol@ipvs.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Providing context-awareness in future applications demands for accurate
information about the positions of a potentially large number of mobile
objects. This requires location management systems that are capable of coping
with a huge amount of such highly dynamic data. To efficiently retrieve
relevant information, e.g., all objects located inside a given area, these
systems must utilize adequate index structures. In the past, suitable indexes
have been explored for geometric representations of location information only.
The contribution of this paper is a generic index structure for the efficient
management of symbolic location information. Based on different index variants
an adaptive approach is derived that can be adjusted to accommodate different
ratios of update and retrieval load. Our experimental results show how this can
significantly increase the overall performance of a location management system.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2006-13&engl=0}
}
@inproceedings {INPROC-2006-08,
author = {Torben Weis and Marcus Handte and Mirko Knoll and Christian Becker},
title = {{Customizable Pervasive Applications}},
booktitle = {Proceedings of 4th IEEE International Conference on Pervasive Computing and Communications},
publisher = {-},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {1--6},
type = {Konferenz-Beitrag},
month = {M{\"a}rz},
year = {2006},
language = {Englisch},
cr-category = {C.2 Computer-Communication Networks,
D.2 Software Engineering,
D.3 Programming Languages},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Human behavior and housing resist every stan-dardization effort. Many aspects
such as different technical equipment, furniture, and usage patterns make our
surroundings as individual as ourselves. Thus, the personalization of pervasive
applications is a fundamental requirement. To enable the development of custom
pervasive applications, we propose a soft-ware development process. This
process is based on the successful process for modern desktop applica-tions.
There, developers create extensible applications and components. Customizers
use the resulting arti-facts to develop custom applications. Finally, users
configure applications to their individual needs by adjusting predefined
settings. To adopt this process for Pervasive Computing, we present a component
system for developers, a graphical toolkit for customizers, and
self-configuration algorithms to ease the deployment.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2006-08&engl=0}
}
@inproceedings {INPROC-2006-06,
author = {Matthias Wieland and Frank Leymann and Lamine Jendoubi and Daniela Nicklas and Frank D{\"u}rr},
title = {{Task-orientierte Anwendungen in einer Smart Factory}},
booktitle = {Mobile Informationssysteme - Potentiale, Hindernisse, Einsatz. Proceedings MMS´06},
editor = {Thomas Kirste and Birgitta K{\"o}nig-Ries and Key Pousttchi and Klaus Turowski},
address = {Bonn},
publisher = {Gesellschaft f{\"u}r Informatik},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
series = {Lecture Notes in Informatics (LNI)},
volume = {P-76},
pages = {139--143},
type = {Konferenz-Beitrag},
month = {Februar},
year = {2006},
isbn = {3-88579-170-6},
keywords = {Kontextbezogene Applikationen; Smart Factory; kontextbezogene Workflows},
language = {Deutsch},
cr-category = {H.4.2 Information Systems Applications Types of Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2006-06/INPROC-2006-06.pdf,
http://www.nexus.uni-stuttgart.de/},
contact = {Matthias Wieland wieland@informatik.uni-stuttgart.de, Daniela Nicklas nicklas@ipvs.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Anwendersoftware;
Universit{\"a}t Stuttgart, Institut f{\"u}r Industrielle Fertigung und Fabrikbetrieb (IFF);
Universit{\"a}t Stuttgart, Institut f{\"u}r Architektur von Anwendungssystemen;
Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {In diesem Beitrag wird aufgezeigt, welche M{\"o}glichkeiten sich durch den Einsatz
task-orientierter, explorativer Anwendungen im Umfeld einer Smart Factory
ergeben. Nach einer kurzen Charakterisierung dieser Anwendungsklasse wird ein
Szenario geschildert, das Wartungsaufgaben in einer Fabrik mit diesen Konzepten
l{\"o}st. Daraus ergibt sich die Vision einer Smart Factory, in der die
Gesch{\"a}ftsprozesse {\"u}ber ein Kontextmodell mit den technischen Prozessen der
Produktionsstra{\ss}e gekoppelt werden.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2006-06&engl=0}
}
@inproceedings {INPROC-2006-05,
author = {Dominique Dudkowski and Pedro Jos{\'e} Marr{\'o}n and Kurt Rothermel},
title = {{An Efficient Resilience Mechanism for Data Centric Storage in Mobile Ad Hoc Networks}},
booktitle = {Proceedings of the 7th International Conference on Mobile Data Management (MDM '06); Nara, Japan, May 2006.},
publisher = {IEEE},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
type = {Konferenz-Beitrag},
month = {Mai},
year = {2006},
keywords = {Mobile Ad Hoc Networks; mobile Ad-hoc-Netze; Data Centric Storage; DCS; datenzentrische Speicherung; infrastrukturlose Systeme; MANETs; MANET},
language = {Englisch},
cr-category = {C.2 Computer-Communication Networks},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2006-05/INPROC-2006-05.pdf},
contact = {dominique.dudkowski@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Data Centric Storage (DCS) is a powerful storage paradigm for wireless ad hoc
networks. In mobile ad hoc networks (MANETs), however, the mobility and varying
density of nodes may significantly impact the efficiency of data access and the
level of data consistency for existing DCS mechanisms. In this paper, we
propose an efficient resilience mechanism for data centric storage that
supports DCS in mobile environments. We introduce a novel indirection strategy
that enables us to distinguish the storage of data at dedicated server nodes
from the storage of additional information to locate these servers. Our
approach places server location information dynamically in strategic parts of
the network based on its current topology. Combining our server location
advertisement with any geographic routing protocol, we provide a robust data
update and query processing technique for data centric storage in MANETs. We
show analytically and by means of experimental evaluations that, despite the
additional indirection during packet forwarding, our approach provides superior
storage and retrieval performance than the original DCS algorithm even for
large amounts of dynamic data.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2006-05&engl=0}
}
@inproceedings {INPROC-2006-04,
author = {Dominique Dudkowski and Pedro Jos{\'e} Marr{\'o}n and Kurt Rothermel},
title = {{Efficient Algorithms for Probabilistic Spatial Queries in Mobile Ad Hoc Networks.}},
booktitle = {Proceedings of the First International Conference on Communication System Software and Middleware (COMSWARE 2006); New Delhi, India, January 2006.},
publisher = {IEEE},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
type = {Konferenz-Beitrag},
month = {Januar},
year = {2006},
keywords = {Mobile Ad Hoc Networks; Mobile Ad-hoc-Netze; infrastrukturlose Systeme; probabilistische Anfragen; r{\"a}umliche Anfragen; spatial queries; probabilistic queries; Anfrageverarbeitung; query processing; data management; MANET},
language = {Englisch},
cr-category = {C.2 Computer-Communication Networks},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2006-04/INPROC-2006-04.pdf},
contact = {dominique.dudkowski@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {With the proliferation of wireless communication and sensor technology, the
importance of location-based applications has tremendously increased. In order
to support these applications, services that implement algorithms for the
efficient processing of spatial queries, such as range and k-nearest neighbor
queries, are definitely beneficial. In this paper, we propose definitions of
probabilistic range and k-nearest neighbor query semantics that take into
account the inaccurate position information acquired from positioning systems.
We introduce efficient algorithms for distributed storage of the dynamic
information captured by positioning sensors on mobile network nodes, and for
processing the aforementioned queries in mobile ad hoc networks. We show by
evaluation that the studied algorithms incur small communication costs, and
that the query algorithms return accurate results in a timely manner.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2006-04&engl=0}
}
@inproceedings {INPROC-2006-02,
author = {Olga Saukh and Pedro Jos{\'e} Marr{\'o}n and Andreas Lachenmann and Matthias Gauger and Daniel Minder and Kurt Rothermel},
title = {{Generic Routing Metric and Policies for WSNs}},
booktitle = {Wireless Sensor Networks: Third European Workshop, EWSN 2006, Zurich, Switzerland, February 13-15, 2006. Proceedings},
editor = {Kay R{\"o}mer and Holger Karl and Friedemann Mattern},
publisher = {Springer-Verlag},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
series = {Lecture Notes in Computer Science},
volume = {3868},
pages = {99--114},
type = {Konferenz-Beitrag},
month = {Januar},
year = {2006},
isbn = {3-540-32158-6},
keywords = {Wireless Sensor Network},
language = {Englisch},
cr-category = {C.3 Special-Purpose and Application-Based Systems,
C.2.2 Network Protocols},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2006-02/INPROC-2006-02.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Energy-aware algorithms have proven to be a crucial part of sensor network
applications, especially if they are required to operate for extended periods
of time. Among these, efficient routing algorithms are of utter importance
since their effect can be experienced by all other layers. Thus, the
optimization and accurate prediction of the lifetime of the system can only be
performed in the presence of accurate execution models that take energy
consumption into account. In this paper, we propose a generic routing metric
and associated policies that encompass most other existing metrics in the
literature and use this model for the optimal construction of a routing tree to
the sink. We also provide experimental results that show the benefits of using
our novel metric.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2006-02&engl=0}
}
@inproceedings {INPROC-2006-01,
author = {Pedro Jos{\'e} Marr{\'o}n and Matthias Gauger and Andreas Lachenmann and Daniel Minder and Olga Saukh and Kurt Rothermel},
title = {{FlexCup: A Flexible and Efficient Code Update Mechanism for Sensor Networks}},
booktitle = {Wireless Sensor Networks: Third European Workshop, EWSN 2006, Zurich, Switzerland, February 13-15, 2006. Proceedings},
editor = {Kay R{\"o}mer and Holger Karl and Friedemann Mattern},
publisher = {Springer-Verlag},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
series = {Lecture Notes in Computer Science},
volume = {3868},
pages = {212--227},
type = {Konferenz-Beitrag},
month = {Januar},
year = {2006},
isbn = {3-540-32158-6},
language = {Englisch},
cr-category = {C.3 Special-Purpose and Application-Based Systems,
D.3.4 Programming Languages Processors,
D.4.9 Systems Programs and Utilities},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2006-01/INPROC-2006-01.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {The ability to update the program code installed on wireless sensor nodes plays
an import role in the highly dynamic environments sensor networks are often
deployed in. Such ode update mechanisms should support flexible reconfiguration
and adaptation of the sensor nodes but should also operate in an energy and
time efficient manner. In this paper, we present FlexCup, a flexible code
update mechanism that minimizes the energy consumed on each sensor node for the
installation of arbitrary code changes. We describe two different versions of
FlexCup and show, using a precise hardware emulator, that our mechanism is able
to perform updates up to 8 times faster than related code update algorithms
found in the literature, while consuming only an eighth of the energy.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2006-01&engl=0}
}
@inproceedings {INPROC-2005-98,
author = {Abdelmajid Khelil and Jos{\'e} Pedro Marr{\'o}n and Kurt Rothermel},
title = {{Contact-Based Mobility Metrics for Delay-Tolerant Ad Hoc Networking}},
booktitle = {Proceedings of the 13th IEEE International Symposium on Modeling, Analysis, and Simulation of Computer and Telecommunication Systems: MASCOTS'05; Atlanta, Georgia, September, 2005},
address = {Los Alamitos, California},
publisher = {IEEE Conference Publishing Services},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
series = {IEEE Computer Society Order Number},
volume = {P2458},
pages = {435--444},
type = {Konferenz-Beitrag},
month = {September},
year = {2005},
isbn = {0-7695-2458-3},
keywords = {MANET; Contact; encounter; delay-tolerant; mobility metrics},
language = {Englisch},
cr-category = {C.2.1 Network Architecture and Design,
C.2.2 Network Protocols,
I.6.5 Model Development},
contact = {Universit{\"a}t Stuttgart / IPVS, Universit{\"a}tsstr. 38 70569 Stuttgart, Germany, {khelil, marron, rothermel}@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Mobility plays a major role in mobile ad hoc networks (MANETs) since it
stresses networking tasks such as routing on one hand but aids to increase the
network capacity and to overcome network partitioning on the other hand. To
benefit from node mobility, a new class of MANET protocols and applications are
designed to be delay-tolerant and mobility-aided. For delay-tolerant
mobility-aided networking mobility on a large time-scale is a key feature. So
far, in MANETs, the mobility is investigated on a short time-scale. That is why
we present novel mobility metrics that quantify a large time-scale mobility.
Our approach is based on the pair-wise contacts between mobile nodes. We
present a detailed statistical study of our novel metrics using the widely used
random waypoint mobility model as an example. For the random waypoint model we
introduce an analytical model, which allows protocol developers to analytically
compute some of the designed metrics. In order to provide an easy access to
these metrics in a network simulator, we provide a framework for ns-2.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2005-98&engl=0}
}
@inproceedings {INPROC-2005-97,
author = {Abdelmajid Khelil and Jos{\'e} Pedro Marr{\'o}n and R{\"u}diger Dietrich and Kurt Rothermel},
title = {{Evaluation of Partition-Aware MANET Protocols and Applications with ns-2}},
booktitle = {Proceedings of the 2005 International Symposium on Performance Evaluation of Computer and Telecommunication Systems (SPECTS ’05), Philadelphia, PA, July 24–28, 2005},
address = {Cherry Hill, NJ, USA},
publisher = {Simulation Councils, Inc.},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
series = {SIM Series},
volume = {37(3)},
pages = {435--444},
type = {Konferenz-Beitrag},
month = {Juli},
year = {2005},
isbn = {1-56555-300-4},
keywords = {MANET; Network Partitioning; Protocol Evaluation; ns-2; Hypergossiping},
language = {Englisch},
cr-category = {C.2.1 Network Architecture and Design,
C.2.2 Network Protocols},
contact = {Universit{\"a}t Stuttgart / IPVS, Universit{\"a}tsstr. 38 70569 Stuttgart, Germany, {khelil, marron, rothermel}@informatik.uni-stuttgart.de, ruediger.dietrich@gmx.net},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Mobile Ad Hoc Networks (MANET) are composed of mobile devices equipped with
short range radio capabilities. Communication is possible between devices
located in each other's transmission range. Especially in sparse MANETs, node
mobility leads to frequent network partitioning, which makes typical
networking tasks much more difficult. Although we observe an increasing need
for partitioning information, the widely used network simulator ns2 does not
support protocol developers to easily evaluate their protocols concerning
network partitioning.
To simplify the evaluation of MANET partitionaware protocols and applications
in ns2, we extend the simulator to provide partitioning information at the
simulation time. Developers might be interested in using this information to
evaluate their partitionaware protocols and applications and to compare their
performance to the optimal case.
Hypergossiping is a partitionaware broadcast protocol for MANETs. Nodes
rebroadcast messages upon joining the partitions that have not yet received
these messages. Hypergossiping uses a heuristic to detect partition joins. We
show the feasibility of our approach and the applicability of the partitioning
information we provide for ns2 users to compare the performance of our
approach to the optimal case.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2005-97&engl=0}
}
@inproceedings {INPROC-2005-96,
author = {Abdelmajid Khelil and Jos{\'e} Pedro Marr{\'o}n and Christian Becker and Kurt Rothermel},
title = {{Hypergossiping: A Generalized Broadcast Strategy for Mobile Ad Hoc Networks}},
booktitle = {Proceedings of Kommunikation in Verteilten Systemen 2005 (KiVS'05); Kaiserslautern, Germany, 2005},
address = {Kaiserslautern},
publisher = {Springer-Verlag},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
pages = {0--1},
type = {Konferenz-Beitrag},
month = {Februar},
year = {2005},
keywords = {mobile ad hoc network (MANET); adaptive broadcast; network partitioning},
language = {Englisch},
cr-category = {C.2.1 Network Architecture and Design,
C.2.2 Network Protocols},
contact = {Universit{\"a}t Stuttgart / IPVS / VS Universit{\"a}tsstrasse 38, 70569 Stuttgart, Germany +49 711 7816 {251, 357, 228, 434} {khelil, marron, becker, rothermel}@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Broadcasting is a commonly used communication primitive needed by many
applications and protocols in mobile ad hoc networks (MANETs). Unfortunately,
most broadcast solutions are tailored to one class of MANETs with respect to
node density and node mobility and are unlikely to operate well in other
classes. In this paper, we introduce hypergossiping, a novel adaptive broadcast
algorithm that combines two strategies. Hypergossiping uses adaptive gossiping
to efficiently distribute messages within single network partitions and
implements an efficient heuristic to distribute them across partitions.
Simulation results in ns-2 show that hypergossiping operates well for a broad
range of MANETs with respect to node densities and mobility levels.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2005-96&engl=0}
}
@inproceedings {INPROC-2005-85,
author = {Arno Wacker and Mirko Knoll and Timo Heiber and Kurt Rothermel},
title = {{A New Approach for Establishing Pairwise Keys for Securing Wireless Sensor Networks}},
booktitle = {Proceedings of the Third International Conference on Embedded Networked Sensor Systems: ACM SenSys'05; San Diego, California, November 2-4, 2005},
address = {San Diego},
publisher = {ACM Press},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {27--38},
type = {Konferenz-Beitrag},
month = {November},
year = {2005},
isbn = {1-59593-054-X},
keywords = {Wireless Sensor Network Security, Key Establishment},
language = {Englisch},
cr-category = {D.4.6 Operating Systems Security and Protection,
C.2.0 Computer-Communication Networks, General,
C.2.1 Network Architecture and Design,
C.2.2 Network Protocols},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2005-85/INPROC-2005-85.pdf},
contact = {Senden sie eine mail an arno.wacker@ipvs.uni-stuttgart.de oder arno@wacker-online.net},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Wireless sensor networks based on highly resource-constrained devices require
symmetric cryptography in order to make them secure. Integral to this is the
exchange of unique symmetric keys between two devices. In this paper, we
propose a novel decentralized key exchange protocol that guarantees the
confidentiality of a key exchange even if an attacker has compromised some of
the devices in the network. A central objective of the protocol design was to
minimize resource consumption on the individual devices. We evaluate the
resource requirements of our protocol in terms of memory requirements, CPU
usage and network traffic both through theoretical analysis and through
simulations.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2005-85&engl=0}
}
@inproceedings {INPROC-2005-73,
author = {Marcus Handte and Christian Becker and Kurt Rothermel},
title = {{Peer-based Automatic Configuration of Pervasive Applications}},
booktitle = {Proceedings of the 2nd IEEE International Conference on Pervasive Services (ICPS 2005), Santorini, Greece, 11-14 July,2005},
publisher = {-},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {249--260},
type = {Konferenz-Beitrag},
month = {Juli},
year = {2005},
language = {Deutsch},
cr-category = {D.2.7 Software Engineering Distribution, Maintenance, and Enhancement},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Pervasive computing envisions seamless support for user tasks through
cooperating devices that are present in an environment. Fluctuating
availability of devices, induced by mobility and failures, requires mechanisms
and algorithms that allow applications to adapt to changing environmental
conditions without user intervention. To ease the development of adaptive
applications, we have proposed the peer-based component system PCOM. This
system provides fundamental mechanisms to support the automated composition of
applications at runtime. In this paper, we discuss the requirements on
peer-based automatic configuration of pervasive applications and present an
approach based on distributed constraint satisfaction. The resulting algorithm
configures applications in the presence of strictly limited resources. To show
the feasibility of the approach, we have integrated the algorithm into PCOM and
provide an evaluation based on simulation and measurements.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2005-73&engl=0}
}
@inproceedings {INPROC-2005-72,
author = {Marcus Handte and Gregor Schiele and Stephan Urbanski and Christian Becker},
title = {{Adaptation Support for Stateful Components in PCOM}},
booktitle = {Workshop on Software Architectures for Self-Organization: Beyond Ad-Hoc Networking at Pervasive 2005, M{\"u}nchen, Germany, 2005},
publisher = {-},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {1--5},
type = {Konferenz-Beitrag},
month = {Mai},
year = {2005},
keywords = {Adaptation, Stateful Services},
language = {Deutsch},
cr-category = {D.2.7 Software Engineering Distribution, Maintenance, and Enhancement},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {In ever-changing environments as they are envisioned in Pervasive Computing,
applications have to adapt to changes in their execution environment.
Reselection of services is a common technique for stateless services. This
paper presents an approach that allows reselection of stateful services by
combining checkpointing techniques and client-side request histories. An
implementation that allows transparent service reselection is outlined and
parameters for the automatic creation of checkpoints are discussed.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2005-72&engl=0}
}
@inproceedings {INPROC-2005-71,
author = {Pedro Jos{\'e} Marr{\'o}n and Matthias Gauger and Andreas Lachenmann and Daniel Minder and Olga Saukh and Kurt Rothermel},
title = {{Adaptive System Software Support for Cooperating Objects}},
booktitle = {Proceedings of the Workshop on Smart Object Systems; Tokyo, Japan},
publisher = {N/A},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
type = {Konferenz-Beitrag},
month = {September},
year = {2005},
language = {Englisch},
cr-category = {C.2.1 Network Architecture and Design,
C.2.2 Network Protocols,
D.4.7 Operating Systems Organization and Design},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2005-71/INPROC-2005-71.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Efficient system software support is essential for cooperating object
applications in order to cope with the complexity and heterogeneity of typical
scenarios in this domain. In this paper, we argue that adaptation capabilities
should be an integral part of such system software and present the TinyCubus
framework as one possible solution that provides the features required of
system software for cooperating objects.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2005-71&engl=0}
}
@inproceedings {INPROC-2005-70,
author = {Daniel Minder and Pedro Jos{\'e} Marr{\'o}n and Andreas Lachenmann and Kurt Rothermel},
title = {{Experimental construction of a meeting model for smart office environments}},
booktitle = {Proceedings of the First REALWSN 2005 Workshop on Real-World Wireless Sensor Networks, SICS Technical Report T2005:09},
publisher = {N/A},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
type = {Konferenz-Beitrag},
month = {Juni},
year = {2005},
keywords = {Wireless Sensor Network},
language = {Englisch},
cr-category = {C.3 Special-Purpose and Application-Based Systems,
I.6.5 Model Development},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2005-70/INPROC-2005-70.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {The simulation of mobile networks requires mobility models that reproduce the
movement of nodes in a realistic way. Although many such models exist, they are
not well suited for model office scenarios in which movements are mostly caused
by people meeting in known locations to discuss some issues. We present first
steps towards a meeting model for office environments which is based on the
real world movement data gathered after performing a one-week sensor network
deployment in our department. We describe details about the processing of the
acquired data, the construction, and the execution of the movement model.
Finally, we discuss some of the lessons learned throughout the experiment.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2005-70&engl=0}
}
@inproceedings {INPROC-2005-69,
author = {Andreas Lachenmann and Pedro Jos{\'e} Marr{\'o}n and Daniel Minder and Kurt Rothermel},
title = {{An Analysis of Cross-Layer Interactions in Sensor Network Applications}},
booktitle = {Proceedings of the 2005 Intelligent Sensors, Sensor Networks \& Information Processing Conference},
publisher = {IEEE},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {121--126},
type = {Konferenz-Beitrag},
month = {Dezember},
year = {2005},
isbn = {0-7803-9400-3},
keywords = {wireless sensor networks; cross-layer interactions; data sharing; TinyXXL},
language = {Englisch},
cr-category = {C.2.2 Network Protocols,
D.2.11 Software Engineering Software Architectures,
D.3.3 Programming Language Constructs and Features},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2005-69/INPROC-2005-69.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {In the field of sensor networks cross-layer interactions are favored over
strict layering of components and regarded as a way to provide the optimization
capabilities required by sensor network applications. Despite their importance,
developers tend to devise specific solutions for the application at hand,
instead of designing more general primitives that can be used across
applications. The contribution of this paper is twofold: We analyze several
typical sensor network applications and provide a classification of the types
of cross-layer interactions found in their code. Based on this classification,
we propose TinyXXL, an extension to the nesC language that defines primitives
for seamless cross-layer data exchange.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2005-69&engl=0}
}
@inproceedings {INPROC-2005-68,
author = {Pedro Jos{\'e} Marr{\'o}n and Daniel Minder and Andreas Lachenmann and Olga Saukh and Kurt Rothermel},
title = {{Generic Model and Architecture for Cooperating Objects in Sensor Network Environments}},
booktitle = {Proceedings of the 12th International Conference on Telecommunications (ICT 2005)},
publisher = {N/A},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
type = {Konferenz-Beitrag},
month = {Mai},
year = {2005},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2005-68/INPROC-2005-68.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {The complexity and heterogeneity of cooperating object applications in
ubiquitous environments or of applications in the sensor network domain require
the use of generic models and architectures. These architectures should provide
support for the following three key issues: flexible installation, management
and reconfiguration of components in the system; optimization strategies whose
implementation usually involves the proper management of cross-layer
information; and proper adaptation techniques that allow for the
self-configuration of nodes and components in the system with minimal human
intervention. In this paper, we present one possible instance of such a generic
model and architecture and show its applicability using Sustainable Bridges, a
sensor network application that requires the analysis of complex sensor data to
achieve its goal of effectively monitoring bridges for the detection of
structural defects.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2005-68&engl=0}
}
@inproceedings {INPROC-2005-67,
author = {Pedro Jos{\'e} Marr{\'o}n and Daniel Minder and Andreas Lachenmann and Kurt Rothermel},
title = {{TinyCubus: A Flexible and Adaptive Cross-Layer Framework for Sensor Networks}},
booktitle = {4. GI/ITG KuVS Fachgespr{\"a}ch ``Drahtlose Sensornetze'', Technical Report TR 481, Computer Science Department, ETH Zurich},
publisher = {N/A},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {49--54},
type = {Konferenz-Beitrag},
month = {M{\"a}rz},
year = {2005},
language = {Deutsch},
cr-category = {C.2.1 Network Architecture and Design,
C.2.2 Network Protocols},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2005-67/INPROC-2005-67.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {With the proliferation of sensor networks and sensor network applications
during the last few years, the overall complexity of such systems is
continuously increasing. Sensor networks are now heterogeneous in terms of
their hardware characteristics and application requirements even within a
single network. In addition, the requirements of current applications are
expected to change over time. All of this makes developing, deploying, and
optimizing sensor network applications an extremely difficult task. In the
TinyCubus project we research a necessary infrastructure to support the
complexity of such systems.
TinyCubus consists of a data management framework, a cross-layer frame work,
and a configuration engine. The data management framework allows the dynamic
selection and adaptation of system and data management components. The
cross-layer framework supports data sharing and other forms of interaction
between components in order to achieve cross-layer optimizations. The
configuration engine allows code to be distributed reliably and efficiently by
taking into account the topology of sensors and their assigned functionality.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2005-67&engl=0}
}
@inproceedings {INPROC-2005-58,
author = {Daniela Nicklas and Susanne B{\"u}rklen and Tobias Drosdol and Nicola H{\"o}nle},
title = {{Benefits of Context Models in Smart Environments}},
booktitle = {2. GI/ITG KuVS Fachgespr{\"a}ch Ortsbezogene Anwendungen und Dienste},
editor = {J{\"o}rg Roth},
address = {Hagen},
publisher = {Fernuniversit{\"a}t Hagen},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
series = {Informatik Bericht},
volume = {324},
pages = {12--15},
type = {Konferenz-Beitrag},
month = {Juni},
year = {2005},
keywords = {context models; smart environment; smart room; Nexus},
language = {Englisch},
cr-category = {H.4 Information Systems Applications},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2005-58/INPROC-2005-58.pdf,
http://dreamteam.fernuni-hagen.de/fg_lbs/meeting_2/meeting_2.html,
http://www.nexus.uni-stuttgart.de},
contact = {daniela.nicklas@informatik.uni-stuttgart.de susanne.buerklen@informatik.uni-stuttgart.de tobias.drosdol@informatik.uni-stuttgart.de nicola.hoenle@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Anwendersoftware;
Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Ongoing technologic advances drive the emergence of smart items, everyday
objects with embedded microcomputers and communication capabilities. In a smart
envi-ronment a multitude of such smart items exist to assist its users. In this
paper, we will show how smart environments can benefit from the concepts of the
Nexus platform, an open pervasive computing system that supports various kinds
of context-aware applica-tions by providing a federated, potentially global
context model.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2005-58&engl=0}
}
@inproceedings {INPROC-2005-37,
author = {Illya Stepanov and Daniel Herrscher and Kurt Rothermel},
title = {{On the Impact of Radio Propagation Models on MANET Simulation Results}},
booktitle = {Proceedings of the 7th IFIP International Conference on Mobile and Wireless Communication Networks (MWCN 2005), Marrakech, Morocco, September 2005},
publisher = {N/A},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
type = {Konferenz-Beitrag},
month = {September},
year = {2005},
language = {Englisch},
cr-category = {C.2.1 Network Architecture and Design,
C.4 Performance of Systems,
I.6.3 Simulation and Modeling Applications},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2005-37/INPROC-2005-37.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Network simulation tools are frequently used to analyze performance of MANET
protocols and applications. They commonly offer only simple radio propagation
models that neglect obstacles of a propagation environment. In this paper, we
integrate a more accurate radio propagation model into a simulation tool. The
model is based on ray tracing and considers geographic data of the simulation
area. We prove that the usage of a more precise propagation model changes
simulated connection topologies considerably. Consequently, we obtain different
performance evaluation results. To our best knowledge, no other study of MANETs
has been performed so far with such a detailed radio propagation model. Hence,
this paper also gives new insights on the realistic performance of MANETs in
outdoor environments.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2005-37&engl=0}
}
@inproceedings {INPROC-2005-31,
author = {Frank D{\"u}rr and Christian Becker and Kurt Rothermel},
title = {{Efficient Forwarding of Symbolically Addressed Geocast Messages}},
booktitle = {Proceedings of the 14th International Conference on Computer Communications an Networks (ICCCN 2005); San Diego, CA, October 2005},
publisher = {IEEE},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
pages = {77--85},
type = {Konferenz-Beitrag},
month = {Oktober},
year = {2005},
doi = {10.1109/ICCCN.2005.1523812},
keywords = {Geocast, Multicast, Networking, Communication Network, Location-based Service},
language = {Englisch},
cr-category = {C.2 Computer-Communication Networks},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2005-31/INPROC-2005-31.pdf,
http://dx.doi.org/10.1109/ICCCN.2005.1523812},
contact = {frank.duerr@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Geocast is used to send messages to all hosts located in a geographic area.
This target area can be defined either by geometric figures like polygons or by
symbolic addresses like city names or room numbers.
Geographic routing algorithms, which forward messages based on geographic
information, can be used to forward geocast messages. If routing of
symbolically addressed messages is based on geometric coordinates, complex
mappings between symbolic addresses and their geometric extent as well as
complex geometric operations are required. Therefore, we propose a routing
algorithm for symbolically addressed geocast messages that operates directly on
a symbolic location model. This approach does not require any geometric
information for message forwarding, and forwarding decisions can be realized
efficiently by comparably simple operations.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2005-31&engl=0}
}
@inproceedings {INPROC-2005-26,
author = {Steffen Maier and Daniel Herrscher and Kurt Rothermel},
title = {{On Node Virtualization for Scalable Network Emulation}},
booktitle = {Proceedings of the 2005 International Symposium on Performance Evaluation of Computer and Telecommunication Systems (SPECTS ’05), Philadelphia, PA, July 24–28, 2005},
publisher = {Simulation Councils, Inc.},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {917--928},
type = {Konferenz-Beitrag},
month = {Juli},
year = {2005},
keywords = {software performance evaluation; network emulation; mobile ad hoc networks; scalability; virtual routing},
language = {Englisch},
cr-category = {C.4 Performance of Systems,
D.4.4 Operating Systems Communications Management,
D.4.8 Operating Systems Performance,
I.6.3 Simulation and Modeling Applications},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2005-26/INPROC-2005-26.pdf,
http://net.informatik.uni-stuttgart.de/},
contact = {e-mail to Steffen Maier maier@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {During the development of network protocols and distributed applications, their
performance has to be analyzed in appropriate environments. Network emulation
testbeds provide a synthetic, configurable network environment for comparative
performance measurements of real implementations. Realistic scenarios have to
consider hundreds of communicating nodes. Common network emulation approaches
limit the number of nodes in a scenario to the number of computers in an
emulation testbed. To overcome this limitation, we introduce a virtual node
concept for network emulation. The key problem for node virtualization is a
transparent, yet efficient separation of node resources. In this paper, we
provide a brief survey of candidate node virtualization approaches to
facilitate scalable network emulation. Based on the gathered insights, we
propose a lightweight virtualization solution to achieve maximum scalability
and discuss the main points regarding its implementation. We present extensive
evaluations that show the scalability and transparency of our approach in both
a traditional wired infrastructure-based, and in a wireless ad hoc network
emulation scenario. The measurements indicate that our solution can push the
upper limit of emulation scenario sizes by a factor of 20 to 30. Given our
emulation testbed consisting of 64 computers, this translates to possible
scenario sizes of up to 1920 nodes.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2005-26&engl=0}
}
@inproceedings {INPROC-2005-21,
author = {Martin Bauer and Kurt Rothermel},
title = {{An Architecture for Observing PhysicalWorld Events}},
booktitle = {Proceedings of the 11th International Conference on Parallel and Distributed Systems: ICPADS 2005; Fukuoka, Japan, July 20-22, 2005},
publisher = {IEEE Computer Society},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
type = {Konferenz-Beitrag},
month = {Juli},
year = {2005},
keywords = {distributed systems; event service; event service architecture; event observation; real-world events; world model; distributed world model},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems,
H.3.3 Information Search and Retrieval,
H.3.4 Information Storage and Retrieval Systems and Software},
ee = {http://www.nexus.uni-stuttgart.de},
contact = {Martin Bauer mabauer@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {In this paper we investigate the observation of physical world events, i.e.
events that occur in the physical world, and are observed through model data,
part of which is collected by sensors. The physical world events of interest
here are those that are suitable for proactively supporting mobile users. This
means that they have to be on the same highabstraction level as perceived by
the user. In a large-scale system as we envision it, the model data needed for
the observation of these high-level physical world events may be distributed
over multiple servers.
We first present a requirement analysis. Then we propose an event service
architecture that fulfills the requirements. Finally, we show the scalability
of the approach through an evaluation based on a prototype implementation.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2005-21&engl=0}
}
@inproceedings {INPROC-2005-15,
author = {Pedro Jos{\'e} Marr{\'o}n and Andreas Lachenmann and Daniel Minder and J{\"o}rg H{\"a}hner and Robert Sauter and Kurt Rothermel},
title = {{TinyCubus: A Flexible and Adaptive Framework for Sensor Networks}},
booktitle = {Proceedings of the Second European Workshop on Wireless Sensor Networks (EWSN 2005)},
editor = {Erdal Cayirci and Sebnem Baydere and Paul Havinga},
address = {Istanbul, Turkey},
publisher = {IEEE},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
pages = {278--289},
type = {Konferenz-Beitrag},
month = {Januar},
year = {2005},
isbn = {0-7803-8801-1},
keywords = {sensor network; system architecture; adaptation; framework; code distribution; cross-layer},
language = {Englisch},
cr-category = {C.2.1 Network Architecture and Design,
C.2.2 Network Protocols,
D.4.7 Operating Systems Organization and Design},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2005-15/INPROC-2005-15.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {With the proliferation of sensor networks and sensor network applications, the
overall complexity of such systems is continuously increasing. Sensor networks
are now heterogeneous in terms of their hardware characteristics and
application requirements even within a single network. In addition, the
requirements of currently supported applications are expected to change over
time. All of this makes developing, deploying, and optimizing sensor network
applications an extremely difficult task. In this paper, we present the
architecture of TinyCubus, a flexible and adaptive cross-layer framework for
TinyOS based sensor networks that aims at providing the necessary
infrastructure to cope with the complexity of such systems. TinyCubus consists
of a data management framework that selects and adapts both system and data
management components, a cross-layer framework that enables optimizations
through cross-layer interactions, and a configuration engine that installs
components dynamically. Furthermore, we show the feasibility of our
architecture by describing and evaluating a code distribution algorithm that
uses application knowledge about the sensor topology in order to optimize its
behavior.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2005-15&engl=0}
}
@inproceedings {INPROC-2005-14,
author = {Dominique Dudkowski and Tobias Drosdol and Pedro Jos{\'e} Marr{\'o}n},
title = {{Towards Scalable and Efficient Processing of Probabilistic Spatial Queries in Mobile Ad Hoc and Sensor Networks}},
booktitle = {Mobile Datenbanken: heute, morgen und in 20 Jahren. 8. Workshop des GI-Arbeitskreises ``Mobile Datenbanken und Informationssysteme''},
editor = {Birgitta K{\"o}nig-Ries and Michael Klein},
address = {Karlsruhe},
publisher = {-},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
pages = {75--84},
type = {Konferenz-Beitrag},
month = {Februar},
year = {2005},
keywords = {Mobile Ad Hoc Networks; MANETs; MANET; Sensor Networks; WSNs; WSN; Wireless Sensor Networks; Mobile Networks; Queries; Probabilistic Queries; Spatial Queries},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2005-14/INPROC-2005-14.pdf},
contact = {Senden Sie eine E-Mail an dudkowski@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {With the proliferation of sensor technology and advances in wireless
communication, gathering, processing, and querying context information in
mobile ad hoc and sensor networks becomes attractive and feasible. To support
context-aware applications in such networks, efficient processing techniques
for frequently used functionality, such as query and event management, are
highly beneficial. In this paper, we discuss the challenges in efficient
processing of spatial queries in mobile ad hoc and sensor networks. These
comprise advanced query semantics based on inaccurate position information,
efficient protocols and algorithms for data storage and query resolution,
scalability with respect to network size, and support for mobile network nodes.
We outline our concepts for solving these issues and show how they can be
implemented in a suitable software architecture. Using current evaluation
results, we show that our prototype implementation fulfills the stated
challenges.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2005-14&engl=0}
}
@inproceedings {INPROC-2005-12,
author = {Timo Heiber and Pedro Jose Marron},
title = {{Exploring the Relationship between Context and Privacy}},
booktitle = {Privacy, Security and Trust within the Context of Pervasive Computing},
editor = {Philip Robinson and Harald Vogt and Waleed Wagealla},
publisher = {Springer-Verlag},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
series = {The Kluwer International Series in Engineering and Computer Science},
volume = {780},
type = {Konferenz-Beitrag},
month = {Januar},
year = {2005},
isbn = {0-387-23461-6},
language = {Englisch},
cr-category = {H.2.8 Database Applications,
K.6.5 Security and Protection},
contact = {timo.heiber@informatik.uni-stuttgart.de pedro.marron@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Privacy is universally regarded as an important consideration for pervasive
computing environments. This is especially true when considering context-aware
systems, because of the fact that context often contains personal information.
Moreover, an adversary who takes the semantics of the context information into
account can potentially infer knowledge beyond the information represented in
the actual context data. In this paper, we describe a generic framework to
model privacy in context-aware systems and discuss possible inferences based on
the context of ID, location and time.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2005-12&engl=0}
}
@inproceedings {INPROC-2005-11,
author = {Michael Kinateder and Ernesto Baschny and Kurt Rothermel},
title = {{Towards a Generic Trust Model}},
booktitle = {Proceedings of the Third International Conference on Trust Management: iTrust'05; Rocquencourt, France, May 23-26, 2005},
publisher = {Springer-Verlag},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
series = {Lecture Notes in Computer Science},
volume = {3477},
pages = {177--192},
type = {Konferenz-Beitrag},
month = {Mai},
year = {2005},
isbn = {3-540-26042-0},
keywords = {Vertrauen, Reputation, Vertrauensmodell, Vertrauensaktualisierung, trust, reputation, trust model, trust-update},
language = {Englisch},
cr-category = {I.6.5 Model Development,
I.2.6 Artificial Intelligence Learning,
J.4 Social and Behavioral Sciences,
K.4.4 Electronic Commerce},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2005-11/INPROC-2005-11.pdf,
http://unitec.informatik.uni-stuttgart.de},
contact = {Michael Kinateder kinateder@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Research in the area of trust and reputation systems has put a lot of effort in
developing various trust models and associated trust update algorithms that
support users or their agents with different behavioral profiles. While each
work on its own is particularly well suited for a certain user group, it is
crucial for users employing different trust representations to have a common
understanding about the meaning of a given trust statement.
The contributions of this paper are three-fold: Firstly we present the UniTEC
generic trust model that provides a common trust representation for the class
of trust update algorithms based on experiences. Secondly, we show how several
well-known representative trust-update algorithms can easily be plugged into
the UniTEC system, how the mappings between the generic trust model and the
algorithm-specific trust models are performed, and most importantly, how our
abstraction from algorithm-specific details in the generic trust model enables
users using different algorithms to interact with each other and to exchange
trust statements. Thirdly we present the results of our comparative evaluation
of various trust update algorithms under a selection of test scenarios.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2005-11&engl=0}
}
@inproceedings {INPROC-2005-08,
author = {Illya Stepanov and Pedro Jose Marron and Kurt Rothermel},
title = {{Mobility Modeling of Outdoor Scenarios for MANETs}},
booktitle = {Proceedings of the 38th Annual Simulation Symposium (ANSS 38), San Diego, USA, April 2005},
publisher = {N/A},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
type = {Konferenz-Beitrag},
month = {April},
year = {2005},
language = {Englisch},
cr-category = {C.2.1 Network Architecture and Design,
C.4 Performance of Systems,
I.6.3 Simulation and Modeling Applications},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2005-08/INPROC-2005-08.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Mobility of users significantly impacts performance of a mobile ad-hoc network.
Most existing simulation tools offer only a few random mobility models, which
poorly reflect user movements in outdoor scenarios. For example, they do not
consider restrictions of a spatial environment. In this paper, we describe a
comprehensive and extensible approach to model mobility of users in outdoor
scenarios. It reflects the main factors that influence user movement: spatial
environments, user travel decisions, and user movement dynamics. We identify
model parameters and show how to set them for concrete scenarios. We provide a
simulation environment implementing our approach. For concrete scenarios, the
environment supports automatic derivation of some parameters from user position
traces.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2005-08&engl=0}
}
@inproceedings {INPROC-2005-07,
author = {Susanne B{\"u}rklen and Pedro Jos{\'e} Marr{\'o}n and Serena Fritsch and Kurt Rothermel},
title = {{User Centric Walk: An Integrated Approach for Modeling the Browsing Behavior of Users on the Web}},
booktitle = {Proceedings of the 38th IEEE Annual Simulation Symposium (ANSS'05), San Diego, CA, USA},
editor = {IEEE Computer Society Press},
address = {San Diego, CA, USA},
publisher = {IEEE Computer Society Press},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
type = {Konferenz-Beitrag},
month = {April},
year = {2005},
keywords = {Browsing behavior model; heavy tailed distribution},
language = {Englisch},
cr-category = {G.3 Probability and Statistics,
I.6 Simulation and Modeling,
H.1 Models and Principles},
contact = {Contact: buerklen@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {The performance evaluation of Web applications usually requires the utilization
of sequences of user requests for determined Web pages. These sequences can be
obtained, for example, by applying empirical methods (recording the real
sequence of requests), or by applying a formal model for generating synthetic
results. In this paper, we present our Web Browsing Model and the User Centric
Walk algorithm as its implementation. By taking into account the hyperlink
structure as well as the different user behavior on the Web, this algorithm
allows us to generate accurate synthetic data that can be used instead of
empirically obtained requests. As another contribution of this paper we have
shown, based on empirical data, that the probability of choosing some hyperlink
from a given page as well as the probability a user leaves a page without
following a hyperlink is best characterized by a power-law. Moreover, we show
the flexibility and applicability of our model by performing the required
correlations to empirical data, which validate our approach.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2005-07&engl=0}
}
@inproceedings {INPROC-2005-05,
author = {Uwe-Philipp K{\"a}ppeler and Georg Kindermann and Daniela Nicklas and Nicola H{\"o}nle and Dominique Dudkowski},
title = {{Shared Dynamic Context Models: Benefits for Advanced Sensor Data Fusion for Autonomous Robots}},
booktitle = {Proceedings of Artificial Intelligence and Applications 2005; Innsbruck, Austria, February, 14-16, 2005},
publisher = {IASTED},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
type = {Konferenz-Beitrag},
month = {Februar},
year = {2005},
keywords = {Autonomous; Robots; Sensor; Fusion; Nexus; Context; Sensorfusion},
language = {Englisch},
cr-category = {H.3.3 Information Search and Retrieval,
I.2.9 Robotics},
contact = {kaeppeler@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme;
Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Bildverstehen;
Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Anwendersoftware},
abstract = {Information provided by a shared dynamic context model offers new possibilities
in the realm of autonomous robots. The availability of external context
information can be used by a robot to extend and to validate the locally
acquired knowledge about its dynamic environment. A lot of helpful context
information is already available in digital form and its quantity will increase
rapidly, according to the vision of ubiquitous computing.
In this paper we present the Nexus Platform capable of managing a global
dynamic context model that can be addressed and accessed in an easy and uniform
way by all kinds of context-aware applications (like robots). Advantages for an
autonomous wheelchair robot using the Nexus Platform are depicted within an
airport scenario. We further present a framework for a sensor fusion agent,
able to perform multi-sensor data fusion with selective attention control,
concerning the current situation of the environment.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2005-05&engl=0}
}
@inproceedings {INPROC-2005-03,
author = {Matthias Grossmann and Martin Bauer and Nicola H{\"o}nle and Uwe-Philipp K{\"a}ppeler and Daniela Nicklas and Thomas Schwarz},
title = {{Efficiently Managing Context Information for Large-scale Scenarios}},
booktitle = {Proceedings of the 3rd IEEE Conference on Pervasive Computing and Communications: PerCom2005; Kauai Island, Hawaii, March 8-12, 2005},
publisher = {IEEE Computer Society},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
type = {Konferenz-Beitrag},
month = {M{\"a}rz},
year = {2005},
language = {Englisch},
cr-category = {H.3.0 Information Storage and Retrieval General,
H.3.4 Information Storage and Retrieval Systems and Software},
ee = {http://www.nexus.uni-stuttgart.de},
contact = {matthias.grossmann@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Anwendersoftware;
Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Bildverstehen;
Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {In this paper, we address the data management aspect of large-scale pervasive
computing systems. We aim at building an infrastructure that simultaneously
supports many kinds of context-aware applications, ranging from room level up
to nation level. This allembracing approach gives rise to synergetic benefits
like data reuse and sensor sharing. We identify major classes of context data
and detail on their characteristics relevant for efficiently managing large
amounts of it. Based on that, we argue that for large-scale systems it is
beneficial to have special-purpose servers that are optimized for managing a
certain class of context data. In the Nexus project we have implemented five
servers for different classes of context data and a very flexible federation
middleware integrating all these servers. For each of them, we highlight in
which way the requirements of the targeted class of data are tackled and
discuss our experiences.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2005-03&engl=0}
}
@inproceedings {INPROC-2005-01,
author = {Michael Kinateder and Ralf Terdic and Kurt Rothermel},
title = {{Strong Pseudonymous Communication for Peer-to-Peer Reputation Systems}},
booktitle = {Proceedings of the 20th Annual ACM Symposium on Applied Computing: SAC'05; Santa Fe, New Mexico, March 13-17, 2005},
publisher = {ACM Press},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {1570--1576},
type = {Konferenz-Beitrag},
month = {M{\"a}rz},
year = {2005},
isbn = {1-58113-964-0},
keywords = {privacy, anonymous communication, pseudonyms, extended destination routing, Chaum mixes, mix-cascade, onion routing, distributed hash table, Chord},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems,
E.3 Data Encryption,
K.4 Computers and Society},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2005-01/INPROC-2005-01.pdf,
http://unitec.informatik.uni-stuttgart.de/},
contact = {Michael Kinateder kinateder@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {In this paper we present a unique approach to enable untraceable communication
between pseudonyms. In contrast to the related work, our approach provides
strong sender and recipient anonymity most notably by eliminating the need to
know of each other's address.
We use a variation of Chaum mixes to achieve unlinkability between sender and
recipient and introduce a concept called extended destination routing (EDR)
which relies on routing headers constructed in multiple layers of encryption
and published in a distributed hash table (DHT). When a sender intends to
communicate, it contacts the DHT and requests the recipient's routing header,
which is then extended and used for routing the message via a mix cascade to
this recipient.
This work was performed in the context of the UniTEC reputation system and
describes the functionality of its anonymous communication layer, which is
completely independent of the other UniTEC layers. Although trust and
reputation systems in general are typical application areas for our
contribution, the presented concepts are easily applicable not only to other
reputation systems but also other application areas. We have implemented a
prototype of UniTEC and present the first results from an ongoing evaluation in
our network emulation testbed.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2005-01&engl=0}
}
@inproceedings {INPROC-2004-86,
author = {Christian Becker and Marcus Handte and Gregor Schiele and Kurt Rothermel},
title = {{PCOM - A Component System for Pervasive Computing}},
booktitle = {Proceedings of the Second IEEE International Conference on Pervasive Computing and Communications},
publisher = {IEEE Computer Society},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {67--77},
type = {Konferenz-Beitrag},
month = {M{\"a}rz},
year = {2004},
keywords = {pervasive computing; ubiquitous computing; system software; component system; 3PC},
language = {Deutsch},
cr-category = {C.2.4 Distributed Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Applications in the Pervasive Computing domain are challenged by the dynamism
in which their execution environment changes, e.g. due to user mobility. As a
result, applications have to adapt to changes regarding their required
resources. In this paper we present PCOM, a component system for Pervasive
Computing. PCOM offers application programmers a high-level programming
abstraction which captures the dependencies between components using contracts.
The resulting application architecture is a tree formed by components and their
dependencies. PCOM supports automatic adaptation in cases where the execution
environment changes to the better or to the worse. User supplied as well as
system provided strategies take users out of the control loop while offering
flexible adaptation control.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2004-86&engl=0}
}
@inproceedings {INPROC-2004-59,
author = {J{\"o}rg H{\"a}hner and Christian Becker and Pedro Jos{\'e} Marr{\'o}n},
title = {{Consistent Context Management in Mobile Ad Hoc Networks}},
booktitle = {Informatik 2004 - Informatik verbindet. Vol. 1},
editor = {Peter Dadam and Manfred Reichert},
publisher = {Gesellschaft f{\"u}r Informatik},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
series = {Lecture Notes in Informatics},
volume = {51},
pages = {308--313},
type = {Konferenz-Beitrag},
month = {September},
year = {2004},
language = {Englisch},
cr-category = {H.1 Models and Principles},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2004-59/INPROC-2004-59.pdf},
contact = {J{\"o}rg H{\"a}hner joerg.haehner@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {John entered his office. John left his office. The order of these updates to a
context-aware system is important to reflect the state in the real world.
Context information obtained by sensor systems requires consistency concepts
which reflect the chronological ordering in which context information has been
captured. This paper introduces a consistency concept which allows to express
the ordering of events which happened outside of a computer system.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2004-59&engl=0}
}
@inproceedings {INPROC-2004-54,
author = {Kay R{\"o}mer and Christian Frank and Pedro Marr{\'o}n and Christian Becker},
title = {{Generic Role Assignment for Wireless Sensor Networks}},
booktitle = {Proceedings of the 11th ACM SIGOPS European Workshop},
address = {Leuven, Belgium},
publisher = {self-publisher},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {7--12},
type = {Konferenz-Beitrag},
month = {September},
year = {2004},
keywords = {sensor network; self-configuration; role assignment},
language = {Englisch},
cr-category = {C.2.2 Network Protocols,
C.2.3 Network Operations,
D.3.2 Programming Language Classifications},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2004-54/INPROC-2004-54.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Wireless ad hoc networks of sensor nodes are envisioned to be deployed in the
physical environment to monitor a wide variety of real-world phenomena. Almost
any sensor network application requires some form of selfconfiguration, where
sensor nodes take on specific functions or roles in the network without manual
intervention. These roles may be based on varying sensor node properties (e.g.,
available sensors, location, network neighbors) and may be used to support
applications requiring heterogeneous node functionality (e.g., clustering, data
aggregation). In this paper we argue that the assignment of user-defined roles
is a fundamental part of a wide range of sensor network applications.
Consequently, a framework for assignment of roles to sensor nodes in an
application-specific manner could significantly ease sensor network
programming. We outline the general structure of such a framework and present a
first approach to its realization. We demonstrate its utility and feasibility
using a number of concrete examples.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2004-54&engl=0}
}
@inproceedings {INPROC-2004-53,
author = {Kurt Rothermel and Frank D{\"u}rr},
title = {{Location-based Services: Auf dem Weg zu kontextbezogenen Informations- und Kommunikationssystemen}},
booktitle = {Zukunft durch Informationstechnik - Schnell-Mobil-Intelligent -- Jubil{\"a}umsfachtagung 50 Jahre ITG},
editor = {VDE},
address = {Frankfurt, Germany},
publisher = {VDE Verlag GmbH},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
pages = {121--128},
type = {Konferenz-Beitrag},
month = {April},
year = {2004},
isbn = {3-8007-2825-7},
keywords = {Location-based Services; Geocast; Hoarding; Context-aware Systems; Context-aware Computing},
language = {Deutsch},
cr-category = {H.3.4 Information Storage and Retrieval Systems and Software,
C.2.2 Network Protocols,
H.2.8 Database Applications},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2004-53/INPROC-2004-53.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Die rasant fortschreitende Entwicklung von drahtloser Kommunikation,
Positionierungssystemen und Rechnertechnologie sowie deren Integration in
multifunktionale Endger{\"a}te unterst{\"u}tzt die vielversprechende neue
Anwendungsklasse der ortsbezogenen Systeme. Ortsinformation kann von solchen
Anwendungen genutzt werden, um ihr Verhalten dem aktuellen Standort der
Benutzer oder auch anderer Objekte anzupassen. Heute schon bieten Netzbetreiber
so genannte ``Location-based Services'' an, die prim{\"a}r Navigationsfunktionen und
eine ortsbezogene Selektion von Informationen unterst{\"u}tzen. Ortsinformation
kann aber auch auf der Systemebene gewinnbringend verwendet werden, etwa zur
Bereitstellung neuer ortsbezogener Kommunikationskonzepte oder zur Optimierung
der Kommunikation.
In diesem Beitrag wird der Begriff der ortsbezogene Anwendungen erl{\"a}utert und
Anwendungen dieser Art am Beispiel existierender Systeme kurz skizziert.
Au{\ss}erdem werden zwei Beispiele f{\"u}r die Nutzung von Ortsinformation auf
Systemebene gegeben, die Geocast-Kommunikation und ein Hoarding-Verfahren.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2004-53&engl=0}
}
@inproceedings {INPROC-2004-52,
author = {Pedro Marr{\'o}n and Andreas Lachenmann and Daniel Minder and J{\"o}rg H{\"a}hner and Kurt Rothermel and Christian Becker},
title = {{Adaptation and Cross-Layer Issues in Sensor Networks}},
booktitle = {Proceedings of the 2004 Intelligent Sensors, Sensor Networks and Information Processing Conference : ISSNIP '04 ; Melbourne, December 14-17, 2004},
publisher = {self-publisher},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
pages = {623--628},
type = {Konferenz-Beitrag},
month = {Dezember},
year = {2004},
isbn = {0-7803-8894-1},
keywords = {sensor network; system architecture; adaptation; framework; code distribution; cross-layer},
language = {Englisch},
cr-category = {C.2.1 Network Architecture and Design,
C.2.2 Network Protocols,
D.4.7 Operating Systems Organization and Design},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2004-52/INPROC-2004-52.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {An intrinsic characteristic of current projects in the area of sensor networks
is the heterogeneity of hardware and application requirements. In addition, the
requirements of current applications are expected to change over time. This
makes developing, deploying, and optimizing sensor network applications an
extremely difficult task. In this paper, we present the architecture of
TinyCubus, a flexible and adaptive crosslayer framework for TinyOS-based sensor
networks that aims at providing the necessary infrastructure to cope with the
complexity of such systems. TinyCubus consists of three parts: a data
management framework that selects and adapts both system and data management
components, a cross-layer framework that enables optimizations through
cross-layer interactions, and a configuration engine that installs components
dynamically. We show the feasibility of our architecture by describing and
evaluating a code distribution algorithm that optimizes its behavior by using
application knowledge about the sensor topology.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2004-52&engl=0}
}
@inproceedings {INPROC-2004-38,
author = {Christian Becker and Daniela Nicklas},
title = {{Where do spatial context-models end and where do ontologies start? A proposal of a combined approach}},
booktitle = {Proceedings of the First International Workshop on Advanced Context Modelling, Reasoning and Management in conjunction with UbiComp 2004},
editor = {Jadwiga Indulska and David De Roure},
address = {Nottingham, England},
publisher = {University of Southhampton},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
pages = {48--53},
type = {Konferenz-Beitrag},
month = {September},
year = {2004},
isbn = {854328130},
keywords = {Context-Models, Adaptation, Infrastructures for Context-Aware Computing, Ubiquitous Computing},
language = {Deutsch},
cr-category = {H.2.1 Database Management Logical Design},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2004-38/INPROC-2004-38.pdf},
contact = {christian.becker@informatik.uni-stuttgart.de, daniela.nicklas@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme;
Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Anwendersoftware},
abstract = {Context-aware applications adapt their behavior depending on the state of the
physical world along with other information representing context. This requires
context management, i.e., the efficient management of context information and
feasible context representations in order to allow reasoning. This paper
discusses two common approaches, spatial context models and contextual
ontologies, and argues for a combined approach providing the efficiency of
context management through context models combined with the semantic
expressiveness of ontologies.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2004-38&engl=0}
}
@inproceedings {INPROC-2004-29,
author = {Frank D{\"u}rr and Nicola H{\"o}nle and Daniela Nicklas and Christian Becker and Kurt Rothermel},
title = {{Nexus--A Platform for Context-Aware Applications}},
booktitle = {1. GI/ITG Fachgespr{\"a}ch Ortsbezogene Anwendungen und Dienste.},
editor = {J{\"o}rg Roth},
address = {Hagen},
publisher = {FernUniversit{\"a}t in Hagen},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
series = {Informatik-Berichte der FernUniversit{\"a}t in Hagen},
volume = {317},
pages = {15--18},
type = {Konferenz-Beitrag},
month = {Juni},
year = {2004},
keywords = {Location-based Service; Context-aware System; Platform; Geocast},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems,
H.2.4 Database Management Systems,
H.2.8 Database Applications,
H.3.4 Information Storage and Retrieval Systems and Software,
C.2.2 Network Protocols},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2004-29/INPROC-2004-29.pdf},
contact = {Senden Sie eine E-Mail an frank.duerr@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme;
Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Anwendersoftware},
abstract = {In this paper we present the Nexus Platform for context-aware applications.
This platform allows to share the effort of setting up a global and detailed
context model between different providers by federating their partial models.
Applications can query data directly, use push-based communication through an
event service, or use value-added services like a navigation or map service for
special tasks. Additional context-aware services like hoarding or geocast can
be implemented on basis of the platform. For the latter we present different
approaches for addressing and efficient message forwarding based on the Nexus
Platform.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2004-29&engl=0}
}
@inproceedings {INPROC-2004-28,
author = {J{\"o}rg H{\"a}hner and Kurt Rothermel and Christian Becker},
title = {{Update-Linearizability: A Consistency Concept for the Chronological Ordering of Events in MANETs}},
booktitle = {Proceedings of the First IEEE International Conference on Mobile Ad Hoc and Sensor Systems},
publisher = {IEEE Press},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
pages = {1--10},
type = {Konferenz-Beitrag},
month = {Oktober},
year = {2004},
language = {Englisch},
cr-category = {H.2 Database Management,
C.2 Computer-Communication Networks},
contact = {J{\"o}rg H{\"a}hner haehner@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Mobile ad hoc networks (MANETs) are used in situations where networks need to
be deployed immediately but no network infrastructure is available. If MANET
nodes have sensing capabilities, they can capture and communicate the state of
their surroundings, including environmental conditions or objects in their
proximity. If the sensed state information is propagated to a database to build
a consistent model of the real world, a variety of promising context-aware
applications becomes possible. In this paper, we introduce a novel consistency
concept that preserves the chronological ordering of sensed state transition
events. Based on this concept, we propose a data replication algorithm for
MANETs that guarantees the consistency concept without relying on synchronized
clocks and show its correctness. Our simulation experiments show that
replicated copies are updated regularly even if the network load in the system
is high.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2004-28&engl=0}
}
@inproceedings {INPROC-2004-27,
author = {Gregor Schiele and Christian Becker and Kurt Rothermel},
title = {{Energy-Efficient Cluster-based Service Discovery}},
booktitle = {Proceedings of the 11th ACM SIGOPS European Workshop (SIGOPSEW04); Leuven, Belgium, September 20-22, 2004},
publisher = {ACM SIGOPS},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {75--79},
type = {Konferenz-Beitrag},
month = {September},
year = {2004},
keywords = {SANDMAN; service discovery; energy-efficient; energy-aware},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
contact = {gregor.schiele@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Service discovery in Ubiquitous Computing is a task which has to be done
frequently due to dynamically changing environments. The limited battery power
of mobile devices requires us to optimize frequent and energy costly tasks,
especially the ones incurring in communication activities. In this paper we
present a novel service discovery algorithm based on node clustering. Nodes
within a cluster may sleep to save energy when idle. A clusterhead node is
always active and answers discovery requests on behalf of other nodes to
achieve low discovery latencies. Simulation experiments show energy savings of
up to 66\% compared to an approach where all nodes are permanently active while
the discovery latencies were not increased.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2004-27&engl=0}
}
@inproceedings {INPROC-2004-26,
author = {Daniel Herrscher and Steffen Maier and Jing Tian and Kurt Rothermel},
title = {{A Novel Approach to Evaluating Implementations of Location-Based Software}},
booktitle = {Proceedings of the 2004 International Symposium on Performance Evaluation of Computer and Telecommunication Systems (SPECTS 2004), San Jose, CA, USA, July 26-29, 2004.},
publisher = {SCS},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
pages = {484--490},
type = {Konferenz-Beitrag},
month = {Juli},
year = {2004},
isbn = {1-56555-284-9},
keywords = {performance analysis; network emulation; location-based software; positioning devices; mobile ad hoc networks},
language = {Englisch},
cr-category = {D.4.4 Operating Systems Communications Management,
I.6.3 Simulation and Modeling Applications},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2004-26/INPROC-2004-26.pdf,
http://net.informatik.uni-stuttgart.de/},
contact = {herrscher@informatik.uni-stuttgart.de, maier@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {There are two main approaches to measuring the performance of location-based
software for mobile ad hoc networks: live testing and measurements in an
emulation testbed. The former is problematic because of high resource costs and
low reproducibility. The latter offers the advantage of reproducible network
conditions in the laboratory. In addition, location-based software has to be
provided with appropriate location information. We develop virtual devices that
mimic the interface and functionality of actual positioning devices, and
integrate these into an existing network emulation testbed. The combination of
mobile network emulation and positioning device emulation facilitates the
evaluation of location-based software in different scenarios. We provide sample
measurements using an existing location-based adhoc routing protocol
implementation for inter-vehicle communication in a scenario with 50 emulated
cars. The results are in good agreement with the available simulations.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2004-26&engl=0}
}
@inproceedings {INPROC-2004-24,
author = {Tobias Drosdol and Thomas Schwarz and Martin Bauer and Matthias Gro{\ss}mann and Nicola H{\"o}nle and Daniela Nicklas},
title = {{Keeping Track of ``Flying Elephants'': Challenges in Large-Scale Management of Complex Mobile Objects}},
booktitle = {Proceedings of INFORMATIK 2004 - the Thirty-Fourth Annual Conference of the Gesellschaft f{\"u}r Informatik e.V.(GI); Ulm, Germany, September 20-24, 2004. Vol. 1},
editor = {Peter Dadam and Manfred Reichert},
address = {Bonn},
publisher = {K{\"o}llen Druck+Verlag GmbH},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
series = {Lecture Notes in Informatics},
volume = {P-50},
pages = {288--292},
type = {Konferenz-Beitrag},
month = {September},
year = {2004},
isbn = {3-88579-379-2},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems,
H.2.4 Database Management Systems,
H.2.8 Database Applications,
H.3.4 Information Storage and Retrieval Systems and Software},
contact = {Tobias Drosdol Tobias.Drosdol@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Anwendersoftware;
Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {The management of mobile objects like cars, persons, or workpieces in a factory
is an important task in many context-aware environments. So far, most solutions
can either cope with many small objects (few properties) or with a limited
number of complex objects in a centralized way. In this paper, we face the
challenge of managing a large number of bulky mobile objects (flying
elephants). We state requirements, propose basic components, and discuss
alternative architectures based on the main influencing factors like mobility
and update rate.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2004-24&engl=0}
}
@inproceedings {INPROC-2004-18,
author = {Martin Bauer and Lamine Jendoubi and Oliver Siemoneit},
title = {{Smart Factory – Mobile Computing in Production Environments}},
booktitle = {Proceedings of the MobiSys 2004 Workshop on Applications of Mobile Embedded Systems (WAMES 2004)},
publisher = {WWW},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
type = {Konferenz-Beitrag},
month = {Juni},
year = {2004},
keywords = {Smart Factory, Production Environment, Mobile Computing, Context-aware Applications},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems,
H.2.4 Database Management Systems,
H.3.3 Information Search and Retrieval,
J.1 Administration Data Processing},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2004-18/INPROC-2004-18.pdf,
http://lcawww.epfl.ch/luo/WAMES%202004.htm,
http://lcawww.epfl.ch/luo/WAMES%202004_files/Smart%20Factory.pdf},
contact = {Martin Bauer Martin.Bauer@informatik.uni-stuttgart.de Lamine Jendoubi LAJ@iff.uni-stuttgart.de Oliver Siemoneit Oliver.Siemoneit@philo.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme;
Universit{\"a}t Stuttgart, Institut f{\"u}r Philosophie, Abteilung f{\"u}r Wissenschaftstheorie und Technikphilosophie (IP/WTTP);
Universit{\"a}t Stuttgart, Institut f{\"u}r Industrielle Fertigung und Fabrikbetrieb (IFF)},
abstract = {Companies want to provide their customers with highly individualized products
so as to gain sustainable advantages over their competitors. The high degree of
individualization has also deep effects on the production: it demands a vast
amount of highly specialized tools for certain steps in the production process
and a frequent changing of machinery settings and tools. As a result, the
management of production resources and their coordination become quite dynamic
and complex, so that existing resource management systems are too static to
handle them.
This paper shows how the use of pervasive and mobile computing can help
companies to address the resulting problems. It derives the requirements and
identifies resulting research challenges, especially pertaining to the mobility
and dynamic state of the tools. Finally, the Nexus platform is presented and it
is shown how some of the identified challenges are addressed.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2004-18&engl=0}
}
@inproceedings {INPROC-2004-16,
author = {Martin Bauer and Kurt Rothermel},
title = {{How to Observe Real-World Events through a Distributed World Model}},
booktitle = {Proceedings of the Tenth International Conference on Parallel and Distributed Systems 2004 (ICPADS 2004);Newport Beach, California, July 7-9, 2004},
publisher = {IEEE Computer Society},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
pages = {467--476},
type = {Konferenz-Beitrag},
month = {Juli},
year = {2004},
keywords = {distributed systems; event systems; event observation; real-world events; world model; distributed world model; occurrence probability},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems,
H.3.3 Information Search and Retrieval,
H.3.4 Information Storage and Retrieval Systems and Software},
ee = {www.nexus.uni-stuttgart.de},
contact = {Martin Bauer Martin.Bauer@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {The observation of events is important in application areas where large amounts
of dynamic data are created all the time and the user just wants to be notified
when this data indicates that an event of interest has occurred. Typically,
these are real-world events, but are observed through a model providing the
relevant data about the state of the physical world. An example are spatial
events, i.e. events that occur when a user enters a certain spatial
relationship with other users or his environment. If the model consists of
local models that together form a large, but distributed, global model, a
number of issues have to be dealt with to allow the observation of events. To
the best of our knowledge, this paper is the first to propose a uniform
approach for observing real-world events through a distributed world model.
The state of the world is only available with limited accuracy in both the
value and time dimension, which is due to sensor inaccuracy and the properties
of the distributed system. Therefore, it is not always possible to determine
for certain, if an event has occurred. We propose a uniform approach to this
problem based on calculating the probability with which an event has occurred.
The event is considered to have occurred when the calculated probability is
above a threshold probability specified by the user. To realize this approach,
we show which system parameters influence the observation, how update protocols
provide the data to the observer model, on which the event is actually
observed, and how the probability that an event has occurred can be calculated
based on this model.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2004-16&engl=0}
}
@inproceedings {INPROC-2004-07,
author = {Michael Kinateder and Kurt Rothermel},
title = {{Bringing Confidence to the Web - Combining the Power of SET and Reputation Systems}},
booktitle = {Proceedings of the 2004 IEEE Consumer Communications \& Networking Conference: CCNC 2004; Las Vegas, Nevada, USA, January 5-8, 2004},
address = {Las Vegas, Nevada, USA},
publisher = {IEEE Communications Society},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {545--550},
type = {Konferenz-Beitrag},
month = {Januar},
year = {2004},
isbn = {0-7803-8145-9},
keywords = {trust; reputation; reputation system; recommendation; recommendation system; payment; payment system; SET; secure electronic transaction},
language = {Englisch},
cr-category = {C.2.0 Computer-Communication Networks, General,
C.2.4 Distributed Systems,
K.4.4 Electronic Commerce,
K.6.5 Security and Protection},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2004-07/INPROC-2004-07.pdf,
http://unitec.informatik.uni-stuttgart.de/,
http://www.ccnc2004.org},
contact = {Michael Kinateder kinateder@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Reputation systems suffer from easy copying of recommendations and recommenders
attaching themselves to trustworthy recommenders to benefit from their good
reputation. Electronic commerce in general and electronic payment systems in
particular suffer from the uncertainty of potential customers about the
reputation of online merchants and the quality of the offered goods or
services. In this paper we address these issues to a certain degree by creating
an originality statement in the payment process that is included in
recommendations to prove, that a particular recommendation is indeed linked to
a real world transaction. We present the initial protocol and two variations
and discuss their distinct features. Although the protocol is described working
in conjunction with the SET payment scheme, it is easily applicable to other
payment systems with the features outlined in this paper.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2004-07&engl=0}
}
@inproceedings {INPROC-2004-06,
author = {J{\"o}rg H{\"a}hner and Dominique Dudkowski and Pedro Jos{\'e} Marr{\'o}n and Christian Becker},
title = {{Partitioning in Mobile Ad Hoc Networks}},
booktitle = {2. GI/ITG KuVS-Fachgespr{\"a}ch ``Drahtlose Sensornetzwerke''},
address = {Karlsruhe, Germany},
publisher = { },
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
type = {Konferenz-Beitrag},
month = {Februar},
year = {2004},
language = {Englisch},
cr-category = {C.2.1 Network Architecture and Design,
D.2.8 Software Engineering Metrics},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {The performance of distributed algorithms in mobile ad hoc networks is strongly
influenced by the connectivity of the network. In cases where the connectivity
is low, network partitioning occurs. The mobility and density of network nodes,
i.e. the movement of nodes and the number of nodes per unit area, are
fundamental properties that have a large impact on the partitioning behavior,
so that a detailed characterization of this behavior may be applied to improve
the performance of distributed algorithms.
In this paper we introduce a set of metrics that describe characteristics
regarding partitioning in mobile ad hoc networks. We have conducted an
extensive set of simulation studies for a wide range of network scenarios to
show the impact of node mobility and density on the proposed metrics. We
present results for the number of partitions, their size over time, and the
frequency of partition changes. From the perspective of individual nodes, we
introduce metrics that describe the time periods in which pairs of nodes are
located in different partitions, and the number of nodes that are in the
partition of an individual node over time.
The results obtained in this paper will allow distributed data management
algorithm designers to characterize those types of network scenarios where
partitioning must be explicitly considered. Especially algorithms in areas such
as replication, data storage, and query processing, may be inspired by the
results at hand. Finally, the optimization of strategies for replica placement,
update frequency, spatial scoping of data, and even more advanced techniques
for data exchange between nodes in frequently partitioned networks will also
benefit from our results.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2004-06&engl=0}
}
@inproceedings {INPROC-2004-05,
author = {J{\"o}rg H{\"a}hner and Dominique Dudkowski and Pedro Jos{\'e} Marr{\'o}n},
title = {{A Quantitative Analysis of Partitioning in Mobile Ad Hoc Networks}},
booktitle = {Accepted for Poster at the Joint International Conference on Measurement and Modeling of Computer Systems : Sigmetrics - Performance 2004},
publisher = { ACM},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
type = {Konferenz-Beitrag},
month = {Juni},
year = {2004},
keywords = {mobile ad hoc networks, network topology, partition metrics},
language = {Englisch},
cr-category = {C.2.1 Network Architecture and Design,
D.2.8 Software Engineering Metrics},
contact = {Please send an email to joerg.haehner@informatik.uni-stuttgart.de or dominique.dudkowski@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {The performance of distributed algorithms in mobile ad hoc networks is strongly
influenced by the connectivity of the network. In cases where the connectivity
is low, network partitioning occurs. The mobility and density of network nodes,
i.e. the movement of nodes and the number of nodes per unit area, are
fundamental properties that have a large impact on the partitioning behavior,
so that a detailed characterization of this behavior may be applied to improve
the performance of distributed algorithms.
In this paper we introduce a set of metrics that describe characteristics
regarding partitioning in mobile ad hoc networks. We have conducted an
extensive set of simulation studies for a wide range of network scenarios to
show the impact of node mobility and density on the proposed metrics. We
present results for the number of partitions, their size over time, and the
frequency of partition changes. From the perspective of individual nodes, we
introduce metrics that describe the time periods in which pairs of nodes are
located in different partitions, and the number of nodes that are in the
partition of an individual node over time.
The results obtained in this paper will allow distributed data management
algorithm designers to characterize those types of network scenarios where
partitioning must be explicitly considered. Especially algorithms in areas such
as replication, data storage, and query processing, may be inspired by the
results at hand. Finally, the optimization of strategies for replica placement,
update frequency, spatial scoping of data, and even more advanced techniques
for data exchange between nodes in frequently partitioned networks will also
benefit from our results.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2004-05&engl=0}
}
@inproceedings {INPROC-2004-04,
author = {Arno Wacker and Timo Heiber and Holger Cermann and Pedro Marron},
title = {{A fault-tolerant Key-Distribution Scheme for Securing Wireless Ad-Hoc Networks}},
booktitle = {Proceedings of the Second International Conference on Pervasive Computing},
address = {Vienna, Austria},
publisher = {Springer-Verlag},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
type = {Konferenz-Beitrag},
month = {April},
year = {2004},
keywords = {wireless, ad-hoc networks, security, key-distribution, fault tolerance},
language = {Englisch},
cr-category = {C.2.0 Computer-Communication Networks, General,
C.2.1 Network Architecture and Design,
C.2.2 Network Protocols,
C.3 Special-Purpose and Application-Based Systems,
G.2.2 Discrete Mathematics Graph Theory},
ee = {http://www.pervasive2004.org},
contact = {Arno Wacker Arno.Wacker@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {We propose a novel solution for securing wireless ad-hoc networks. Our goal is
to provide secure key exchange in the presence of device failures and
denial-of-service attacks. The proposed solution relies solely on symmetric
cryptography and therefore is applicable for highly resource-limited devices.
In order to avoid a single point of trust, no master device or base station is
used. We achieve this by enhancing our previously published approach with
redundancy and algorithms for recovery on device failures.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2004-04&engl=0}
}
@inproceedings {INPROC-2004-03,
author = {Arno Wacker and Timo Heiber and Holger Cermann},
title = {{A Key-Distribution Scheme for Wireless Home Automation Networks}},
booktitle = {Proceedings of the first IEEE Consumer Communications and Networking Conference: CCNC04; January 5-8, 2004},
address = {Las Vegas, Nevada, USA},
publisher = {IEEE Communications Society},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
type = {Konferenz-Beitrag},
month = {Januar},
year = {2004},
isbn = {0-7803-8145-9},
keywords = {wireless, ad-hoc networks, security, key-distribution},
language = {Englisch},
cr-category = {C.2.0 Computer-Communication Networks, General,
C.2.1 Network Architecture and Design,
C.2.2 Network Protocols,
C.3 Special-Purpose and Application-Based Systems,
G.2.2 Discrete Mathematics Graph Theory},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2004-03/INPROC-2004-03.pdf,
http://www.ccnc2004.org},
contact = {Arno Wacker Arno.Wacker@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Wireless home automation networks are one example of how wireless technologies
may soon become part of our daily life, yet security in existing products is
woefully inadequate. An important problem in this area is the question of
secure key distribution. In this paper we present a key-distribution scheme
geared towards home automation networks, but applicable to other networks with
related properties as well. Our approach uses a decentralized scheme that is
designed to work on resource-poor devices, allows easy addition and removal of
devices and limits the workload on the end user while guaranteeing the secrecy
of the exchanged keys even in the presence of subverted nodes.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2004-03&engl=0}
}
@inproceedings {INPROC-2004-02,
author = {Othmar Lehmann and Martin Bauer and Christian Becker and Daniela Nicklas},
title = {{From Home to World - Supporting Context-aware Applications through World Models}},
booktitle = {Proceedings of the Second IEEE International Conference on Pervasive Computing and Communications},
publisher = {IEEE Computer Society},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
pages = {297--306},
type = {Konferenz-Beitrag},
month = {M{\"a}rz},
year = {2004},
keywords = {context; context-awareness; pervasive computing; ubiquitous computing; world model; Nexus},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems,
H.2.1 Database Management Logical Design,
H.3.4 Information Storage and Retrieval Systems and Software},
ee = {http://www.percom.org/,
http://www.nexus.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme;
Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Anwendersoftware},
abstract = {In the vision of pervasive computing smart everyday objects communicate and
cooperate to provide services and information to users. Interoperability
between devices and applications not only requires common protocols but also
common context management. In this paper we discuss requirements on the context
management based on the Georgia Tech's Aware Home environment and the global
context management perspective of the Nexus project. Our experiences with
integrating the Aware Home Spatial Service into the Nexus platform show how
federation concepts and a common context model can provide applications with
uniform context information in different administrative and application
domains.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2004-02&engl=0}
}
@inproceedings {INPROC-2004-01,
author = {Susanne B{\"u}rklen and Pedro Jos{\'e} Marr{\'o}n and Kurt Rothermel},
title = {{An Enhanced Hoarding Approach Based on Graph Analysis}},
booktitle = {Proceedings of the 5th IEEE International Conference on Mobile Data Management (MDM 2004); Berkeley, California, USA; January 19-22, 2004},
address = {Los Alamitos},
publisher = {IEEE Computer Society},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
pages = {358--369},
type = {Konferenz-Beitrag},
month = {Januar},
year = {2004},
language = {Englisch},
cr-category = {H.3.4 Information Storage and Retrieval Systems and Software,
I.5.3 Pattern Recognition Clustering},
ee = {http://www.nexus.uni-stuttgart.de/},
contact = {buerklse@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {The proliferation of mobile devices has led to the creation of hoarding
algorithms that attempt to mitigate the problems related with disconnected
operation or with the operation in areas where bandwidth is either scarce or
very expensive. Traditional hoarding approaches use probability access tables
to determine what information needs to be sent to the mobile device, but fail
to take the structured nature of data into account. In this paper, we present
an enhanced hoarding approach for semistructured information that relies on the
analysis of graphs to determine the information that needs to be hoarded. We
show by means of experimental evaluations on webpages that our approach
outperforms other hoarding algorithms that treat information as the combination
of unrelated items.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2004-01&engl=0}
}
@inproceedings {INPROC-2003-65,
author = {Illya Stepanov and J{\"o}rg H{\"a}hner and Christian Becker and Jing Tian and Kurt Rothermel},
title = {{A Meta-Model and Framework for User Mobility in Mobile Networks}},
booktitle = {Proceedings of the 11th International Conference on Networking 2003 (ICON 2003), Sydney, Australia, September 28 - October 1, 2003},
publisher = {IEEE},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
pages = {231--238},
type = {Konferenz-Beitrag},
month = {September},
year = {2003},
isbn = {0-7803-7788-5},
keywords = {simulation; mobility modeling; user movement},
language = {Englisch},
cr-category = {C.2.1 Network Architecture and Design,
C.4 Performance of Systems,
I.6.3 Simulation and Modeling Applications},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2003-65/INPROC-2003-65.pdf,
http://canu.informatik.uni-stuttgart.de/mobisim},
contact = {illya.stepanov@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Mobility patterns play an important role for performance evaluations of mobile
networks. To simulate user movement, existing simulation tools provide only a
few simple mobility models (e.g., random movement) suitable for particular
scenarios. To evaluate a new scenario, an appropriate model needs to be
created, but this requires extra work that distracts the researcher from
his/her main task. In general, three key elements determine the mobility of
users: the spatial environment, the user trip sequences, and the user movement
dynamics (e.g., speed). In this paper, we introduce a meta-model that
integrates these three elements in an easy-to-use framework, allowing a
flexible modeling of user mobility in custom scenarios. The framework is
available for download as a stand-alone trace generator and may be used
together with any simulation or emulation tool for mobile networks to evaluate
a specific scenario.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2003-65&engl=0}
}
@inproceedings {INPROC-2003-36,
author = {Jing Tian and Lu Han and Kurt Rothermel and Christian Cseh},
title = {{Spatially Aware Packet Routing for Mobile Ad Hoc Inter-Vehicle Radio Networks}},
booktitle = {Proceedings of the IEEE 6th International Conference on Intelligent Transportation Systems (ITSC). Vol. 2},
publisher = {IEEE},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {1546--1552},
type = {Konferenz-Beitrag},
month = {Oktober},
year = {2003},
isbn = {0-7803-8125-4},
language = {Englisch},
cr-category = {C.2.1 Network Architecture and Design,
C.2.2 Network Protocols},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2003-36/INPROC-2003-36.pdf},
contact = {jing.tian@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Inter-Vehicle Communication will become an important building block for ITS
telematics applications like safety and warning functions. Mobile ad hoc
networks (MANETs) can serve as a local wireless network for exchanging
information between cars for cooperative driver assistance applications. For
the routing of data packets in such large-scale MANETs consisting of vehicles
on the road, geographic multi-hop packet forwarding is a promising approach.
However, a main drawback is that it performs poorly in networks with many
topology holes. In this paper, we propose a spatially aware packet routing
approach to predict permanent topology holes caused by spatial constraints and
avoid them aforehand. This approach is generic and can be used in combination
with any existing geographic forwarding protocol as an extension. Our
simulations demonstrate that spatial awareness can significantly improve
geographic forwarding performance in situations with many permanent topology
holes, like in dynamic vehicle networks.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2003-36&engl=0}
}
@inproceedings {INPROC-2003-26,
author = {Marcus Handte and Christian Becker and Gregor Schiele},
title = {{Experiences: Minimalism and Extensibility in BASE}},
booktitle = {Proceedings of the System Support for Ubiquitous Computing Workshop (Ubisys03) at the Fifth Annual Conference on Ubiquitous Computing (Ubicomp03); Seattle, Washington, October 12, 2003},
publisher = {online proceedings},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {1--8},
type = {Konferenz-Beitrag},
month = {Oktober},
year = {2003},
keywords = {micro-broker; BASE; PCOM; 3PC; ubiquitous computing; pervasive computing; middleware},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems,
D.2.11 Software Engineering Software Architectures,
D.2.12 Software Engineering Interoperability,
D.4.4 Operating Systems Communications Management},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2003-26/INPROC-2003-26.pdf,
http://ciae.cs.uiuc.edu/ubisys/program.html,
http://ciae.cs.uiuc.edu/ubisys/},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {In the vision of Ubiquitous Computing everyday objects become smart.
Technically, this requires some sort of processing and communication
technology. We have designed and implemented a middleware for spontaneous
networking in Ubiquitous Computing environments. The major objectives were
minimalism and extensibility in order to deploy the middleware on a variety of
devices ranging from sensor nodes to classical general purpose computers. In
this paper we will assess the taken approach based on two follow-up projects:
the port of BASE to a small embedded system and the design and implementation
of a component system on top of BASE. While the fundamental concepts and design
principles of BASE have proven to be solid, both projects provided insights
that led to minor conceptual and major technical changes.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2003-26&engl=0}
}
@inproceedings {INPROC-2003-24,
author = {Frank D{\"u}rr and Kurt Rothermel},
title = {{On a Location Model for Fine-Grained Geocast}},
booktitle = {UbiComp 2003: Ubiquitous Computing (Proceedings of the Fifth International Conference on Ubiquitous Computing 2003); Seattle, WA, October 2003},
editor = {Anind K. Dey and Albrecht Schmidt and Joseph F. McCarthy},
publisher = {Springer-Verlag},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
series = {Lecture Notes in Computer Science},
volume = {2864},
pages = {18--35},
type = {Konferenz-Beitrag},
month = {Oktober},
year = {2003},
isbn = {3-540-20301-X},
keywords = {Ubiquitous Computing; Location Model; Geocast},
language = {Englisch},
cr-category = {C.2.2 Network Protocols},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2003-24/INPROC-2003-24.pdf,
http://www.springerlink.com/content/e9apt8y1w5nmem89/},
contact = {frank.duerr@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Geographic communication (geocast) is used to send messages to geographic
areas, e.g. to distribute warning messages or other information within these
areas. It is based on a location model which is used to determine a message's
target area and the receivers' positions and therefore has strong influence on
the achievable granularity of geographic addressing.
A hybrid location model and and a fine-grained addressing scheme for geocast
based on this model are presented in this paper which support two- and
three-dimensional geometric locations as well as symbolic locations like room
numbers, embedded local coordinate systems, and mobile target areas like
trains.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2003-24&engl=0}
}
@inproceedings {INPROC-2003-21,
author = {Martin Bauer and Lamine Jendoubi and Kurt Rothermel and Engelbert Westk{\"a}mper},
title = {{Grundlagen ubiquit{\"a}rer Systeme und deren Anwendung in der ``Smart Factory''}},
booktitle = {Industrie Management - Zeitschrift f{\"u}r industrielle Gesch{\"a}ftsprozesse},
editor = {Norbert Gronau and Hermann Krallmann and Bernd Scholz-Reiter},
address = {Berlin},
publisher = {GITO mbH Verlag f{\"u}r Industrielle Organisation},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
volume = {19},
number = {6},
pages = {17--20},
type = {Konferenz-Beitrag},
month = {Dezember},
year = {2003},
keywords = {Smart Factory; Ubiquitous Computing; R{\"a}umliche Umgebungsmodelle; kontext-bezogene Systeme; context-aware systems; spatial world models; Nexus},
language = {Deutsch},
cr-category = {C.2.4 Distributed Systems,
H.2.4 Database Management Systems,
H.2.8 Database Applications,
H.3.4 Information Storage and Retrieval Systems and Software,
J.1 Administration Data Processing,
J.7 Computers in Other Systems},
ee = {http://www.nexus.uni-stuttgart.de,
http://www.industrie-management.de},
contact = {Kurt.Rothermel@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme;
Universit{\"a}t Stuttgart, Institut f{\"u}r Industrielle Fertigung und Fabrikbetrieb (IFF)},
abstract = {Die rasch fortschreitende Entwicklung kleiner mobiler Ger{\"a}te sowie mit
eingebetteter Sensorik und Aktorik versehener Alltagsgegenst{\"a}nde erm{\"o}glicht
eine Vielzahl neuartiger Anwendungen. Die F{\"a}higkeit zur drahtlosen
Kommunikation und zur Positionsbestimmung bereitet die Basis lokations- und
kontextbezogener Systeme, die seit einigen Jahren im Projekt Nexus an der
Universit{\"a}t Stuttgart untersucht werden. Der Einsatz dieser Technologien im
produktionstechnischem Umfeld, z.B. der hier vorgestellten dezentralen
Betriebsmittelverwaltung, er{\"o}ffnet dabei ein vollkommen neues Anwendungsgebiet.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2003-21&engl=0}
}
@inproceedings {INPROC-2003-20,
author = {Kurt Rothermel and Dominique Dudkowski and Frank D{\"u}rr and Martin Bauer and Christian Becker},
title = {{Ubiquitous Computing - More than Computing Anytime Anyplace?}},
booktitle = {Proceedings of the 49. Photogrammetrische Woche},
address = {Stuttgart},
publisher = {ifp},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
type = {Konferenz-Beitrag},
month = {September},
year = {2003},
keywords = {Kontext; kontextbezogene Systeme; Ubiquitous Computing; Nexus},
language = {Deutsch},
cr-category = {H.2.8 Database Applications,
H.3.4 Information Storage and Retrieval Systems and Software},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2003-20/INPROC-2003-20.pdf,
http://www.nexus.uni-stuttgart.de},
contact = {Kurt.Rothermel@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {The rapid development of mobile communication networks and the availability of
miniaturized and inexpensive sensor technology allow for the development of
multifunctional mobile devices that are able to collect and communicate context
information. We also currently see a clear trend towards the integration of
embedded systems including sensors into {\ss}mart`` everyday things, which is also
referred to as Ubiquitous Computing. The deployment of sensor technology allows
for so-called context-aware applications, going far beyond of providing mobile
access to information and computing resources. Context-aware applications
exploit captured sensor information to adapt to the current situation of mobile
users. For instance, the information offered to a user may depend on his
current location, and the way how it is presented to him may depend on the
speed he moves, whether he is on its own or with others, and so on.
In this paper, we characterize context-aware applications and present the
vision of a digital world model as the foundation for this class of
applications. Further, the paper discusses the benefits and reseach challenges
associated with digital world models, which allow applications to take into
account the state of the real world and react to state changes.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2003-20&engl=0}
}
@inproceedings {INPROC-2003-19,
author = {Audun J{\o}sang and Elizabeth Gray and Michael Kinateder},
title = {{Analysing Topologies of Transitive Trust}},
booktitle = {Proceedings of the First International Workshop on Formal Aspects in Security \& Trust: FAST 2003; Pisa, Italy, September 2003},
publisher = {IIT-CNR},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {9--22},
type = {Konferenz-Beitrag},
month = {September},
year = {2003},
keywords = {trust; transitive; reputation; recommendation},
language = {Englisch},
cr-category = {J.4 Social and Behavioral Sciences,
C.2.4 Distributed Systems,
H.3.5 Online Information Services},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2003-19/INPROC-2003-19.pdf,
http://unitec.informatik.uni-stuttgart.de/},
contact = {Michael Kinateder Kinateder@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Transacting and interacting through computer networks makes it difficult to use
traditional methods for establishing trust between parties. Creating
substitutes by which people, organisations and software agents can derive trust
in others through computer networks requires computerised analysis of trust
topologies. This paper describes diverse dimensions of trust that are needed
for analysing trust topologies, and provides a notation with which to express
trust relationships in terms of these dimensions. The result is a simple way of
specifying topologies of trust from which derived trust relationships can be
automatically and securely computed.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2003-19&engl=0}
}
@inproceedings {INPROC-2003-18,
author = {Michael Kinateder and Siani Pearson},
title = {{A Privacy-Enhanced Peer-to-Peer Reputation System}},
booktitle = {Proceedings of the 4th International Conference on Electronic Commerce and Web Technologies: EC-Web 2003; Prague, Czech Republic, September 2003},
editor = {Kurt Bauknecht and A Min Tjoa and Gerald Quirchmayr},
address = {Heidelberg},
publisher = {Springer-Verlag},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
series = {Lecture Notes in Computer Science},
volume = {2738},
pages = {206--215},
type = {Konferenz-Beitrag},
month = {September},
year = {2003},
isbn = {3-540-40808-8},
keywords = {trust; reputation; recommendation; trusted platforms; trusted computing platform alliance; TCPA; trusted computing group; TCG; privacy; security},
language = {Englisch},
cr-category = {B.8 Performance and Reliability,
D.4.6 Operating Systems Security and Protection,
H.3.4 Information Storage and Retrieval Systems and Software,
H.3.5 Online Information Services,
H.4.2 Information Systems Applications Types of Systems,
K.4.1 Computers and Society Public Policy Issues,
K.4.4 Electronic Commerce,
K.6.5 Security and Protection},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2003-18/INPROC-2003-18.pdf,
http://unitec.informatik.uni-stuttgart.de/},
contact = {Michael Kinateder kinateder@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {In this paper, a method is described for providing a distributed reputation
system with enhanced privacy and security as a design feature. This is achieved
using a network of trusted agents on each client platform that exploit Trusted
Computing Platform Alliance (TCPA) technology.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2003-18&engl=0}
}
@inproceedings {INPROC-2003-17,
author = {Kurt Rothermel and Dieter Fritsch and Bernhard Mitschang and Paul J. K{\"u}hn and Martin Bauer and Christian Becker and Christian Hauser and Daniela Nicklas and Steffen Volz},
title = {{SFB 627: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme}},
booktitle = {Proceedings Informatik 2003},
address = {Frankfurt},
publisher = {Gesellschaft f{\"u}r Informatik},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
type = {Konferenz-Beitrag},
month = {September},
year = {2003},
keywords = {Umgebungsmodelle; kontext-bezogene Systeme; Nexus; Spatial World Models; context-aware systems},
language = {Deutsch},
cr-category = {C.2.4 Distributed Systems,
H.2.4 Database Management Systems,
H.2.8 Database Applications,
H.3.4 Information Storage and Retrieval Systems and Software},
ee = {http://www.nexus.uni-stuttgart.de},
contact = {Kurt.Rothermel@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme;
Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Anwendersoftware;
Universit{\"a}t Stuttgart, Institut f{\"u}r Kommunikationsnetze und Rechnersysteme (IKR);
Universit{\"a}t Stuttgart, Institut f{\"u}r Photogrammetrie (ifp)},
abstract = {Ziel des Sonderforschungsbereichs 627 ``Umgebungsmodelle f{\"u}r mobile
kontextbezogene Systeme'' ist die Erforschung von Methoden und Verfahren f{\"u}r die
Definition, die Verwaltung und die Nutzung von digitalen Umgebungsmodellen.
Existierende Informationsr{\"a}ume werden mit komplexen Modellen der realen Welt
verschr{\"a}nkt und erlauben so neuartige Anwendungen. Insbesondere die Klasse der
ortsbezogenen Anwendungen und aktuelle Forschungsgebiete wie das Ubiquitous
Computing k{\"o}nnen von solchen Umgebungsmodellen profitieren, oder werden durch
sie erst erm{\"o}glicht.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2003-17&engl=0}
}
@inproceedings {INPROC-2003-13,
author = {Christian Becker and Gregor Schiele and Holger Gubbels and Kurt Rothermel},
title = {{BASE - A Micro-broker-based Middleware For Pervasive Computing}},
booktitle = {Proceedings of the First IEEE International Conference on Pervasive Computing and Communication (PerCom), March 23-26, Fort Worth, USA},
address = {Los Alamitos},
publisher = {IEEE Computer Society},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {443--451},
type = {Konferenz-Beitrag},
month = {M{\"a}rz},
year = {2003},
isbn = {0-7695-1895},
keywords = {Middleware, Ubiquitous Computing, Microbroker, Micro-broker, BASE},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2003-13/INPROC-2003-13.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Pervasive computing environments add a multitude of additional devices to our
current computing landscapes. Specialized embedded systems provide sensor
information about the real world or offer a distinct functionality, e.g.
presentation on a “smart wall”. Spontaneous networking leads to constantly
changing availability of services. This requires middleware support to ease
application development. Additionally, we argue that an extensible middleware
platform covering small embedded systems to full-fledged desktop computers is
needed. Such a middleware should provide easy-to-use abstractions to access
remote services and device-specific capabilities. We present a micro-broker-
based approach which meets these requirements by allowing uniform access to
device capabilities and services through proxies and the integration of
different interoperability protocols. A minimum configuration of the middleware
can be executed on embedded systems. Resource-rich execution environments are
supported by the extensibility of the middleware.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2003-13&engl=0}
}
@inproceedings {INPROC-2003-12,
author = {Daniel Herrscher and Steffen Maier and Kurt Rothermel},
title = {{Distributed Emulation of Shared Media Networks}},
booktitle = {Proceedings of the 2003 International Symposium on Performance Evaluation of Computer and Telecommunication Systems (SPECTS 2003), Montr{\'e}al, Quebec, Canada, July 20-24, 2003},
publisher = {SCS},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {226--233},
type = {Konferenz-Beitrag},
month = {Juli},
year = {2003},
isbn = {1-56555-269-5},
keywords = {network emulation; distributed emulation; performance analysis; shared media; CSMA/CD},
language = {Englisch},
cr-category = {C.2.5 Local and Wide-Area Networks,
D.4.4 Operating Systems Communications Management,
I.6.3 Simulation and Modeling Applications},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2003-12/INPROC-2003-12.pdf,
ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2003-12/INPROC-2003-12.ps,
http://net.informatik.uni-stuttgart.de/},
contact = {herrscher@informatik.uni-stuttgart.de, maier@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Comparative performance measurements of distributed applications and network
protocols require the availability of appropriate network environments. Network
emulation approaches offer a flexible way to mimic the properties of a variety
of networks. While there are several centralized and distributed emulation
tools available that can mimic the behavior of point-to-point links, shared
media communication can only be emulated by totally centralized tools so far.
To permit the emulation of large-scale mixed network scenarios, the emulation
of shared media networks has to be performed in a distributed way also.
In this paper, we introduce several strategies to emulate shared media networks
in a distributed fashion. For one promising approach, the distributed emulation
of carrier sensing, we present a prototype implementation. Measurements show
the applicability and limitations of our solution.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2003-12&engl=0}
}
@inproceedings {INPROC-2003-11,
author = {Christian Becker and Gregor Schiele},
title = {{Middleware and Application Adaptation Requirements and their Support in Pervasive Computing}},
booktitle = {Proceedings of the 23rd International Conference on Distributed Computing Systems Workshops (ICDCS 2003), 3rd International Workshop on Distributed Auto-adaptive and Reconfigurable Systems (DARES), Providence, USA, May 19-22},
address = {Los Alamitos},
publisher = {IEEE Computer Society},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {98--103},
type = {Konferenz-Beitrag},
month = {Mai},
year = {2003},
isbn = {0-7695-1921-0},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2003-11/INPROC-2003-11.pdf},
contact = {Email an christian.becker@informatik.uni-stuttgart.de oder gregor.schiele@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Pervasive computing environments are characterized by an additional
heterogeneity compared to existing computing infrastructures. Devices ranging
from small embedded systems to full-fledged computers are connected via
spontaneously formed networks. In this paper we analyze requirements of
applications and system software to cope with the dynamically changing
execution environment. Based on our micro-broker-based middleware BASE a
component framework for pervasive computing supporting application adaptation
is proposed.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2003-11&engl=0}
}
@inproceedings {INPROC-2003-10,
author = {Michael Kinateder and Kurt Rothermel},
title = {{Architecture and Algorithms for a Distributed Reputation System}},
booktitle = {Proceedings of the First International Conference on Trust Management: iTrust'03; Heraklion, Crete, Greece, May 28-30, 2003},
editor = {Paddy Nixon and Sotirios Terzis},
address = {Heidelberg},
publisher = {Springer-Verlag},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
series = {Lecture Notes in Computer Science},
volume = {2692},
pages = {1--16},
type = {Konferenz-Beitrag},
month = {Mai},
year = {2003},
isbn = {3-540-40224-1},
keywords = {trust; trust management; reputation; recommendation; distributed; peer-to-peer},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems,
H.3.3 Information Search and Retrieval,
H.3.4 Information Storage and Retrieval Systems and Software,
H.3.5 Online Information Services,
H.4.2 Information Systems Applications Types of Systems,
I.2.4 Knowledge Representation Formalisms and Methods,
I.2.11 Distributed Artificial Intelligence,
J.4 Social and Behavioral Sciences},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2003-10/INPROC-2003-10.pdf,
http://www.springerlink.com/link.asp?id=1e11b5pcvww3qvuf,
http://unitec.informatik.uni-stuttgart.de},
contact = {Michael Kinateder kinateder@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Trust is an essential component of successful interactions in social life as
well as in business relationships. In this paper we propose a system that
closely reflects real-world trust building in an online environment. We
describe the models used to represent trust in entities in various categories,
algorithms to calculate and update trust based on experiences of entities with
each other and the agent interactions necessary for finding and exchanging
trust information.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2003-10&engl=0}
}
@inproceedings {INPROC-2003-09,
author = {Martin Bauer and Christian Becker and J{\"o}rg H{\"a}hner and Gregor Schiele},
title = {{ContextCube - Providing Context Information Ubiquitously}},
booktitle = {Proceedings of the 23rd International Conference on Distributed Computing Systems Workshops (ICDCS 2003)},
address = {Los Alamitos},
publisher = {IEEE Computer Society},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
pages = {308--313},
type = {Konferenz-Beitrag},
month = {Mai},
year = {2003},
isbn = {0-7695-1921-0},
language = {Englisch},
cr-category = {H.3.4 Information Storage and Retrieval Systems and Software},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2003-09/INPROC-2003-09.pdf,
http://www.nexus.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Sensing the state of the environment is an important source for context-aware
applications. Several approaches exist to provide sensor information to mobile
application nodes. As the extreme cases we have pure infrastructures and pure
ad hoc networks. In order to allow sensor platforms to serve both of these
approaches, we have designed a universal sensor platform and integrated it into
an infrastructure-based approach as well as into ad hoc networks. In this paper
we discuss the requirements on such a platform, the design, and the
experiences.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2003-09&engl=0}
}
@inproceedings {INPROC-2003-08,
author = {Jing Tian and Luca Coletti},
title = {{Routing approach in CarTALK 2000 project}},
booktitle = {Proceedings of the IST Mobile \& Wireless Communications Summit 2003. Vol. 2},
address = {Aveiro - Portugal},
publisher = {Instituto de Telecomunica{\,c}{\~o}es (IT)},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {473--477},
type = {Konferenz-Beitrag},
month = {Juni},
year = {2003},
keywords = {mobile ad hoc routing},
language = {Englisch},
cr-category = {C.2.1 Network Architecture and Design,
C.2.2 Network Protocols},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2003-08/INPROC-2003-08.pdf},
contact = {jing.tian@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {The CarTALK 2000 project aims at the development of new driver assistance
systems that are based upon inter-vehicle communication. To this purpose, a
mobile ad hoc network (MANET) consisting of vehicles will be developed as the
communication platform to support co-operative driver assistance applications.
Routing in such a vehicular MANET faces a number of new challenges, in
particular due to the extremely dynamic network topology and a large variable
number of mobile nodes. Therefore, an efficient and scalable ad hoc routing
mechanism is crucial for the performance of the CarTALK 2000 communication
system. After analyzing the system characteristics and requirements, this paper
introduces a spatially aware routing protocol and a distributed location
service. The key of Spatially Aware Routing is to improve position-based
routing performance by integrating spatial environment information into
routing, such as the underlying road topology.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2003-08&engl=0}
}
@inproceedings {INPROC-2003-07,
author = {Kurt Rothermel and Martin Bauer and Christian Becker},
title = {{Digitale Weltmodelle - Grundlage kontextbezogener Systeme}},
booktitle = {Total vernetzt - Szenarien einer informatisierten Welt},
editor = {Friedemann Mattern},
address = {Berlin, Heiderlberg, New York},
publisher = {Springer-Verlag},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
series = {Xpert.press},
pages = {123--141},
type = {Konferenz-Beitrag},
month = {Mai},
year = {2003},
isbn = {3-540-0023-8},
keywords = {Kontext; kontextbezogene Systeme; Ubiquitous Computing; Nexus},
language = {Deutsch},
cr-category = {H.3.4 Information Storage and Retrieval Systems and Software},
ee = {http://www.nexus.uni-stuttgart.de},
contact = {E-Mail: Kurt.Rothermel@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Die rasant fortschreitende Entwicklung von Sensorsystemen und drahtloser
Kommunikation f{\"u}hrt zu multifunktionalen mobilen Endger{\"a}ten, die in der Lage
sind, Kontextinformation zu erfassen, zu verarbeiten und zu kommunizieren.
Durch die extreme Miniaturisierung eingebetteter Systeme entstehen au{\ss}erdem
``intelligente'' Alltagsgegenst{\"a}nde, die in Netzwerke eingebunden sind und {\"u}ber
sensorische F{\"a}higkeiten verf{\"u}gen. Vor dem Hintergrund dieser Entwicklungen ist
es absehbar, dass in wenigen Jahren Milliarden von Sensoren existieren werden,
die kontinuierlich den Zustand der Realwelt erfassen und kommunizieren. F{\"u}hrt
man die sensorisch gewonnen Informationen in einem r{\"a}umlichen Modell zusammen,
so entsteht ein digitales Abbild der Realwelt, also ein digitales Weltmodell,
das analog zum heutigen Web einen globalen Informationsraum darstellt. Das
digitale Weltmodell kann Grundlage sein f{\"u}r ein breites Spektrum
kontextbezogener Anwendungen, deren Kontext prinzipiell keinen r{\"a}umlichen
Beschr{\"a}nkungen unterworfen ist.
In diesem Beitrag wird der Begriff der kontextbezogene Anwendungen erl{\"a}utert
und Anwendungen dieser Art am Beispiel existierender Systeme beschrieben und
klassifiziert. Au{\ss}erdem wird die Vision, Kontextinformationen in Form digitaler
Weltmodelle zu verwalten, dargelegt und motiviert. Schlie{\ss}lich werden die sich
aus dieser Vision ergebenden wissenschaftlichen Fragestellungen diskutiert.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2003-07&engl=0}
}
@inproceedings {INPROC-2003-06,
author = {J{\"o}rg H{\"a}hner and Christian Becker and Kurt Rothermel},
title = {{A Protocol for Data Dissemination in Frequently Partitioned Mobile Ad Hoc Networks}},
booktitle = {Proceedings of the Eighth IEEE Symposium on Computers and Communications (ISCC 2003). Vol. I},
editor = {Ahmed Tantawy and Kemal Inan},
address = {Los Alamitos},
publisher = {IEEE Computer Society},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {633--640},
type = {Konferenz-Beitrag},
month = {Juni},
year = {2003},
isbn = {0-7695-1961-X},
language = {Englisch},
cr-category = {C.2.1 Network Architecture and Design},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2003-06/INPROC-2003-06.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Distribution of data in mobile ad hoc networks is challenged when the mobility
of nodes leads to frequent topology changes. Existing approaches so far address
either the network partitioning problem or are capable of handling large
amounts of data, but not both at the same time. In this paper a novel approach
is presented which is based on a negotiation scheme enhanced by an adaptive
repetition strategy. Different strategies for the selection of repeated data
are presented and evaluated. Simulation results show a reduction of data
transfer volume compared to hyper-flooding by 30 to 40\% even in the presence of
frequent network partitions.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2003-06&engl=0}
}
@inproceedings {INPROC-2003-05,
author = {Cora Burger and Matthias Papesch},
title = {{Eine interaktive und kollaborative Selbstlernumgebung f{\"u}r den Bereich der Sicherheitsprotokolle}},
booktitle = {Tagungsband der 1. e-Learning Fachtagung Informatik der Gesellschaft f{\"u}r Informatik e.V., DeLFI 2003},
editor = {Sabine Rathmayer Arndt Bode},
publisher = {GI Edition „Lecture Notes in Informatics“},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
type = {Konferenz-Beitrag},
month = {September},
year = {2003},
keywords = {E-Learning; Security Protocols; Validation},
language = {Deutsch},
cr-category = {D.2.4 Software Engineering Software/Program Verification,
I.6.7 Simulation Support Systems,
K.3.1 Computer Uses in Education},
ee = {http://www.informatik.uni-stuttgart.de/ipvr/vs/de/projects/index.html#ito,
http://www.delfi2003.de},
contact = {caburger@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Im Bereich Verteilter Systeme und Rechnernetze spielen Sicherheitsprotokolle
zum Schutz von Identit{\"a}t und anderweitigen Ressourcen einzelner Personen eine
wichtige Rolle. Um die Verst{\"a}ndlichkeit dieser komplexen Materie in der Lehre
zu erh{\"o}hen und f{\"u}r dieses Gebiet ein von Ort und Zeit unabh{\"a}ngiges Lernen zu
erm{\"o}glichen, entstand eine speziell darauf ausgelegte Selbstlernumgebung. Sie
verbindet vielf{\"a}ltige Funktionen f{\"u}r ein exploratives Vorgehen sowie
automatisiert auswertbare Selbsttests zur Lernkontrolle mit der M{\"o}glichkeit der
gemeinsamen Erarbeitung von Inhalten im Lernteam.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2003-05&engl=0}
}
@inproceedings {INPROC-2002-30,
author = {Alexander Leonhardi and Kurt Rothermel},
title = {{Architecture of a Large-scale Location Service}},
booktitle = {Short Paper in Proceedings of the 22nd Conference on Distributed Computing Systems : ICDCS 2002; Vienna, Austria, July 2002},
publisher = {IEEE},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
pages = {465--466},
type = {Konferenz-Beitrag},
month = {Juli},
year = {2002},
keywords = {Location Service; Nexus},
language = {Englisch},
cr-category = {H.0 Information Systems General,
C.2.4 Distributed Systems},
ee = {http://csdl.computer.org/comp/proceedings/icdcs/2002/1585/00/15850465.pdf,
http://www.nexus.uni-stuttgart.de},
contact = {Alexander.Leonhardi@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Location-aware services are a promising way of exploiting the special
possibilities created by ubiquitous mobile devices and wireless communication.
Advanced locationaware applications will require highly accurate information
about the geographic location of mobile objects and functionality that goes
beyond simply querying the user's position, for example determining all mobile
objects inside a certain geographic area. In this paper, we propose a generic
large-scale location service, which has been designed with the goal of managing
the highly dynamic location information for a large number of mobile objects,
thus providing a common infrastructure that can be employed by location-aware
applications. We propose a hierarchical distributed architecture, which can
efficiently process these queries in a scalable way. To be able to deal with
the frequent updates and queries resulting from highly dynamic location
information, we propose a data storage component, which makes use of a main
memory database.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2002-30&engl=0}
}
@inproceedings {INPROC-2002-27,
author = {Alexander Leonhardi and Christian Nicu and Kurt Rothermel},
title = {{A Map-based Dead-reckoning Protocol for Updating Location Information}},
booktitle = {Proceedings of the 2nd International Workshop on Parallel and Distributed Computing Issues in Wireless Networks and Mobile Computing (IPDPSWPIM 2002)},
address = {Fort Lauderdale, FL, USA},
publisher = {k.A.},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
type = {Konferenz-Beitrag},
month = {Januar},
year = {2002},
language = {Englisch},
cr-category = {H Information Systems},
ee = {www.nexus.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {k.A.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2002-27&engl=0}
}
@inproceedings {INPROC-2002-23,
author = {Abdelmajid Khelil and Christian Becker and Jing Tian and Kurt Rothermel},
title = {{An Epidemic Model for Information Diffusion in MANETs}},
booktitle = {Proceedings of the 5th International Workshop on Modeling, Analysis and Simulation of Wireless and Mobile Systems (MSWiM'02) at MobiCom 2002},
editor = {Teresa Dahlberg and Michela Meo and Albert Zomaya},
address = {Atlanta, Georgia, USA},
publisher = {ACM PRESS},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
series = {ACM MSWiM Proceedings},
pages = {54--60},
type = {Konferenz-Beitrag},
month = {September},
year = {2002},
isbn = {1-58113-610-2},
keywords = {Algorithms; Performance; Reliability; MANET; analytical modeling; adaptive information diffusion},
language = {Englisch},
cr-category = {C.2.1 Network Architecture and Design,
C.2.2 Network Protocols,
I.6.5 Model Development},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2002-23/INPROC-2002-23.pdf,
http://canu.informatik.uni-stuttgart.de/},
contact = {University of Stuttgart / IPVS Breitwiesenstr. 20-22 70565 Stuttgart, Germany +49 711 7816 {251, 357, 228, 434} {khelil, becker, tian, rothermel}@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {Choosing appropriate information dissemination strategies is crucial in mobile
ad hoc networks (MANET) due to the frequent topology changes. Flooding-based
approaches like diffusion have a strong similarity with epidemic spreading of
diseases. Applying epidemiological models to information diffusion allows the
evaluation of such strategies depending on the MANET characteristics, e.g. the
node density. In order to choose appropriate strategies at run time, the model
should be easily evaluated.
In this paper, an epidemic model is developed for a simple information
diffusion algorithm based on simulation results. We analytically investigate
the impact of node density on information diffusion. The analytical model
allows the evaluation at runtime, even on devices with restricted resources,
and thus enables mobile nodes to dynamically adapt their diffusion strategies
depending on the local node density.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2002-23&engl=0}
}
@inproceedings {INPROC-2002-22,
author = {Christian Becker and Martin Bauer and J{\"o}rg H{\"a}hner},
title = {{Usenet-on-the-fly - Supporting Locality of Information in Spontaneous Networking Entironments}},
booktitle = {Workshop on Ad Hoc Communications and Collaboration in Ubiquitous Computing Envirnments},
editor = {Ramiro Liscano and Gerd Kortuem},
publisher = {n/a},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
pages = {1--1},
type = {Konferenz-Beitrag},
month = {November},
year = {2002},
language = {Englisch},
cr-category = {H.4.3 Information Systems Applications Communications Applications,
H.5.3 Group and Organization Interfaces},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2002-22/INPROC-2002-22.pdf},
contact = {christian.becker@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {People on the move are typically interested in information with respect to
their proximity. Location-based services in general supply users with
information about their proximity typically relying on an infrastructure
storing the information and tracking the mobile objects, i.e. users. In this
paper we present an approach for spontaneous, i.e. ad hoc, networks inspired by
the Usenet. Information is exchanged using a peer-to-peer synchronization
mechanism. The information is made available through channels grouping related
information. The information propagation is solely based on spontaneously
connected devices not requiring any infrastructure. Our prototype
implementation shows the technical feasibility of our approach, whereas
simulation results show the applicability of information diffusion in outdoor
scenarios with a realistic number of nodes, covering a city center.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2002-22&engl=0}
}
@inproceedings {INPROC-2002-21,
author = {Daniel Herrscher and Kurt Rothermel},
title = {{A Dynamic Network Scenario Emulation Tool}},
booktitle = {Proceedings of the 11th International Conference on Computer Communications and Networks (ICCCN 2002), Miami (FL), Oct 14-16, 2002},
publisher = {IEEE},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
pages = {262--267},
type = {Konferenz-Beitrag},
month = {Oktober},
year = {2002},
isbn = {0-7803-7553-X},
keywords = {Network Emulation; Network Scenario; Emulation Tool},
language = {Englisch},
cr-category = {C.2.1 Network Architecture and Design,
C.2.2 Network Protocols},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2002-21/INPROC-2002-21.pdf},
contact = {herrscher@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {Comparative performance measurements of distributed applications and network
protocols require the availability of appropriate network environments. Network
emulation approaches offer a flexible way to mimic the properties of a variety
of networks. Existing emulation tools work either with centralized real-time
simulation components, limiting the scenario size and maximum traffic, or focus
on the emulation of some network properties at a single point. We propose a
tool for the realistic emulation of network links, and show how several
emulated links can be combined to reproduce a comprehensive network model. In
addition to that, the model can include changing network properties, e.g.
emerging from mobile communication partners. This facilitates the distributed
emulation of a comprehensive, dynamic network scenario to support repeatable
performance measurements.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2002-21&engl=0}
}
@inproceedings {INPROC-2002-20,
author = {Detlef Bosau and Cora Burger and Arno Wacker and Martin Pfletschinger},
title = {{Context-Sensitive Interaction Support during Augmented Lectures}},
booktitle = {Proceedings of the 7th Cabernet Radicals Workshop},
editor = {Joe Finney and Mads Haahr and Alberto Montresor},
address = {Bertinoro (Forly, Italy)},
publisher = {-},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
type = {Konferenz-Beitrag},
month = {Oktober},
year = {2002},
keywords = {e-learning; Application sharing; teaching; mobile computing},
language = {Englisch},
cr-category = {H.4.3 Information Systems Applications Communications Applications},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2002-20/INPROC-2002-20.pdf,
http://www.newcastle.research.ec.org/cabernet/,
http://www.informatik.uni-stuttgart.de/ipvr/vs/en/projects/NUSS/},
contact = {Send an E-Mail to Arno.Wacker@informatik.uni-stuttgart.de or phone +49-711-7816-236},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {With mobile devices and wireless networks, new possibilities evolve to improve
the interaction between teacher and students in class. The paper introduces the
idea of DONUT, a Distributed annOtation tool for Notebook University Teachware,
which is going to be developed within the NUSS (Notebook University Stuttgart)
project being funded by the German Ministry for Education and Research. DONUT
is integrated into an existing framework for application sharing. It is based
on defining and making use of semantic relationships between presented teaching
material and contributions of students. Hence, automatic categorization of
contributions becomes available in advance. This supports the teacher's
decision, whether to integrate contributions into the lecture or postpone them.
Especially, a lot of questions regarding the same topic can indicate problems
in understanding on the side of students quite well.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2002-20&engl=0}
}
@inproceedings {INPROC-2002-19,
author = {Martin Bauer and Kurt Rothermel},
title = {{Towards the Observation of Spatial Events in Distributed Location-Aware Systems}},
booktitle = {Proceedings of the 22nd International Conference on Distributed Computing Systems Workshops},
editor = {Roland Wagner},
address = {Los Alamitos, California},
publisher = {IEEE Computer Society},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
pages = {581--582},
type = {Konferenz-Beitrag},
month = {Juli},
year = {2002},
isbn = {0-7695-1588-6},
keywords = {event; event observation; location awareness; Nexus},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
ee = {http://www.computer.org/proceedings/icdcsw/1588/15880581.pdf,
http://www.nexus.uni-stuttgart.de},
contact = {Martin Bauer Martin.Bauer@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {In this paper, the event concept is applied to support the interaction between
mobile users and distributed location-aware systems. Taking a number of
examples, the components of an event specification language are derived that
can be used beyond the domain of location-aware systems.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2002-19&engl=0}
}
@inproceedings {INPROC-2002-16,
author = {Daniel Herrscher and Alexander Leonhardi and Kurt Rothermel},
title = {{Modeling Computer Networks for Emulation}},
booktitle = {Proceedings of the 2002 International Conference on Parallel and Distributed Processing Techniques and Applications (PDPTA'02), Las Vegas},
publisher = {CSREA Press},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
pages = {1725--1731},
type = {Konferenz-Beitrag},
month = {Juni},
year = {2002},
keywords = {Network Emulation; Modeling Language; Network Topologies},
language = {Englisch},
cr-category = {C.2.1 Network Architecture and Design,
C.2.5 Local and Wide-Area Networks},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2002-16/INPROC-2002-16.pdf},
contact = {herrscher@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {The Network Emulation Testbed project provides a configurable network
environment for the performance analysis of distributed applications and
protocols. An emulation scenario consists of a network topology, link
parameters, and dynamic change models. In order to set up a scenario
automatically, it has to be modeled in an appropriate description language. In
this paper, we analyze the requirements for an emulation scenario description
language and propose a possible solution.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2002-16&engl=0}
}
@inproceedings {INPROC-2002-15,
author = {Xuejun Chen},
title = {{Dynamic Reconfiguration of a Component-Based Software System for Vehicles}},
booktitle = {Proceeding of the 15th IFAC World Congress on Automatic Control},
address = {Oxford, UK},
publisher = {Elsevier Science Ltd.},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
pages = {1--1},
type = {Konferenz-Beitrag},
month = {Juli},
year = {2002},
keywords = {Mobile Application; Dynamic Reconfiguration; Distributed System; Update Strategy; Component Deployment Strategy},
language = {Englisch},
cr-category = {D.2 Software Engineering},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {The component system information and management architecture is a component
architecture to build the application software which is used in modern
vehicles. The components are distributed in the system: the individual
components are mainly located in different computers in vehicles, while the
rest runs on computers in the infrastructure. The components can be dynamically
loaded to different places of the component system, executed, removed and
updated at runtime. In this article, we describe dynamic reconfiguration of a
software component system for vehicles. Furthermore, we propose update
strategies for updating components and component deployment strategies for
optimizing the distributed system. By the use of dynamic reconfiguration, the
flexibility and adaptability of the component based distributed system in
vehicles are enhanced. In addition, the dynamic reconfiguration can improve the
performance of the component system and reduce the costs of communication
between a vehicle and the infrastructure.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2002-15&engl=0}
}
@inproceedings {INPROC-2002-14,
author = {Xuejun Chen and Martin Simons},
title = {{A Component Framework for Dynamic Reconfiguration of Distributed Systems}},
booktitle = {Proceeding of the First International IFIP/ACM Working Conference on Component Deployment (CD 2002)},
publisher = {Springer Verlag},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
series = {Lecture Notes in Computer Science},
pages = {1--1},
type = {Konferenz-Beitrag},
month = {Juni},
year = {2002},
language = {Englisch},
cr-category = {D.2 Software Engineering},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {The growing popularity of wired and wireless Internet requires distributed
systems to be more flexible, adaptive and easily extendable. Dynamic
reconfiguration of distributed component-based systems is one possible solution
to meet these demands. However, current component frameworks that support
dynamic reconfiguration either place the burden of preparing a component for
reconfiguration completely on the component's developer or impose strong
restrictions on the component model and the communication mechanisms. We
investigate a middle ground between these two extremes and propose a component
framework that supports a framework guided reconfiguration and places minimal
burden on the component's developer. This component framework offers mechanisms
to analyze and treat the interactions between the target component and other
components during a dynamic reconfiguration.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2002-14&engl=0}
}
@inproceedings {INPROC-2002-13,
author = {Xuejun Chen},
title = {{Extending RMI to Support Dynamic Reconfiguration of Distributed Systems}},
booktitle = {Proceeding of the 22nd International Conference on Distributed Computing Systems (ICDCS 2002)},
publisher = {IEEE Computer Society},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
pages = {1--1},
type = {Konferenz-Beitrag},
month = {Juli},
year = {2002},
keywords = {Java RMI; Middleware; Dynamic Reconfiguration; Mobile Object; Distributed Systems},
language = {Englisch},
cr-category = {C.2 Computer-Communication Networks,
D.1 Programming Techniques},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {By the use of the ability of dynamic reconfiguration, the flexibility,
adaptability, and extensibility of distributed systems are enhanced. How to
treat interactions among components during a dynamic reconfiguration is still
one of the most crucial problems in this research area. This challenge should
be met by middleware design and development. However, the current standard
middleware offers little support for dynamic reconfiguration of distributed
systems. In this paper, we describe an extended Java RMI that supports
efficiently dynamic reconfiguration of distributed systems. This extended Java
RMI can automatically monitor and manipulate invocations between components
during a dynamic reconfiguration. Moreover, the extended Java RMI can
automatically switch invocations from remote to local and vice versa.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2002-13&engl=0}
}
@inproceedings {INPROC-2002-11,
author = {Uwe Kubach and Kurt Rothermel},
title = {{Estimating the Benefit of Location-Awareness for Mobile Data Management Mechanisms}},
booktitle = {Proceedings of the International Conference on Pervasive Computing 2002},
address = {Heidelberg},
publisher = {Springer-Verlag},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
pages = {1--14},
type = {Konferenz-Beitrag},
month = {August},
year = {2002},
keywords = {location awareness; mobile data management; evaluation},
language = {Englisch},
cr-category = {H.2 Database Management},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2002-11/INPROC-2002-11.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {With the increasing popularity of mobile computing devices, the need to access
information in mobile environments has also grown rapidly. In order to support
such mobile information accesses, location-based services and mobile
information systems often rely on location-aware data management mechanisms
like location-aware caching, data dissemination or prefetching. As we explain
in this paper, the location-awareness of such mechanisms is only useful, if the
accessed information is location-dependent, i.e. if the probability with that a
certain information object is accessed depends on the user’s location. Although
the location-dependency of the accessed information is crucial for the
efficiency of location-aware data management mechanisms and the benefit they
can get out of their location-awareness, no metric to measure the
location-dependency of information has been proposed so far. In this paper, we
describe such a metric together with a second one for a further important
characteristic of mobile information accesses, the so-called focus.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2002-11&engl=0}
}
@inproceedings {INPROC-2002-10,
author = {Jing Tian and J{\"o}rg H{\"a}hner and Christian Becker and Illya Stepanov and Kurt Rothermel},
title = {{Graph-Based Mobility Model for Mobile Ad Hoc Network Simulation}},
booktitle = {Proceedings of the 35th Annual Simulation Symposium: San Diego, California, April 14-18, 2002},
editor = {IEEE Computer Society Press},
address = {Washington, Brussels, Tokyo},
publisher = {IEEE Computer Society Press},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
pages = {337--345},
type = {Konferenz-Beitrag},
month = {April},
year = {2002},
isbn = {0-7695-1552-5},
keywords = {Mobility Model; Mobile Ad Hoc Network; Simulation; Spatial Model},
language = {Englisch},
cr-category = {I.6 Simulation and Modeling,
G.3 Probability and Statistics},
contact = {canu@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {Imagine a world where people constantly try to pass through walls and cars
suddenly leave the roads and drive into rivers. Although this is unrealistic,
most simulations for mobile ad hoc networks so far are based on the so called
``random walk'' of mobile objects, which are not constrained by their surrounding
spatial environments. In this paper we propose a novel graph-based mobility
model, which provides a more realistic movement than the random walk model by
reflecting the spatial constraints in the real world. We analyzed three
commonly used ad hoc network routing protocols, DSDV, DSR and AODV with both a
random walk-based and our graph-based mobility model. Our simulation results
show that the spatial constraints have a strong impact on the performance of ad
hoc routing protocols.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2002-10&engl=0}
}
@inproceedings {INPROC-2002-09,
author = {Joachim Jordan and Ulrich Kleinhans and Ottokar Kulendik and J{\"u}rgen Porscha and Alwin Pross and Reiner Siebert},
title = {{Transparent and Flexible Cross-Organizational Workflows for Engineering Cooperations in Vehicle Development}},
booktitle = {PDT Europe 2002},
address = {Torino, Italy},
publisher = {Quality Marketing Services, Sandhurst, UK},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
pages = {101--108},
type = {Konferenz-Beitrag},
month = {Mai},
year = {2002},
isbn = {1 901782 06 9},
keywords = {cross-organizational workflow management; engineering},
language = {Englisch},
cr-category = {H.5.3 Group and Organization Interfaces,
C.2.4 Distributed Systems,
H.4.1 Office Automation,
J.1 Administration Data Processing,
J.2 Physical Sciences and Engineering},
contact = {ottokar.kulendik@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {Engineering cooperations for vehicle development have proven to be successful
not just to extend capacities but to profit from each other's specific
know-how. Workflow management bears the potential to reduce cooperation
barriers and costs. Within a cooperation project between DaimlerChrysler AG and
EDAG, application scenarios have been defined to identify goals and benefits,
to analyse important requirements, and to develop an IT solution concept,
together with the University of Stuttgart.
Manufacturer and supplier both would profit from 1.) manageable automation of
cross-organizational workflows, 2.) transparency of their partner's processes,
3.) flexibility of specifying own workflows autonomously, and 4.) integration
of heterogeneous workflow management systems. For research, this field of
application is challenging because existing approaches so far do not seem to be
sufficient.
We describe a relevant scenario from an engineering cooperation project in
detail. The resulting requirements do not only occur across companies, but in
general even inside a single company. An appropriate solution should be able to
deal with multiple interactions and some more complex dependencies between
different workflows. It should be possible to make relevant data visible but
keep irrelevant information private, and to support a late evolution of
partner's workflows.
To address those requirements appropriately, our approach minimizes the
specification agreed between the partners, therefore allowing to specify the
associated partner's workflows in a decentralized, delayed manner. External
workflow schemata can be used to give partners a view on each other's workflow.
We use a peer-to-peer architecture in which complex dependencies between
workflows are mapped onto simpler messages.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2002-09&engl=0}
}
@inproceedings {INPROC-2002-08,
author = {Peter Coschurba and Kurt Rothermel and Frank D{\"u}rr},
title = {{A fine grained addressing concept for GeoCast}},
booktitle = {Trends in Network and Pervasive Computing -- ARCS 2002 (Proceedings of the International Conference on Architecture of Computing Systems 2002)},
editor = {Hartmut Schmeck and Theo Unger and Lars Wolf},
address = {Karlsruhe, Germany},
publisher = {Springer-Verlag},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
series = {Lecture Notes in Computer Science},
volume = {2299},
pages = {101--113},
type = {Konferenz-Beitrag},
month = {April},
year = {2002},
isbn = {3-540-43409-7},
keywords = {routing; location-based services; geographic communication; GeoCast},
language = {Englisch},
cr-category = {C.2 Computer-Communication Networks},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2002-08/INPROC-2002-08.pdf,
http://www.springerlink.com/content/8hcep0e11k61tx53/},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {GeoCast provides the functionality of sending messages to everyone in a
specific area. So far, only the addressing of larger two-dimensional areas was
possible. For the use in an urban environment it is crucial that small and
three-dimensional areas can be addressed. For example, GeoCast can then be used
to send lecture notes to all in a classroom. In this paper we describe a
fine-grained addressing concept for GeoCast that supports such areas. In
addition we present an architecture that allows the use of that addressing
concept together with the GeoRouting-approach developed by Navas and
Imielinski. We also present some modifications necessary to enhance the
scalability of GeoCast.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2002-08&engl=0}
}
@inproceedings {INPROC-2002-06,
author = {Cora Burger and Stella Papakosta and Eric Bullinger and Thomas Wagner},
title = {{Investigation of application sharing systems for teaching purposes in engineering disciplines}},
booktitle = {4th International Conference on New Educational Environment 2002},
publisher = {EduSwiss},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
type = {Konferenz-Beitrag},
month = {Mai},
year = {2002},
keywords = {Application Sharing; Wireless Campus; Awareness},
language = {Englisch},
cr-category = {H.4.3 Information Systems Applications Communications Applications},
ee = {http://www.informatik.uni-stuttgart.de/ipvr/vs/projekte/Festival/sascia.html,
http://www.eduswiss.ch/4th-conf/default.asp},
contact = {caburger@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {With portable devices and wireless networks, a new potential is arising to
improve teaching in collocated, remote and hybrid scenarios. This can be
achieved by a suitable mixture of theoretical and practical elements, where
students can try out applications by themselves during lectures. Existing
systems for application sharing do not cope with the specific requirements of
this environment. Hence, the system SASCIA (System architecture supporting
cooperative and interactive applications) has been developed and tested
successfully.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2002-06&engl=0}
}
@inproceedings {INPROC-2002-04,
author = {Cora Burger and Stella Papakosta and Kurt Rothermel},
title = {{Application sharing in teaching context with wireless networks}},
booktitle = {Proc. World Congress NETWORKED LEARNING IN A GLOBAL ENVIRONMENT - Challenges and Solutions for Virtual Education},
publisher = {NAISO (Natural and Artificial Intelligence Systems Organization) The Netherlands},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
type = {Konferenz-Beitrag},
month = {Mai},
year = {2002},
keywords = {Application sharing; teaching},
language = {Englisch},
cr-category = {H.4.3 Information Systems Applications Communications Applications},
ee = {http://www.icsc-naiso.org/conferences/nl2002/,
http://www.informatik.uni-stuttgart.de/ipvr/vs/projekte/Festival/sascia.engl.html},
contact = {caburger@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {The success of teaching is depending on a couple of factors where collaboration
among all participants, teachers and students are the most important ones. With
mobile devices and wireless networks, new possibilities evolve for improvement.
By promoting existing concepts of application sharing systems, the project
SASCIA (System architecture supporting cooperative and interactive
applications) aims at developing a framework for multiple applications to
support teaching in collocated, remote and hybrid scenarios. It provides
annotation and recording to support latecomers and further exceptions as well
as subsequent replay. Moreover, configurable context awareness among
participants as well as floor and consistency control cover a wide spectrum of
applications and learning situations. According to first experiments, the
prototype is performing well and was readily accepted by students.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2002-04&engl=0}
}
@inproceedings {INPROC-2002-02,
author = {Cora Burger and Eric Bullinger and Stella Papakosta and Thomas Wagner},
title = {{Context awareness for application sharing in teaching environment}},
booktitle = {International Conference on Advances in Infrastructure for e-Business, e-Education, e-Science, and e-Medicine on the Internet},
publisher = {Scuola Superiore G. Reiss Romoli},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
pages = {00--00},
type = {Konferenz-Beitrag},
month = {Januar},
year = {2002},
keywords = {Application sharing, context awareness, teaching},
language = {Englisch},
cr-category = {H.4.3 Information Systems Applications Communications Applications,
H.5.3 Group and Organization Interfaces,
J.1 Administration Data Processing},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2002-02/INPROC-2002-02.ps,
http://www.ssgrr.it/en/ssgrr2002w/index.htm,
http://www.informatik.uni-stuttgart.de/ipvr/vs/projekte/Festival/sascia.html},
contact = {caburger@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {Mobile and ubiquitous computing offer new possibilities to increase the
awareness in class and support an active participation of students. To this
end, context information is captured and distributed about sessions,
participants and those applications that are used during a lecture or encounter
among students (e. g. presentations, development and simulation environments,
experiments in natural and engineering sciences). The framework of SASCIA
(System Architecture Supporting Cooperative and Interactive Applications) cares
for appropriate usage of this information to enable new ways of application
sharing. First experiments have proofed the usefulness of the system and an
acceptable performance.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2002-02&engl=0}
}
@inproceedings {INPROC-2001-50,
author = {Darko Klinec and Alexander Leonhardi},
title = {{Positioning and Location Services for Indoor Areas in Nexus}},
booktitle = {Proceedings of the International Symposium on Indoor Navigation (INDOORNAV 2001)},
address = {M{\"u}nchen},
publisher = {k.A.},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
type = {Konferenz-Beitrag},
month = {Januar},
year = {2001},
language = {Englisch},
cr-category = {H Information Systems},
ee = {www.nexus.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme;
Universit{\"a}t Stuttgart, Institut f{\"u}r Photogrammetrie (ifp)},
abstract = {k.A.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2001-50&engl=0}
}
@inproceedings {INPROC-2001-49,
author = {Xuejun Chen and Matthias St{\"u}mpfle},
title = {{Dynamic Configuration Management of a Telematics System for Vehicles}},
booktitle = {Proceeding of the 1st IFAC Conference on Telematics Applications in Automation and Robotics (TA 2001)},
address = {Oxford, UK},
publisher = {Elsevier Science Ltd},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
pages = {279--284},
type = {Konferenz-Beitrag},
month = {Juli},
year = {2001},
keywords = {Configuration Management; Software Component; Dynamic Reconfiguration; Telematics System},
language = {Englisch},
cr-category = {D.2 Software Engineering},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {The Component System Information and Management Architecture is a component
architecture to build telematics systems which are used in modern vehicles. The
components are distributed in the architecture: the individual components are
mainly located in different computers in vehicles, while the rest runs on
computers in the infrastructure. The components can be dynamically loaded to
different places of a mobile component system, executed, removed and updated at
runtime. The dynamic reconfiguration requires an efficient and robust
configuration management. This article describes a configuration management
which supports a dynamic reconfiguration at runtime for a component system of
this kind. The dynamic reconfiguration can improve the performance of the
component system and reduce the communication costs between a vehicle and the
infrastructure.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2001-49&engl=0}
}
@inproceedings {INPROC-2001-48,
author = {Kurt Rothermel and Alexander Leonhardi},
title = {{Maintaining Worls Models for Context-aware Applications}},
booktitle = {Proceedings of the 8th International Conference on Advances in Communication and Control (COMCON-8)},
editor = {William R. Wells},
address = {New York, Los Angeles},
publisher = {Optimization Software Inc.},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
pages = {235--245},
type = {Konferenz-Beitrag},
month = {Juni},
year = {2001},
isbn = {0-911575-78-2},
keywords = {NEXUS; context-aware; location-aware; location service},
language = {Englisch},
cr-category = {H.2 Database Management},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2001-48/INPROC-2001-48.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {In this paper we describe the architecture and world model of the neXus
platform for location- and context-aware applications. An important aspect of
the neXus world model is that it also describes highly mobile objects, such as
persons or vehicles. Therefore, we look in more detail at the management of
location information in the neXus platform and the neXus Location Service,
which provides for tracking the location of mobile objects with a high
accuracy. In particular, we present a comparison of and simulation results for
different protocols that are suitable for the frequent updating of highly
accurate location information.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2001-48&engl=0}
}
@inproceedings {INPROC-2001-47,
author = {Ottokar Kulendik and Kurt Rothermel and Reiner Siebert},
title = {{Cross-organizational workflow management - General Approaches and their Suitability for Engineering Processes}},
booktitle = {Proceedings of the First IFIP-Conference on E-Commerce, E-Business, E-Government : I3E 2001 ; Zuerich, Switzerland, October 3-5, 2001},
editor = {Beat Schmid and Katarina Stanoevska-Slabeva and Volker Tschammer},
address = {Zuerich, Switzerland},
publisher = {Kluwer Academic Publishers},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
pages = {143--158},
type = {Konferenz-Beitrag},
month = {Oktober},
year = {2001},
isbn = {0-7923-7529-7},
keywords = {cross-organizational workflow management; engineering},
language = {Englisch},
cr-category = {H.5.3 Group and Organization Interfaces,
C.2.4 Distributed Systems,
H.4.1 Office Automation,
J.1 Administration Data Processing,
J.2 Physical Sciences and Engineering},
contact = {ottokar.kulendik@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {Cross-organizational workflow management deals with the need for transparent
and controlled process automation across organizational boundaries. Cooperation
between manufacturers and suppliers in the field of engineering requires
coupling of parallel workflows of autonomous organization units. So far,
several approaches with different architectures exist but they address this
field of application differently. This paper presents some requirements of
cross-organizational workflow management in the engineering domain by using an
application scenario. Existing research approaches are classified
distinguishing used specification schemata and expressiveness concerning
cross-workflow dependencies. We describe a new approach in a class that matches
the presented requirements.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2001-47&engl=0}
}
@inproceedings {INPROC-2001-46,
author = {Christian Becker and Gregor Schiele},
title = {{New mechanisms for routing in ad hoc networks}},
booktitle = {Proceedings of the Fourth CaberNet Plenary Workshop; Pisa, Italy, October 9-11, 2001.},
publisher = {not available},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
type = {Konferenz-Beitrag},
month = {Oktober},
year = {2001},
keywords = {mobile ad hoc routing; model based routing; user profiles},
language = {Englisch},
cr-category = {C.2.2 Network Protocols},
contact = {gregor.schiele@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {Routing in ad hoc networks is challenged by mobility and dynamics of mobile
devices. Hence, classic routing algorithms hardly cope with partitions and
constant topology changes in such networks. Existing routing algorithms are
based on flooding to explore a location or known node locations. In this paper
we present an approach based on additional information available in such
networks that will help to reduce the network load without relying on known
receiver locations.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2001-46&engl=0}
}
@inproceedings {INPROC-2001-45,
author = {Christian Maih{\"o}fer and Kurt Rothermel},
title = {{A Delay Analysis of Tree-based Reliable Multicast Protocols}},
booktitle = {Proceedings of the International Conference on Computer Communications and Networks (ICCCN 01)},
editor = {IEEE},
address = {Scottsdale, Arizona, USA},
publisher = {IEEE Press},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
pages = {274--281},
type = {Konferenz-Beitrag},
month = {Januar},
year = {2001},
language = {Englisch},
cr-category = {C.2 Computer-Communication Networks},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2001-45/INPROC-2001-45.ps},
contact = {christian.maihoefer@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {We present a comparative delay analysis of tree-based reliable multicast
protocols and show the influence of varying sending rates, group sizes, packet
loss probabilities and branching factors of the control tree. Besides the
average delivery delay we consider the delay to reliably deliver all packets
and the round trip delay. The former two examines the delay between generation
of a packet at the sender and correct reception at a randomly chosen receiver
or all receivers, respectively. The latter is the delay between generation of a
packet at the sender and reception of all acknowledgement packets at the
sender. Our numerical results show that all tree-based protocols provide low
delays and good scalability. From the four considered protocol classes,
NAK-based protocols achieve the best scalability but ACK-based protocols
achieve the lowest delays.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2001-45&engl=0}
}
@inproceedings {INPROC-2001-36,
author = {Martin Bauer and Christian Becker and Kurt Rothermel},
title = {{Location Models from the Perspective of Context-Aware Applications and Mobile Ad Hoc Networks}},
booktitle = {Workshop on Location Modeling for Ubiquitous Computing, UbiComp 2001},
address = {Atlanta},
publisher = {-},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
type = {Konferenz-Beitrag},
month = {September},
year = {2001},
keywords = {location, location-aware, location model, modeling language, Nexus, Canu},
language = {Englisch},
cr-category = {H.3.4 Information Storage and Retrieval Systems and Software},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2001-36/INPROC-2001-36.pdf},
contact = {Martin.Bauer@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {Location models are crucial to location-aware applications. In this paper we
present two approaches for modeling location information in an
infrastructure-based and an ad hoc network based application scenario. From
these approaches we deduce requirements for a general location modeling
language for ubiquitous computing.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2001-36&engl=0}
}
@inproceedings {INPROC-2001-35,
author = {S. Papakosta and C. Burger},
title = {{Generating Interactive Protocol Simulations and Visualizations for Learning Environments}},
booktitle = {CaberNet: 4th Plenary Workshop. Vol. 2001},
publisher = {Not available},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
type = {Konferenz-Beitrag},
month = {Oktober},
year = {2001},
keywords = {SPIN; Promela; model checking; simulation; animation},
language = {Englisch},
cr-category = {C.2.2 Network Protocols,
I.6 Simulation and Modeling,
K.3 Computers and Education,
H.5.1 Multimedia Information Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2001-35/INPROC-2001-35.ps,
http://www.informatik.uni-stuttgart.de/ipvr/vs/projekte/HiSAP/hisap.html,
http://iasc88.ias.uni-stuttgart.de/ito/},
contact = {papakosi@informatik.uni-stuttgart.de caburger@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {This position paper introduces the idea and concept of generating interactive
protocol simulations and visualizations for teaching environments in lectures
as well as for learning environments over the internet. Since the realisation
is based on the SPIN model checker, a short presentation of this verification
tool and its language Promela is shortly been given before sketching the
generation procedure itself. The architecture presented here is open to further
extensions.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2001-35&engl=0}
}
@inproceedings {INPROC-2001-28,
author = {J{\"u}rgen Hauser and Kurt Rothermel},
title = {{Specification and Implementation of an Extensible Multimedia System}},
booktitle = {Tagungsband Kommunikation in Verteilten Systemen (KiVS) 2001},
publisher = {Springer},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
pages = {216--226},
type = {Konferenz-Beitrag},
month = {Januar},
year = {2001},
language = {Englisch},
cr-category = {H Information Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {The research project MAVA (Multimedia Document Versatile Architecture) focuses
on simplification of specification and dissemination of multimedia documents.
The problems discussed and solved by the MAVA approach are observed by using
existing authoring systems. Application specific multimedia systems provide
fixed concepts for only one application area. Generic systems allow the
specification of documents of arbitrary application areas. This leads to
complex specifications and the requirement of programming skills for authors.
Goal of the MAVA approach is to simplify authoring of multimedia documents in
different application areas by an extensible specification language. This
allows to add new language elements for particular application areas to
simplify authoring. While the extension with new media types is addressed by
several approaches the MAVA approach considers also the extension for new
particular application areas. Document dissemination plays also an important
role. For the presentation of a document basing on arbitrary language
extensions also the presentation system itself has to be dynamically extended
over the Internet.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2001-28&engl=0}
}
@inproceedings {INPROC-2001-20,
author = {Rolf Mecklenburg and Cora Burger and Kurt Rothermel},
title = {{Visualized Interactive Protocols: A Way to Teach and Test Rules of Computer Communication}},
booktitle = {Fourth World Conference on Integrated Design \& Process Technology},
publisher = {(not available)},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
type = {Konferenz-Beitrag},
month = {Januar},
year = {2001},
language = {Englisch},
cr-category = {H Information Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {By understanding protocols in computer communication, different cognition
levels are involved. After a mere observation phase of predefined scenarios,
interactively modifying parameters and rules to test the resulting behavior are
best suited to become acquainted with a protocol. Because of the complexity of
protocols, only a few consequences of such modifications can be seen directly.
Therefore, support is needed to be able to estimate changes in protocol
behavior caused by such modifications. We describe ``HISAP'' (Highly Interactive
Simulation of Algorithms and Protocols), whose features enable such a way of
training in computer protocols.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2001-20&engl=0}
}
@inproceedings {INPROC-2001-18,
author = {Uwe Kubach and Mario Hegele and Kurt Rothermel},
title = {{A Simulation Framework for Mobile, Location-Dependent Information Access}},
booktitle = {Proceedings of the 6th IEEE Symposium on Computers and Communications (ISCC 2001)},
address = {Hammamet, Tunesia},
publisher = {not available},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
pages = {506--511},
type = {Konferenz-Beitrag},
month = {Juli},
year = {2001},
language = {Englisch},
cr-category = {H Information Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {With the increasing pervasiveness of mobile computing devices, the need to
access information in mobile environments has grown rapidly. Consequently, many
mechanisms, e.g. broadcast dissemination, hoarding, or specialized caching
mechanisms have been developed to overcome the disadvantages of wireless
communication systems, which are usually used to access the information. To
evaluate such mechanisms a simulation tool is needed that simulates both the
users' mobility and their information access patterns. Since most existing user
models either model only the mobility or the information access, we developed a
new model that covers both aspects. Based on this model, we realized a flexible
framework that allows to simulate all aspects of a mobile information access.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2001-18&engl=0}
}
@inproceedings {INPROC-2001-16,
author = {Peter Coschurba},
title = {{Ein {\"U}berblick {\"u}ber GeoCast}},
booktitle = {Praxis der Informationsverarbeitung (PIK)},
address = {M{\"u}nchen},
publisher = {K.G. Saur Verlag},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
volume = {24},
number = {2001},
pages = {63--66},
type = {Konferenz-Beitrag},
month = {April},
year = {2001},
isbn = {3-598-01236-5},
keywords = {GeoCast},
language = {Deutsch},
cr-category = {C.2.0 Computer-Communication Networks, General,
C.2.2 Network Protocols},
contact = {Peter.Coschurba@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {Die vorhandenen Internetprotokolle erlauben das effiziente Versenden von
Nachrichten an mehrere Empfaenger. Allerdings muessen die Empfaenger den
Empfangswunsch explizit erkl{\"a}ren. F{\"u}r viele Anwendungen ist es w{\"u}nschenswert,
eine Nachricht an alle Empf{\"a}nger in einem bestimmten geographischen Gebiet zu
senden. Dieses wird durch GeoCast realisiert. Bei GeoCast spezifiziert der
Sender ein Gebiet und alle potentiellen Empfaenger in diesem Gebiet erhalten
diese Nachricht.
In desem Artikel wird betrachtet, was m{\"o}gliche Anwendungen fuer diese Technik
sind. Zudem wird der derzeitige Stand der Technik im Bereich GeoCast
erlaeutert.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2001-16&engl=0}
}
@inproceedings {INPROC-2001-13,
author = {U. Kubach and K. Rothermel},
title = {{A Map-Based Hoarding Mechanism for Location-Dependent Information}},
booktitle = {Proceedings of the 2nd International Conference on Mobile Data Management (MDM 2001)},
address = {Hong Kong, China},
publisher = {not available},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
pages = {145--157},
type = {Konferenz-Beitrag},
month = {Januar},
year = {2001},
language = {Englisch},
cr-category = {H Information Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {In mobile environments, information systems are often accessed through wireless
WANs. Thus the users often have to cope with difficulties such as low
bandwidth, high delay, and frequent disconnections. Hoarding is an efficient
method to overcome these difficulties. The idea is to transfer information,
which is probably needed by the user in the near future, in advance, so that it
is already stored on the user's mobile device when it is actually accessed. In
this paper, we present a location-aware hoarding mechanism that is based on the
use of wireless LANs, so-called info-stations. Due to its flexibility, we claim
that our mechanism can be applied in any location-dependent information system.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2001-13&engl=0}
}
@inproceedings {INPROC-2001-12,
author = {U. Kubach and K. Rothermel},
title = {{Exploiting Location Information for Infostation-Based Hoarding}},
booktitle = {Proceedings of the 7th ACM SIGMOBILE Annual International Conference on Mobile Computing and Networking (MobiCom 2001)},
address = {Rome, Italy},
publisher = {not available},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
pages = {15--27},
type = {Konferenz-Beitrag},
month = {Juli},
year = {2001},
keywords = {Mobile data management, mobile information access, infostations, hoarding, location-awareness},
language = {Englisch},
cr-category = {C.2.0 Computer-Communication Networks, General,
C.2.1 Network Architecture and Design,
C.2.4 Distributed Systems},
contact = {Uwe.Kubach@informatik.uni-stuttgart.de Kurt.Rothermel@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {With the increasing popularity of mobile computing devices, the need to access
information in mobile environments has grown rapidly. Since the information has
to be accessed over wireless networks, mobile information systems often have to
deal with problems like low bandwidth, high delay, and frequent disconnections.
Information hoarding is a method that tries to overcome these problems by
transferring information, which the user will probably need, in advance. The
hoarding mechanism that we describe in this paper exploits the location
dependence of the information access, which is often found in mobile
information systems. Our simulation results show that it is beneficial to do so
and that we achieve higher hit ratios than with a caching mechanism.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2001-12&engl=0}
}
@inproceedings {INPROC-2001-11,
author = {J.-U. Kloecking and C. Maih{\"o}fer and K. Rothermel},
title = {{Reducing Multicast Inter-Receiver Delay Jitter - A Server Based Approach}},
booktitle = {Proceedings of the IEEE International Conference on Networking (ICN 2001)},
address = {Colmar, France},
publisher = {IEEE Press},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
type = {Konferenz-Beitrag},
month = {Juli},
year = {2001},
language = {Englisch},
cr-category = {C.2 Computer-Communication Networks},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {(not available)},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2001-11&engl=0}
}
@inproceedings {INPROC-2001-10,
author = {J{\"u}rgen Klarmann},
title = {{Using Conceptual Graphs for Organization Modelling in Workflow Management Systems}},
booktitle = {Proceedings of the Conference Professionelles Wissensmanagement (WM 2001)},
address = {Baden-Baden, Germany},
publisher = {Shaker-Verlag},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
pages = {19--23},
type = {Konferenz-Beitrag},
month = {M{\"a}rz},
year = {2001},
isbn = {3-8265-8611-5},
keywords = {Workflow Management, Conceptual Graphs, Organization Modeling, Flexibility},
language = {Englisch},
cr-category = {H.4.1 Office Automation},
contact = {juergen.klarmann@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {Workflow management systems reflect business structures in a separate
organizational model and a process model because these models describe
different aspects of business structures. The organizational model comprises
members of an organization and organizational relationships (organizational
structure) whereas the process model contains information about the tasks and
their dependencies (process structure). Linking both of these models becomes
more and more problematic because organizational models change much more
nowadays than they have before and so lead to orphaned references in the
process model. Moreover, organizational models should be unknown during process
modeling, and equivalent process models should run with different
organizational structures. For this, we introduce conceptual graphs for
specifying organizational structures in the organizational model and for
specifying potential task holders in the process model. We cover organizational
knowledge and retrieve it at runtime exploiting the benefits of these knowledge
representation technique. With this, it is possible to renounce name
referencing and gain more degrees of freedom for the linking process},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2001-10&engl=0}
}
@inproceedings {INPROC-2001-09,
author = {J{\"u}rgen Klarmann},
title = {{A Comprehensive Support for Changes in Organizational Models of Workflow Management Systems}},
booktitle = {Proceedings of the 4th International Conference on Information Systems Modeling (ISM '01)},
address = {Hradec nad Moravici, Czech Republic},
publisher = {not available},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
pages = {165--172},
type = {Konferenz-Beitrag},
month = {Mai},
year = {2001},
keywords = {workflow, organization modeling},
language = {Englisch},
cr-category = {H.4.1 Office Automation},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {In today's rapidly changing markets, organizations repeatedly change their
structures. Existing workflow management systems reflect these structures in a
separate organizational model and a process model (workflow model). However,
these systems cannot cope with repetitive and frequent structural change of
organizational and process structure and thus hamper continuous operation and
quick reactions to turbulent markets. Change in the structure of the
organizational model can cause orphaned references in the process model which
leads to inconsistent workflow specifications. We describe the problem domain
of structural change and classify it by eight categories. A powerful
organizational meta model is introduced that allows to describe meta
information about organizational structures. With this and with an underlying
ontology, it enables workflow management systems to efficiently adapt to
change. Finally, we show exemplarily how our approach is able to deal with the
identified categories of structural change.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2001-09&engl=0}
}
@inproceedings {INPROC-2001-08,
author = {Christian Maih{\"o}fer and Kurt Rothermel},
title = {{Optimal Branching Factor for Tree-Based Reliable Multicast Protocols}},
booktitle = {Proceedings of the 2001 International International Symposium on Performance Evaluation on computer and Telecommunication Systems (SPECTS)},
editor = {SCS},
address = {Orlando, USA},
publisher = {SCS},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
pages = {10--21},
type = {Konferenz-Beitrag},
month = {Juli},
year = {2001},
language = {Englisch},
cr-category = {C.2 Computer-Communication Networks},
contact = {christian.maihoefer@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {In recent years, a number of reliable multicast protocols on transport layer
have been proposed. Previous analysis and simulation studies gave evidence for
the superiority of tree-based approaches in terms of throughput and bandwidth
requirements.
In many tree-based protocols, the nodes of the tree are formed of multicast
group members. In this case, the branching factor, i.e.$\backslash$ the maximum number of
child nodes is adjustable. In this paper we analyze the influence of the
branching factor on a protocol's throughput and bandwidth consumption. This
knowledge is important to configure protocols for best performance and to
optimize the tree creation process.
Our results show that the optimal branching factor depends mainly on the
probability for receiving messages from other local groups. If local groups are
assigned to a separate multicast address, the optimal branching factor is 2. On
the other hand, if TTL scoping is used and therefore the probability for
receiving messages from other local groups is greater than zero, larger local
groups provide better performance.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2001-08&engl=0}
}
@inproceedings {INPROC-2001-07,
author = {Christian Maih{\"o}fer and Kurt Rothermel},
title = {{A Delay Analysis of Generic Multicast Transport Protocols}},
booktitle = {Proceedings of the 2001 IEEE International Conference on Multimedia and Expo (ICME2001)},
editor = {IEEE},
address = {Tokyo, Japan},
publisher = {IEEE Press},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
type = {Konferenz-Beitrag},
month = {Juli},
year = {2001},
language = {Englisch},
cr-category = {C.2 Computer-Communication Networks},
contact = {christian.maihoefer@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {We present a delay analysis of three generic classes of multicast transport
protocols. The first class considered is an unreliable scheme that works
without retransmission of messages. This class also includes forward error
correction approaches. The second class uses a positive acknowledgment and
retransmission scheme to guarantee reliability. Finally, the third class is a
hierarchical approach to avoid the well-known ACK implosion problem for large
receiver groups. Our results show that only the unreliable and the hierarchical
protocol class provide scalability for large receiver groups. For delay
sensitive applications we can conclude from the results that in case of low
packet loss probabilities, reliable multicast protocols provide low average
delays, which are only slightly increased compared to unreliable protocols.
However, if we take the maximum delay, the delay is significantly increased.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2001-07&engl=0}
}
@inproceedings {INPROC-2001-06,
author = {Christian Maih{\"o}fer and Kurt Rothermel},
title = {{A Bandwidth Analysis of Tree-based Reliable Multicast Protocols}},
booktitle = {Proceedings of the 2001 International Symposium on the Convergence of IT and Communications (ITCOM)},
editor = {Spie},
address = {Denver, USA},
publisher = {not available},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
pages = {354--368},
type = {Konferenz-Beitrag},
month = {August},
year = {2001},
language = {Englisch},
cr-category = {C.2 Computer-Communication Networks},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2001-06/INPROC-2001-06.ps},
contact = {christian.maihoefer@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {In this paper, an analytical bandwidth evaluation of generic tree-based
reliable multicast protocols is presented. Our analysis is based on a realistic
system model, including data packet and control packet loss, asynchronous local
clocks and imperfect scope-limited local groups. Two of the four considered
protocol classes use aggregated acknowledgments (AAKs). With AAKs they are able
to provide reliability even in case of node failures. All tree-based protocols
provide good scalability for large receiver groups. Relating to protocols with
aggregated acknowledgments, the analysis shows only little additional bandwidth
overhead and therefore high throughput rates. Finally, we have analyzed the
influence of the branching factor on a protocol's performance. Our results show
that the optimal branching factor depends mainly on the probability for
receiving messages from other local groups. If local groups are assigned to a
separate multicast address, the optimal branching factor is 2. On the other
hand, if TTL scoping is used as in RMTP or TMTP and therefore the probability
for receiving messages from other local groups is greater than zero, larger
local groups provide better performance.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2001-06&engl=0}
}
@inproceedings {INPROC-2001-05,
author = {Christian Maih{\"o}fer and Kurt Rothermel},
title = {{A Delay Analysis of Reliable Multicast Protocols}},
booktitle = {Proceedings of the 2001 International Symposium on Performance Evaluation of Computer and Telecommunication Systems (SPECTS)},
editor = {SCS},
address = {Orlando, USA},
publisher = {SCS},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
pages = {1--9},
type = {Konferenz-Beitrag},
month = {Juli},
year = {2001},
language = {Englisch},
cr-category = {C.2 Computer-Communication Networks},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2001-05/INPROC-2001-05.ps},
contact = {christian.maihoefer@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {We present a delay analysis of one sender- and two receiver-initiated classes
of reliable multicast protocols. Besides the average delivery delay we consider
the delay to reliably deliver all packets and the round trip delay. The former
two examines the delay between generation of a packet at the sender and correct
reception at a randomly chosen receiver or all receivers, respectively. The
latter is the delay between generation of a packet at the sender and reception
of all acknowledgement packets at the sender.
Our numerical results show that receiver-initiated protocols provide
significantly better scalability for large receiver groups and transmission
rates compared to the sender-initiated protocol. However, the delays of the
sender-initiated protocol within its scalability range is substantially lower
compared to the receiver-initiated protocols.
To assess the quality of our analytical model we have compared the analytical
results with a SRM-like protocol simulation. We show that the analytical and
simulation results are strongly correlated, which demonstrates the
appropriateness of our analytical model.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2001-05&engl=0}
}
@inproceedings {INPROC-2001-04,
author = {J{\"u}rgen Hauser},
title = {{A Component-based Extensible Multimedia System}},
booktitle = {Proceedings of the International Conference on Parallel and Distributed Processing Techniques and Applications (PDPTA '2001)},
editor = {H. R. Arabnia},
address = {Las Vegas, NV, USA},
publisher = {CSREA Press},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
pages = {1243--1249},
type = {Konferenz-Beitrag},
month = {Juni},
year = {2001},
isbn = {1-892512-69-6},
language = {Englisch},
cr-category = {H Information Systems},
contact = {juergen.hauser@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {(not available)},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2001-04&engl=0}
}
@inproceedings {INPROC-2001-03,
author = {J{\"u}rgen Hauser and Kurt Rothermel},
title = {{Document Specification and Dissemination with an Extensible Multimedia System}},
booktitle = {Proceedings of the 12th Kommunikation in Verteilten Systemen (KiVS)},
editor = {Ulrich Killat and Winfried Lamersdorf},
address = {Hamburg, Germany},
publisher = {Springer-Verlag},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
pages = {215--226},
type = {Konferenz-Beitrag},
month = {Februar},
year = {2001},
isbn = {3-540-41645-5},
language = {Englisch},
cr-category = {H Information Systems},
contact = {juergen.hauser@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {(not available)},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2001-03&engl=0}
}
@inproceedings {INPROC-2000-16,
author = {Alexander Leonhardi and Martin Bauer},
title = {{The VIT-System: Experiences with Developing a Location-Aware System for the Internet}},
booktitle = {Workshop on Infrastructure for Smart Devices, How to Make Ubiquity an Actuality, at the HUC2k, Bristol, Great Britain, 2000.},
publisher = {(not available)},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
type = {Konferenz-Beitrag},
month = {Januar},
year = {2000},
language = {Deutsch},
cr-category = {H Information Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2000-16/INPROC-2000-16.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {A lot of information is interesting in a local context, e.g. the bus schedule
of the local bus station or the location and opening hours of the closest
supermarket. Therefore, location-aware access to information and services is an
important feature of applications for mobile and ubiquitous devices. Most
existing location-aware systems have been designed for certain applications,
for example office information systems or tourist guides. At the University of
Stuttgart we have developed a system for location-aware information access that
serves as a platform for different kinds of information systems. Its main
objectives were the seamless integration with existing Internet mechanisms and
protocols and the intention to make publishing location-aware information as
easy as setting up a page on the World Wide Web.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2000-16&engl=0}
}
@inproceedings {INPROC-2000-15,
author = {P. Coschurba and U. Kubach and A. Leonhardi},
title = {{Research Issues in Developing a Platform for Spatial-Aware Applications}},
booktitle = {Proceedings of the 9th ACM SIGOPS European Workshop},
address = {Kolding, Denmark},
publisher = {not available},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
pages = {153--158},
type = {Konferenz-Beitrag},
month = {September},
year = {2000},
language = {Englisch},
cr-category = {H Information Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {(not available)},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2000-15&engl=0}
}
@inproceedings {INPROC-2000-14,
author = {Cora Burger},
title = {{Context Notification in Mobile Environments to find the Right Person in Time}},
booktitle = {Trends in Distributed Systems: Towards a Universal Service Market - Third International IFIP/GI Working Conference, USM 2000},
editor = {Claudia Linnhoff--Popien and Heinz--Gerd Hegering},
address = {Munich, Germany},
publisher = {Springer-Verlag},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
series = {Lecture Notes in Computer Science},
volume = {1890},
pages = {278--283},
type = {Konferenz-Beitrag},
month = {September},
year = {2000},
keywords = {context awareness; trading},
language = {Englisch},
cr-category = {H.3.4 Information Storage and Retrieval Systems and Software},
ee = {http://Festival.informatik.uni-stuttgart.de/,
http://usm2000.informatik.uni-muenchen.de/index.shtml},
contact = {caburger@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {(not available)},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2000-14&engl=0}
}
@inproceedings {INPROC-2000-12,
author = {Christian Maih{\"o}fer and Kurt Rothermel and Nicole Mantei},
title = {{A Throughput Analysis of Reliable Multicast Transport Protocols}},
booktitle = {Proceedings of the 9th International Conference on Computer Communciations and Networks (IEEE ICCCN 2000)},
editor = {IEEE},
address = {Las Vegas, USA},
publisher = {IEEE Press},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
pages = {250--257},
type = {Konferenz-Beitrag},
month = {Oktober},
year = {2000},
language = {Englisch},
cr-category = {C.2 Computer-Communication Networks},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2000-12/INPROC-2000-12.pdf,
ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2000-12/INPROC-2000-12.ps},
contact = {christian.maihoefer@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {Tree-based reliable multicast protocols are known to provide better scalability
than the protocols based on pure sender- and receiver-initiated schemes.
However, previous analytical work that has provided these results is based on a
system model which assumes reliable control message delivery and synchronized
local clocks. These assumptions are questionable simplifications, since they
favor protocols using multicasted negative acknowledgments with NAK avoidance
scheme. In this paper, we extend previous analysis by taking into account
control data loss and asynchronous local clocks.
We further analyze a new protocol class with particular importance, the
tree-based approach with aggregated acknowledgments. In contrast to other
approaches, this class provides reliability not only in case of message loss
but also in case of node failures. Our results show that the additional
overhead to cope with node failures is very low and therefore acceptable for
reliable multicast implementations.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2000-12&engl=0}
}
@inproceedings {INPROC-2000-11,
author = {Christian Maih{\"o}fer},
title = {{Improving Multicast ACK Tree Construction with the Token Repository Service}},
booktitle = {Proceedings of the ICDCS 2000 Workshop on Group Communication},
editor = {IEEE},
address = {Taipei, Taiwan},
publisher = {IEEE Press},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
pages = {57--64},
type = {Konferenz-Beitrag},
month = {April},
year = {2000},
language = {Englisch},
cr-category = {C.2 Computer-Communication Networks},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2000-11/INPROC-2000-11.pdf,
ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2000-11/INPROC-2000-11.ps},
contact = {christian.maihoefer@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {Many new applications like groupware systems, news and file distribution or
audio/video systems are based on multicast as a prerequisite for scalability.
Many of these applications need the multicast support to be reliable, which is
realized in a scalable way by tree based multicast transport protocols, where
the receivers are organized in a ACK tree. Tree based approaches raise the
problem of setting up and maintaining the ACK tree, which is usually done by
variations of the expanding ring search (ERS) approach. In this paper we
present an alternative approach for creating ACK trees which is based on the
concept of a distributed token repository service. Simulation results show that
our approach leads to a lower message overhead than ERS and results in better
shaped ACK trees.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2000-11&engl=0}
}
@inproceedings {INPROC-2000-10,
author = {Christian Maih{\"o}fer},
title = {{Scalable and Reliable Multicast ACK Tree Construction wit the Token Repository Service}},
booktitle = {Proceedings of the 8th IEEE International Conference on Networks (ICON 2000)},
editor = {IEEE},
address = {Singapore},
publisher = {IEEE Press},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
pages = {351--358},
type = {Konferenz-Beitrag},
month = {September},
year = {2000},
language = {Englisch},
cr-category = {C.2 Computer-Communication Networks},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2000-10/INPROC-2000-10.pdf,
ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2000-10/INPROC-2000-10.ps},
contact = {christian.maihoefer@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {Reliable multicast is realized in a scalable way by tree based approaches,
where the receivers are organized in an ACK tree. Usually, expanding ring
search (ERS) is used to create such ACK trees. However, ERS has some
shortcomings like poor scalability, strong dependency on the multicast routing
protocol and the need for bidirectional multicast capable networks, which makes
it difficult to use ERS as the Internet standard mechanism. In this paper we
propose the Token Repository Service (TRS), which is based on a token
repository and a modification of ERS. The TRS stores tokens, which represents
the right for a joining node to connect to a certain parent node in the ACK
tree. Performance evaluations show that the TRS approach has several
advantageous compared to ERS, like improved scalability and independence of the
routing protocol.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2000-10&engl=0}
}
@inproceedings {INPROC-2000-09,
author = {Christian Maih{\"o}fer},
title = {{A Bandwidth Analysis of Reliable Multicast Transport Protocols}},
booktitle = {Proceedings of the 2nd International Workshop on Networked Group Communication (NGC 2000)},
address = {Palo Alto, USA},
publisher = {ACM Press},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
pages = {15--26},
type = {Konferenz-Beitrag},
month = {November},
year = {2000},
language = {Englisch},
cr-category = {C.2 Computer-Communication Networks},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2000-09/INPROC-2000-09.pdf,
ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2000-09/INPROC-2000-09.ps},
contact = {christian.maihoefer@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {Multicast is an efficient communication technique to save bandwidth for group
communication purposes. A number of protocols have been proposed in the past to
provide a reliable multicast service. Briefly classified, they can be
distinguished into sender-initiated, receiver-initiated and tree-based
approaches.
In this paper, an analytical bandwidth evaluation of generic reliable multicast
protocols is presented. Of particular importance are new classes with
aggregated acknowledgments. In contrast to other approaches, these classes
provide reliability not only in case of message loss but also in case of node
failures. Our analysis is based on a realistic system model, including data
packet and control packet loss, asynchronous local clocks and imperfect
scope-limited local groups.
Our results show that hierarchical approaches are superior. They provide higher
throughput as well as lower bandwidth consumption. Relating to protocols with
aggregated acknowledgments, the analysis shows only little additional bandwidth
overhead and therefore high throughput rates.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2000-09&engl=0}
}
@inproceedings {INPROC-2000-08,
author = {J{\"u}rgen Hauser and Kurt Rothermel},
title = {{Specification and Implementation of an Extensible Multimedia System}},
booktitle = {Proceedings of the 7th International Workshop on Interactive Distributed Multimedia Systems and Telecommunication Services (IDMS 2000)},
editor = {Hans Scholten and Marten J. van Sinderen},
address = {Enschede, Netherlands},
publisher = {Springer},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
series = {Lecture Notes in Computer Science},
volume = {1905},
pages = {241--253},
type = {Konferenz-Beitrag},
month = {Oktober},
year = {2000},
isbn = {3-540-41130-5},
language = {Englisch},
cr-category = {H Information Systems},
contact = {juergen.hauser@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {(not available)},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2000-08&engl=0}
}
@inproceedings {INPROC-2000-07,
author = {J{\"u}rgen Hauser},
title = {{Multimedia Authoring with MAVA}},
booktitle = {Proceedings of the 8th International Conference on Digital Documents and Eletronic Publishing (DDEP'00)},
address = {Munich, Germany},
publisher = {Springer-Verlag},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
type = {Konferenz-Beitrag},
month = {August},
year = {2000},
language = {Englisch},
cr-category = {H Information Systems},
contact = {juergen.hauser@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {(not available)},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2000-07&engl=0}
}
@inproceedings {INPROC-2000-06,
author = {W. Theilmann and K. Rothermel},
title = {{Dynamic Maps of the Internet}},
booktitle = {Proceedings of the 19th Annual Joint Conference of the IEEE Computer and Communications Societies (INFOCOM 2000)},
address = {Tel Aviv, Israel},
publisher = {IEEE Press},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
type = {Konferenz-Beitrag},
month = {M{\"a}rz},
year = {2000},
language = {Englisch},
cr-category = {H Information Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {(not available)},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2000-06&engl=0}
}
@inproceedings {INPROC-2000-04,
author = {U. Kubach and K. Rothermel},
title = {{An Adaptive Location-Aware Hoarding Mechanism}},
booktitle = {Proceedings of the 5th IEEE Symposium on Computers and Communications (ISCC 2000)},
address = {Antibes, France},
publisher = {IEEE Press},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
pages = {615--620},
type = {Konferenz-Beitrag},
month = {Juli},
year = {2000},
language = {Englisch},
cr-category = {H Information Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {When used in an outdoor environment mobile information systems often suffer
from the disadvantages of wireless WANs. Hoarding is a method to overcome these
disadvantages by transferring information which is probably needed by the user
in advance. Existing hoarding mechanisms are either developed for a certain
type of application or do not consider the user's location when selecting the
information items to hoard. However, exploiting location information can be of
great benefit with respect to the achievable hit-ratios.
The hoarding mechanism suggested in this paper is both location-aware and
universally applicable. Therefore, it can be used as a generic mechanism in a
platform which supports different kinds of mobile information systems. In
addition, it can be adapted to different degrees of knowledge about the user's
movement.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2000-04&engl=0}
}
@inproceedings {INPROC-2000-03,
author = {M. Strasser and K. Rothermel},
title = {{System Mechanisms for Partial Rollback of Mobile Agent Execution}},
booktitle = {Proceedings of the 20th International Conference on Distributed Computing Systems (ICDCS 2000)},
address = {Taipei, Taiwan, Republic of China},
publisher = {not available},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
pages = {20--28},
type = {Konferenz-Beitrag},
month = {April},
year = {2000},
language = {Englisch},
cr-category = {H Information Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {(not available)},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2000-03&engl=0}
}
@inproceedings {INPROC-2000-02,
author = {Cora Burger},
title = {{A Comparison of different platforms for a collaborative distributed document environment}},
booktitle = {Proceedings of International ICSC Symposium on Multi-Agents and Mobile Agents in Virtual Organizations and E-Commerce (MAMA 2000)},
editor = {ISA 2000},
publisher = {ICSC},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
type = {Konferenz-Beitrag},
month = {Dezember},
year = {2000},
keywords = {Joint editing; CORBA; Mobile Agent},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems,
H.4.1 Office Automation},
ee = {http://Festival.informatik.uni-stuttgart.de/,
http://www.icsc-naiso.org/conferences/isa2000/},
contact = {caburger@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {In the context of joint working on documents by a team, awareness of each
others actions and context as well as consistency of data are crucial aspects.
We present two different alternatives to realize a distributed document
environment for such purposes. One is based on a CORBA platform, the other one
on mobile agents. These approaches are compared according to a number of
essential criteria.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2000-02&engl=0}
}
@inproceedings {INPROC-1999-31,
author = {Steffen Volz and Dieter Fritsch and Darko Klinec and Alexander Leonhardi and Johannes Sch{\"u}tzner},
title = {{Nexus: Spatial Model Servers for location aware applications on the basis of ArcView}},
booktitle = {Proceedings of hte 14th ESRI European User Conference},
address = {M{\"u}nchen},
publisher = {k.A.},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
type = {Konferenz-Beitrag},
month = {Januar},
year = {1999},
language = {Englisch},
cr-category = {H Information Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme;
Universit{\"a}t Stuttgart, Institut f{\"u}r Photogrammetrie (ifp)},
abstract = {k.A.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-1999-31&engl=0}
}
@inproceedings {INPROC-1999-29,
author = {Joachim Baumann and Fritz Hohl and Kurt Rothermel and Markus Schwehm and Markus Stra{\ss}er},
title = {{The Future of Mole}},
booktitle = {Mobility, Mobile Agents and Process Migration - An Edited Collection},
publisher = {Springer-Verlag},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
type = {Konferenz-Beitrag},
month = {Januar},
year = {1999},
language = {Deutsch},
cr-category = {H Information Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {This short paper describes the future development of the mobile agent system
MOLE and applications based on it.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-1999-29&engl=0}
}
@inproceedings {INPROC-1999-23,
author = {Stefan Wirag},
title = {{Adaptive Scheduling of Multimedia Documents}},
booktitle = {Proceedings of the GI/ITG-Fachtagung ``Kommunikation in Verteilten Systemen},
address = {Darmstadt},
publisher = {not available},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
type = {Konferenz-Beitrag},
month = {M{\"a}rz},
year = {1999},
language = {Englisch},
cr-category = {H Information Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {Multimedia documents are of importance in several application areas, such as
education, advertising and entertainment. Since multimedia documents may
comprise continuous media, such as audio and video, the presentation of those
documents may require a significant amount of processing and network resources.
The amount of resources available during a presentation depends on the system
configuration and the current system load. Hence, it can happen that there are
not enough resources to render a multimedia document according to the
specification resulting in a reduced presentation quality. To cope with those
situations, documents can integrate presentation alternatives permitting to
adapt the document presentation to different system configurations and load
conditions. In this paper, we present an adaptive scheduling algorithm which
allows to adapt documents conform to our document model Tiempo in environments
with best-effort assignment of resources.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-1999-23&engl=0}
}
@inproceedings {INPROC-1999-21,
author = {Stefan Wirag},
title = {{Adaptive Scheduling of Multimedia Documents}},
booktitle = {Proceedings of the 11. ITG/VDE Fachtagung, Kommunikation in Verteilten Systemen (KiVS '99)},
address = {Darmstadt},
publisher = {Springer},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
type = {Konferenz-Beitrag},
month = {M{\"a}rz},
year = {1999},
language = {Englisch},
cr-category = {H Information Systems},
contact = {stefan.wirag@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {Multimedia documents are of importance in several application areas, such as
education, advertising and entertainment. Since multimedia documents may
comprise continuous media, such as audio and video, the presentation of those
documents may require a significant amount of processing and network resources.
The amount of resources available during a presentation depends on the system
configuration and the current system load. Hence, it can happen that there are
not enough resources to render a multimedia document according to the
specification resulting in a reduced presentation quality. To cope with those
situations, documents can integrate presentation alternatives permitting to
adapt the document presentation to different system configurations and load
conditions. In this paper, we present an adaptive scheduling algorithm which
allows to adapt documents conform to our document model Tiempo in environments
with best-effort assignment of resources.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-1999-21&engl=0}
}
@inproceedings {INPROC-1999-18,
author = {Wolfgang Theilmann and Kurt Rothermel},
title = {{Disseminating Mobile Agents for Distributed Information Filtering}},
booktitle = {Proc. Joint Symposium ASA/MA'99 of 1st Int. Symp. on Agent Systems and Applications (ASA'99) and 3rd Int. Symp. on Mobile Agents (MA'99), Palm Springs (CA), USA, October 3-6, 1999, IEEE Press (to appear)},
publisher = {(not available)},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
type = {Konferenz-Beitrag},
month = {M{\"a}rz},
year = {1999},
language = {Englisch},
cr-category = {H Information Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {An often claimed benefit of mobile agent technology is the reduction of
communication cost. Especially the area of information filtering has been
proposed for the application of mobile filter agents. However, an effective
coordination of agents, which takes into account the current network
conditions, is difficult to achieve. This contribution analyses the situation
that data distributed among various remote data servers has to be examined with
mobile filter agents. We present an approach for coordinating the agents'
employment, which minimizes communication costs. Validation studies on the
possible cost savings for various constellations show that savings up to 90\%
can be achieved in the face of actual Internet conditions.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-1999-18&engl=0}
}
@inproceedings {INPROC-1999-17,
author = {Uwe Kubach and Kurt Rothermel},
title = {{A Universal, Location-Aware Hoarding Mechanism}},
booktitle = {Proceedings of the International Symposium on Handheld and Ubiquitous Computing (HUC '99)},
address = {Karlsruhe, Germany},
publisher = {(not available)},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
pages = {377--379},
type = {Konferenz-Beitrag},
month = {September},
year = {1999},
language = {Englisch},
cr-category = {H Information Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {Hoarding is an often used technique to overcome the disadvantages of wireless
wide area communication. The basic idea of hoarding is to transfer information
to a mobile device before it is actually accessed on the device. The main
problem is to decide which information will be needed on the devices. We
propose a hoarding mechanism which exploits the fact that the information a
user accesses depends on his/her geographic location.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-1999-17&engl=0}
}
@inproceedings {INPROC-1999-16,
author = {Michael Becht and Thorsten Gurzki and J{\"u}rgen Klarmann and Matthias Muscholl},
title = {{ROLE: Role Oriented Programming Environment for Multiagent Systems}},
booktitle = {Proceedings of the Fourth International Conference on Cooperative Information Systems (CoopIS'99)},
address = {Edinburgh, Scotland},
publisher = {Los Alamitos, California},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
pages = {325--333},
type = {Konferenz-Beitrag},
month = {September},
year = {1999},
isbn = {0-7695-0384-5},
keywords = {Cooperation Architecture, Multi Agent Framework},
language = {Englisch},
cr-category = {F.4 Mathematical Logic and Formal Languages},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {This paper introduces a programming environment and architecture for the
development of agent based cooperative applications using a role based
approach. We focus on the cooperative aspects by introducing cooperation
processes (CP) as a concept of its own. CPs describe all and only the
coordination and cooperation parts of an application. The explicit
documentation of the coordination and cooperation mechanisms used in a MAS
allows their evaluation and reuse. We are able to change existing and introduce
new cooperation processes at runtime without modifying the existing agents. We
specify the cooperative behaviour of an agent in a separate role description.
The interconnection of these roles constitutes the CP. Describing cooperation
independent from concrete agents allows to build heterogeneous, federative and
transformable MAS. We show how agents decide what roles to accept and how the
agent-role interaction works. Finally we present the ROPE framework and runtime
environment.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-1999-16&engl=0}
}
@inproceedings {INPROC-1999-15,
author = {Michael Becht and J{\"u}rgen Klarmann and Ottokar Kulendik and Paul Levi and Matthias Muscholl},
title = {{A Platform for Supporting Integrated Human and Agent Based Cooperation}},
booktitle = {Proceedings of the 15th GI/ITG-Fachtagung Architektur von Rechensystemen (ARCS'99)},
address = {Jena, Germany},
publisher = {VDE-Verlag},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
pages = {221--224},
type = {Konferenz-Beitrag},
month = {Oktober},
year = {1999},
isbn = {3-8007-2482-0},
language = {Englisch},
cr-category = {H.1.0 Information Systems Models and Principles General},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {Cooperation between humans is supported by means of workflow management systems
and groupware tools, whereas support for agents mainly consists in
standardising agent communication languages and developing co-operation
protocols. Most of these mechanisms are designed for special situations. Thus,
they do not take into account that characteristics of environment, work,
persons and agents can change and that relations between dif-ferent
cooperations exist. In the following, an innovative cooperation model and
platform is introduced. An ex-tended concept of roles and structured
communication cares for integration of humans and agents and increases
flexibility. Our approach enables to change the organisational structure
without the need to restructure the coop-eration protocols and vice versa.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-1999-15&engl=0}
}
@inproceedings {INPROC-1999-14,
author = {Cora Burger and Oliver Schramm},
title = {{Co-authoring in dynamic teams with mobile inividuals}},
booktitle = {Proceedings of the International Symposium on Handheld and Ubiquitous Computing (HUC 99)},
editor = {Gellersen},
address = {Karlsruhe, Germany},
publisher = {Springer-Verlag},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
series = {Lecture Notes in Computer Science},
volume = {1707},
pages = {374--376},
type = {Konferenz-Beitrag},
month = {September},
year = {1999},
keywords = {Handheld CSCW; joint editing; CORBA},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems,
H.4.1 Office Automation},
ee = {http://Festival.informatik.uni-stuttgart.de/},
contact = {caburger@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {Current solutions to support co-authoring of documents focus on building new
systems for participants who are assumed to be connected permanently by a
network. We propose an alternate approach, that copes with heterogeneous
editing systems and increasing usage of mobile/handheld devices. Each person is
allowed to use its favorite editor for isolated as well as for cooperative
work. This is achieved by using a global standardized document format and a
suited platform. By choosing a wide spread platform, the flexibility to
constitute arbitrary teams in spontaneous manner is increased. To treat the
mobility problem, participants have representatives in a static part of the
network. A prototypical implementation is presented connecting Emacs with LaTex
mode to a distributed document environment based on SGML and CORBA.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-1999-14&engl=0}
}
@inproceedings {INPROC-1999-13,
author = {M. Strasser and J. Baumann and M. Schwehm},
title = {{An Agent-Based Framework for the Transparent Distribution of Computations}},
booktitle = {Proceedings of the International Conference on Parallel and Distrbuted Processing Techniques and Applications (PDPTA 1999)},
address = {Las Vegas, Nevada, USA},
publisher = {not available},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
type = {Konferenz-Beitrag},
month = {Juni},
year = {1999},
language = {Englisch},
cr-category = {H Information Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {(not available)},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-1999-13&engl=0}
}
@inproceedings {INPROC-1999-12,
author = {A. Leonhardi and U. Kubach},
title = {{An Architecture for a Distributed Universal Location Service}},
booktitle = {Proceedings of the European Wireless '99 Conference},
address = {Munich, Germany},
publisher = {not available},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
pages = {351--355},
type = {Konferenz-Beitrag},
month = {Oktober},
year = {1999},
language = {Englisch},
cr-category = {H Information Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {(not available)},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-1999-12&engl=0}
}
@inproceedings {INPROC-1999-11,
author = {J{\"u}rgen Hauser},
title = {{Realization of an Extensible Document Model}},
booktitle = {Proceedings of the Eurographics Multimedia '99 Workshop},
address = {Milan, Italy},
publisher = {not available},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
series = {Eurographics},
pages = {113--122},
type = {Konferenz-Beitrag},
month = {September},
year = {1999},
isbn = {3-211-83437-0},
language = {Englisch},
cr-category = {H Information Systems},
contact = {juergen.hauser@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {(not available)},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-1999-11&engl=0}
}
@inproceedings {INPROC-1999-10,
author = {J{\"u}rgen Hauser and Frank Scholze and Uwe Albrecht},
title = {{MAVA - Entwicklung und Integration eines erweiterbaren multimedialen Dokumentationssystems}},
booktitle = {Proceedings of the 89th Deutscher Bibliothekartag},
editor = {Margit R{\"u}tzel-Banz},
address = {Freiburg, Germany},
publisher = {Vittorio KLostermann},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
pages = {57--69},
type = {Konferenz-Beitrag},
month = {Mai},
year = {1999},
isbn = {3-465-02961-5},
language = {Deutsch},
cr-category = {H Information Systems},
contact = {frank.scholze@ub.uni-stuttgart.de juergen.hauser@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {(not available)},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-1999-10&engl=0}
}
@inproceedings {INPROC-1999-09,
author = {A. Leonhardi and U. Kubach and K. Rothermel and A. Fritz},
title = {{Virtual Information Towers - A Metaphor for Intuitive, Location-Aware Information Access in a Mobile Environment}},
booktitle = {Proceedings of the Third International Symposium on Wearable Computers (ISCW '99)},
address = {San Francisco, CA, USA},
publisher = {not available},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
pages = {15--20},
type = {Konferenz-Beitrag},
month = {Oktober},
year = {1999},
language = {Englisch},
cr-category = {H Information Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {(not available)},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-1999-09&engl=0}
}
@inproceedings {INPROC-1999-08,
author = {Kurt Rothermel and Christian Maih{\"o}fer},
title = {{A Robust and Efficient Mechanism for Constructing Multicast Acknowledgement Trees}},
booktitle = {Proceedings of the IEEE Eight International Conference on Computer Communications and Networks (IEEE ICCCN '99)},
address = {Boston, MA, USA},
publisher = {IEEE Press},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
pages = {139--147},
type = {Konferenz-Beitrag},
month = {Oktober},
year = {1999},
language = {Englisch},
cr-category = {C.2 Computer-Communication Networks},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-1999-08/INPROC-1999-08.pdf,
ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-1999-08/INPROC-1999-08.ps},
contact = {christian.maihoefer@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {A great variety of todays networked applications require a reliable multicast
service. A number of the proposed reliable multicast protocols use a positive
acknowledgment scheme, which returns ACKs to the sender to confirm correct
delivery. To avoid the well-known implosion problem in the case of large
receiver groups, often a tree-based approach is used, i.e., receivers are
organized in a tree and ACK messages are passed along the edges of this
so-called ACK tree. For building up this tree variations of the Expanding Ring
Search (ERS) scheme have been proposed. However, our simulations show that ERS
scales poorly. In this paper, we propose an alternative scheme for building up
ACK trees. This scheme is based on a so-called token repository service, where
a token represents the right to connect to a certain node in the corresponding
ACK tree. Nodes that want to join a group just request a token for this group
from the (distributed) token repository service. Our simulations show that our
scheme causes a much lower message overhead than ERS. Moreover, the quality of
the resulting ACK trees in terms of delay and reliability is in many cases
higher if generated with our scheme.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-1999-08&engl=0}
}
@inproceedings {INPROC-1999-06,
author = {L. Feldmann and E. Gilles and A. Reuter and K. Rothermel and V. Sviatniyj and M. Zeitz and G. Hohmann},
title = {{Frontiers in Simulation}},
booktitle = {Tagungsband 13, ASIM Symposium Simuolationstechnik},
address = {Weimar, Germany},
publisher = {not available},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
type = {Konferenz-Beitrag},
month = {September},
year = {1999},
language = {Englisch},
cr-category = {H Information Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {(not available)},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-1999-06&engl=0}
}
@inproceedings {INPROC-1999-05,
author = {F. Hohl and U. Kubach and A. Leonhardi and K. Rothermel and M. Schwehm},
title = {{Next Century Challenges: Nexus - An Open Global Infrastructure for Spatial-Aware Applications}},
booktitle = {Proceedings of the Fifth Annual International Conference on Mobile Computing and Networking (MobiCom '99)},
address = {Seattle, WA, USA},
publisher = {not available},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
pages = {249--255},
type = {Konferenz-Beitrag},
month = {August},
year = {1999},
language = {Englisch},
cr-category = {H Information Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {Due to the lack of a generic platform for location- and spatial-aware systems,
many basic services have to be reimplemented in each application that uses
spatial-awareness. A cooperation among different applications is also difficult
to achieve without a common platform. In this paper we present a platform that
solves these problems. It provides an infrastructure that is based on computer
models of regions of the physical world, which are augmented by virtual
objects. We show how virtual objects make the integration of existing
information systems and services in spatial-aware systems easier. Furthermore,
our platform supports interactions between the computer models and the real
world and integrates single models in a global ``Augmented World''.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-1999-05&engl=0}
}
@inproceedings {INPROC-1999-04,
author = {W. Theilmann and K. Rothermel},
title = {{Maintaining Specialized Search Engines through Mobile Filter Agents}},
booktitle = {Proceedings of the Third International Workshop on Cooperative Information Agents (CIA'99)},
address = {Uppsala, Sweden},
publisher = {Springer-Verlag},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
series = {Lecture Notes in Artificial Intelligence},
volume = {1652},
type = {Konferenz-Beitrag},
month = {Juni},
year = {1999},
language = {Englisch},
cr-category = {H Information Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {(not available)},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-1999-04&engl=0}
}
@inproceedings {INPROC-1999-03,
author = {W. Theilmann and K. Rothermel},
title = {{Efficient Dissemination of Mobile Agents}},
booktitle = {Proceedings of the Workshop on Electronic Commerce and Web-based Applications at the 19th International Conference on Distributed Computing Systems (ICDCS-99)},
address = {Austin, Texas, USA},
publisher = {IEEE Press},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
type = {Konferenz-Beitrag},
month = {Juni},
year = {1999},
language = {Englisch},
cr-category = {H Information Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {(not available)},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-1999-03&engl=0}
}
@inproceedings {INPROC-1999-02,
author = {Christian Maih{\"o}fer and Kurt Rothermel},
title = {{Building Multicast Acknowledgement Trees}},
booktitle = {Proceedings of GI Multicast Workshop},
address = {Braunschweig, Germany},
publisher = {not available},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
pages = {129--144},
type = {Konferenz-Beitrag},
month = {Mai},
year = {1999},
language = {Englisch},
cr-category = {C.2 Computer-Communication Networks},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-1999-02/INPROC-1999-02.pdf,
ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-1999-02/INPROC-1999-02.ps},
contact = {christian.maihoefer@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {To avoid the well-known implosion problem, the majority of reliable multicast
protocols use hierarchical structures to pass acknowledgment messages back to
the sender. In most cases, a technique called expanding ring search (ERS) is
used to construct the acknowledgment tree. In this paper we analyse ERS by
simulation studies. ERS is a simple and fault tolerant approach, but our
simulation results show that it has disadvantages like great reliance on the
multicast routing protocol and poor scalability. If the background load exceeds
a critical level, the message overhead rises exponentially. In this paper, we
will present an alternative approach based on a so-called token repository
service. The token repository service stores a token for each successor, a node
in an ACK tree can accept. To find a node to connect to, the searching node
just retrieves a token from the token repository. We describe how such a
service can be implemented in a way that it can handle a large number of
multicast groups. Our simulation results show that the token repository service
is scalable, independent of the multicast routing protocol and builds
well-shaped ACK trees, causing message delays that are comparable to ERS or
even lower.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-1999-02&engl=0}
}
@inproceedings {INPROC-1998-17,
author = {Joachim Baumann and Fritz Hohl and Kurt Rothermel and Markus Schwehm and Markus Stra{\ss}er},
title = {{Mole 3.0: A Middleware for Java-Based Mobile Software Agents}},
booktitle = {Proceedings Middleware'98, Springer Verlag London},
publisher = {not available},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
type = {Konferenz-Beitrag},
month = {Januar},
year = {1998},
language = {Englisch},
cr-category = {H Information Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {Mole is one of the first Java-based mobile agent systems. It runs on an
unmodified Java virtual machine on PCs under Windows 95/NT and on Workstations
under several UNIX dialects. Earlier versions of Mole have provided a basic
infrastructure for communication and migration of mobile agents. Version of
Mole has been strongly revised and several requests and proposals from users of
the earlier ver sions of Mole were integrated into the new release. In
particular Mole supports communication between agent groups and concept of
sessions. The infrastructure of Mole includes a resource manager, a direc tory
service and a global naming scheme for agents. In order to support the design
of agents, a graphical agent monitor allows to visualize the system behaviour
as a whole or of a single agent in particular. Mole further provides a thread
management unit to overcome some shortcomings of the Java virtual machine. Mole
provides a simple means for installation and configuration of the system. This
paper describes the architecture and infrastructure provided by Version 3.0 of
Mole.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-1998-17&engl=0}
}
@inproceedings {INPROC-1998-15,
author = {Cora Burger and Rolf Mecklenburg and Kurt Rothermel},
title = {{Internetbasiertes Lernen - Interaktive Animation von Kommunikationsprotokollen auf generischem Wege}},
booktitle = {Proceedings of the GI-Tagung ``Informatik und Ausbildung''},
publisher = {Springer-Verlag},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
pages = {176--185},
type = {Konferenz-Beitrag},
month = {April},
year = {1998},
keywords = {animation; communication protocol},
language = {Deutsch},
cr-category = {K.3 Computers and Education,
C.2.2 Network Protocols,
H.5.1 Multimedia Information Systems},
ee = {http://www.informatik.uni-stuttgart.de/ipvr/vs/projekte/HiSAP/hisap.html},
contact = {caburger@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {Im Bereich der Lehre werden traditionell haupts{\"a}chlich Text und Bilder auf
Folien oder Dias und im Skript zur Vermittlung von Lehrinhalten eingesetzt.
Diese Lehrverfahren sto{\ss}en jedoch an Grenzen, wenn es darum geht, dynamische
Prozesse wie z. B. Kommunikationsprotokolle in verteilten Systemen verst{\"a}ndlich
zu machen. Da sich Dynamik mit unbewegten Bildern nur eingeschr{\"a}nkt darstellen
l{\"a}{\ss}t, gewinnt rechnergest{\"u}tzte Animation in der Lehre an Bedeutung. Au{\ss}erdem
sind Lehrvorg{\"a}nge dann am wirkungsvollsten, wenn der Lernende aktiv und
gestaltend daran mitwirken kann. Um internetbasiertes und interaktives Erlernen
von Protokollen aus dem Bereich der verteilten Systeme auf generischem Wege zu
erm{\"o}glichen, und somit eine Verbesserung der Qualit{\"a}t der Lehre auf diesem
Sektor zu erreichen, werden im Projekt «ProtoVis« am IPVR der Universit{\"a}t
Stuttgart die Programmiersprache Java und das Konstrukt des Java Applets
eingesetzt. Diese Applets entstehen durch Konvertierung aus einer formalen
Spezifikation des darzustellenden Protokolls in der Beschreibungssprache SDL.
Sie stellen die dynamischen Abl{\"a}ufe innerhalb eines Protokolls bildlich und
animiert dar und k{\"o}nnen interaktiv gesteuert werden.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-1998-15&engl=0}
}
@inproceedings {INPROC-1998-14,
author = {Hartmut Benz and Steffen Fischer and Rolf Mecklenburg},
title = {{A Framework for Integrating Custom Applications into Multimedia Annotations}},
booktitle = {Proceedings of the European Multimedia, Microprocessor Systems andElectronic Commerce Conference (EMMSEC'98)},
publisher = {(not available)},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
type = {Konferenz-Beitrag},
month = {Januar},
year = {1998},
language = {Englisch},
cr-category = {H Information Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {In the ACTS-project DIANE (Design, Implementation and Operation of a
Distributed Annotation Environment), a multimedia annotation system has been
developed. One of it's greatest benefits over legacy multimedia authoring
systems is it's simplicity. It enables users to create multimedia documents
instantly without requiring great knowledge of programming languages or other
details of the authoring system. Media can be integrated into annotations
ranging from standard monomedia objects like audio, images, etc. to recorded
application output from legacy applications. The client/server architecture has
been implemented in a platform-neutral way using Java and it's extensions (e.g.
Java Media Framework) and is running on either Internet/Intranet and broadband
network technologies like ATM. This paper will present the architecture and the
document model of DIANE with a focus on integrating custom user applications
into multimedia annotations. A usage scenario will describe the system in
general.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-1998-14&engl=0}
}
@inproceedings {INPROC-1998-13,
author = {Cora Burger},
title = {{Fachvortr{\"a}ge {\"U}ber Rechnernetze und Internet}},
booktitle = {K. Schneider (Hrsg.). Die Informatik AG - Telekooperation. B.G. Teubner Stuttgart, 1998},
publisher = {Teubner-Stuttgart-Verlag},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
type = {Konferenz-Beitrag},
month = {Januar},
year = {1998},
language = {Deutsch},
cr-category = {C Computer Systems Organization},
ee = {http://medoc.informatik.uni-stuttgart.de/~medoc/},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {none},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-1998-13&engl=0}
}
@inproceedings {INPROC-1998-11,
author = {H. Benz and S. Fischer and R. Mecklenburg},
title = {{A Framework for Custom Applications into Multimedia Annotations}},
booktitle = {Proceedings of the European Multimedai, Microprocessor Systems and Electronic Commerce Conference EMMSEC'98},
address = {Bordeaux, France},
publisher = {not available},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
type = {Konferenz-Beitrag},
month = {September},
year = {1998},
language = {Englisch},
cr-category = {H Information Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {(not available)},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-1998-11&engl=0}
}
@inproceedings {INPROC-1998-10,
author = {Cora Burger and Kerstin Schneider},
title = {{Informatik-AG fuer Schuelerinnen - Konzepte und Erfahrungen}},
booktitle = {Proceedings of GI-Fachtagung ``Informatik und Ausbildung''},
address = {Stuttgart, Germany},
publisher = {Springer-Verlag},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
pages = {133--142},
type = {Konferenz-Beitrag},
month = {M{\"a}rz},
year = {1998},
keywords = {Studieninformation; Frauenf{\"o}rderung; gender; computer science},
language = {Deutsch},
cr-category = {K.3 Computers and Education},
ee = {http://www.informatik.uni-stuttgart.de/fakultaet/frauen/frauen.html},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Anwendersoftware (Prof. Reuter);
Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {Einem wachsenden Interesse an weiblichen Absolventen der Informatik von seiten
der Industrie steht eine seit einiger Zeit recht niedrige Zahl an
Informatikstudentinnen gegen{\"u}ber. Diesem Mi{\ss}verh{\"a}ltnis kann durch vermehrte
Information {\"u}ber das Studienfach begegnet werden.
Aus diesem Grund wurde im ersten Halbjahr 1997 an der Universit{\"a}t Stuttgart
eine Informatik-AG f{\"u}r Sch{\"u}lerinnen durchgef{\"u}hrt. Den Schwerpunkt dieser
Veranstaltung bildeten Vortr{\"a}ge durch Mitarbeiterinnen sowie praktische
aufgaben an den Rechnern. Im folgenden werden die zugrundeliegenden Konzepte
und die unter anderen aus Frageb{\"o}gen gewonnenen Erfahrungen dieses Projektes
geschildert.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-1998-10&engl=0}
}
@inproceedings {INPROC-1998-09,
author = {H. Benz and M.E. Lijding},
title = {{Asynchronously Replicated Shared Workspaces for a Multi-Media Annotation Service over Internet}},
booktitle = {Proceedings of the 5th International Workshop on Distributed Multimedia Systems and Telecommunication Services (IDMS 1998)},
address = {Oslo, Norway},
publisher = {not available},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
type = {Konferenz-Beitrag},
month = {September},
year = {1998},
language = {Englisch},
cr-category = {H Information Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {(not available)},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-1998-09&engl=0}
}
@inproceedings {INPROC-1998-08,
author = {Cora Burger},
title = {{Team Awareness with Mobile Agents in Mobile Environments}},
booktitle = {Proceedings of the 7th International Conference on Computer Communications and Networks (IC3N'98)},
address = {Lafayette, Louisianna, USA},
publisher = {not available},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
pages = {45--49},
type = {Konferenz-Beitrag},
month = {Oktober},
year = {1998},
keywords = {CSCW; team awareness; notification; mobile agents; mobile computing},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems,
H.3.4 Information Storage and Retrieval Systems and Software},
ee = {http://Festival.informatik.uni-stuttgart.de/},
contact = {caburger@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {There are several aspects involved in supporting human cooperative work by
computers. One of them concerns team awareness to avoid unnecessary effort or
even chaos. Notification services provide suited information about other team
members and team relevant events. Traditionally, such services are realized by
a central or distributed approach but exhibit shortcomings with respect to
filtering policies and mobility of notified participants. A third alternative
consists in applying mobile software agents. In this case, each participant is
represented by one immobile and a number of mobile agents. The immobile agent
manages all events that are caused by its user. Mobile agents are responsible
to observe events being caused by other team members. They communicate either
remotely or locally with managers of their partners. Advantages and
disadvantages of all possible mechanisms are discussed.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-1998-08&engl=0}
}
@inproceedings {INPROC-1998-07,
author = {J{\"u}rgen Klarmann and Michael Becht and Matthias Muscholl},
title = {{Modellierung flexibler Workflows mit teilausf{\"u}hrbaren Aktivit{\"a}ten}},
booktitle = {Proceedings of the Workshop at the German Computer-Supported Cooperative Work Conference (D-CSCW'98)},
address = {Dortmund, Germany},
publisher = {not available},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
pages = {44--55},
type = {Konferenz-Beitrag},
month = {September},
year = {1998},
keywords = {Workflow Management, Process Modeling, Flexibility},
language = {Deutsch},
cr-category = {H.4.1 Office Automation},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {Obwohl es allgemein anerkannt ist, da{\ss} Workflow-Management-Systeme flexibel
sein m{\"u}ssen, gen{\"u}gen bestehende Mechanismen zur Flexibilisierung von
Workflow-Management-Systemen nur in eingeschr{\"a}nkter Weise den Anforderungen des
Anwendungsfeldes. Wir f{\"u}hren Modellierungskonzepte ein, mit denen zus{\"a}tzliche
Flexibilit{\"a}t modellierbar ist. Wir pr{\"a}sentieren einen Ansatz, der insbesondere
das Vor-, Nacharbeiten und {\"U}berspringen und damit das nebenl{\"a}ufige Ausf{\"u}hren
von Teilen von Aktivit{\"a}ten sowie einen erweiterten Akteurswechsel unterst{\"u}tzt.
Im Gegensatz zu der Methode des Vorformulierens mehrerer Alternativen, bei der
die gewonnene Flexibilit{\"a}t durch einen wesentlich h{\"o}heren Modellierungsaufwand
bezahlt wird, bleibt bei unserem Ansatz der Modellierungsaufwand ann{\"a}hernd
gleich. Dies erfordert eine feingranulare Modellierung der Aktivit{\"a}ten sowie
ein feingranulares Modell der Workflow-relevanten Dokumente.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-1998-07&engl=0}
}
@inproceedings {INPROC-1998-06,
author = {J. Baumann and K. Rothermel},
title = {{The Shadow Approach: An Orphan Detection Protocol for Mobile Agents}},
booktitle = {Proceedings of the 2nd International Workshop on Mobile Agents (MA'98)},
address = {Stuttgart, Germany},
publisher = {Springer},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
type = {Konferenz-Beitrag},
month = {September},
year = {1998},
language = {Englisch},
cr-category = {H Information Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {(not available)},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-1998-06&engl=0}
}
@inproceedings {INPROC-1998-05,
author = {J. Baumann and F. Hohl and K. Rothermel and M. Schwehm and M. Strasser},
title = {{Mole 3.0: A Middleware for Java-Based Mobile Software Agents}},
booktitle = {Proceedings of the IFIP International Conference on Distributed Systems, Platforms and Open Distributed Processing (Middleware'98)},
address = {Lake District, United Kingdom},
publisher = {not available},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
type = {Konferenz-Beitrag},
month = {September},
year = {1998},
language = {Englisch},
cr-category = {H Information Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {(not available)},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-1998-05&engl=0}
}
@inproceedings {INPROC-1998-04,
author = {K. Rothermel and M. Strasser},
title = {{A Fault-Tolerant Protocol for Providing the Exaclty-Once Property of Mobile Agents}},
booktitle = {Proceedings of the 17th IEEE Symposium on Reliable Distributed Systems (SRDS'98)},
address = {West Lafayette, USA},
publisher = {not available},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
type = {Konferenz-Beitrag},
month = {September},
year = {1998},
language = {Englisch},
cr-category = {H Information Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {(not available)},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-1998-04&engl=0}
}
@inproceedings {INPROC-1998-03,
author = {C. Burger and R. Mecklenburg and K. Rothermel},
title = {{Interactive Protocol Simulation Applets for Distance Education}},
booktitle = {Proceedings of the 5th International Workshop on Interactive Distruted Multimedia Systems and Telecommunication Services (IDMS'98)},
address = {Oslo, Norway},
publisher = {not available},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
type = {Konferenz-Beitrag},
month = {September},
year = {1998},
language = {Englisch},
cr-category = {H Information Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {(not available)},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-1998-03&engl=0}
}
@inproceedings {INPROC-1998-02,
author = {M. Strasser and K. Rothermel and C. Maihoefer},
title = {{Providing Reliable Agents for Electronic Commerce}},
booktitle = {Proceedings of Trends in Distrbuted Systems for Eletronic Commerce, International IFIP/GI Working Conference (TREC'98)},
address = {Hamburg, Germany},
publisher = {not available},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
pages = {241--253},
type = {Konferenz-Beitrag},
month = {Juni},
year = {1998},
language = {Englisch},
cr-category = {H Information Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {(not available)},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-1998-02&engl=0}
}
@inproceedings {INPROC-1998-01,
author = {Wolfgang Theilmann and Kurt Rothermel},
title = {{Domain experts for Information Retrieval in the World Wide Web}},
booktitle = {Proceedings of the 2nd International Workshop on cooperative Information Agents},
address = {Paris, France},
publisher = {not available},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
type = {Konferenz-Beitrag},
month = {Juli},
year = {1998},
language = {Englisch},
cr-category = {H Information Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {(not available)},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-1998-01&engl=0}
}
@inproceedings {INPROC-1997-26,
author = {Joachim Baumann},
title = {{Neue Objekttechnologien}},
booktitle = {Informatik und Lernen in der Informationsgesellschaft},
editor = {W. Luther H.U. Hoppe},
address = {Berlin, Heidelberg},
publisher = {Springer-Verlag},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
type = {Konferenz-Beitrag},
month = {Januar},
year = {1997},
isbn = {3-540-63432-0},
language = {Deutsch},
cr-category = {H Information Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {Objektorientierung und verteilte Objekttechnologien sind heutzutage in aller
Munde. Hierbei findet viel Mystifizierung statt, die das Verst{\"a}ndnis erschwert.
In diesem Text werden wir uns mit den Begriffen der Objektorientierung
besch{\"a}ftigen, um dann verteilte Objekttechnologien wie Corba, ActiveX, OLE und
andere beleuchten zu k{\"o}nnen. Wir werden sehen, inwieweit diese den an
Objektorientierung gestellten Anspr{\"u}chen tats{\"a}chlich gerecht werden k{\"o}nnen.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-1997-26&engl=0}
}
@inproceedings {INPROC-1997-25,
author = {Klaus Villinger and Cora Burger},
title = {{Generic mobile agents for electronic markets}},
booktitle = {Proceedings of the 4th Conference of the International Society for Decision Support Systems ISDSS'97},
editor = {Institut d'informatique et organisation},
address = {Lausanne},
publisher = {Ecole des HEC},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
pages = {205--218},
type = {Konferenz-Beitrag},
month = {Juni},
year = {1997},
keywords = {mobile agents; electronic market},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems,
D.1.m Programming Techniques Miscellaneous,
J.1.7 Marketing},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-1997-25/INPROC-1997-25.html,
http://www.informatik.uni-stuttgart.de/ipvr/vs/projekte/Festival/festival.html},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {Electronic markets are one important application of agent technology. A common
approach consists in representing buyers and sellers of markets by agents. To
cope with the whole spectrum of possible market mechanisms, we identified
generic parts of such agents. From this, a general framework for generic buying
and selling agents was derived. It allows to integrate arbitrary mechanisms for
information filtering, for negotiation between agents and for electronic
delivery and payment. Based on measurement, we discuss benefits of realizing
electronic markets with agent technology.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-1997-25&engl=0}
}
@inproceedings {INPROC-1997-24,
author = {Thomas Kindler},
title = {{Activity based security in intranet and internet workflows}},
booktitle = {Proceedings of the Seventh Annual Workshop on Information Technologies \& Systems,},
editor = {Arie Segev and Vijay K. Vaishnavi},
address = {Atlanta, USA},
publisher = {not available},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
type = {Konferenz-Beitrag},
month = {Dezember},
year = {1997},
language = {Englisch},
cr-category = {H Information Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-1997-24/INPROC-1997-24.ps},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {This paper deals with a model to support security requirements of intra-/
internet based workflows. The model is emerged from deficiencies of today's
security models in the context of workflows. The basic idea is the
consideration of time that extends subject-object based or role based access
control models. Access control should be modeled in the context of workflows
and their activities and is leading to activity based access control (ABAC). As
a result access control will be defined in conjunction with workflows instead
of defining them implicitly in enterprise policies.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-1997-24&engl=0}
}
@inproceedings {INPROC-1997-22,
author = {Joachim Baumann and Christian Tschudin and Jan Vitek},
title = {{Mobile Object Systems: Workshop Summary}},
booktitle = {Proc. 2nd ECOOP Workshop on Mobile Object Systems},
publisher = {dpunkt-Verlag},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
type = {Konferenz-Beitrag},
month = {Januar},
year = {1997},
language = {Englisch},
cr-category = {H Information Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {This workshop summary introduces the notion of Mobile Object Systems, discusses
the essentials, generic architectures, and points out the workshop highlights.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-1997-22&engl=0}
}
@inproceedings {INPROC-1997-21,
author = {Joachim Baumann},
title = {{Mobility in the Mobile-Agent-System Mole}},
booktitle = {Proceeding of the 3rd CaberNet Plenary Workshop},
publisher = {not available},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
type = {Konferenz-Beitrag},
month = {Januar},
year = {1997},
language = {Englisch},
cr-category = {H Information Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-1997-21/INPROC-1997-21.html},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {Mobile agent systems are the focus of many researchers in the area of
distributed systems and operating systems since General Magic released their
Telescript system in Mobile agent systems add to the well known distributed
operating systems the notion of autonomous mobility of its participants, the
agents. We will present our agent model and our agent system Mole, and show how
mobility is implemented in it.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-1997-21&engl=0}
}
@inproceedings {INPROC-1997-20,
author = {Hartmut Benz and Sandford Bessler and Steffen Fischer and Hager Michael and Mecklenburg Rolf},
title = {{DIANE: A Multimedia Annotation System}},
booktitle = {Proceedings of the Second European Conference on Multimedia Applications, Services and Techniques},
publisher = {Springer-Verlag},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
pages = {183--198},
type = {Konferenz-Beitrag},
month = {Januar},
year = {1997},
language = {Englisch},
cr-category = {H Information Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {In this paper we introduce a new application called multimedia annotation,
which is currently developed in the EU-funded ACTS project DIANE. Starting from
the annotation scenarios, we derive different system requirements, a multimedia
document model, quality of service and in particular - synchronisation
requirements. Abstractions, such as stream components and clocks are presented.
The paper concludes with an annotation example, showing the involvement of
previously described system components.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-1997-20&engl=0}
}
@inproceedings {INPROC-1997-19,
author = {Markus Stra{\ss}er and Markus Schwehm},
title = {{A Performance Model for Mobile Agent Systems}},
booktitle = {Proceedings of the International Conference on Parallel and Distributed Processing Techniques and Applications},
publisher = {(not available)},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
pages = {1132--1140},
type = {Konferenz-Beitrag},
month = {Januar},
year = {1997},
language = {Englisch},
cr-category = {H Information Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-1997-19/INPROC-1997-19.ps},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {A performance model for the interaction of agents in mobile agent systems is
presented. Two interaction models, namely the remote procedure call and the
agent migration are considered. Performance models for a single interaction are
introduced, which are then used to derive a performance model for a sequence of
interactions. This performance model can be used to evaluate the performance of
any possible behaviour of an agent in a given scenario. The application of the
performance model for a typical scenario in mobile computing shows that the
optimal behaviour of an agent is achieved by a mixed sequence of remote
procedure calls and agent migrations. The performance model is validated by
measurements of interactions of real agents in the mobile agent system Mole.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-1997-19&engl=0}
}
@inproceedings {INPROC-1997-18,
author = {Joachim Baumann and Fritz Hohl and Nikolaos Radouniklis and Rothermel Kurt and Stra{\ss}er Markus},
title = {{Communication Concepts for Mobile Agent Systems}},
booktitle = {Mobile Agents, First International Workshop},
publisher = {Springer-Verlag},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
pages = {123--135},
type = {Konferenz-Beitrag},
month = {Januar},
year = {1997},
language = {Englisch},
cr-category = {H Information Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-1997-18/INPROC-1997-18.pdf,
ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-1997-18/INPROC-1997-18.ps},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {Driven by the question how to identify potential communication partners and the
need for well-suited communication schemes in agent-based systems, we discuss
two communication concepts: sessions and global event management. Sessions
establish either actively or passively a context for inter-agent interactions.
Communication partners are addressed by globally unique agent identifiers or
via badges. Communication in sessions is based on RPC or message mechanisms.
Global event management addresses the need for anonymous communication. Event
managers are employed as a synchronization means within agent groups. Based on
this approach, we introduce synchronization objects, - active components that
offer various synchronization services. The presented model is finally mapped
onto OMG event services.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-1997-18&engl=0}
}
@inproceedings {INPROC-1997-16,
author = {H. Benz and S. Fischer and R. Mecklenburg and A. Wenger},
title = {{Application Output Recording for the Instant Authoring in a Distributed Multimedia Annotation Environment}},
booktitle = {Proceedings of the 4th International Workshop on Interactive Distribtued Multimedia Systems and Telecommuncation Services (IDMS'97)},
address = {Darmstadt, Germany},
publisher = {not available},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
pages = {220--230},
type = {Konferenz-Beitrag},
month = {September},
year = {1997},
language = {Englisch},
cr-category = {H Information Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {(not available)},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-1997-16&engl=0}
}
@inproceedings {INPROC-1997-14,
author = {R. Siebert and T. Kindler and T. Soyez},
title = {{Integrated Workflow Support for the German Government}},
booktitle = {Proceedings of the 1997 ACM Symposium on Applied Computing},
address = {Hyatt St. Claire, San Jose, California, USA},
publisher = {not available},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
type = {Konferenz-Beitrag},
month = {Februar},
year = {1997},
language = {Englisch},
cr-category = {H Information Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {(not available)},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-1997-14&engl=0}
}
@inproceedings {INPROC-1997-13,
author = {H. Benz and S. Fischer and R. Mecklenburg and A. Wenger},
title = {{Instant Authoring with Application Output Recording: Taxonomy and Usage in DIANE}},
booktitle = {Proceedings of the IEEE Conference on Multimedia Computing and Systems (ICMCS'97)},
address = {Ottawa, Ontario, Canada},
publisher = {not available},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
type = {Konferenz-Beitrag},
month = {Juni},
year = {1997},
language = {Englisch},
cr-category = {H Information Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {(not available)},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-1997-13&engl=0}
}
@inproceedings {INPROC-1997-11,
author = {J. Baumann},
title = {{Mobile Agents and their Role in Future Distributed Systems}},
booktitle = {Proceedings of the 4th CaberNet Radicals Workshop},
address = {Rethinmon, Crete},
publisher = {not available},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
type = {Konferenz-Beitrag},
month = {September},
year = {1997},
language = {Englisch},
cr-category = {H Information Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {(not available)},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-1997-11&engl=0}
}
@inproceedings {INPROC-1997-10,
author = {T. Kindler},
title = {{Activity Based Securtiy in Intranet and Internet Workflows}},
booktitle = {Proceedings of the 7th Annual Workshop on Information Technologies and Systems (WITS'97)},
address = {Atlanta, Georgia, USA},
publisher = {not available},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
type = {Konferenz-Beitrag},
month = {Dezember},
year = {1997},
language = {Englisch},
cr-category = {H Information Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {(not available)},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-1997-10&engl=0}
}
@inproceedings {INPROC-1997-09,
author = {H. Benz and S. Fischer and R. Mecklenburg and G. Dermler},
title = {{DIANE: Hypermedia Documents in a Distributed Annotation Environment}},
booktitle = {Proceedings of the Conference on Hypertext Information Retrieval Multimedia (HIM'97)},
address = {Dortmund, Germany},
publisher = {not available},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
type = {Konferenz-Beitrag},
month = {Januar},
year = {1997},
language = {Englisch},
cr-category = {H Information Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {(not available)},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-1997-09&engl=0}
}
@inproceedings {INPROC-1997-07,
author = {H. Benz and S. Fischer and R. Mecklenburg},
title = {{Technical Overview of an Annotation Service for Medical Training in a Heterogeneous Healthcare Envirionment}},
booktitle = {Proceedings of the European Workshop on Multimedia Technology in Medical Traning (MTMT'97)},
address = {Aachen, Germany},
publisher = {not available},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
type = {Konferenz-Beitrag},
month = {September},
year = {1997},
language = {Englisch},
cr-category = {H Information Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {(not available)},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-1997-07&engl=0}
}
@inproceedings {INPROC-1997-06,
author = {H. Benz and S. Fischer and R. Mecklenburg},
title = {{Architecture and Implementation of a Distributed Multimedia Annotation Environment: Practical Experiences usingJava}},
booktitle = {Proceedings of the IFIP WG 6.1 International Working Conference on Distributed Applications and Interoperable Systems (DAIS'97)},
address = {Cottbus, Germany},
publisher = {not available},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
type = {Konferenz-Beitrag},
month = {September},
year = {1997},
language = {Englisch},
cr-category = {H Information Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {(not available)},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-1997-06&engl=0}
}
@inproceedings {INPROC-1997-05,
author = {J. Baumann and N. Radouniklis},
title = {{Agent Groups in Mobile-Agent Systems}},
booktitle = {Proceedings of the IFIP WG 6.1 International Workgin Conference on Distrbuted Applications and Interoperable Systems (DAIS'97)},
address = {Cottbus, GermanyBau},
publisher = {not available},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
type = {Konferenz-Beitrag},
month = {September},
year = {1997},
language = {Englisch},
cr-category = {H Information Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {(not available)},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-1997-05&engl=0}
}
@inproceedings {INPROC-1997-04,
author = {K. Rothermel and F. Hohl and N. Radouniklis},
title = {{Mobile Agent Systems: What is missing?}},
booktitle = {Invited Paper to the IFIP WG 6.1 International Working Conference on Distributed Applications and Interoperable Systems (DAIS'97)},
address = {Cottbus, Germany},
publisher = {not available},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
type = {Konferenz-Beitrag},
month = {September},
year = {1997},
language = {Englisch},
cr-category = {H Information Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {(not available)},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-1997-04&engl=0}
}
@inproceedings {INPROC-1997-03,
author = {J. Baumann and F. Hohl and N. Radouniklis and K. Rothermel and M. Strasser},
title = {{Concepts for Mobile Agent Systems}},
booktitle = {Proceedings of 1st Workshop on Mobile Agents},
address = {Berlin},
publisher = {not available},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
type = {Konferenz-Beitrag},
month = {April},
year = {1997},
language = {Englisch},
cr-category = {H Information Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {(not available)},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-1997-03&engl=0}
}
@inproceedings {INPROC-1997-02,
author = {Stefan Wirag},
title = {{Modeling of Adaptable Multimedia Documents}},
booktitle = {Proceedings of the 4th International Workshop on Interactive Distributed Multimedia Systems and Telecommunication Services (IDMS'97)},
address = {Darmstadt, Germany},
publisher = {not available},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
pages = {220--230},
type = {Konferenz-Beitrag},
month = {September},
year = {1997},
language = {Englisch},
cr-category = {H Information Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {(not available)},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-1997-02&engl=0}
}
@inproceedings {INPROC-1996-13,
author = {J. Baumann and C. Tschudin and J. Vitek},
title = {{Mobile Object Systems: Workshop Summary}},
booktitle = {Workshop Proceedings of the 2nd ECOOP Workshop on Mobile Object Systems},
publisher = {Linz, Austria},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
type = {Konferenz-Beitrag},
month = {Juli},
year = {1996},
language = {Englisch},
cr-category = {H Information Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {(not available)},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-1996-13&engl=0}
}
@inproceedings {INPROC-1996-12,
author = {Markus Strasser and Joachim Baumann and Fritz Hohl},
title = {{Mole - A Java Based Mobile Agent System}},
booktitle = {Workshop Reader of the 10th European Conference on Object-Oriented Programming (ECOOP96)},
address = {Linz, Austria},
publisher = {not available},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
type = {Konferenz-Beitrag},
month = {Juli},
year = {1996},
language = {Englisch},
cr-category = {H Information Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {(not available)},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-1996-12&engl=0}
}
@inproceedings {INPROC-1996-11,
author = {Arno Puder and Cora Burger},
title = {{New Concepts for Qualitative Trader Cooperation}},
booktitle = {Proceedings of the IFIP International Conference on Distributed Platforms (ICDP'96)},
editor = {Schill},
address = {Dresden, Germany},
publisher = {IFIP},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
pages = {301--313},
type = {Konferenz-Beitrag},
month = {Februar},
year = {1996},
keywords = {Trading; cooperation; IDL-based types; AI-based types},
language = {Englisch},
cr-category = {H.2.4 Database Management Systems,
F.3.3 Studies of Program Constructs},
contact = {caburger@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {Traders serve as mediators between service providers and users. The trader
returns to a service requester by delivering a set of suitable providers that
satisfy the request. Because of the size and complexity of distributed systems,
one trader manages a certain part of the whole set of providers only. To
enlarge this restricted set of potential service providers, a lightweight form
of cooperation (called interworking) between two or more traders was
introduced. Therefore, the main purpose of such cooperations was concerned with
quantitative aspects, neglecting the possibilities of more general concepts of
cooperation. A need for qualitative trader cooperations arises. Traditional
trader approaches focus upon the operational interface of providers as a basis
for type descriptions. But in general, application users in an open electronic
market require mediation at different levels of abstraction. Suitable traders
are specialized in one of these levels. By combining these isolated solutions,
a qualitative trader cooperation can be achieved.
In the following, we take a closer look at type descriptions at different
levels of abstraction. Similarities will be discovered that can be used to
derive appropriate mappings. In particular we demonstrate that ODP--types based
on an arbitrary interface definition language can be described in terms of
conceptual graphs that are used in knowledge--based trading. From this
relationship, a general type manager can be derived, coping with both type
concepts. As a consequence, the trading of operational interfaces and the
trading based on a knowledge representation scheme can be combined. Together
they exhibit a more powerful trading service by offering different interfaces
to different kinds of users.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-1996-11&engl=0}
}
@inproceedings {INPROC-1996-10,
author = {Tobias Helbig},
title = {{Timing Control of Stream Handlers in a Distributed Multi-threaded Environment}},
booktitle = {Proceedings of the 6th International Workshop on Network and Operation Systems Support for Digital Audio and Video (NOSSDAV'96)},
address = {Zushi, Japan},
publisher = {not available},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
type = {Konferenz-Beitrag},
month = {April},
year = {1996},
language = {Englisch},
cr-category = {H Information Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {(not available)},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-1996-10&engl=0}
}
@inproceedings {INPROC-1996-09,
author = {Ingo Barth},
title = {{Configuring Distributed Multimedia Applications Using CINEMA}},
booktitle = {Proceedings of the IEEE Workshop on Multimedia Software Development (MMSD'96)},
address = {Berlin},
publisher = {not available},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
type = {Konferenz-Beitrag},
month = {M{\"a}rz},
year = {1996},
language = {Englisch},
cr-category = {H Information Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {(not available)},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-1996-09&engl=0}
}
@inproceedings {INPROC-1996-08,
author = {T. Kindler and T. Soyez},
title = {{Modelling Security for Integrated Enterprise Workflow and Telecooperation Systems}},
booktitle = {Proceedings of the IEEE 5th Workshop on Enabling Technologies: Infrastructure for Collaborative Enterprises (WETICE'96)},
address = {Stanford University, California, USA},
publisher = {not available},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
type = {Konferenz-Beitrag},
month = {Juni},
year = {1996},
language = {Englisch},
cr-category = {H Information Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {(not available)},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-1996-08&engl=0}
}
@inproceedings {INPROC-1996-07,
author = {E. Kovacs},
title = {{Advanced Trading Service Through Mobile Agents}},
booktitle = {Proceedings of Trends in Distributed Systems: CORBA and Beyond, International Workshop (TreDS'96)},
address = {Aachen, Germany},
publisher = {not available},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
type = {Konferenz-Beitrag},
month = {Oktober},
year = {1996},
language = {Englisch},
cr-category = {H Information Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {(not available)},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-1996-07&engl=0}
}
@inproceedings {INPROC-1996-06,
author = {E. Kovacs},
title = {{Trader Customization Using Mobile Agents}},
booktitle = {Proceedings of the Seventh IFIP/IEEE International Workshop on Distributed Systems: Operations and Management (DSOM'96)},
address = {L'Aquila, Italy},
publisher = {IEEE},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
type = {Konferenz-Beitrag},
month = {Oktober},
year = {1996},
language = {Englisch},
cr-category = {H Information Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {(not available)},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-1996-06&engl=0}
}
@inproceedings {INPROC-1996-05,
author = {A. Hagin and K. Rothermel and G. Dermler},
title = {{Issues of Mapping Distributed Multimedia Applications to Distributed Computersystems}},
booktitle = {Proceedings of the International Conference on informational Networks and Systems (ICINAS-96)},
address = {St. Petersburg, Russia},
publisher = {not available},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
type = {Konferenz-Beitrag},
month = {September},
year = {1996},
language = {Englisch},
cr-category = {H Information Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {(not available)},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-1996-05&engl=0}
}
@inproceedings {INPROC-1996-04,
author = {K. Rothermel and G. Dermler and W. Fiederer},
title = {{A Communication Infrastructure for Multimedia Applications}},
booktitle = {Proceedings of the European Conference on Networks Optical Communications (NOC'96)},
address = {Heidelberg},
publisher = {not available},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
type = {Konferenz-Beitrag},
month = {Juni},
year = {1996},
language = {Englisch},
cr-category = {H Information Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {(not available)},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-1996-04&engl=0}
}
@inproceedings {INPROC-1996-03,
author = {G. Dermler and W. Fiederer and I. Barth and K. Rothermel},
title = {{A Negotiation and Resource Reservation Protocol for Configurable Multimedia Applications}},
booktitle = {Proceedings of the International Conference on Multimedia Computing and Systems (Multimedia 1996)},
address = {Hiroshima, Japan},
publisher = {not available},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
type = {Konferenz-Beitrag},
month = {Juni},
year = {1996},
language = {Englisch},
cr-category = {H Information Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {(not available)},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-1996-03&engl=0}
}
@inproceedings {INPROC-1996-02,
author = {Tobias Helbig and Kurt Rothermel},
title = {{An Architecture for a Distributed Stream Synchronization Service}},
booktitle = {Proceeding s of the European Workshop on Interactive Distributd Multimedia Systems},
address = {Berlin},
publisher = {not available},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
type = {Konferenz-Beitrag},
month = {M{\"a}rz},
year = {1996},
language = {Englisch},
cr-category = {H Information Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {(not available)},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-1996-02&engl=0}
}
@inproceedings {INPROC-1996-01,
author = {T. Magedanz and K. Rothermel and S. Krause},
title = {{Intelligent Agents: An Emerging Technology for Next Generation Telecommunications?}},
booktitle = {Proceedings of the INFOCOM 96},
address = {San Francisco, CA, USA},
publisher = {not available},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
type = {Konferenz-Beitrag},
month = {Juni},
year = {1996},
language = {Englisch},
cr-category = {H Information Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {(not available)},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-1996-01&engl=0}
}
@inproceedings {INPROC-1995-09,
author = {Joachim Baumann},
title = {{A Triptychon of Problems}},
booktitle = {Workshop at ECOOP '95: Objects \& Agents: Love at first sight or shotgun wedding?``},
publisher = {N.N.},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
type = {Konferenz-Beitrag},
month = {August},
year = {1995},
language = {Englisch},
cr-category = {H Information Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-1995-09/INPROC-1995-09.ps},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {In this position paper three problems of mobile agent systems are discussed.
The first is the conceptual problem of security in agent systems. The second,
is the speed of the system, and where it is important. The third, following
from it, is an implementation problem: how can the transfer size of agents be
minimized?},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-1995-09&engl=0}
}
@inproceedings {INPROC-1995-08,
author = {Stefan Wirag and Kurt Rothermel and Thomas Wahl},
title = {{Modelling Interaction with HyTime}},
booktitle = {Kommunikation in Verteilten Systemen, GI/ITG-Fachtagung},
editor = {K. Franke and U. H{\"u}bner and W. W. Kalfa},
address = {Chemnitz, Germany},
publisher = {not available},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
pages = {188--202},
type = {Konferenz-Beitrag},
month = {Februar},
year = {1995},
language = {Englisch},
cr-category = {H Information Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {Interactive multimedia presentations are an essential issue in many advanced
multimedia application tools. Before presenting multimedia data, media items,
interaction types and synchronization constraints have to be specified in a
multimedia document. This paper identifies and classifies the temporal
interaction types in multimedia systems, and shows their impact on the
specification process and the supporting system. Then, we describe how to
specify the interaction types by using the standardized multimedia document
language HyTime. The HyTime mechanisms are demonstrated by examples followed by
a discussion of the advantages and limits of each technique.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-1995-08&engl=0}
}
@inproceedings {INPROC-1995-07,
author = {Thomas Wahl and Stefan Wirag and Kurt Rothermel},
title = {{Temporal Modeling and Authoring of Interactive Multimedia}},
booktitle = {Proceedings of the 2nd. Intl. Conference on Multimedia Computing and Systems},
address = {Washington D.C., USA},
publisher = {not available},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
pages = {274--277},
type = {Konferenz-Beitrag},
month = {Mai},
year = {1995},
language = {Englisch},
cr-category = {H Information Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {Future multimedia titles will provide many ways to interact with the presented
information. When creating an interactive multimedia title, the author has to
specify the temporal layout and the interaction elements. However, this part of
the authoring process is not trivial as the temporal layout and the interaction
forms are not independent because some interaction forms affect the
presentation schedule of the title. This paper identifies various temporal
interaction forms and their temporal dependencies, an integrated model for time
and interaction is proposed, and we show how this model is applied to ease
rapid authoring of multimedia titles.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-1995-07&engl=0}
}
@inproceedings {INPROC-1995-06,
author = {Kurt Rothermel and Tobias Helbig},
title = {{An Adaptive Stream Synchronization Protocol}},
booktitle = {Proceedings of the 5th International Workshop on Network and Operating System Support for Digital Audio and Video},
address = {Durham, New Hampshire, USA},
publisher = {not available},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
type = {Konferenz-Beitrag},
month = {April},
year = {1995},
language = {Englisch},
cr-category = {H Information Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-1995-06/INPROC-1995-06.ps},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {Protocols for synchronizing data streams should be highly adaptive with regard
to both changing network conditions as well as to individual user needs. The
Adaptive Synchronization Protocol we are going to describe in this paper
supports any type of distribution of the stream group to be synchronized. It
incorporates buffer level control mechanisms allowing an immediate reaction on
overflow or underflow situations. Moreover, the proposed mechanism is flexible
enough to support a variety of synchronization policies and allows to switch
them dynamically during presentation. Since control messages are only exchanged
when the network conditions actually change, the message overhead of the
protocol is very low.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-1995-06&engl=0}
}
@inproceedings {INPROC-1995-05,
author = {Tobias Helbig and Soufiane Noureddine and Kurt Rothermel},
title = {{Activation Set: An abstraction for accessing periodic data streams}},
booktitle = {IS\&T/SPIE Proceedings Vol.2417, Multimedia Computing and Networking'95},
publisher = {(not available)},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
type = {Konferenz-Beitrag},
month = {Februar},
year = {1995},
language = {Englisch},
cr-category = {H Information Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-1995-05/INPROC-1995-05.ps},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {In distributed multimedia applications time-dependent data streams are conveyed
and processed under real-time conditions. The timely accurate activation of the
stream handlers processing the data units of streams requires deriving their
scheduling times from the temporal properties of the data streams and the
amount of data that is processed in each activation. In this paper, we propose
the activation set concept as a data access abstraction to consume sets of data
units from a group of time-dependent data streams having synchronization
relationships among each other. The concept supports the consumption of
multiple periodic data streams of different rates as well as the integration of
aperiodic streams. It is shown how scheduling times of activations are derived
from the streams' temporal properties and the requested amount of data. When a
stream handler is activated, data units of the streams are selected for
consumption according to synchronization relationships and tolerated skew
bounds. The effects of the approach on delays are discussed in the context of a
rate-monotonic scheduling algorithm. The concept provides a configurable
interface to groups of time-dependent data streams which, for example, is
required when mixing streams. It is widely applicable in multimedia system
architectures that allow for configuration of distributed multimedia
applications based on interconnected stream handling components.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-1995-05&engl=0}
}
@inproceedings {INPROC-1995-04,
author = {Cora Burger},
title = {{Cooperation policies for traders}},
booktitle = {Proceedings IFIP International Conference on Open Distributed Processing ICODP '95},
editor = {Kerry Raymond and Liz Armstrong},
publisher = {Chapman and Hall},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
pages = {208--218},
type = {Konferenz-Beitrag},
month = {Februar},
year = {1995},
keywords = {ODP; trading; cooperation},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
contact = {caburger@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {In ODP a general mechanism has been constructed, how cooperation between trader
entities can be performed. But little has been said about when and in which
cases such a cooperation should be initiated. Furthermore, the above mentioned
cooperation mechanism requires an enormous amount of computer and communication
resources, counteracting the profit of cooperation, e.g., by degrading the mean
response time of traders. As a consequence, policies are needed to resolve such
conflicts. In the following, a general cooperation model is introduced and
applied to traders. From this general model cooperation policies for traders
are derived. One of these policies can be adapted to optimize the quality of
trader service by observing the dynamic behaviour of traders, their clients and
servers.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-1995-04&engl=0}
}
@inproceedings {INPROC-1995-03,
author = {Benz Hartmut},
title = {{KGB; A Customizable Graph Browser}},
booktitle = {Graph Drawing: Symposium on Graph Drawing, GD '95 Passau, Germany, September 20-22, 1995 Proceedings},
publisher = {(not available)},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
pages = {20--23},
type = {Konferenz-Beitrag},
month = {September},
year = {1995},
language = {Englisch},
cr-category = {H Information Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-1995-03/INPROC-1995-03.ps},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {This paper presents the architecture of a generic, customizable graph browser
KGB. The KGB has been designed to handle very large and dynamically changing
graphs which are frequently used as repository management graphs in large
applications. Special emphasis has been put on the flexible presentation of the
information encoded in the graph and the reduction of the user's workload when
adapting the presentation to his or her special needs. The KGB was built as a
debugging and visualization tool for document hierarchies of the CASE tool
KOGGE currently under development at the Institute for Softwaretechnik,
University of Koblenz.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-1995-03&engl=0}
}
@inproceedings {INPROC-1995-02,
author = {Ingo Barth and Gabriel Dermler and Walter Fiederer},
title = {{Levels of Quality of Service in CINEMA}},
booktitle = {GI-SI Jahrestagung, September 18-20, 1995, Z{\"u}rich, Switzerland.},
publisher = {(not available)},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
type = {Konferenz-Beitrag},
month = {September},
year = {1995},
language = {Englisch},
cr-category = {H Information Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-1995-02/INPROC-1995-02.ps},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {Distributed multimedia systems require quality of service at various
abstraction levels. At the application level, QoS describes communication in
terms of application specific processing units, e.g. frames. At the transport
level QoS is used to describe the communication load for the transport system.
An architecture integrating the various levels is presented. The architecture
provides the framework for performing negotiation of QoS and resource
reservation. It includes the specification of a programmer interface and a
flowspec carrying QoS information between communication nodes.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-1995-02&engl=0}
}
@inproceedings {INPROC-1995-01,
author = {Ingo Barth and Tobias Helbig and Kurt Rothermel},
title = {{Implementierung multimedialer Systemdienste in CINEMA}},
booktitle = {GI/ITG-Fachtagung ``Kommunikation in Verteilten Systemen''},
publisher = {(not available)},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
type = {Konferenz-Beitrag},
month = {Februar},
year = {1995},
language = {Englisch},
cr-category = {H Information Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-1995-01/INPROC-1995-01.ps},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {Die Erstellung verteilter Multimedia-Anwendungen setzt leistungsf{\"a}hige
Entwicklungsplattformen voraus, innerhalb deren Probleme wie die {\"U}bertragung
multimedialer Daten, die Gew{\"a}hrleistung der Dienstg{\"u}te durch Reservierung von
Ressourcen und die Synchronisation von Datenstr{\"o}men gel{\"o}st werden. CINEMA
(Configurable INtEgrated Multimedia Architecture) bietet als eine solche
Entwicklungsplattform Abstraktionen zur Nutzung multimedialer Systemdienste an,
womit funktionale Bearbeitungseinheiten erstellt, komplexe
Verarbeitungstopologien in verteilten Systemen aufgebaut und unter Einhaltung
von Synchronisations- und Dienstg{\"u}te-Spezifikationen gesteuert werden k{\"o}nnen.
In diesem Papier werden nach einem kurzen {\"U}berblick {\"u}ber die Abstraktionen der
CINEMA-Dienstschnittstelle die internen Strukturen und Abl{\"a}ufe vorgestellt, mit
denen die Multimedia- Dienste in verteilten Systemen erbracht werden.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-1995-01&engl=0}
}
@inproceedings {INPROC-1994-08,
author = {Ern{\"o} Kovacs},
title = {{Trading und Management verteilter Anwendungen: zentrale Aufgaben f{\"u}r zuk{\"u}nftige verteilte System}},
booktitle = {1. Aachener Arbeitstreffen ``Neue Konzepte f{\"u}rur die Offene Verteilte Verarbeitung''},
publisher = {Verlag der Augustinus Buchhandlung},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
series = {Aachener Beitrt{\"a}ge zur Informatik},
volume = {7},
type = {Konferenz-Beitrag},
month = {September},
year = {1994},
isbn = {3-86073-143-2},
language = {Deutsch},
cr-category = {H Information Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-1994-08/INPROC-1994-08.ps},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-1994-08&engl=0}
}
@inproceedings {INPROC-1994-06,
author = {Ern{\"o} Kovacs and Stefan Wirag},
title = {{Trading and Distributed Application Managment:An Integrated Approach}},
booktitle = {Proceedings of the Fifth IFIP/IEEE International Workshop on Distributed Systems: Operations \& Management (DSOM'94)},
publisher = {not available},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
type = {Konferenz-Beitrag},
month = {Januar},
year = {1994},
language = {Englisch},
cr-category = {H Information Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {Trading and distributed application management are two research areas that are
strongly related. Trading is a supporting service for distributed systems that
utilizes configuration data and current state information to mediate services.
Distributed application management collects this information and controls the
operation of the system. An integrated approach has to focus on the
collaboration of both sides. This paper explores some of the arising problems.
The use of configuration information, the notification of events, and access to
dynamic state information requires carefully designed interaction interfaces to
minimize the effects of communication and distribution on the mediation
process. In the other direction, application management can steer the operation
and performance of the distributed system through influencing the trading
process. We describe our implementation for both approaches and present some
exemplary performance measures.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-1994-06&engl=0}
}
@inproceedings {INPROC-1994-05,
author = {Tobias Helbig and Kurt Rothermel},
title = {{Programming Abstractions for Handling Multimedia Data in CINEMA}},
booktitle = {Proceedings of the 2nd CaberNet Plenary Workshop},
address = {Dublin, Ireland},
publisher = {not available},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
type = {Konferenz-Beitrag},
month = {M{\"a}rz},
year = {1994},
language = {Englisch},
cr-category = {H Information Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-1994-05/INPROC-1994-05.ps},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {(not available)},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-1994-05&engl=0}
}
@inproceedings {INPROC-1994-04,
author = {Tobias Helbig},
title = {{Development and Control of Distributed Multimedia Applications}},
booktitle = {Proceedings of the 4th Open Workshop on High-Speed Networks},
editor = {Paul K{\"u}hn},
address = {Brest, France},
publisher = {not available},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
pages = {208--213},
type = {Konferenz-Beitrag},
month = {September},
year = {1994},
language = {Englisch},
cr-category = {H Information Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-1994-04/INPROC-1994-04.ps},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {Distributed multimedia applications make use of high-speed networks to transmit
data units. Processing of multimedia data is done at end-systems. Appropriate
support is required to provide for integrated processing and communicating of
multimedia data streams and for efficient development of distributed multimedia
applications. It is given by a middleware layer which uses services of
operating systems and networks and enriches them by protocols and mechanisms to
offer multimedia system services including multimedia communication, resource
reservation, synchronization and configuration management. By that, the gap
between system services of general purpose operating systems and the
requirements of developing distributed multimedia applications is closed. The
CINEMA (Configurable INtEgrated Multimedia Architecture) system is such a
middleware layer which offers abstractions to develop arbitrarily structured
multimedia applications and provides protocols and mechanisms to control them.
Its multimedia system services are accessible via easy-to-use interfaces.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-1994-04&engl=0}
}
@inproceedings {INPROC-1994-03,
author = {Gabriel Dermler},
title = {{Ein Konzept zur Integration von Netzwerk-Filtern in verteilte Multimedi-Systemen}},
booktitle = {Tagungsband der GI-Fachtagung ``Innovationen bei Rechen- und Kommunikationssystemen},
address = {Hamburg, Germany},
publisher = {not available},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
type = {Konferenz-Beitrag},
month = {Januar},
year = {1994},
language = {Deutsch},
cr-category = {H Information Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-1994-03/INPROC-1994-03.ps},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {Multicast-Uebertragungen mit heterogenen Empfaengern koennen mit Hilfe von
Filtern im Netzwerk optimiert werden. Dieser Artikel beschreibt die Einbettung
des Filter-Konzepts in eine Architektur, die die Realisierung verteilter
Multimedia-Systeme erlaubt. Die Schichtung der Architektur entspricht einer
Trennung in Anwendungs- und Systemsicht. Die Rolle des Systems bei der
Konfiguration multimedialer Kommunikation sowie der Reservierung von Ressourcen
wird beschrieben im Hinblick Teilstrom- und Filterbildung. Die Verzahnung der
Ressourcenreservierung und der Propagierung der Filter durchs Netzwerk wird
erlaeutert.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-1994-03&engl=0}
}
@inproceedings {INPROC-1994-02,
author = {Gabriel Dermler and Thomas Gutekunst and Edgar Ostrowski and Frank Ruge},
title = {{Sharing Audio/Video Applications among Heterogeneous Platforms}},
booktitle = {Proceedings of the 5th IEEE COMSOC Workshop Multimedia `94},
address = {Kyoto, Japan},
publisher = {not available},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
type = {Konferenz-Beitrag},
month = {Mai},
year = {1994},
language = {Englisch},
cr-category = {H Information Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {JVTOS (Joint Viewing and Tele-Operation Service), which is being implemented
within CEC/RACE II project CIO (R2060), is a new teleservice for high-speed
networks enabling distributed users to work in a collaborative fashion with
multimedia. Core functionality of JVTOS is provided by an application sharing
service that allows multimedia applications to be displayed and interacted with
on multiple users' workstations simultaneously. The focus of this paper is on
the audio/video elements of shared applications. We discuss the problems of
sharing multimedia applications and describe our conception that supports
interoperability between heterogeneous platforms.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-1994-02&engl=0}
}
@inproceedings {INPROC-1994-01,
author = {Gabriel Dermler and Thomas Gutekunst and Edgar Ostrowski and Nelson Pires and Thomas Schmidt and Michael Weber and Heiner Wolf},
title = {{JVTOS - Multimedia Telecooperation Interconnecting Heterogeneous Platforms}},
booktitle = {Proceedings of Broadband Islands '94: Connecting with the End-User.},
editor = {W. Bauerfeld and O. Spaniol and F. Williams},
address = {Kyoto, Japan},
publisher = {Elsevier Science B.V.},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
pages = {463--478},
type = {Konferenz-Beitrag},
month = {Januar},
year = {1994},
language = {Englisch},
cr-category = {H Information Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-1994-01/INPROC-1994-01.ps},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {JVTOS, the ``Joint Viewing and Tele-Operation Service'', is an advanced
teleservice allowing distributed users to work in a collaborative fashion with
multimedia. JVTOS offers services for multimedia collaboration across
high-speed networks and is primarily aimed at running in heterogeneous
workstation environments comprising different hardware platforms and also
different operating and window systems.
JVTOS comprises facilities for session management, floor control, multimedia
application sharing, telepointing, and audio/video communication.
This paper describes the desgin and implmentation of JVTOS on different
platforms. ~},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-1994-01&engl=0}
}
@inproceedings {INPROC-1993-06,
author = {Gabriel Dermler and Thomas Gutekunst and Bernhard Plattner and Edgar Ostrowski and Frank Ruge and Michael Weber},
title = {{Constructing a Distributed Multimedia Joint Viewing and Tele-Operation Service for Heterogeneous Workstation Environments}},
booktitle = {Proceedings of the Fourth Workshop on Future Trends in Distributed Systems},
address = {Lissabon, Portugal},
publisher = {IEEE Computer Society Press},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
pages = {8--15},
type = {Konferenz-Beitrag},
month = {September},
year = {1993},
language = {Englisch},
cr-category = {H Information Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-1993-06/INPROC-1993-06.ps},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {JVTOS (Joint Viewing and Tele-Operation Service) is an advanced teleservice to
support cooperative work over distance which allows distributed users to work
in a collaborative fashion with multimedia. JVTOS comprises facilities for
session management, floor control, multimedia application sharing, telepointing
and audio/video communication. JVTOS offers services for multimedia
collaboration across high-speed networks and is primarily aimed at running in
heterogeneous environments comprising different hardware platforms and also
different operating and window systems. This paper describes the design of
JVTOS as well as its implemeentation on different platforms which is currently
under development.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-1993-06&engl=0}
}
@inproceedings {INPROC-1993-05,
author = {Ern{\"o} Kovacs},
title = {{The MELODY Management System for Distributed Applications}},
booktitle = {Proceedings of the GI/ITG Workshop ``Development and Management of Distributed Applications},
address = {Frankfurt, Germany},
publisher = {not available},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
type = {Konferenz-Beitrag},
month = {Januar},
year = {1993},
language = {Deutsch},
cr-category = {H Information Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-1993-05/INPROC-1993-05.ps},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {Distributed applications contain an inherent complexity which in praxis become
apparent through high costs for installation, maintenance and problem
determination. This complexity must be reduced by appropriate management tools.
The MELODY management system supports the integration of management functions
into distributed applications. It realizes an object oriented information model
which is directly integrated into the component of a distributed application.
The realized object services hides the necessary communication procedures from
the application. The supporting management platform enables a location
transparent, efficient access with respect to preset actuality requirements.
Management applications are supported through functions to monitor and control
the system.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-1993-05&engl=0}
}
@inproceedings {INPROC-1993-04,
author = {Ern{\"o} Kovacs},
title = {{Automatic Selection of an Update Strategy for Management Data}},
booktitle = {Proceedings of the IEEE First International Workshop on System s Management (IWSM'93)},
address = {Los Angeles, USA},
publisher = {not available},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
type = {Konferenz-Beitrag},
month = {Januar},
year = {1993},
language = {Englisch},
cr-category = {H Information Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-1993-04/INPROC-1993-04.ps},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {(not available)},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-1993-04&engl=0}
}
@inproceedings {INPROC-1993-03,
author = {Ingo Barth and Gabriel Dermler and Tobias Helbig and Kurt Rothermel and Frank Sembach and Thomas Wahl},
title = {{CINEMA: Eine konfigurierbare integrierte Multimedia-Architektur}},
booktitle = {Verteilte Multimedia Systeme, Tagungsband GI/ITG-Arbeitstreffen},
editor = {Wolfgang Effelsberg and Kurt Rothermel},
address = {Stuttgart, Germany},
publisher = {Saur-Verlag},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
pages = {33--47},
type = {Konferenz-Beitrag},
month = {Februar},
year = {1993},
language = {Deutsch},
cr-category = {H Information Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-1993-03/INPROC-1993-03.ps},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {Anwendungen ben{\"o}tigen Unterst{\"u}tzung bei der Manipulation multimedialer Daten,
um die besonderen Probleme bez{\"u}glich zeitlicher Anforderungen und
Ressourcenverwaltung zu bew{\"a}ltigen. Diese zu erbringen, ist die Zielsetzung des
CINEMA-Projekts. Hierbei wird eine Systemplattform entwickelt, durch die die
Trennung der Funktionen zur Bearbeitung multimedialer Daten von Problemen der
Ressourcenverwaltung, der Transportmechanismenvon Problemen der
Ressourcenverwaltung, der Transportmechanismen und von zeitlichen Aspekten
erm{\"o}glicht wird. Zus{\"a}tzlich bietet die Architektur Abstraktionen zur
Modellierung multimedialer Anwendungen bez{\"u}glich der Funktionalit{\"a}t und der
Dienstg{\"u}te.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-1993-03&engl=0}
}
@inproceedings {INPROC-1993-02,
author = {Ern{\"o} Kovacs},
title = {{Abstractions and Hierarchies in a Distributed Management System}},
booktitle = {Proceedings of the GI/ITG Workshop ``Development and Management of Distributed Applications},
address = {Dortmund},
publisher = {not available},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
type = {Konferenz-Beitrag},
month = {Januar},
year = {1993},
language = {Deutsch},
cr-category = {H Information Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {(not available)},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-1993-02&engl=0}
}
@inproceedings {INPROC-1993-01,
author = {Ern{\"o} Kovacs},
title = {{Abstractions and Hierarchies in a Distributed Management System (in German)}},
booktitle = {Proceedings of the GI/ITG Workshop ``Development and Management of Distributed Applications''},
publisher = {(not available)},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
type = {Konferenz-Beitrag},
month = {Januar},
year = {1993},
language = {Deutsch},
cr-category = {H Information Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {We present a delay analysis of one sender- and two receiver-initiated classes
of reliable multicast protocols. Besides the average delivery delay we consider
the delay to reliably deliver all packets and the round trip delay. The former
two examines the delay between generation of a packet at the sender and correct
reception at a randomly chosen receiver or all receivers, respectively. The
latter is the delay between generation of a packet at the sender and reception
of all acknowledgment packets at the sender. Our numerical results show that
receiver-initiated protocols provide significantly better scalability for large
receiver groups and transmission rates compared to the sender-initiated
protocol. However, the delay of the sender-initiated protocol within its
scalability range is substantially lower compared to the receiver-initiated
protocols. To assess the quality of our analytical model we have compared the
analytical results with a SRM-like protocol simulation. We show that the
analytical and simulation results are strongly correlated, which demonstrates
the appropriateness of our analytical model.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-1993-01&engl=0}
}
@inproceedings {INPROC-1992-02,
author = {Gabriel Dermler and Konrad Froitzheim},
title = {{JVTOS - A Reference Model for a New Multimedia Service}},
booktitle = {Proceedings of the Fourth IFIP Conf. on High Performance Networking},
address = {Liege, Belgium},
publisher = {not available},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
type = {Konferenz-Beitrag},
month = {Januar},
year = {1992},
keywords = {Distributed Systems; Communications Managment; Multimedia Systems},
language = {Englisch},
cr-category = {H Information Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {Multimedia Joint Viewing and Teleoperation is a new service for highspeed
networks. It allows physically separated users to work in a collaborative
fashion with documents and applications. It is however not a cooperative
application but a system level service exporting the functionality of
applications to many workstations.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-1992-02&engl=0}
}
@inproceedings {INPROC-1992-01,
author = {Kurt Rothermel and Gabriel Dermler},
title = {{Synchronization in Joint-Viewing Environments}},
booktitle = {Proceedings of the Third Intl. Workshop on Network and Operating System Support for Digital Audio and Video.},
publisher = {not available},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Germany},
pages = {97--109},
type = {Konferenz-Beitrag},
month = {Januar},
year = {1992},
language = {Deutsch},
cr-category = {H Information Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-1992-01/INPROC-1992-01.ps},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {Recent technology advances have made computer-based multimedia cooperation
among distributed users feasible. Joint-Viewing (JV) is one such proposed
cooperation concept. Correct interaction in it requires synchronization at
various levels. In this paper we focus on synchronization aspects on the data
stream level. We present several JV scenarios and state for each of these
requirements concerning interstream synchronization. Then we introduce basic
abstractions of a synchronisazion scheme which is powerful enough to model a
variety of JV configurations with their various synchronization needs. The
presented scheme is based on the notion of a referencing system which consists
of a set of logical clocks each defining a different time zone in the
referencing system. Logical clocks provide timing information for input and
output devices which are used to produce and consume data in a synchronized
fashion.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-1992-01&engl=0}
}
@inproceedings {INPROC-1989-02,
author = {Kurt Rothermel and C. Mohan},
title = {{ARIES/NT: a Recovery Method Based on Write-ahead Logging for Nested Transactions}},
booktitle = {Proceedings of the 15th International Conference on Very Large Data Bases (VLDB'89); Amsterdam, The Netherlands},
address = {San Francisco, CA, USA},
publisher = {Morgan Kaufmann Publishers Inc.},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {337--346},
type = {Konferenz-Beitrag},
month = {August},
year = {1989},
isbn = {1-55860-101-5},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems,
H.2.4 Database Management Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-1989-02/INPROC-1989-02.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {A simple and efficient recovery method for nested transactions, called ARIES/NT
(Algorithm for Recovery and Isolation Exploiting Semantics for Nested
Transactions), that uses write-ahead logging and supports semantically-rich
modes of locking and operation logging is presented. This method applies to a
very general model of nested transactions, which includes parlial rollbacks of
subtransactions, upward and downward inheritance of locks, and concurrent
execution of ancestor and descendent subtransactions. The adopted system
architecture encompasses aspects of distributed data base management also.
ARIES/NT is an extension of the ARIES recovery and concurrency control method
developed recently for the single-level transaction model by Mohan. et. al. in
the IBM Research Report RJ6649.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-1989-02&engl=0}
}
@article {ART-2022-05,
author = {Jonathan Falk and Heiko Geppert and Frank D{\"u}rr and Sukanya Bhowmik and Kurt Rothermel},
title = {{Dynamic QoS-Aware Traffic Planning for Time-Triggered Flows in the Real-time Data Plane}},
journal = {IEEE Transactions on Network and Service Management},
publisher = {IEEE},
volume = {19},
number = {2},
pages = {1807--1825},
type = {Artikel in Zeitschrift},
month = {Juni},
year = {2022},
isbn = {10.1109/TNSM.2022.3150664},
keywords = {traffic planning, QoS, reconfiguration, time-triggered},
language = {Deutsch},
cr-category = {C.2.3 Network Operations,
C.2.5 Local and Wide-Area Networks},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/ART-2022-05/ART-2022-05.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Many networked applications, e.g., in the domain of cyber-physical systems,
require strict service guarantees for time-triggered traffic flows, usually in
the form of jitter and latency bounds. It is a notoriously hard problem to
compute a network-wide traffic plan, i.e., a set of routes and transmission
schedules, that satisfies these requirements, and dynamic changes in the flow
set add even more challenges. Existing traffic-planning methods are ill-suited
for dynamic scenarios because they either suffer from high computational cost,
can result in low network utilization, or provide no explicit guarantees when
transitioning to a new traffic plan that incorporates new flows.
Therefore, we present a novel approach for dynamic traffic planning of
time-triggered flows. Our conflict-graph-based modeling of the traffic planning
problem allows for the reconfiguration of active flows to increase the network
utilization, while also providing per-flow QoS guarantees during the transition
to the new traffic plan. Additionally, we introduce a novel heuristic for
computing the new traffic plans. Evaluations of our prototypical implementation
show that we can efficiently compute new traffic plans in scenarios with
hundreds of active flows for a wide range of settings.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2022-05&engl=0}
}
@article {ART-2022-04,
author = {Jonathan Falk and Heiko Geppert and Frank D{\"u}rr and Sukanya Bhowmik and Kurt Rothermel},
title = {{Dynamic QoS-Aware Traffic Planning for Time-Triggered Flows in the Real-time Data Plane}},
journal = {IEEE Transactions on Network and Service Management},
publisher = {IEEE},
volume = {19},
number = {2},
pages = {1807--1825},
type = {Artikel in Zeitschrift},
month = {Juni},
year = {2022},
isbn = {10.1109/TNSM.2022.3150664},
keywords = {traffic planning, QoS, reconfiguration, time-triggered},
language = {Deutsch},
cr-category = {C.2.3 Network Operations,
C.2.5 Local and Wide-Area Networks},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/ART-2022-04/ART-2022-04.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Many networked applications, e.g., in the domain of cyber-physical systems,
require strict service guarantees for time-triggered traffic flows, usually in
the form of jitter and latency bounds. It is a notoriously hard problem to
compute a network-wide traffic plan, i.e., a set of routes and transmission
schedules, that satisfies these requirements, and dynamic changes in the flow
set add even more challenges. Existing traffic-planning methods are ill-suited
for dynamic scenarios because they either suffer from high computational cost,
can result in low network utilization, or provide no explicit guarantees when
transitioning to a new traffic plan that incorporates new flows.
Therefore, we present a novel approach for dynamic traffic planning of
time-triggered flows. Our conflict-graph-based modeling of the traffic planning
problem allows for the reconfiguration of active flows to increase the network
utilization, while also providing per-flow QoS guarantees during the transition
to the new traffic plan. Additionally, we introduce a novel heuristic for
computing the new traffic plans. Evaluations of our prototypical implementation
show that we can efficiently compute new traffic plans in scenarios with
hundreds of active flows for a wide range of settings.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2022-04&engl=0}
}
@article {ART-2022-03,
author = {Jonathan Falk and Heiko Geppert and Frank D{\"u}rr and Sukanya Bhowmik and Kurt Rothermel},
title = {{Dynamic QoS-Aware Traffic Planning for Time-Triggered Flows in the Real-time Data Plane}},
journal = {IEEE Transactions on Network and Service Management},
publisher = {IEEE},
volume = {19},
number = {2},
pages = {1807--1825},
type = {Artikel in Zeitschrift},
month = {Juni},
year = {2022},
isbn = {10.1109/TNSM.2022.3150664},
keywords = {traffic planning, QoS, reconfiguration, time-triggered},
language = {Deutsch},
cr-category = {C.2.3 Network Operations,
C.2.5 Local and Wide-Area Networks},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/ART-2022-03/ART-2022-03.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Many networked applications, e.g., in the domain of cyber-physical systems,
require strict service guarantees for time-triggered traffic flows, usually in
the form of jitter and latency bounds. It is a notoriously hard problem to
compute a network-wide traffic plan, i.e., a set of routes and transmission
schedules, that satisfies these requirements, and dynamic changes in the flow
set add even more challenges. Existing traffic-planning methods are ill-suited
for dynamic scenarios because they either suffer from high computational cost,
can result in low network utilization, or provide no explicit guarantees when
transitioning to a new traffic plan that incorporates new flows.
Therefore, we present a novel approach for dynamic traffic planning of
time-triggered flows. Our conflict-graph-based modeling of the traffic planning
problem allows for the reconfiguration of active flows to increase the network
utilization, while also providing per-flow QoS guarantees during the transition
to the new traffic plan. Additionally, we introduce a novel heuristic for
computing the new traffic plans. Evaluations of our prototypical implementation
show that we can efficiently compute new traffic plans in scenarios with
hundreds of active flows for a wide range of settings.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2022-03&engl=0}
}
@article {ART-2022-02,
author = {Jonathan Falk and Heiko Geppert and Frank D{\"u}rr and Sukanya Bhowmik and Kurt Rothermel},
title = {{Dynamic QoS-Aware Traffic Planning for Time-Triggered Flows in the Real-time Data Plane}},
journal = {IEEE Transactions on Network and Service Management},
publisher = {IEEE},
volume = {19},
number = {2},
pages = {1807--1825},
type = {Artikel in Zeitschrift},
month = {Juni},
year = {2022},
isbn = {10.1109/TNSM.2022.3150664},
keywords = {traffic planning, QoS, reconfiguration, time-triggered},
language = {Deutsch},
cr-category = {C.2.3 Network Operations,
C.2.5 Local and Wide-Area Networks},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/ART-2022-02/ART-2022-02.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Many networked applications, e.g., in the domain of cyber-physical systems,
require strict service guarantees for time-triggered traffic flows, usually in
the form of jitter and latency bounds. It is a notoriously hard problem to
compute a network-wide traffic plan, i.e., a set of routes and transmission
schedules, that satisfies these requirements, and dynamic changes in the flow
set add even more challenges. Existing traffic-planning methods are ill-suited
for dynamic scenarios because they either suffer from high computational cost,
can result in low network utilization, or provide no explicit guarantees when
transitioning to a new traffic plan that incorporates new flows.
Therefore, we present a novel approach for dynamic traffic planning of
time-triggered flows. Our conflict-graph-based modeling of the traffic planning
problem allows for the reconfiguration of active flows to increase the network
utilization, while also providing per-flow QoS guarantees during the transition
to the new traffic plan. Additionally, we introduce a novel heuristic for
computing the new traffic plans. Evaluations of our prototypical implementation
show that we can efficiently compute new traffic plans in scenarios with
hundreds of active flows for a wide range of settings.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2022-02&engl=0}
}
@article {ART-2021-02,
author = {Otto Bibartiu and Frank D{\"u}rr and Kurt Rothermel and Beate Ottenw{\"a}lder and Andreas Grau},
title = {{Scalable k-out-of-n models for dependability analysis with Bayesian networks}},
journal = {Reliability Engineering \& System Safety},
editor = {Paolo Gardoni},
publisher = {Elsevier Science Ltd.},
volume = {210},
pages = {1--13},
type = {Artikel in Zeitschrift},
month = {Februar},
year = {2021},
isbn = {10.1016/S0951-8320(21)00145-9},
keywords = {Availability; Scalability; Voting Gate; Fault-Tree; Bayesian networks},
language = {Englisch},
cr-category = {B.8.1 Reliability, Testing, and Fault-Tolerance,
C.4 Performance of Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/ART-2021-02/ART-2021-02.pdf,
https://doi.org/10.1016/j.ress.2021.107533},
contact = {otto.bibartiu@ipvs.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Availability analysis is indispensable in evaluating the dependability of
safety and business-critical systems, for which fault tree analysis (FTA) has
proven very useful throughout research and industry. Fault trees (FT) can be
analyzed by means of a rich set of mathematical models. One particular model
are Bayesian networks (BNs) which have gained considerable popularity recently
due to their powerful inference abilities. However, large-scale systems, as
found in modern data centers for cloud computing, pose modeling challenges that
require scalable availability models. An equivalent BN of a FT has no scalable
representation for the k-out-of-n (k/n) voting gate because the conditional
probability table that constitutes the k/n voting gate grows exponentially in
n. Thus, the memory becomes the limiting factor. We propose a scalable k/n
voting gate representation for BNs, based on the temporal noisy adder. The
resulting model reduces the initial exponential to polynomial memory growth
without a custom inference algorithm. Previous BN implementations of the k/n
voting gate could only handle around 30 input events until memory limits make
inference infeasible. However, our evaluation shows that our scalable model can
handle more than 700 input events per gate, making it possible to evaluate
large scale systems.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2021-02&engl=0}
}
@article {ART-2020-21,
author = {Ahmad Slo and Sukanya Bhowmik and Kurt Rothermel},
title = {{State-Aware Load Shedding from Input Event Streams in Complex Event Processing}},
journal = {IEEE Transactions on Big Data},
publisher = {IEEE},
pages = {1--18},
type = {Artikel in Zeitschrift},
month = {Dezember},
year = {2020},
isbn = {10.1109/TBDATA.2020.3047438},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/ART-2020-21/ART-2020-21.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {In complex event processing (CEP), load shedding is performed to maintain a
given latency bound during overload situations when there is a limitation on
resources. However, shedding load implies degradation in the quality of results
(QoR). Therefore, it is crucial to perform load shedding in a way that has the
lowest impact on QoR. Researchers, in the CEP domain, propose to drop either
events or partial matches (PMs) in overload cases. They assign utilities to
events or PMs by considering either the importance of events or the importance
of PMs but not both together. In this paper, we combine these approaches where
we propose to assign a utility to an event by considering both the event
importance and the importance of PMs. We propose two load shedding approaches
for CEP systems. The first approach drops events from PMs, while the second
approach drops events from windows. We adopt a probabilistic model that uses
the type and position of an event in a window and the state of a PM to assign a
utility to an event. We, also, propose an approach to predict a utility
threshold that is used to drop the required amount of events to maintain a
given latency bound. By extensive evaluations on two real-world datasets and
several representative queries, we show that, in the majority of cases, our
load shedding approach outperforms state-of-the-art load shedding approaches,
w.r.t. QoR.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2020-21&engl=0}
}
@article {ART-2020-03,
author = {Mohamed Abdelaal and Suriya Sekar and Frank Duerr and Susanne Becker and Kurt Rothermel and Dieter Fritsch},
title = {{MapSense: Grammar-Supported Inference of Indoor Objects from Crowd-Sourced 3D Point Clouds}},
journal = {Transactions on Internet of Things (TIOT)},
publisher = {ACM (Online)},
pages = {1--28},
type = {Artikel in Zeitschrift},
month = {Januar},
year = {2020},
doi = {10.1145/3379342},
keywords = {Indoor Mapping; Crowd-sensing; Machine Learning; Formal Grammars; QoS-aware Sensing},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/ART-2020-03/ART-2020-03.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Recently, indoor modeling has gained increased attention thanks to the immense
need for realizing efficient indoor location-based services. Indoor
environments de facto differ from outdoor spaces in two aspects: spaces are
smaller and there are many structural objects such as walls, doors, and
furniture. To model the indoor environments in a proper manner, novel data
acquisition concepts and data modeling algorithms have been devised to meet the
requirements of indoor spatial applications. In this realm, several research
efforts have been exerted. Nevertheless, these efforts mostly suffer either
from adopting impractical data acquisition methods or from being limited to 2D
modeling.
To overcome these limitations, we introduce the MapSense approach that
automatically derives indoor models from 3D point clouds collected by
individuals using mobile devices, such as Google Tango, Apple ARKit, and
Microsoft HoloLens. To this end, MapSense leverages several computer vision and
machine learning algorithms for precisely inferring the structural objects. In
MapSense, we mainly focus on improving the modeling accuracy through adopting
formal grammars which encode design-time knowledge, i.e. structural information
about the building. In addition to modeling accuracy, MapSense considers the
energy overhead on the mobile devices via developing a probabilistic quality
model through which the mobile devices solely upload high-quality point clouds
to the crowd-sensing servers. To demonstrate the performance of MapSense, we
implemented a crowdsensing Android App to collect 3D point clouds from two
different buildings by six volunteers. The results showed that MapSense can
accurately infer the various structural objects together with drastically
reducing the energy overhead on the mobile devices.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2020-03&engl=0}
}
@article {ART-2019-20,
author = {Henriette R{\"o}ger and Ruben Mayer},
title = {{A Comprehensive Survey on Parallelization and Elasticity in Stream Processing}},
journal = {ACM Computing Surveys (CSUR)},
address = {New York},
publisher = {ACM},
volume = {52},
number = {2},
pages = {1--37},
type = {Artikel in Zeitschrift},
month = {April},
year = {2019},
doi = {10.1145/3303849},
keywords = {Stream Processing; Complex Event Processing; Parallelization; Elasticity},
language = {Deutsch},
cr-category = {C.1.4 Processor Architectures, Parallel Architectures},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/ART-2019-20/ART-2019-20.pdf,
https://dl.acm.org/citation.cfm?id=3303849},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Stream Processing (SP) has evolved as the leading paradigm to process and gain
value from the high volume of streaming data produced, e.g., in the domain of
the Internet of Things. An SP system is a middleware that deploys a network of
operators between data sources, such as sensors, and the consuming
applications. SP systems typically face intense and highly dynamic data
streams. Parallelization and elasticity enable SP systems to process these
streams with continuous high quality of service. The current research landscape
provides a broad spectrum of methods for parallelization and elasticity in SP.
Each method makes specific assumptions and focuses on particular aspects.
However, the literature lacks a comprehensive overview and categorization of
the state of the art in SP parallelization and elasticity, which is necessary
to consolidate the state of the research and to plan future research directions
on this basis. Therefore, in this survey, we study the literature and develop a
classification of current methods for both parallelization and elasticity in SP
systems.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2019-20&engl=0}
}
@article {ART-2018-10,
author = {Thomas Kohler and Frank D{\"u}rr and Kurt Rothermel},
title = {{ZeroSDN: A Highly Flexible and Modular Architecture for Full-range Distribution of Event-based Network Control}},
journal = {IEEE Transactions on Network and Service Management},
editor = {Wolfgang Kellerer},
publisher = {IEEE Communications Society},
pages = {1--14},
type = {Artikel in Zeitschrift},
month = {Januar},
year = {2018},
keywords = {Software-defined Networking; OpenFlow; Control Plane Distribution; Publish/Subscribe; White-box Networking; Virtualization},
language = {Englisch},
cr-category = {C.2.1 Network Architecture and Design,
C.2.4 Distributed Systems,
C.2.3 Network Operations},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/ART-2018-10/ART-2018-10.pdf},
contact = {thomas.kohler@ipvs.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2018-10&engl=0}
}
@article {ART-2018-09,
author = {Sukanya Bhowmik and Muhammad Adnan Tariq and Jonas Grunert and Deepak Srinivasan and Kurt Rothermel},
title = {{Expressive Content-Based Routing in Software-Defined Networks}},
journal = {IEEE Transactions on Parallel and Distributed Systems},
publisher = {IEEE},
pages = {1--18},
type = {Artikel in Zeitschrift},
month = {Mai},
year = {2018},
language = {Englisch},
cr-category = {C.2.1 Network Architecture and Design,
C.2.4 Distributed Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/ART-2018-09/ART-2018-09.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2018-09&engl=0}
}
@article {ART-2018-01,
author = {Christoph Dibak and Bernard Haasdonk and Andreas Schmidt and Frank D{\"u}rr and Kurt Rothermel},
title = {{Enabling Interactive Mobile Simulations Through Distributed Reduced Models}},
journal = {Pervasive and Mobile Computing},
publisher = {Elsevier BV},
pages = {1--26},
type = {Artikel in Zeitschrift},
month = {Februar},
year = {2018},
doi = {10.1016/j.pmcj.2018.02.002},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2018-01&engl=0}
}
@article {ART-2016-24,
author = {Sukanya Bhowmik and Muhammad Adnan Tariq and Boris Koldehofe and Frank D{\"u}rr and Thomas Kohler and Kurt Rothermel},
title = {{High Performance Publish/Subscribe Middleware in Software-Defined Networks}},
journal = {IEEE/ACM Transactions on Networking},
publisher = {IEEE},
volume = {25},
number = {3},
pages = {1--16},
type = {Artikel in Zeitschrift},
month = {Dezember},
year = {2016},
isbn = {10.1109/TNET.2016.2632970},
language = {Englisch},
cr-category = {C.2.1 Network Architecture and Design,
C.2.4 Distributed Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/ART-2016-24/ART-2016-24.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2016-24&engl=0}
}
@article {ART-2016-07,
author = {Thomas Kohler and Frank D{\"u}rr and Kurt Rothermel},
title = {{Consistent Network Management for Software-defined Networking based Multicast}},
journal = {IEEE Transactions on Network and Service Management},
editor = {Rolf Stadler},
publisher = {IEEE Communications Society},
pages = {1--1},
type = {Artikel in Zeitschrift},
month = {September},
year = {2016},
isbn = {10.1109/TNSM.2016.2585672},
keywords = {Software-defined networking, configuration management, update consistency, quality-of-service management, multicast communication},
language = {Englisch},
cr-category = {C.2.1 Network Architecture and Design,
C.2.3 Network Operations,
C.2.4 Distributed Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/ART-2016-07/ART-2016-07.pdf,
http://dx.doi.org/10.1109/TNSM.2016.2585672},
contact = {thomas.kohler@ipvs.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Updating a network is an essential and continual task in the management of
today{\^a}€™s softwarized networks. When applying updates on distributed network
elements, desired network properties, such as drop- and loop-freeness, might be
transiently violated. Although being crucial, update consistency has yet been
less considered in network management.
In this article, we argue for incorporating the particularities of update
consistency into the reconfiguration process of continuous network management.
We present a generic management architecture allowing for an appropriate
selection of an update mechanism and its parameters based on expected
inconsistency effects. We investigate update consistency for the case of
multicast routing and show in an extensive analysis why simultaneous drop- and
duplicate-freeness is not possible. We present an update procedure for
multicast routing updates that identifies critical update steps, which are fed
back into the reconfiguration process, along with a lightweight approach that
allows for the selection of an update strategy, preventing either drops or
duplicates. Furthermore, we present an optimization of an existing powerful,
but resource-intensive update approach as well as an approach for in-network
filtering of duplicates.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2016-07&engl=0}
}
@article {ART-2015-02,
author = {Ruben Mayer and Boris Koldehofe and Kurt Rothermel},
title = {{Predictable Low-Latency Event Detection with Parallel Complex Event Processing}},
journal = {IEEE Internet of Things Journal},
publisher = {IEEE},
pages = {1--13},
type = {Artikel in Zeitschrift},
month = {Januar},
year = {2015},
keywords = {Complex Event Processing, Stream Processing, Data Parallelization, Self-Adaptation, Quality of Service},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems,
C.4 Performance of Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/ART-2015-02/ART-2015-02.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {The tremendous number of sensors and smart objects being deployed in the
Internet of Things pose the potential for IT systems to detect and react to
live-situations. For using this hidden potential, Complex Event Processing
(CEP) systems offer means to efficiently detect event patterns (complex events)
in the sensor streams and therefore help in realizing a “distributed
intelligence” in the Internet of Things. With the increasing number of data
sources and the increasing volume at which data is produced, parallelization of
event detection is crucial to limit the time events need to be buffered before
they actually can be processed. In this article, we propose a pattern-sensitive
partitioning model for data streams that is capable of achieving a high degree
of parallelism in detecting event patterns which formerly could only be
consistently detected in a sequential manner or at a low parallelization
degree. Moreover, we propose methods to dynamically adapt the parallelization
degree to limit the buffering imposed on event detection in the presence of
dynamic changes to the workload. Extensive evaluations of the system behavior
show that the proposed partitioning model allows for a high degree of
parallelism and that the proposed adaptation methods are able to meet a
buffering limit for event detection under high and dynamic workloads.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2015-02&engl=0}
}
@article {ART-2015-01,
author = {Pericle Perazzo and Pavel Skvortsov and Gianluca Dini},
title = {{On Designing Resilient Location-Privacy Obfuscators}},
journal = {The Computer Journal},
publisher = {Oxford University Press},
type = {Artikel in Zeitschrift},
month = {Februar},
year = {2015},
doi = {10.1093/comjnl/bxv009},
keywords = {location-based service; privacy; obfuscation; sharing},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems,
H.3.5 Online Information Services},
ee = {http://comjnl.oxfordjournals.org/content/early/2015/02/11/comjnl.bxv009.abstract},
contact = {Pericle Perazzo pericle.perazzo@iet.unipi.it, Pavel Skvortsov skvortsov@hlrs.de, Gianluca Dini gianluca.dini@iet.unipi.it},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {The success of location-based services is growing together with the diffusion
of GPS-equipped smart devices. As a consequence, privacy concerns are raising
year by year. Location privacy is becoming a major interest in research and
industry world, and many solutions have been proposed for it. One of the
simplest and most flexible approaches is obfuscation, in which the precision of
location data is artificially degraded before disclosing it. In this paper, we
present an obfuscation approach capable of dealing with measurement
imprecision, multiple levels of privacy, untrusted servers, and adversarial
knowledge of the map. We estimate its resistance against statistical-based
deobfuscation attacks, and we improve it by means of three techniques, namely
extreme vectors, enlarge-and-scale, and hybrid vectors.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2015-01&engl=0}
}
@article {ART-2014-07,
author = {Beate Ottenw{\"a}lder and Boris Koldehofe and Kurt Rothermel and Kirak Hong and David Lillethun and Umakishore Ramachandran},
title = {{MCEP: A Mobility-Aware Complex Event Processing System}},
journal = {ACM Transactions Internet Technology},
editor = {Munindar P. Singh},
publisher = {ACM},
volume = {14},
number = {1},
pages = {1--24},
type = {Artikel in Zeitschrift},
month = {August},
year = {2014},
issn = {1533-5399 EISSN:1557-6051},
keywords = {Mobility, complex event processing, migration, moving range queries},
language = {Englisch},
cr-category = {C.2.1 Network Architecture and Design,
C.2.4 Distributed Systems},
ee = {http://doi.acm.org/10.1145/2633688},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {With the proliferation of mobile devices and sensors, complex event processing
(CEP) is becoming increasingly important to scalably detect situations in real
time. Current CEP systems are not capable of dealing efficiently with highly
dynamic mobile consumers whose interests change with their location. We
introduce the distributed mobile CEP (MCEP) system which automatically adapts
the processing of events according to a consumer's location. MCEP significantly
reduces latency, network utilization, and processing overhead by providing
on-demand and opportunistic adaptation algorithms to dynamically assign event
streams and computing resources to operators of the MCEP system.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2014-07&engl=0}
}
@article {ART-2014-03,
author = {Marius Wernke and Pavel Skvortsov and Frank D{\"u}rr and Kurt Rothermel},
title = {{A Classification of Location Privacy Attacks and Approaches}},
journal = {Personal and Ubiquitous Computing (Special Issue on Security and Trust in Context-Aware Systems)},
publisher = {Springer London},
volume = {18},
number = {1},
pages = {163--175},
type = {Artikel in Zeitschrift},
month = {Januar},
year = {2014},
issn = {1617-4909},
doi = {10.1007/s00779-012-0633-z},
keywords = {location-based services; location privacy; adversary; attack; classification; location privacy approaches},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems,
H.3.5 Online Information Services},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/ART-2014-03/ART-2014-03.pdf,
http://link.springer.com/article/10.1007%2Fs00779-012-0633-z,
http://www.priloc.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {In recent years, location-based services have become very popular, mainly
driven by the availability of modern mobile devices with integrated position
sensors. Prominent examples are points of interest finders or geo-social
networks like Facebook Places, Qype, Loopt. Because these services access
private position information, location privacy concepts become mandatory in
order to ensure that users accept these services.
Many different concepts and approaches for the protection of location privacy
have been described in the literature. These approaches differ with respect to
the protected information and their effectiveness against different attacks.
The goal of this paper is to assess the applicability and effectiveness of
location privacy approaches systematically. We first identify different
protection goals, namely, personal information (user identity), spatial
information (user position), and temporal information (identity/position +
time). Secondly, we give an overview of basic principles and existing
approaches to protect these privacy goals. In a third step, we classify
possible attacks. Finally, we analyzed existing approaches with respect to
their protection goals and their ability to resists the introduced attacks.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2014-03&engl=0}
}
@article {ART-2014-01,
author = {Muhammad Adnan Tariq and Boris Koldehofe and Kurt Rothermel},
title = {{Securing Broker-Less Publish/Subscribe Systems using Identity-Based Encryption}},
journal = {IEEE Transactions on Parallel and Distributed Systems},
address = {Los Alamitos, CA, USA},
publisher = {IEEE Computer Society},
volume = {25},
number = {2},
pages = {518--528},
type = {Artikel in Zeitschrift},
month = {Februar},
year = {2014},
doi = {10.1109/TPDS.2013.256},
issn = {1045-9219},
keywords = {Identity-based encryption; Routing; Servers; Subscriptions; Distributed Systems; Security and Privacy Protection},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
ee = {http://dx.doi.org/10.1109/TPDS.2013.256,
http://doi.ieeecomputersociety.org/10.1109/TPDS.2013.256,
http://www.computer.org/cms/Computer.org/dl/trans/td/2014/02/extras/ttd2014020518s.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {The provisioning of basic security mechanisms such as authentication and
confidentiality is highly challenging in a content-based publish/subscribe
system. Authentication of publishers and subscribers is difficult to achieve
due to the loose coupling of publishers and subscribers. Likewise,
confidentiality of events and subscriptions conflicts with content-based
routing. This article presents a novel approach to provide confidentiality and
authentication in a broker-less content-based publish-subscribe system. The
authentication of publishers and subscribers as well as confidentiality of
events is ensured, by adapting the pairing-based cryptography mechanisms, to
the needs of a publish/subscribe system. Furthermore, an algorithm to cluster
subscribers according to their subscriptions preserves a weak notion of
subscription confidentiality. In addition to our previous work, this article
contributes i) use of searchable encryption to enable efficient routing of
encrypted events, ii) Multi-credential routing a new event dissemination
strategy to strengthen the weak subscription confidentiality, and iii) thorough
analysis of different attacks on subscription confidentiality. The overall
approach provides fine grained key management and the cost for encryption,
decryption and routing is in the order of subscribed attributes. Moreover, the
evaluations show that providing security is affordable w.r.t. i) throughput of
the proposed cryptographic primitives, and ii) delays incurred during the
construction of the publish/subscribe overlay and the event dissemination.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2014-01&engl=0}
}
@article {ART-2013-13,
author = {Hannes Wolf and Klaus Herrmann and Kurt Rothermel},
title = {{Dealing with uncertainty: Robust workflow navigation in the healthcare domain}},
journal = {ACM Transactions on Intelligent Systems and Technology (TIST)},
address = {New York, NY, USA},
publisher = {ACM},
volume = {4},
number = {4},
type = {Artikel in Zeitschrift},
month = {September},
year = {2013},
doi = {10.1145/2508037.2508046},
issn = {2157-6904},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems,
H.4.1 Office Automation},
ee = {http://doi.acm.org/10.1145/2508037.2508046},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Processes in the healthcare domain are characterized by coarsely predefined
recurring procedures that are flexibly adapted by the personnel to
suite-specific situations. In this setting, a workflow management system that
gives guidance and documents the personnel's actions can lead to a higher
quality of care, fewer mistakes, and higher efficiency. However, most existing
workflow management systems enforce rigid inflexible workflows and rely on
direct manual input. Both are inadequate for healthcare processes. In
particular, direct manual input is not possible in most cases since (1) it
would distract the personnel even in critical situations and (2) it would
violate fundamental hygiene principles by requiring disinfected doctors and
nurses to touch input devices. The solution could be activity recognition
systems that use sensor data (e.g., audio and acceleration data) to infer the
current activities by the personnel and provide input to a workflow (e.g.,
informing it that a certain activity is finished now). However,
state-of-the-art activity recognition technologies have difficulties in
providing reliable information. We describe a comprehensive framework tailored
for flexible human-centric healthcare processes that improves the reliability
of activity recognition data. We present a set of mechanisms that exploit the
application knowledge encoded in workflows in order to reduce the uncertainty
of this data, thus enabling unobtrusive robust healthcare workflows. We
evaluate our work based on a real-world case study and show that the robustness
of unobtrusive healthcare workflows can be increased to an absolute value of up
to 91\% (compared to only 12\% with a classical workflow system). This is a major
breakthrough that paves the way towards future IT-enabled healthcare systems.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2013-13&engl=0}
}
@article {ART-2013-04,
author = {Anders Gidenstam and Boris Koldehofe and Marina Papatriantafilou and Philippas Tsigas},
title = {{Scalable group communication supporting configurable levels of consistency}},
journal = {Concurrency and Computation: Practice and Experience},
publisher = {John Wiley \& Sons, Ltd.},
volume = {25},
number = {5},
pages = {649--671},
type = {Artikel in Zeitschrift},
month = {Januar},
year = {2013},
doi = {10.1002/cpe.1801},
keywords = {Distributed Systems, Group Communication, Consistency},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Group communication is deployed in many evolving Internet-scale cooperative
applications such as multiplayer online games and virtual worlds to efficiently
support interaction on information relevant to a potentially very large number
of users or objects. Especially peer-to-peer based group communication
protocols have evolved as a promising approach to allow intercommunication
between many distributed peers. Yet, the delivery semantics of robust and
scalable protocols such as gossiping is not sufficient to support consistency
semantics beyond eventual consistency because no relationship on the order of
events is enforced. On the other hand, traditional consistency models provided
by reliable group communication providing causal or even total order are
restricted to support only small groups. This article proposes the cluster
consistency model which bridges the gap between traditional and current
approaches in supporting both scalability and ordered event delivery. We
introduce a dynamic and fault tolerant cluster management method that can
coordinate concurrent access to resources in a peer-to-peer system and can be
used to establish fault-tolerant configurable cluster consistency with
predictable reliability, running on top of decentralised probabilistic
protocols supporting scalable group communication. This is achieved by a
general two-layered architecture that can be applied on top of the standard
Internet communication layers and offers a modular, layered set of services to
the applications that need them. Further, we present a fault-tolerant method
implementing causal cluster consistency with predictable reliability, running
on top of decentralised probabilistic protocols supporting group communication.
This paper provides analytical and experimental evaluation of the properties
regarding the fault tolerance of the approach. Furthermore, our experimental
study, conducted by implementing and evaluating the two-layered architecture on
top of standard Internet transport services, shows that the approach scales
well, imposes an even load on the system, and provides high-probability
reliability guarantees.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2013-04&engl=0}
}
@article {ART-2013-02,
author = {Marius Wernke and Frank D{\"u}rr and Kurt Rothermel},
title = {{PShare: Ensuring location privacy in non-trusted systems through multi-secret sharing}},
journal = {Pervasive and Mobile Computing},
publisher = {Elsevier},
pages = {1--17},
type = {Artikel in Zeitschrift},
month = {Februar},
year = {2013},
doi = {10.1016/j.pmcj.2013.01.001},
keywords = {Location-based applications; Privacy; Position sharing; Location management},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/ART-2013-02/ART-2013-02.pdf,
http://www.priloc.de,
http://dx.doi.org/10.1016/j.pmcj.2013.01.001},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Location-based applications such as Facebook Places, Foursquare, or Loopt
typically use location services to manage mobile object positions. However,
exposing precise user positions raises user privacy concerns, especially if
location service providers are not fully trusted. To enable the secure
management of private user positions in non-trusted systems, we present two
novel position sharing approaches based on the concept of multi-secret sharing.
We improve existing geometric position sharing approaches [1, 2] by considering
continuous position updates and by increasing the robustness against various
attacks. Furthermore, we present the first position sharing approach for
symbolic location models.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2013-02&engl=0}
}
@article {ART-2013-01,
author = {Stephan Schuhmann and Klaus Herrmann and Kurt Rothermel and Yazan Boshmaf},
title = {{Adaptive Composition of Distributed Pervasive Applications in Heterogeneous Environments}},
journal = {ACM Transactions on Autonomous and Adaptive Systems},
publisher = {ACM},
volume = {8},
number = {2},
pages = {1--21},
type = {Artikel in Zeitschrift},
month = {Juli},
year = {2013},
doi = {10.1145/2491465.2491469},
issn = {1556-4665},
keywords = {Adaptivity; Algorithms; Automation; Components; Design; Heterogeneity; Hybrid Configuration; Management; Measurement; Middleware; Partial Configurations; Pervasive Applications; Service Composition},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems,
D.2.11 Software Engineering Software Architectures},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/ART-2013-01/ART-2013-01.pdf,
http://doi.acm.org/10.1145/2491465.2491469},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Complex pervasive applications need to be distributed for two main reasons: due
to the typical resource restrictions of mobile devices, and to use local
services to interact with the immediate environment. To set up such an
application, the distributed components require spontaneous composition. Since
dynamics in the environment and device failures may imply the unavailability of
components and devices at any time, finding, maintaining, and adapting such a
composition is a nontrivial task. Moreover, the speed of such a configuration
process directly influences the user since in the event of a configuration, the
user has to wait. In this article, we introduce configuration algorithms for
homogeneous and heterogeneous environments. We discuss a comprehensive approach
to pervasive application configuration that adapts to the characteristics of
the environment: It chooses the most efficient configuration method for the
given environment to minimize the configuration latency. Moreover, we propose a
new scheme for caching and reusing partial application configurations. This
scheme reduces the configuration latency even further such that a configuration
can be executed without noticeable disturbance of the user.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2013-01&engl=0}
}
@article {ART-2012-21,
author = {Ralph Lange},
title = {{Scalable Management of Trajectories and Context Model Descriptions}},
journal = {PIK -- Praxis der Informationsverarbeitung und Kommunikation},
publisher = {De Gruyter},
volume = {35},
number = {4},
pages = {281--287},
type = {Artikel in Zeitschrift},
month = {November},
year = {2012},
doi = {10.1515/pik-2012-0041},
isbn = {ISSN 1865-8342},
keywords = {moving objects database; trajectory tracking; spatio-temporal indexing; heterogeneous information systems; defined classes},
language = {Englisch},
cr-category = {H.2.5 Heterogeneous Databases,
H.2.8 Database Applications,
H.3.3 Information Search and Retrieval},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/ART-2012-21/ART-2012-21.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {The ongoing proliferation of sensing technologies constitutes a huge potential
for context-aware computing. It allows selecting relevant information about our
physical environment from different sources and providers all over the globe. A
fundamental challenge is how to provide efficient access to these immense
amounts of distributed dynamic context information - particularly due to the
mobility of devices and other entities. To enable such access to current and
past position information about moving objects, we propose a family of
protocols (CDR, GRTS) for efficiently tracking a moving object's trajectory at
some remote database in real-time as well as a distributed indexing scheme
(DTI) for optimized access to trajectory data that is partitioned in space to
multiple database servers. For discovering context information that is relevant
for the situation of an application, we propose a powerful formalism for
describing context models in a concise manner and a tailored multidimensional
data structure (SDC-Tree) for retrieving relevant context models out of
potentially millions of descriptions.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2012-21&engl=0}
}
@article {ART-2012-18,
author = {Kurt Rothermel and Stephan Schnitzer and Ralph Lange and Frank D{\"u}rr and Tobias Farrell},
title = {{Context-aware and quality-aware algorithms for efficient mobile object management}},
journal = {Pervasive and Mobile Computing},
publisher = {Elsevier},
volume = {8},
number = {1},
pages = {131--146},
type = {Artikel in Zeitschrift},
month = {Februar},
year = {2012},
doi = {10.1016/j.pmcj.2011.04.009},
issn = {1574-1192},
keywords = {context-awareness; location management; mobile object tracking; range queries; efficiency},
language = {Englisch},
cr-category = {C.2 Computer-Communication Networks,
H.2.8 Database Applications},
ee = {http://dx.doi.org/10.1016/j.pmcj.2011.04.009},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {The management of positions of mobile objects is an essential prerequisite for
many context-aware systems such as advanced traffic management systems or
personal assistance systems. In this paper, we present two approaches for the
scalable tracking of mobile object trajectories and the efficient processing of
continuous spatial range queries, respectively. We show in detail how both
approaches utilize the basic concepts of accuracy relaxation and utilization of
context information, such as movement predictions, to minimize the number of
position updates, the size of trajectory data, and the number of
energy-consuming position sensing operations.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2012-18&engl=0}
}
@article {ART-2012-17,
author = {Umakishore Ramachandran and Kirak Hong and Liviu Iftode and Ramesh Jain and Rajnish Kumar and Kurt Rothermel and Junsuk Shin and Raghupathy Sivakumar},
title = {{Large-Scale Situation Awareness With Camera Networks and Multimodal Sensing}},
journal = {Proceedings of the IEEE},
publisher = {IEEE},
volume = {100},
number = {4},
pages = {878--892},
type = {Artikel in Zeitschrift},
month = {April},
year = {2012},
issn = {0018-9219},
doi = {10.1109/JPROC.2011.2182093},
keywords = {Cameras; Computer vision; Intelligent sensors; Large-scale systems; Real time systems; Resource management; Surveillance; Target tracking; Video recording; cameras; image sensors; multimedia communication; ubiquitous computing; video surveillance; Moore law; data-intensive nature; disaster recovery; emergency response; functional situation awareness system; health care; ill-defined research area; large-scale camera network deployment; large-scale reliable system; large-scale situation awareness; media-rich sensor-based application; multimedia algorithm; multimodal sensing; real-time analysis; resource requirement; sensing data; Large-scale distributed systems; programing model; resource management; scalability; situation awareness; video-based surveillance},
language = {Deutsch},
cr-category = {C.2 Computer-Communication Networks,
I.4 Image Processing and Computer Vision,
D.1 Programming Techniques},
ee = {http://dx.doi.org/10.1109/JPROC.2011.2182093},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Sensors of various modalities and capabilities, especially cameras, have become
ubiquitous in our environment. Their intended use is wide ranging and
encompasses surveillance, transportation, entertainment, education, healthcare,
emergency response, disaster recovery, and the like. Technological advances and
the low cost of such sensors enable deployment of large-scale camera networks
in large metropolises such as London and New York. Multimedia algorithms for
analyzing and drawing inferences from video and audio have also matured
tremendously in recent times. Despite all these advances, large-scale reliable
systems for media-rich sensor-based applications, often classified as
situation-awareness applications, are yet to become commonplace. Why is that?
There are several forces at work here. First, the system abstractions are just
not at the right level for quickly prototyping such applications on a large
scale. Second, while Moore's law has held true for predicting the growth of
processing power, the volume of data that applications are called upon to
handle is growing similarly, if not faster. Enormous amount of sensing data is
continually generated for real-time analysis in such applications. Further, due
to the very nature of the application domain, there are dynamic and demanding
resource requirements for such analyses. The lack of right set of abstractions
for programing such applications coupled with their data-intensive nature have
hitherto made realizing reliable large-scale situation-awareness applications
difficult. Incidentally, situation awareness is a very popular but ill-defined
research area that has attracted researchers from many different fields. In
this paper, we adopt a strong systems perspective and consider the components
that are essential in realizing a fully functional situation-awareness system.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2012-17&engl=0}
}
@article {ART-2012-04,
author = {Andreas Grau and Klaus Herrmann and Kurt Rothermel},
title = {{Scalable Network Emulation - The NET Approach}},
journal = {Journal of Communications - Special Issue: Advances in Communications and Networking - II},
publisher = {Academy Publisher},
volume = {7},
number = {1},
pages = {3--16},
type = {Artikel in Zeitschrift},
month = {Januar},
year = {2012},
issn = {1796-2021},
doi = {10.4304/jcm.7.1.3-16},
keywords = {Scalable Network Emulation; Placement; Migration; Node Virtualization; Virtual Time},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Network emulation is an efficient method for evaluating distributed
applications and communication protocols bycombining the benefits of real world
experiments and networksimulation. The process of network emulation involves
the executionof connected virtual nodes running the software under test ina
controlled environment. Our Network Emulation Testbed (NET) achieves high
scalability by combining efficient node virtualization and adaptive virtual
time.
In this paper, we provide an overview of our system. First, we introduce our
efficient emulation architecture. Second, we present our approaches (NETplace
and NETbalance) to minimize the runtime of the network experiments. The idea of
NETplace is to minimize the load of the testbed by calculating an initial
placement of virtual nodes onto the testbed nodes. During the runtime of the
experiment NETbalance adapts this placement to changed resource requirements of
the software under test. Finally, we introduce NETcaptain, a graphical user
interface to setup, control and visualize network experiments.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2012-04&engl=0}
}
@article {ART-2011-21,
author = {Tobias Farrell and Kurt Rothermel and Reynold Cheng},
title = {{Processing Continuous Range Queries with Spatiotemporal Tolerance}},
journal = {IEEE Journal Transactions on Mobile Computing (TCM)},
publisher = {IEEE Computer Society},
volume = {10},
number = {3},
pages = {320--334},
type = {Artikel in Zeitschrift},
month = {M{\"a}rz},
year = {2011},
doi = {10.1109/TMC.2010.159},
issn = {1536-1233},
keywords = {accuracy; delay; energy consumption; sensors; uncertainty; query; spatial; temporal; spatiotemporal},
language = {Englisch},
cr-category = {C.2 Computer-Communication Networks},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Continuous queries are often employed to monitor the locations of mobile
objects (MOs), which are determined by sensing devices like GPS receivers. In
this paper, we tackle two challenges in processing continuous range queries
(CRQs): coping with data uncertainty inherently associated with location data,
and reducing the energy consumption of battery-powered MOs. We propose the
concept of spatiotemporal tolerance for CRQ to relax a query's accuracy
requirements in terms of a maximal acceptable error. Unlike previous works, our
definition considers tolerance in both the spatial and temporal dimensions,
which offers applications more flexibility in specifying their individual
accuracy requirements. As we will show, these tolerance bounds can provide
well-defined query semantics in spite of different sources of data uncertainty.
In addition, we present efficient algorithms that carefully control when an MO
should sense or report a location, while satisfying these tolerances. Thereby,
we particularly reduce the number of position sensing operations substantially,
which constitute a considerable source of energy consumption. Extensive
simulations confirm that the proposed algorithms result in large energy savings
compared to nontolerant query processing.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2011-21&engl=0}
}
@article {ART-2011-11,
author = {Ralph Lange and Frank D{\"u}rr and Kurt Rothermel},
title = {{Efficient real-time trajectory tracking}},
journal = {The VLDB Journal},
publisher = {Springer Berlin Heidelberg},
volume = {20},
number = {5},
pages = {671--694},
type = {Artikel in Zeitschrift},
month = {Oktober},
year = {2011},
doi = {10.1007/s00778-011-0237-7},
issn = {1066-8888},
keywords = {moving objects database; MOD; trajectory tracking; dead reckoning; line simplification},
language = {Englisch},
cr-category = {H.2.8 Database Applications},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/ART-2011-11/ART-2011-11.pdf,
http://dx.doi.org/10.1007/s00778-011-0237-7},
contact = {ralph.lange@ipvs.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Moving objects databases (MOD) manage trajectory information of vehicles,
animals, and other mobile objects. A crucial problem is how to efficiently
track an object's trajectory in real-time, in particular if the trajectory data
is sensed at the mobile object and thus has to be communicated over a wireless
network. We propose a family of tracking protocols that allow trading the
communication cost and the amount of trajectory data stored at a MOD off
against the spatial accuracy. With each of these protocols, the MOD manages a
simplified trajectory that does not deviate by more than a certain accuracy
bound from the actual movement. Moreover, the different protocols enable
several trade-offs between computational costs, communication cost, and the
reduction in the trajectory data: Connection-Preserving Dead Reckoning
minimizes the communication cost using dead reckoning, a technique originally
designed for tracking an object's current position. Generic Remote Trajectory
Simplification (GRTS) further separates between tracking of the current
position and simplification of the past trajectory and can be realized with
different line simplification algorithms. For both protocols, we discuss how to
bound the space consumption and computing time at the moving object and thereby
present an effective compression technique to optimize the reduction
performance of real-time line simplification in general. Our evaluations with
hundreds of real GPS traces show that a realization of GRTS with a simple
simplification heuristic reaches 85-90\% of the best possible reduction rate,
given by retrospective offline simplification. A realization with the optimal
line simplification algorithm by Imai and Iri even reaches more than 97\% of the
best possible reduction rate.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2011-11&engl=0}
}
@article {ART-2011-01,
author = {Muhammad Adnan Tariq and Boris Koldehofe and Gerald G. Koch and Imran Khan and Kurt Rothermel},
title = {{Meeting subscriber-defined QoS constraints in publish/subscribe systems}},
journal = {Concurrency and Computation: Practice and Experience},
publisher = {John Wiley \& Sons, Ltd.},
volume = {23},
number = {17},
pages = {2140--2153},
type = {Artikel in Zeitschrift},
month = {Mai},
year = {2011},
doi = {10.1002/cpe.1751},
keywords = {Content-based; P2P; Event-based; Bandwidth; End-to-end Delay; Spatial indexing; QoS},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/ART-2011-01/ART-2011-01.pdf,
http://dx.doi.org/10.1002/cpe.1751},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Current distributed publish/subscribe systems assume that all participants have
similar QoS requirements and equally contribute to the system's resources.
However, in many real-world applications, the message delay tolerance of
individual peers may differ widely. Disseminating messages according to
individual delay requirements not only allows for the satisfaction of
user-specific needs but also significantly improves the utilization of the
resources in a publish/subscribe system. In this paper, we propose a
peer-to-peer-based approach to satisfy the individual delay requirements of
subscribers in the presence of bandwidth constraints. Our approach allows
subscribers to dynamically adjust the granularity of their subscriptions
according to their bandwidth constraints and delay requirements. Subscribers
maintain the publish/subscribe overlay in a decentralized manner by
establishing connections to peers that provide messages meeting exactly their
subscription granularity and complying to their delay requirements. Evaluations
show that for practical workloads, the proposed system scales up to a large
number of subscribers and performs robustly in a very dynamic setting.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2011-01&engl=0}
}
@article {ART-2010-03,
author = {Sven Schulz and Wolfgang Blochinger and Mathias Poths},
title = {{Orbweb - A Network Substrate for Peer-to-Peer Grid Computing Platforms based on Open Standards}},
journal = {Journal of Grid Computing},
address = {Heidelberg},
publisher = {Springer-Verlag},
volume = {8},
number = {1},
pages = {77--107},
type = {Artikel in Zeitschrift},
month = {Juni},
year = {2010},
doi = {10.1007/s10723-009-9121-8},
language = {Englisch},
cr-category = {C.2.1 Network Architecture and Design,
C.2.2 Network Protocols,
C.2.4 Distributed Systems,
C.2.6 Internetworking},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {In this paper, we propose to use the open industrial-strength eXtensible
Messaging and Presence Protocol (XMPP) to build a network substrate for
Peer-to-Peer Grid computing called Orbweb. We describe how to employ XMPP to
tackle domain-specific challenges, including high scalability, support for
volatility, NAT/Firewall traversal, and protocol efficiency. Where XMPP fails
to meet these requirements, we contribute pertinent extensions. In particular,
we boost the scalability of XMPP by taking load of the XMPP servers through
dynamically negotiated direct Peer-to-Peer communication channels between XMPP
peers. We pave the way for scalable group membership management by substituting
the existing XMPP Multi-User Chat protocol for one that does not suffer from
limitations imposed by a everyone knows everyone visibility model and allows
for selecting a membership model that matches the requirements of a given
application. As efficient multicasting is an essential prerequisite for many
distributed algorithms and the centralized XMPP multicast is of limited
scalability, we adapt the well-known Bimodal Multicast protocol to work in a
highly volatile Peer-to-Peer Grid computing environment. Finally, we show how
to improve the protocol efficiency of XMPP by leveraging a standardized binary
encoding of the XML Information Set for XMPP packet transmission. To
substantiate the applicability of our approach and the effectiveness of our
extensions, we describe how some important higher-level services used in
Peer-to-Peer Grid Computing can be implemented on top of Orbweb and provide a
detailed experimental analysis.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2010-03&engl=0}
}
@article {ART-2009-31,
author = {Andreas Lachenmann and Klaus Herrmann and Kurt Rothermel and Pedro Jos{\'e} Marr{\'o}n},
title = {{On Meeting Lifetime Goals and Providing Constant Application Quality}},
journal = {Transactions on Sensor Networks},
publisher = {ACM},
volume = {5},
number = {4},
pages = {1--36},
type = {Artikel in Zeitschrift},
month = {November},
year = {2009},
doi = {10.1145/1614379.1614388},
keywords = {Wireless sensor network; Coordination; Energy; Lifetime goal; Programming abstraction},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/ART-2009-31/ART-2009-31.pdf,
http://portal.acm.org/citation.cfm?id=1614388},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Most work in sensor networks tries to maximize network lifetime. However, for
many applications the required lifetime is known in advance. Therefore,
application quality should rather be maximized for that given time. Levels, the
approach presented in this article, is a programming abstraction for
energy-aware sensor network applications that helps to meet a user-defined
lifetime goal by deactivating optional functionality. With this programming
abstraction, the application developer defines so-called energy levels.
Functionality in energy levels can be deactivated if the required lifetime
cannot be met otherwise. The runtime system uses data about the energy
consumption of different levels to compute an optimal level assignment that
maximizes each node's quality for the time remaining. In addition, Levels
includes a completely distributed coordination algorithm that balances energy
level assignments and keeps the application quality of the network roughly
constant over time. In this approach, each node computes its schedule based on
those of its neighbors. As the evaluation shows, applications using Levels can
accurately meet given lifetime goals with only small fluctuations in
application quality. In addition, the runtime overhead both for computation and
for communication is negligible.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2009-31&engl=0}
}
@article {ART-2009-27,
author = {Matthias Gauger and Pedro Jos{\'e} Marr{\'o}n and Daniel Kauker and Kurt Rothermel},
title = {{Low Overhead Assignment of Symbolic Coordinates in Sensor Networks}},
journal = {Telecommunication Systems},
publisher = {Springer},
volume = {40},
number = {3-4},
pages = {117--128},
type = {Artikel in Zeitschrift},
month = {April},
year = {2009},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/ART-2009-27/ART-2009-27.pdf,
http://www.springerlink.com/content/b651j055q0m40003/},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Approximate information on the location of nodes in a sensor network is
essential to many types of sensor network applications and algorithms. In many
cases, using symbolic coordinates is an attractive alternative to the use of
geographic coordinates due to lower costs and lower requirements on the
available location information during coordinate assignment. In this paper, we
investigate different possible methods of assigning symbolic coordinates to
sensor nodes. We present a method based on broadcasting coordinate messaging
and filtering using sensor events. We show in the evaluation that this method
allows a reliable assignment of symbolic coordinates while only generating a
low overhead.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2009-27&engl=0}
}
@article {ART-2009-26,
author = {Sven Schulz and Wolfgang Blochinger and Hannes Hannak},
title = {{Capability-Aware Information Aggregation in Peer-to-Peer Grids}},
journal = {Journal of Grid Computing},
address = {Heidelberg},
publisher = {Springer-Verlag},
volume = {7},
number = {2},
pages = {135--167},
type = {Artikel in Zeitschrift},
month = {Januar},
year = {2009},
doi = {10.1007/s10723-008-9114-z},
language = {Englisch},
cr-category = {C.2.1 Network Architecture and Design,
C.2.2 Network Protocols,
C.2.4 Distributed Systems,
C.2.6 Internetworking},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {Information aggregation is the process of summarizing information across the
nodes of a distributed system. We present a hierarchical information
aggregation system tailored for Peer-to-Peer Grids which typically exhibit a
high degree of volatility and heterogeneity of resources. Aggregation is
performed in a scalable yet efficient way by merging data along the edges of a
logical self-healing tree with each inner node providing a summary view of the
information delivered by the nodes of the corresponding subtree. We describe
different tree management methods suitable for high-efficiency and
high-scalability scenarios that take host capability and stability diversity
into account to attenuate the impact of slow and/or unstable hosts. We propose
an architecture covering all three phases of the aggregation process: Data
gathering through a highly extensible sensing framework, data aggregation using
reusable, fully isolated reduction networks, and application-sensitive data
delivery using a broad range of propagation strategies. Our solution combines
the advantages of approaches based on Distributed Hash Tables (DHTs) (i.e.,
load balancing and self-maintenance) and hierarchical approaches (i.e.,
respecting administrative boundaries and resource limitations). Our approach is
integrated into our Peer-to-Peer Grid platform Cohesion. We substantiate its
effectiveness through performance measurements and demonstrate its
applicability through a graphical monitoring solution leveraging our
aggregation system.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2009-26&engl=0}
}
@article {ART-2009-15,
author = {Jorge A. Briones and Boris Koldehofe and Kurt Rothermel},
title = {{SPINE : Adaptive Publish/Subscribe for Wireless Mesh Networks}},
journal = {Studia Informatika Universalis},
publisher = {Hermann},
volume = {7},
number = {3},
pages = {320--353},
type = {Artikel in Zeitschrift},
month = {Oktober},
year = {2009},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/ART-2009-15/ART-2009-15.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Application deployment on Wireless Mesh Networks (WMNs) is a challenging issue.
First it requires communication abstractions that allow for interoperation with
Internet applications and second the offered solution should be sensitive to
the available resources in the underlying network. Loosely coupled
communication abstractions, like publish/subscribe, promote interoperability,
but unfortunately are typically implemented at the application layer without
considering the available resources at the underlay imposing a significant
degradation of application performance in the setting of Wireless Mesh
Networks. In this paper we present SPINE, a content-based publish/subscribe
system, which considers the particular challenges of deploying
application-level services in Wireless Mesh Networks. SPINE is designed to
reduce the overhead which stems from both publications and reconfigurations, to
cope with the inherent capacity limitations on communication links as well as
with mobility of the wireless mesh-clients. We demonstrate the effectiveness of
SPINE by comparison with traditional approaches in implementing content-based
publish/subscribe.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2009-15&engl=0}
}
@article {ART-2009-14,
author = {Bj{\"o}rn Schilling and Udo Pletat and Kurt Rothermel},
title = {{Event Correlation in Heterogeneous Environments}},
journal = {it --- Information Technology -- Complex Event Processing},
publisher = {Oldenbourg Wissenschaftsverlag GmbH},
pages = {270--275},
type = {Artikel in Zeitschrift},
month = {Oktober},
year = {2009},
language = {Deutsch},
cr-category = {C.2.1 Network Architecture and Design,
C.2.4 Distributed Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/ART-2009-14/ART-2009-14.pdf,
http://www.oldenbourg-wissenschaftsverlag.de/olb/de/1.c.1495462.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {The condition and location of a business item are of central interest in many
business applications such as supply chain management, manufacturing, or
ensuring safety and security for people and goods. Recent advances in sensor
technology allow to transmit condition and location information about goods,
materials and people to enterprise software systems in real-time. In this
context, complex event processing is an emerging software technology for
detecting business-relevant situations in streams of events and for providing
these detected situations to various business processes. While currently
complex event processing systems are mostly deployed within a single business
domain at a limited scale, the cooperative nature of business applications
gives reason that complex event processing will soon address multiple business
domains and involve an increasingly large number of business events. In order
to ensure interoperability as well as efficient utilization of processing and
network capability, we motivate the need for heterogeneous correlation
technology in the context of business applications.
In this article we give an overview of the project $\backslash$emph{Distributed
heterogeneous event processing} (DHEP) involving the IBM B{\"o}blingen lab and the
Universit{\"a}t Stuttgart. In particular, we highlight how business applications
can benefit from using event correlation technology in heterogeneous
environments. The key aspects of the project address the deployment of
collections of event correlation rules to a network of heterogeneous event
correlation engines. We give an overview of challenges and possible solutions
for the dynamic configuration of such environments and present our architecture
which supports network-wide cooperation between different correlation engines.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2009-14&engl=0}
}
@article {ART-2008-23,
author = {Oliver P. Waldhorst and Christian Blankenhorn and Dirk Haage and Ralph Holz and Gerald G. Koch and Boris Koldehofe and Fleming Lampi and Christoph P. Mayer and Sebastian Mies},
title = {{Spontaneous Virtual Networks: On the Road Towards the Internet's Next Generation}},
journal = {it --- Information Technology -- Methods and Applications of Informatis and Information Technology},
address = {M{\"u}nchen},
publisher = {Oldenbourg Wissenschaftsverlag GmbH},
volume = {50},
number = {6},
pages = {367--375},
type = {Artikel in Zeitschrift},
month = {Dezember},
year = {2008},
issn = {1611-2776},
doi = {10.1524/itit.2008.0508},
keywords = {SpoVNet; Spontane Virtuelle Netze; Next Generation Internet},
language = {Englisch},
cr-category = {C.2.1 Network Architecture and Design,
C.2.4 Distributed Systems,
C.2.2 Network Protocols,
C.2.6 Internetworking},
contact = {Correspondence address: University of Karlsruhe, Institute of Telematics, Zirkel 2, 76131 Karlsruhe, Deutschland, waldhorst@tm.uka.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Novel Internet applications demand global availability of complex services that
can adapt dynamically to application requirements. At the same time, pervasive
Internet usage and heterogeneous access technologies impose new challenges for
service deployment. We present Spontaneous Virtual Networks (SpoVNet), a
methodology that enables easy development of new services with transparent
support for mobility, multi-homing, and heterogeneous environments. This
article presents the overlay-based architecture of SpoVNet that supports the
spontaneous deployment of new services as well as a seamless transition towards
future networks. SpoVNet´s architecture offers support for the underlay aware
adaptation of overlays by the use of cross-layer information. In the context of
two exemplary services like a group communication service and an event service
as well as two demanding applications – a realtime online game and a video
streaming application – we illustrate how SpoVNet is of value in establishing
services and applications for the Next Generation Internet.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2008-23&engl=0}
}
@article {ART-2008-22,
author = {Klaus Herrmann},
title = {{Self-Organized Service Placement in Ambient Intelligence Environments}},
journal = {ACM Transactions on Autonomous and Adaptive Systems - Special Issue on Ambient Intelligence},
publisher = {ACM},
type = {Artikel in Zeitschrift},
month = {M{\"a}rz},
year = {2008},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Ambient Intelligence (AmI) is an IT concept by which mobile users shall be
seamlessly supported in their every-day activities. This includes interactions
with remote resources as well as with their current physical environment. We
have developed the so-called Ad hoc Service Grid (ASG) infrastructure that
supports the latter form of interactions. It allows operators to cover
arbitrary locations with Ambient Services in a Drop-and-Deploy fashion. An
Ambient Service may autonomously distribute (replicate and migrate) within an
ASG network to optimize its availability, response times, and network usage. In
this paper, we propose a fully decentralized, dynamic, and adaptive service
placement algorithm for AmI environments like the ASG. This algorithm achieves
a coordinated global placement pattern that minimizes the communication costs
without any central controller. It does not even require additional
communication among the replicas. Moreover, placement patterns stabilize if no
changes occur in the environment while replicas still retain their ability to
adapt. Mechanisms for self-organized placement of services are very important
for AmI environments in general since they allow for autonomous adaptations to
dynamic changes and, thus, remove the need for manual (re)configuration of a
running system. We present a detailed evaluation of the algorithm's performance
and compare it with three other algorithms to show its competitiveness.
Furthermore, we discuss how the desired self-organizing behavior emerges from
the interactions of a few simple, local rules that govern the individual
placement decisions. In order to do so, we give an in-depth analysis of a
series of hidden effects that are not directly encoded into the placement
algorithm but stem from its collective dynamics.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2008-22&engl=0}
}
@article {ART-2007-17,
author = {Klaus Herrmann and Gero M{\"u}hl and Michael Jaeger},
title = {{MESHMdl Event Spaces -- A Coordination Middleware for Self-Organizing Applications in Ad hoc Networks}},
journal = {Journal on Pervasive and Mobile Computing - Special Issue on Middleware for Pervasive Computing},
publisher = {Elsevier Science Publishers B. V.},
volume = {3},
number = {4},
pages = {467--487},
type = {Artikel in Zeitschrift},
month = {August},
year = {2007},
issn = {1574-1192},
doi = {http://dx.doi.org/10.1016/j.pmcj.2007.04.003},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
contact = {Please contact me by a href=``mailto:klaus.herrmann@ipvs.uni-stuttgart.de?subject=Paper\%20inquiry''email if you need a copy of this article.},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Mobile ad hoc networks (MANETs) are gaining importance as a promising
technology for flexible, proximity-based, mobile communication. However, the
inherent dynamics of MANETs imposes strong limitations on the design of
distributed applications. They need to be able to adapt to changing conditions
quickly and organize themselves in terms of component placement and
communication habits. In this paper, we present MESHMdl, a middleware that
provides a high level of awareness and decoupling for application components to
make them more flexible and adaptable. We focus on the Event Space as the
central communication medium of MESHMdl. The Event Space offers a simple,
unified communication interface for inter-agent communication as well as for
communication with the middleware and resource access. Furthermore, it serves
as a means for flexibly extending a MESHMdl daemon. We investigate the
performance of the Event Space on different mobile devices and show that it is
superior to comparable systems.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2007-17&engl=0}
}
@article {ART-2007-11,
author = {Lorenzo Alvisi and Jeroen Doumen and Rachid Guerraoui and Boris Koldehofe and Harry Li and Robbert van Renesse and Gilles Tredan},
title = {{How robust are gossip-based communication protocols?}},
journal = {ACM SIGOPS Operating Systems Review},
address = {New York, NY, USA},
publisher = {ACM Press},
volume = {41},
number = {5},
pages = {14--18},
type = {Artikel in Zeitschrift},
month = {Oktober},
year = {2007},
doi = {10.1145/1317379.1317383},
issn = {0163-5980},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems,
D.2.4 Software Engineering Software/Program Verification},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Gossip-based communication protocols are often touted as being robust. Not
surprisingly, such a claim relies on assumptions under which gossip protocols
are supposed to operate. In this paper, we discuss and in some cases expose
some of these assumptions and discuss how sensitive the robustness of gossip is
to these assumptions. This analysis gives rise to a collection of new research
challenges.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2007-11&engl=0}
}
@article {ART-2007-02,
author = {Illya Stepanov and Kurt Rothermel},
title = {{Simulating mobile ad hoc networks in city scenarios}},
journal = {Computer Communications},
publisher = {Elsevier},
volume = {30},
number = {7},
pages = {1466--1475},
type = {Artikel in Zeitschrift},
month = {April},
year = {2007},
keywords = {Communication systems; Geographic information systems; Mobile communication; Modeling; Simulation},
language = {Englisch},
cr-category = {C.2.1 Network Architecture and Design,
C.4 Performance of Systems,
I.6.3 Simulation and Modeling Applications},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Simulation tools are frequently used for the performance evaluations of mobile
ad hoc networks. Currently the tools do not take a spatial environment into
account, thus providing a poor support for urban scenarios. In this paper, we
describe a platform for the modeling of city scenarios. We extend the mostly
used MANET simulator ns-2 by the corresponding mobility and wireless
transmission models. These models have been evaluated against real-world
measurements. By using the tool’s emulation facility, we integrate unmodified
applications and real implementations of network protocols. We demonstrate the
usefulness of the platform by modeling a mobile application in a simulated
environment of Stuttgart downtown. We show that obtained simulation results
differ extensively from those with simpler models.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2007-02&engl=0}
}
@article {ART-2007-01,
author = {Steffen Maier and Daniel Herrscher and Kurt Rothermel},
title = {{Experiences with node virtualization for scalable network emulation}},
journal = {Computer Communications},
publisher = {Elsevier},
volume = {30},
number = {5},
pages = {943--956},
type = {Artikel in Zeitschrift},
month = {M{\"a}rz},
year = {2007},
keywords = {software performance evaluation; network emulation; mobile ad hoc network; scalability; virtual routing},
language = {Englisch},
cr-category = {C.4 Performance of Systems,
D.4.4 Operating Systems Communications Management,
D.4.8 Operating Systems Performance,
I.6.3 Simulation and Modeling Applications},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/ART-2007-01/ART-2007-01.pdf,
http://dx.doi.org/10.1016/j.comcom.2006.08.018},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {During the development of network protocols and distributed applications, their
performance has to be analyzed in appropriate environments. Network emulation
testbeds provide a synthetic, configurable network environment for comparative
performance measurements of real implementations. Realistic scenarios have to
consider hundreds of communicating nodes. Common network emulation approaches
limit the number of nodes in a scenario to the number of computers in an
emulation testbed. To overcome this limitation, we introduce a virtual node
concept for network emulation. The key problem for node virtualization is a
transparent, yet efficient separation of node resources. In this paper, we
provide a brief survey of candidate node virtualization approaches to
facilitate scalable network emulation. Based on the gathered insights, we
propose a lightweight virtualization solution to achieve maximum scalability
and discuss the main points regarding its implementation. We present extensive
evaluations that show the scalability and transparency of our approach in both
a traditional wired infrastructure-based, and in two wireless ad hoc network
emulation scenarios. The measurements indicate that our solution can push the
upper limit of emulation scenario sizes by a factor of 10--28. Given our
emulation testbed consisting of 64 computers, this translates to possible
scenario sizes of up to 1792 nodes. In addition to the evaluation of our
virtualization approach, we discuss key concepts for controlling comprehensive
emulation scenarios to support scalability of our system as a whole.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2007-01&engl=0}
}
@article {ART-2006-20,
author = {Christian Becker and Frank D{\"u}rr and Mirko Knoll and Daniela Nicklas and Torben Weis},
title = {{Entwicklung ortsbezogener Anwendungen}},
journal = {Praxis der Informationsverarbeitung und Kommunikation (PIK)},
editor = {Hans G. Kruse},
publisher = {K. G. Saur Verlag},
volume = {29},
number = {1},
pages = {30--36},
type = {Artikel in Zeitschrift},
month = {Januar},
year = {2006},
doi = {10.1515/PIKO.2006.30},
keywords = {ortsbezogene Dienste; Anwendungsentwicklung},
language = {Deutsch},
cr-category = {D.2.2 Software Engineering Design Tools and Techniques},
contact = {Torben Weis torben.weis@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme;
Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Anwendersoftware},
abstract = {Ortsbezogene Anwendungen versorgen Benutzer mit Diensten und Informationen in
Abh{\"a}ngigkeit ihrer aktuellen Position. Beispiele sind im Bereich der
Telematikdienste, Touristenf{\"u}hrer und Informationsdienste zu finden.
Anwendungen k{\"o}nnen sich an den Ort oder ganz allgemein an den Kontext des
Benutzers anpassen, indem sie ortsspezifische Informationen anzeigen oder Daten
der jeweiligen Situation entsprechend pr{\"a}sentieren. Es existieren verschieden
Ans{\"a}tze und Architekturen, um ortsbezogene Anwendungen zu realisieren. In
diesem Beitrag stellen wir unterschiedliche Ans{\"a}tze vor, diskutieren deren Vor-
und Nachteile und leiten daraus ein abstraktes Anwendungsmodell f{\"u}r
ortsbezogene Anwendungen ab. Des Weiteren stellen wir Entwicklungswerkzeuge
vor, die wir auf Basis dieses Anwendungsmodells konzipiert haben. Die
Kombination aus Anwendungsmodell und spezialisierten Werkzeugen wird die
Entwicklung ortsbezogener Anwendungen systematisieren und wesentlich
vereinfachen.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2006-20&engl=0}
}
@article {ART-2006-13,
author = {Kurt Rothermel and Thomas Ertl and Fritsch Dieter and Paul J. K{\"u}hn and Bernhard Mitschang and Engelbert Westk{\"a}mper and Christian Becker and Dominique Dudkowski and Andreas Gutscher and Christian Hauser and Lamine Jendoubi and Daniela Nicklas and Steffen Volz and Matthias Wieland},
title = {{SFB 627 – Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme}},
journal = {Informatik - Forschung und Entwicklung},
publisher = {Springer-Verlag},
volume = {21},
number = {1-2},
pages = {105--113},
type = {Artikel in Zeitschrift},
month = {Juni},
year = {2006},
language = {Deutsch},
cr-category = {C.2.4 Distributed Systems,
H.2.4 Database Management Systems,
H.2.8 Database Applications,
H.3 Information Storage and Retrieval},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/ART-2006-13/ART-2006-13.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Anwendersoftware;
Universit{\"a}t Stuttgart, Institut f{\"u}r Industrielle Fertigung und Fabrikbetrieb (IFF);
Universit{\"a}t Stuttgart, Institut f{\"u}r Visualisierung und Interaktive Systeme, Visualisierung und Interaktive Systeme;
Universit{\"a}t Stuttgart, Institut f{\"u}r Photogrammetrie (ifp);
Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme;
Universit{\"a}t Stuttgart, Institut f{\"u}r Kommunikationsnetze und Rechnersysteme (IKR)},
abstract = {Computersysteme, wie wir sie heute kennen, passen sich typischerweise nicht an
den Benutzer und dessen Situation an. Erste Beispiele von Systemen, die durch
den Bezug zur Realwelt den Kontext des Benutzers einbeziehen, sind
Navigationssysteme, die unter Ber{\"u}cksichtigung der Position eines Benutzers und
der Verkehrslage Richtungsanweisungen geben k{\"o}nnen. Damit innovative
kontextbezogene Anwendungen m{\"o}glich werden, muss der Kontext, also der Zustand
der Realwelt, durch Sensoren erfasst, in das Computersystem {\"u}bermittelt und
dort in Form dynamischer Umgebungsmodelle den Anwendungen zur Verf{\"u}gung
gestellt werden.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2006-13&engl=0}
}
@article {ART-2006-12,
author = {Illya Stepanov and Kurt Rothermel},
title = {{On the impact of a more realistic physical layer on MANET simulations results}},
journal = {Ad Hoc Networks. To appear.},
publisher = {Elsevier},
pages = {1--1},
type = {Artikel in Zeitschrift},
month = {September},
year = {2006},
doi = {10.1016/j.adhoc.2006.08.001},
keywords = {Communication systems; Mobile communication; UHF propagation; Geographic information systems; Simulation},
language = {Englisch},
cr-category = {C.2.1 Network Architecture and Design,
C.4 Performance of Systems,
I.6.3 Simulation and Modeling Applications},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/ART-2006-12/ART-2006-12.pdf,
http://dx.doi.org/10.1016/j.adhoc.2006.08.001},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Network simulation tools are frequently used to analyze the performance of
MANET protocols and applications. Currently they offer only simple wireless
communication models that neglect many radio propagation effects. In this
paper, we integrate a more realistic physical layer model into a simulation
tool. It consists of a radio propagation model and a model of wireless
transmission errors. They have been evaluated against real-world measurements.
We prove that such more realistic models change simulation results
considerably. To the best of our knowledge, no other study of MANETs has been
performed so far with such a detailed physical layer model. Hence, this paper
also gives new insights on the performance of MANETs in real outdoor
environments.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2006-12&engl=0}
}
@article {ART-2006-01,
author = {Audun J{\o}sang and Elizabeth Gray and Michael Kinateder},
title = {{Simplification and Analysis of Transitive Trust Networks}},
journal = {Web Intelligence and Agent Systems: An International Journal},
address = {Amsterdam, The Netherlands},
publisher = {IOS Press},
volume = {4},
number = {2},
pages = {139--161},
type = {Artikel in Zeitschrift},
month = {Mai},
year = {2006},
issn = {1570-1263},
keywords = {trust, reputation, transitive, transitivity, trust-graph, trust-chains},
language = {Englisch},
cr-category = {J.4 Social and Behavioral Sciences,
C.2.4 Distributed Systems,
H.3.5 Online Information Services},
ee = {http://unitec.informatik.uni-stuttgart.de},
contact = {Michael Kinateder Kinateder@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {When transacting and interacting through open computer networks, traditional
methods used in the physical world for establishing trust can no longer be
used. Creating virtual network substitutes with which people, organizations and
software agents can derive trust in other parties requires computerized
analysis of the underlying trust networks. This article describes an approach
to trust network analysis using subjective logic (TNA-SL), that consists of the
three following elements. Firstly it uses a concise notation with which trust
transitivity and parallel combination of trust paths can be expressed. Secondly
it defines a method for simplifying complex trust networks so that they can be
expressed in this concise form. Finally it allows trust measures to be
expressed as beliefs, so that derived trust can be automatically and securely
computed with subjective logic. We compare our approach with trust derivation
algorithms that are based on normalization such as PageRank and EigenTrust. We
also provide a numerical example to illustrates how TNA-SL can be applied.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2006-01&engl=0}
}
@article {ART-2005-19,
author = {Christian Becker and Frank D{\"u}rr},
title = {{On Location Models for Ubiquitous Computing}},
journal = {Personal and Ubiquitous Computing},
publisher = {Springer-Verlag},
volume = {9},
number = {1},
pages = {20--31},
type = {Artikel in Zeitschrift},
month = {Januar},
year = {2005},
keywords = {Location Model; Umgebungsmodell, Ubiquitous Computing; Context-aware Computing; Location-based Services},
language = {Englisch},
cr-category = {H.0 Information Systems General},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/ART-2005-19/ART-2005-19.pdf,
http://www.springerlink.com/content/7qjyl3g9hly15ky2/},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Common queries regarding information processing in ubiquitous computing are
based on the location of physical objects. No matter if the next printer, next
restaurant, or friend is searched for, a notion of distances between objects is
required. A search for all objects in a certain geographic area requires the
possibility to define spatial ranges and spatial inclusion of locations. In
this paper we discuss general properties of symbolic and geometric coordinates.
Based on that, we present an overview of existing location models allowing for
position, range, and nearest neighbor queries. The location models are
classified according to their suitability with respect to the query processing
and the involved modeling effort along with other requirements. Besides an
overview of existing location models and approaches the classification of
location models with respect to application requirements can assist developers
in their design decisions.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2005-19&engl=0}
}
@article {ART-2005-08,
author = {Marcus Handte and Christian Becker and Kurt Rothermel},
title = {{Peer-based Automatic Configuration of Pervasive Applications}},
journal = {Journal of Pervasive Computing and Communications},
publisher = {Troubadour Publishing},
volume = {1},
number = {4},
pages = {251--264},
type = {Artikel in Zeitschrift},
month = {Dezember},
year = {2005},
language = {Englisch},
cr-category = {C.2 Computer-Communication Networks,
D.2 Software Engineering,
D.3 Programming Languages},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Pervasive Computing envisions seamless support for user tasks through
cooperating devices that are present in an environment. Fluctuating
availability of devices, induced by mobility and failures, requires mechanisms
and algorithms that allow applications to adapt to their ever-changing
execution environments without user intervention. To ease the development of
adaptive applications, Becker et al. [3] have proposed the peer-based component
system PCOM. This system provides fundamental mechanisms to support the
automated composition of applications at runtime. In this article, we discuss
the requirements on algorithms that enable automatic configuration of pervasive
applications. Furthermore, we show how finding a configuration can be
interpreted as Distributed Constraint Satisfaction Problem. Based on this, we
present an algorithm that is capable of finding an application configuration in
the presence of strictly limited resources. To show the feasibility of this
algorithm, we present an evaluation based on simulations and real-world
measurements and we compare the results with a simple greedy approximation.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2005-08&engl=0}
}
@article {ART-2005-06,
author = {Pedro Jos{\'e} Marr{\'o}n and Andreas Lachenmann and Daniel Minder and Matthias Gauger and Olga Saukh and Kurt Rothermel},
title = {{Management and configuration issues for sensor networks}},
journal = {International Journal of Network Management},
publisher = {John Wiley \& Sons, Inc.},
volume = {15},
number = {4},
pages = {235--253},
type = {Artikel in Zeitschrift},
month = {Juli},
year = {2005},
isbn = {1099-1190},
keywords = {wireless sensor network; self-organization; code distribution},
language = {Englisch},
cr-category = {C.2.3 Network Operations,
C.2.1 Network Architecture and Design},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/ART-2005-06/ART-2005-06.pdf,
http://www.interscience.wiley.com},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {In this paper, we define three of the key issues that need to be solved in
order to provide efficient management and configuration of applications and
system software in sensor networks: the distribution and management of roles
within the network, efficient code distribution algorithms, and efficient
on-the-fly code update algorithms for sensor networks. The first issue is
motivated by the increasing heterogeneity of sensor network applications and
their need for more complex (nonhomogeneous) network topologies and structures.
The second one is motivated by the intrinsic energy constraint issues and, in
general, the resource limitation of sensor networks. Finally, the third one is
needed due to the nature of monitoring applications and optimization needs from
applications that should be able to efficiently incorporate code updates so
that the network can adapt to its surroundings on the fly. In this paper we
present related work and some results for each of these issues as we have dealt
with them within the TinyCubus project.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2005-06&engl=0}
}
@article {ART-2005-05,
author = {Pedro Jos{\'e} Marr{\'o}n and Daniel Minder and Andreas Lachenmann and Kurt Rothermel},
title = {{TinyCubus: An Adaptive Cross-Layer Framework for Sensor Networks}},
journal = {it - Information Technology},
publisher = {Oldenbourg Verlag},
volume = {47},
number = {2},
pages = {87--97},
type = {Artikel in Zeitschrift},
month = {April},
year = {2005},
isbn = {1611-2776},
keywords = {wireless sensor network; system architecture; adaptation; framework; code distribution; cross-layer},
language = {Englisch},
cr-category = {C.2.1 Network Architecture and Design,
C.2.2 Network Protocols,
D.4.7 Operating Systems Organization and Design},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/ART-2005-05/ART-2005-05.pdf,
http://www.it-inftech.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {With the proliferation of sensor networks and sensor network applications, the
overall complexity of such systems is continuously increasing. Sensor networks
are now heterogeneous in terms of their hardware characteristics and
application requirements even within a single network. In addition, the
requirements of currently supported applications are expected to change over
time. All of this makes developing, deploying, and optimizing sensor network
applications an extremely difficult task. In this paper, we present the
architecture of TinyCubus, a flexible and adaptive cross-layer framework for
TinyOS-based sensor networks that aims at providing the necessary
infrastructure to cope with the complexity of such systems. TinyCubus consists
of a cross-layer framework that enables optimizations through cross-layer
interactions, a configuration engine that distributes components efficiently by
considering the roles of the sensor nodes and provides support to install
components dynamically, and a data management framework that selects and adapts
both system and data management components. Finally, relevant research
challenges associated with the development of each framework are identified and
discussed in the paper.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2005-05&engl=0}
}
@article {ART-2005-03,
author = {Audun J{\o}sang and Elizabeth Gray and Michael Kinateder},
title = {{Simplification and Analysis of Transitive Trust Networks}},
journal = {Web Intelligence and Agent Systems: An International Journal},
address = {Amsterdam, The Netherlands},
publisher = {IOS Press},
pages = {1--1},
type = {Artikel in Zeitschrift},
month = {September},
year = {2005},
issn = {1570-1263},
keywords = {trust, reputation, transitive, transitivity, trust-graph, trust-chains},
language = {Englisch},
cr-category = {J.4 Social and Behavioral Sciences,
C.2.4 Distributed Systems,
H.3.5 Online Information Services},
ee = {http://unitec.informatik.uni-stuttgart.de},
contact = {Michael Kinateder Kinateder@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {When transacting and interacting through open computer networks, traditional
methods used in the physical world for establishing trust can no longer be
used. Creating virtual network substitutes with which people, organisations and
software agents can derive trust in other parties requires computerised
analysis of the underlying trust networks. This article describes an approach
to trust network analysis using subjective logic (TNA-SL), that consists of the
three following elements. Firstly it uses a concise notation with which trust
transitivity and parallel combination of trust paths can be expressed. Secondly
it defnes a method for simplifying complex trust networks so that they can be
expressed in this concise form. Finally it allows trust measures to be
expressed as beliefs, so that derived trust can be automatically and securely
computed with subjective logic. We compare our approach with trust derivation
algorithms that are based on normalisation such as PageRank and EigenTrust. We
also provide a numerical example to illustrates how TNA-SL can be applied.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2005-03&engl=0}
}
@article {ART-2005-02,
author = {Michael Kinateder and Ralf Terdic and Kurt Rothermel},
title = {{Trusting Pseudonyms – Anonymous Communication in Peer-to-Peer Reputation Systems}},
journal = {International Journal for Infonomics},
publisher = {e-Centre for Infonomics},
pages = {1--1},
type = {Artikel in Zeitschrift},
month = {September},
year = {2005},
isbn = {ISSN 1742-4720},
keywords = {privacy, anonymous communication, pseudonyms, extended destination routing, Chaum mixes, mix-cascade, onion routing, distributed hash table, Chord},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems,
E.3 Data Encryption,
K.4 Computers and Society},
ee = {http://unitec.informatik.uni-stuttgart.de/,
http://www.i-journal.org.uk/Special-issues/Special-Issues.htm},
contact = {Michael Kinateder kinateder@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {In this paper we present a novel approach to enable untraceable communication
between pseudonyms. Our work provides strong sender and recipient anonymity by
eliminating the need to know of each other’s address.
We use a variation of Chaum mixes to achieve unlinkability between sender and
recipient and introduce a concept called extended destination routing (EDR)
which relies on routing headers constructed in multiple layers of encryption
and published in a distributed hash table (DHT). In order to communicate, a
sender requests from the DHT the recipient’s routing header, which is extended
and used for routing the message via a mix cascade to this recipient.
This work was performed in the context of the UniTEC reputation system and
describes the functionality of its anonymous communication layer, which is
completely independent of the other UniTEC layers. Although trust and
reputation systems in general are typical application areas for our
contribution, the presented concepts are suitable for various other application
areas as well. We have implemented a prototype of UniTEC and present results
from an ongoing evaluation in our network emulation testbed.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2005-02&engl=0}
}
@article {ART-2003-04,
author = {Kurt Rothermel and Martin Bauer and Christian Becker},
title = {{SFB 627 - ``Nexus'' Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme}},
journal = {it - Information Technology},
editor = {Paul Molitor and Klaus K{\"u}spert and Kurt Rothermel},
address = {M{\"u}nchen},
publisher = {Oldenbourg Wissenschaftsverlag GmbH},
volume = {45},
number = {5},
pages = {293--300},
type = {Artikel in Zeitschrift},
month = {Oktober},
year = {2003},
keywords = {ubiquitous computing; spatial world models; Umgebungsmodelle; context-awareness; kontext-bezogene Systeme; Nexus},
language = {Deutsch},
cr-category = {C.2.4 Distributed Systems,
H.2.4 Database Management Systems,
H.2.8 Database Applications,
H.3.4 Information Storage and Retrieval Systems and Software},
ee = {http://www.nexus.uni-stuttgart.de},
contact = {kurt.rothermel@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Die Entwicklungen im Bereich der Sensortechnologie erlauben eine zunehmende
Miniaturisierung von Sensorplattformen. Diese k{\"o}nnen in Alltagsgegenst{\"a}nde
integriert werden und Umgebungsinformationen durch drahtlose Kommunikation
bereitstellen. F{\"u}hrt man die erfassten Sensordaten zusammen und ordnet diese
Informationen Orten in r{\"a}umlichen Modellen zu, entstehen Umgebungsmodelle. Die
Erforschung von Methoden und Verfahren f{\"u}r die Erstellung, das Management und
die Nutzung der F{\"o}deration solcher Umgebungsmodelle ist Ziel des
Sonderforschungsbereichs 627 an der Universit{\"a}t Stuttgart.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2003-04&engl=0}
}
@article {ART-2002-05,
author = {Christian Hauser and Alexander Leonhardi and Paul J. K{\"u}hn},
title = {{Sicherheitsaspekte in Nexus - einer Plattform f{\"u}r ortsbezogene Anwendungen}},
journal = {it+ti, Zeitschrift f{\"u}r Informationstechnik und Technische Informatik},
address = {M{\"u}nchen},
publisher = {Oldenbourg},
volume = {5},
pages = {268--277},
type = {Artikel in Zeitschrift},
month = {Oktober},
year = {2002},
isbn = {0944-2774},
language = {Deutsch},
cr-category = {H Information Systems},
ee = {www.nexus.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme;
Universit{\"a}t Stuttgart, Institut f{\"u}r Kommunikationsnetze und Rechnersysteme (IKR)},
abstract = {abstract},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2002-05&engl=0}
}
@article {ART-2002-04,
author = {Martin Bauer and Christian Becker and Kurt Rothermel},
title = {{Location Models from the Perspective of Context-Aware Applications Mobile Ad Hoc Networks}},
journal = {Personal and Ubiquitous Computing},
address = {London},
publisher = {Springer-Verlag},
volume = {6},
number = {5-6},
pages = {322--328},
type = {Artikel in Zeitschrift},
month = {Dezember},
year = {2002},
issn = {1617-4909},
keywords = {context-awareness; location models; ubiquitous computing; MANET; Nexus},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems,
D.2.12 Software Engineering Interoperability,
H.2.3 Database Management Languages},
ee = {http://link.springer.de/link/service/journals/00779/bibs/2006005/20060322.htm,
http://www.nexus.uni-stuttgart.de},
contact = {Martin Bauer Martin.Bauer@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {Location models are crucial for providing location-dependent data to
context-aware applications. In this paper, we present two approaches for
modeling location information taken from an infrastructure-based and an ad hoc
network-based application scenario. From these approaches we derive
requirements for a general location modeling language for ubiquitous computing.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2002-04&engl=0}
}
@article {ART-2002-01,
author = {Christian Maih{\"o}fer and Kurt Rothermel},
title = {{Optimal Branching Factor for Tree-based Reliable Multicast Protocols}},
journal = {Computer Communications},
editor = {Elsevier},
publisher = {Elsevier},
type = {Artikel in Zeitschrift},
month = {Januar},
year = {2002},
language = {Englisch},
cr-category = {C.2 Computer-Communication Networks},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/ART-2002-01/ART-2002-01.pdf,
ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/ART-2002-01/ART-2002-01.ps},
contact = {christian.maihoefer@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {In recent years, many reliable multicast protocols on transport layer have been
proposed. Previous analysis and simulation studies gave evidence for the
superiority of tree-based approaches in terms of throughput and bandwidth
requirements.
In many tree-based protocols, the nodes of the tree are formed of multicast
group members. In this case, the branching factor, i.e. the maximum number of
child nodes is adjustable. In this paper we analyze the influence of the
branching factor on a protocol's throughput and bandwidth consumption. This
knowledge is important to configure protocols for best performance and to
optimize the tree creation process.
Our results show that the optimal branching factor depends mainly on the
probability for receiving messages from other local groups. If local groups are
assigned to a separate multicast address, the optimal branching factor is
small. On the other hand, if TTL scoping is used and therefore the probability
for receiving messages from other local groups is greater than zero, larger
local groups provide better performance.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2002-01&engl=0}
}
@article {ART-2001-14,
author = {Tobias Drosdol and Christoph Ruffner},
title = {{Infobox: Virtual Information Towers}},
journal = {GIS Geo-Informations-Systeme},
address = {Heidelberg},
publisher = {Herbert Wichmann Verlag},
volume = {6},
pages = {18--19},
type = {Artikel in Zeitschrift},
month = {September},
year = {2001},
keywords = {Nexus, VIT, ViLiS},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems,
H.3.3 Information Search and Retrieval},
contact = {Tobias Drosdol Tobias.Drosdol@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {The VIT System is an early prototype developed within the context of the NEXUS
project for demonstrating location-based information access. One important
issue when designing an application is to find a suitable concept for user
interaction. Information has to be shown in an intuitive way so that everyone
can handle the system and understands what is going on. Therefore an easily
understandable metaphor for visualizing the information is needed.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2001-14&engl=0}
}
@article {ART-2001-12,
author = {Alexander Leonhardi and Kurt Rothermel},
title = {{A Comparison of Protocols for Updating Location Information}},
journal = {Baltzer Cluster Computing Journal},
publisher = {Baltzer Science Publishers},
volume = {4},
number = {4},
pages = {355--367},
type = {Artikel in Zeitschrift},
month = {Januar},
year = {2001},
language = {Englisch},
cr-category = {H Information Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/ART-2001-12/ART-2001-12.pdf,
www.nexus.uni-stuttgart.de,
http://dx.doi.org/10.1023/A:1011872831932},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {k.A.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2001-12&engl=0}
}
@article {ART-2001-10,
author = {Peter Coschurba and Martin Bauer},
title = {{Infobox: GeoCast}},
journal = {GIS Geo-Informations-Systeme},
address = {Heidelberg},
publisher = {Herbert Wichmann Verlag},
volume = {6},
pages = {34--34},
type = {Artikel in Zeitschrift},
month = {September},
year = {2001},
keywords = {Nexus, geographic communication, geographic addressing, GeoCast},
language = {Englisch},
cr-category = {C.2.0 Computer-Communication Networks, General,
C.2.2 Network Protocols},
ee = {http://www.nexus.uni-stuttgart.de},
contact = {Martin Bauer mabauer@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {If we look at the means of communication that human beings use, we find that
there are different categories of how we determine the receiver of a message.
If we speak, everyone who is at the same location will get the message. If we
write a letter, we address someone specific and only that person will get the
message. Finally, if we publish something, then everyone who is interested in
it can get that information. These ways of communication are also reflected in
the Internet. We can send messages to a specific receiver using unicast. If we
use multicast, everyone who is interested in the information can tune into the
group and receive the messages. Finally, as an equivalent to speech, which is a
location-specific way of communication, we find GeoCast.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2001-10&engl=0}
}
@article {ART-2001-09,
author = {Martin Bauer},
title = {{Infobox: Spatial Events}},
journal = {GIS Geo-Informations-Systeme},
address = {Heidelberg},
publisher = {Herbert Wichmann Verlag},
volume = {6},
pages = {29--29},
type = {Artikel in Zeitschrift},
month = {September},
year = {2001},
keywords = {Nexus, Event, Spatial Event, Event Service, Location, Location Service},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems,
H.3.3 Information Search and Retrieval,
H.3.4 Information Storage and Retrieval Systems and Software},
ee = {http://www.nexus.uni-stuttgart.de},
contact = {Martin Bauer mabauer@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {When looking at typical Nexus scenarios, we observe that they are very
different from those we find in traditional desktop computing scenarios. The
focus of the user is often on other tasks, e.g. walking around, talking to
other people, trying to find something etc. In order to optimally support the
user in these situations, the application has to be more proactive, which can
be achieved with the support of spatial events.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2001-09&engl=0}
}
@article {ART-2001-08,
author = {Alexander Leonhardi and Martin Bauer},
title = {{Managing Highly Dynamic Location Data}},
journal = {GIS Geo-Informations-Systeme},
address = {Heidelberg},
publisher = {Herbert Wichmann Verlag},
volume = {6},
pages = {26--28},
type = {Artikel in Zeitschrift},
month = {September},
year = {2001},
keywords = {Nexus, Location, Location Service},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems,
H.3.3 Information Search and Retrieval,
H.3.4 Information Storage and Retrieval Systems and Software},
ee = {http://www.nexus.uni-stuttgart.de},
contact = {Martin Bauer mabauer@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {Managing the location information of mobile objects is an important aspect of
location-aware applications. Because of their highly dynamic nature, there is a
special component inside the Nexus platform that is designed especially for
this task. The functionality and architecture of the Nexus Location Service are
described in this article.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2001-08&engl=0}
}
@article {ART-2001-06,
author = {Matthias Gro{\ss}mann and Alexander Leonhardi and Bernhard Mitschang and Kurt Rothermel},
title = {{A World Model for Location-Aware Systems}},
journal = {Informatik},
publisher = {Schweizerischer Verband der Informatikorganisationen SVI/FSI},
volume = {8},
number = {5},
pages = {22--25},
type = {Artikel in Zeitschrift},
month = {Oktober},
year = {2001},
keywords = {Mobile Computing; Location-Aware Applications; Augmented World Model},
language = {Englisch},
cr-category = {H.2.3 Database Management Languages,
H.3.4 Information Storage and Retrieval Systems and Software},
ee = {http://www.nexus.uni-stuttgart.de},
contact = {matthias.grossmann@informatik.uni-stuttgart.de, alexander.leonhardi@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme;
Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Anwendersoftware},
abstract = {Advanced location-aware applications require a detailed model of the real
world. The goal of the Nexus platform is to provide such a model together with
generic functionality to a wide variety of location-aware applications. In this
paper, we describe the characteristics of this Augmented World Model and the
architecture of the Nexus platform. We look in more detail at the two main
components responsible for the main aspects of the world model, namely the
spatial data and the position information of mobile objects.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2001-06&engl=0}
}
@article {ART-2001-05,
author = {Cora Burger and Kurt Rothermel},
title = {{A framework to support teaching in the area of distributed systems}},
journal = {acm Journal on Educational Resources in Computing (JERIC)},
publisher = {acm digital library},
volume = {1},
type = {Artikel in Zeitschrift},
month = {M{\"a}rz},
year = {2001},
isbn = {1531-4278},
keywords = {Teachware; simulation; animation applet},
language = {Englisch},
cr-category = {C.2.2 Network Protocols,
H.5.1 Multimedia Information Systems,
I.6.8 Types of Simulation,
K.3.1 Computer Uses in Education},
contact = {caburger@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {Computer networks and distributed systems are characterized by highly dynamic,
concurrent and complex processes. Thus, training in this area requires great
effort from both teachers and learners. Teachers are unsatisfied with available
methods for presentation, explanation and exercises. They are looking for more
adequate ones to better support learners. We have developed an architecture
called HiSAP (Highly interactive Simulation of Algorithms and Protocols). It
consists of a framework to build simulations and generate applets from formally
specified algorithms or protocols. By modifying this specification and
observing the resulting behavior, teaching and learning in a constructive
manner is enabled. The framework is open to plug-in tools to show different
aspects of this behavior. We present results of some experiments concerning the
usage of HiSAP during three different lectures about distributed systems and
computer networks for graduate students.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2001-05&engl=0}
}
@article {ART-2001-03,
author = {Uwe Kubach and Kurt Rothermel},
title = {{Ein Hoarding-Verfahren f{\"u}r ortsbezogene Informationen}},
journal = {Informatik - Forschung und Entwicklung},
publisher = {Springer, to appear},
type = {Artikel in Zeitschrift},
month = {Januar},
year = {2001},
language = {Deutsch},
cr-category = {H Information Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {Mit der zunehmenden Verbreitung mobiler Endger{\"a}te w{\"a}chst auch der Bedarf in
mobilen Umgebungen auf entfernt gespeicherte Informationen zuzugreifen. Da
dieser Informationszugriff meist {\"u}ber drahtlose Netzwerke erfolgt, treten in
mobilen Informationssystemen h{\"a}ufig Probleme, wie geringe Bandbreite, gro{\ss}e
Verz{\"o}gerungen oder Verbindungsausf{\"a}lle auf. Hoarding-Verfahren versuchen diese
Probleme zu l{\"o}sen, indem sie Informationen, auf die der Benutzer
voraussichtlich zugreifen wird, im voraus {\"u}bertragen. Dazu m{\"u}ssen sie jedoch
vorhersagen, welche Informationen der Benutzer ben{\"o}tigen wird. In diesem
Beitrag stellen wir ein Hoarding-Verfahren vor, das f{\"u}r diese Vorhersage die
Ortsabh{\"a}ngigkeit von Informationszugriffen ausnutzt. Wie wir durch Simulationen
zeigen, wird der Speicherplatz auf dem Endger{\"a}t dadurch sehr effizient genutzt.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2001-03&engl=0}
}
@article {ART-2001-02,
author = {Peter Coschurba and Joachim Baumann and Uwe Kubach and Alexander Leonhardi},
title = {{Metaphors for Context-Aware Information Access}},
journal = {Springer Personal Technologies Journal},
publisher = {Springer},
volume = {5},
number = {1},
pages = {16--19},
type = {Artikel in Zeitschrift},
month = {Januar},
year = {2001},
language = {Deutsch},
cr-category = {H Information Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {(not available)},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2001-02&engl=0}
}
@article {ART-2001-01,
author = {Juergen Hauser and Frank Scholze},
title = {{Integration und Verarbeitung Multimedialer Dokumente in Digitalen Bibliotheken - Der MAVA-Ansatz}},
journal = {In B.I.T. online Zeitschrift f{\"u}r Bibliothek, Information und Technologie},
address = {Karlsruhe},
publisher = {Dinges \& Frick GmbH - B.I.T. online},
volume = {4},
number = {1},
pages = {35--41},
type = {Artikel in Zeitschrift},
month = {M{\"a}rz},
year = {2001},
isbn = {1435-7607},
keywords = {digital libraries; multimedia documents; presentation systems},
language = {Deutsch},
cr-category = {H Information Systems},
contact = {juergen.hauser@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {Ohne Inhalt},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2001-01&engl=0}
}
@article {ART-2000-07,
author = {Steffen Volz and Monika Sester and Dieter Fritsch and Alexander Leonhardi},
title = {{Multi-Scale Data Sets in Distributed Environments}},
journal = {International Archives of Photogrammetry and Temote Sensing},
address = {Amsterdam},
publisher = {k.A.},
volume = {33},
number = {Part B4},
type = {Artikel in Zeitschrift},
month = {Januar},
year = {2000},
language = {Englisch},
cr-category = {H Information Systems},
ee = {www.nexus.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme;
Universit{\"a}t Stuttgart, Institut f{\"u}r Photogrammetrie (ifp)},
abstract = {k.A.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2000-07&engl=0}
}
@article {ART-2000-05,
author = {A. Hagin and G. Dermler and K. Rothermel and G. Shchemelev},
title = {{Distributed Multimedia Application Configuration Management}},
journal = {IEEE Journal on Parallel and Distributed Systems},
publisher = {IEEE},
volume = {11},
number = {7},
type = {Artikel in Zeitschrift},
month = {Juli},
year = {2000},
language = {Englisch},
cr-category = {H Information Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {(not available)},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2000-05&engl=0}
}
@article {ART-2000-04,
author = {Wolfgang Theilmann and Kurt Rothermel},
title = {{Optimizing the Dissemination of Mobile Agents for Distibuted Information Filtering}},
journal = {IEEE Concurrency},
publisher = {IEEE},
volume = {8},
number = {2},
type = {Artikel in Zeitschrift},
month = {April},
year = {2000},
language = {Englisch},
cr-category = {H Information Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {(not available)},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2000-04&engl=0}
}
@article {ART-2000-03,
author = {Kurt Rothermel and Wolfgang Theilmann},
title = {{Effiziente Informationssuche im Internet mit Hilfe mobiler Programme}},
journal = {Informatik - Forschung und Entwicklung},
publisher = {not available},
volume = {15},
number = {4},
type = {Artikel in Zeitschrift},
month = {Januar},
year = {2000},
language = {Deutsch},
cr-category = {H Information Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {(not available)},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2000-03&engl=0}
}
@article {ART-2000-02,
author = {K. Rothermel and A. Hagin},
title = {{Distributed Multimeda Application Configuration Management}},
journal = {IEEE Transactions on Parallel and Distributed Systems (TPDS)},
publisher = {IEEE},
volume = {11},
number = {7},
type = {Artikel in Zeitschrift},
month = {Januar},
year = {2000},
language = {Englisch},
cr-category = {H Information Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {(not available)},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2000-02&engl=0}
}
@article {ART-1999-01,
author = {Wolfgang Becker and Cora Burger and J{\"u}rgen Klarmann and Ottokar Kulendik and Frank Schiele and Kerstin Schneider},
title = {{Rechnerunterst{\"u}tzung f{\"u}r Interaktionen zwischen Menschen: Begriffskl{\"a}rung, Anwendungsgebiete und Basiswerkzeuge.}},
journal = {Informatik Spektrum},
publisher = {Springer-Verlag},
volume = {22},
number = {6},
pages = {422--435},
type = {Artikel in Zeitschrift},
month = {Dezember},
year = {1999},
keywords = {CSCW, Groupware, Teleteaching, Workflow-Management, Elektronischer Handel},
language = {Deutsch},
cr-category = {H.4.3 Information Systems Applications Communications Applications},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Anwendersoftware;
Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {Die Rechnerunterst{\"u}tzung von Interaktionen zwischen Menschen wird in
unterschiedlichen Forschungsgebieten untersucht. Das f{\"u}hrt zu einer
vielf{\"a}ltigen, {\"u}berlappenden Begriffsbildung unter den Disziplinen. Die dadurch
bedingte Begriffsverwirrung behindert fach{\"u}bergreifende gemeinsame Entwicklung,
Standardisierung und Wieder- / Weiterverwendung von Ergebnissen. Im folgenden
werden daher breit verwendete Grundbegriffe wie CSCW, Kooperation, Konkurrenz,
Koordination, Kommunikation, Groupware, Workflow-Management, Teleteaching und
Elektronischer Markt geeignet geordnet. Schwerpunkte liegen dabei auf den
m{\"o}glichen Anwendungsgebieten sowie auf den durch Rechner unterst{\"u}tzten
technischen Grundinteraktionen. Damit soll der Beitrag Anwendern und
Entwicklern helfen, f{\"u}r konkrete Anwendungsprobleme Anforderungen ermitteln zu
k{\"o}nnen und Grundelemente in existierenden komplexen Systemen zu identifizieren.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-1999-01&engl=0}
}
@article {ART-1998-09,
author = {K. Rothermel and M. Schwehm},
title = {{Mobile Agents}},
journal = {Encyclopedia for Computer Science and Technology},
editor = {A. Kent and J. G. Williams},
address = {New York},
publisher = {unbekannt},
type = {Artikel in Zeitschrift},
month = {Januar},
year = {1998},
language = {Englisch},
cr-category = {A General Literature},
contact = {rothermel@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {Ohne Inhalt},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-1998-09&engl=0}
}
@article {ART-1998-08,
author = {Kurt Rothermel},
title = {{Mobile Agents}},
journal = {Editorial for Personal Technologies},
address = {London, UK},
publisher = {Springer-Verlag},
volume = {2},
number = {3},
type = {Artikel in Zeitschrift},
month = {Dezember},
year = {1998},
language = {Englisch},
cr-category = {A General Literature},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {Ohne Inhalt},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-1998-08&engl=0}
}
@article {ART-1998-07,
author = {Kurt Rothermel and W. Theilmann},
title = {{Agentenbasierte Informationssuche und -filterung in globalen Netzen}},
journal = {Industrie Management},
publisher = {GITO-Verlag-Berlin},
pages = {61--63},
type = {Artikel in Zeitschrift},
month = {Januar},
year = {1998},
keywords = {information retrieval; Internet; agent; mobile},
language = {Deutsch},
cr-category = {A General Literature},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {Die {\"U}berf{\"u}lle und Un{\"u}bersichtlichkeit der verf{\"u}gbaren Information in gro{\ss}en
Datenr{\"a}umen stellt ein zunehmendes Problem in der modernen
Informationsgesellschaft dar. W{\"a}hrend in Intranets die Informationsflut zum
momentanen Zeitpunkt noch handhabbar scheint, {\"u}berfordert die schiere Gr{\"o}{\ss}e des
Internets jeden bisher unternommenen L{\"o}sungsansatz. Herk{\"o}mmliche Ans{\"a}tze
reichen von ``brute-force''-Methoden, die das gesamte Internet indizieren, bis
hin zu administrativen Ans{\"a}tzen, um das Informationsangebot inhaltlich zu
stukturieren. Hier zeigt das Paradigma der autonomen Softwareagenten neue und
vielversprechende L{\"o}sungsans{\"a}tze auf. Softwareagenten zeichnen sich durch
Intelligenz, Mobilit{\"a}t und Sozialkompetenz aus, die es ihnen erm{\"o}glichen,
selbst{\"a}ndig in gro{\ss}en Datenr{\"a}umen navigieren und handeln k{\"o}nnen.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-1998-07&engl=0}
}
@article {ART-1998-06,
author = {Stefan Wirag and Kurt Rothermel},
title = {{Adaptive Multimedia Documents}},
journal = {Journal of Computing and Information Technology (CIT)},
publisher = {not available},
volume = {6},
number = {3},
pages = {233--244},
type = {Artikel in Zeitschrift},
month = {September},
year = {1998},
language = {Englisch},
cr-category = {H Information Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {(not available)},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-1998-06&engl=0}
}
@article {ART-1998-05,
author = {Markus Strasser and Kurt Rothermel},
title = {{Reliability Concepts for Mobile Agents}},
journal = {International Journal of Cooperative Information Systems},
publisher = {not available},
type = {Artikel in Zeitschrift},
month = {Dezember},
year = {1998},
language = {Englisch},
cr-category = {H Information Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {(not available)},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-1998-05&engl=0}
}
@article {ART-1998-04,
author = {Kurt Rothermel and Joachim Baumann},
title = {{The Shadow Approach: An Orphan Detection Protocol for Mobile Agents}},
journal = {Personal Technologies},
publisher = {Springer Verlag},
type = {Artikel in Zeitschrift},
month = {Dezember},
year = {1998},
language = {Englisch},
cr-category = {H Information Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {(not available)},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-1998-04&engl=0}
}
@article {ART-1998-03,
author = {Kurt Rothermel},
title = {{Mobile Agents}},
journal = {Editorial for Personal Technologies},
address = {London, United Kingdom},
publisher = {Springer Verlag},
volume = {2},
number = {3},
type = {Artikel in Zeitschrift},
month = {Januar},
year = {1998},
language = {Englisch},
cr-category = {H Information Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {(not available)},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-1998-03&engl=0}
}
@article {ART-1998-02,
author = {Joachim Baumann and Fritz Hohl and Kurt Rothermel and Markus Strasser},
title = {{Mole - Concepts of a Mobile Agent System}},
journal = {World Wide Web Journal, Special Issue on Applications and Techniques of Web Agents},
publisher = {Springer-Verlag},
volume = {1},
number = {3},
pages = {123--137},
type = {Artikel in Zeitschrift},
month = {Januar},
year = {1998},
language = {Englisch},
cr-category = {H Information Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {(not available)},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-1998-02&engl=0}
}
@article {ART-1998-01,
author = {Kurt Rothermel and Wolfgang Theilmann},
title = {{Agentenbasierte Informationssuche und -filterung in globalen Netzen}},
journal = {Industrie Management},
address = {Berlin},
publisher = {GITO Verlag},
volume = {1},
pages = {61--63},
type = {Artikel in Zeitschrift},
month = {Januar},
year = {1998},
language = {Deutsch},
cr-category = {H Information Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {(not available)},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-1998-01&engl=0}
}
@article {ART-1997-09,
author = {K.Rothermel and J.Baumann},
title = {{Internet - von der Grundlagentechnologie zum Wirtschaftsfaktor}},
journal = {Mobile Software-Agenten: Chancen und Risiken},
publisher = {dpunkt-Verlag},
type = {Artikel in Zeitschrift},
month = {Januar},
year = {1997},
language = {Deutsch},
cr-category = {A General Literature},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {Ohne Inhalt},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-1997-09&engl=0}
}
@article {ART-1997-08,
author = {Kurt Rothermel and Tobias Helbig},
title = {{An Adaptive Protocol for Synchronizing Media Stream}},
journal = {An Adaptive Protocol for Synchronizing Media Streams},
address = {Uni\_Stuttgart},
publisher = {ACM/Springer-Verlag},
volume = {5},
number = {5},
pages = {324--336},
type = {Artikel in Zeitschrift},
month = {Januar},
year = {1997},
keywords = {distributed systems; communication networks; multimedia; stream synchronization; quality of service},
language = {Englisch},
cr-category = {A General Literature},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/ART-1997-08/ART-1997-08.pdf,
ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/ART-1997-08/ART-1997-08.ps},
contact = {[rothermel,helbig]@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {Stream synchronization is widely regarded as a fundamental problem in the field
of multimedia systems. Solutions to this problem can be divided into adaptive
and rigid mechanisms. While rigid mechanisms are based on worst-case
assumptions, adaptive ones monitor the underlying network and are able to adapt
themselves to changing network conditions. In this paper, we will present an
adaptive stream synchronization protocol. This protocol supports any kind of
distribution of the sources and sinks of the streams to be synchronized. It is
based on a buffer level control mechanism, allowing immediate corrections when
the danger of a buffer overflow or underflow is recognized. Moreover, the
proposed protocol is flexible enough to support a wide variety of
synchronization policies, which can be dynamically changed while
synchronization is in progress. Finally, the message overhead of this protocol
is low because control messages are only exchanged when network conditions
change.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-1997-08&engl=0}
}
@article {ART-1997-07,
author = {Kurt Rothermel and A.Schill},
title = {{Neue Kommunikationsarchitekturen}},
journal = {Neue Kommunikationsarchitekturen},
publisher = {Oldenbourg-Verlag},
type = {Artikel in Zeitschrift},
month = {Januar},
year = {1997},
language = {Deutsch},
cr-category = {A General Literature},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {Ohne inhalt},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-1997-07&engl=0}
}
@article {ART-1997-06,
author = {K. Rothermel and F. Mattern and F. Schneider and B. Welch},
title = {{Mobile Software-Agents}},
journal = {Dagstuhl Seminar Report},
publisher = {not available},
volume = {192},
type = {Artikel in Zeitschrift},
month = {Januar},
year = {1997},
language = {Deutsch},
cr-category = {H Information Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {(not available)},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-1997-06&engl=0}
}
@article {ART-1997-04,
author = {K. Rothermel},
title = {{Multimedia Synchronization and Resource Management in Advanced Multimedia Environments}},
journal = {Dagstuhl Seminar Report},
editor = {K. Rothermel and N. Georganas and T. Little and R. Steinmetz},
publisher = {--},
volume = {184},
type = {Artikel in Zeitschrift},
month = {Januar},
year = {1997},
language = {Englisch},
cr-category = {H Information Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {(not available)},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-1997-04&engl=0}
}
@article {ART-1997-03,
author = {Kurt Rothermel and Joachim Baumann},
title = {{Mobile Software-Agenten: Chancen und Risiken}},
journal = {Internet - von der Grundlagentechnologie zum Wirtschaftsfaktor},
publisher = {dpunkt-Verlag},
type = {Artikel in Zeitschrift},
month = {Januar},
year = {1997},
language = {Deutsch},
cr-category = {H Information Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {(not available)},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-1997-03&engl=0}
}
@article {ART-1997-02,
author = {Kurt Rothermel and Tobias Helbig},
title = {{An Adaptive Protocol for Synchronizing Media Streams}},
journal = {ACM/Springer Multimedia Systems},
publisher = {Springer},
volume = {5},
number = {5},
pages = {324--336},
type = {Artikel in Zeitschrift},
month = {Januar},
year = {1997},
language = {Englisch},
cr-category = {H Information Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {(not available)},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-1997-02&engl=0}
}
@article {ART-1997-01,
author = {Alexander Schill and Kurt Rothermel},
title = {{Neue Kommunikationsarchitekturen}},
journal = {it+ti},
publisher = {Oldenbourg-Verlag},
volume = {39},
number = {4},
type = {Artikel in Zeitschrift},
month = {Januar},
year = {1997},
language = {Deutsch},
cr-category = {H Information Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {(not available)},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-1997-01&engl=0}
}
@article {ART-1996-04,
author = {Kurt Rothermel},
title = {{Protocols for Synchronizing Media Streams}},
journal = {ACM/Springer Multimedia Systems},
publisher = {ACM/Springer},
type = {Artikel in Zeitschrift},
month = {Januar},
year = {1996},
language = {Englisch},
cr-category = {H Information Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/ART-1996-04/ART-1996-04.ps},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {The evolution of technologies in the area of both telecommunication and
multimedia have significantly contributed to the emergence of new multimedia
applications. Those applications integrate various media types, such as text,
graphics, audio and video, which typically possess timeliness requirements with
respect to their presentation. Media synchronization mechanisms are needed to
assure the correct temporal alignment of such time-critical activities. Two
levels of multimedia synchronization can be distinguished, continuous
synchronization and event-based synchronization. While the first one aims at
the synchronized play-out of data streams, the latter ones orchestrates the
presentation of possibly distributed multimedia objects. Multimedia objects may
consist of a variety of timely related subobjects, such as video clips, audio,
text fragments and images. If a multimedia object contains continuous media,
object synchronization comprises stream synchronization at a lower level of
abstraction. In other words, stream synchronization functions form the basis
for synchronization mechanisms operating at the object-level. In the remainder
of this paper, we will focus on stream synchronization functions. The next
section, gives a brief classification of the various approaches existing in
this field. Then, in Sec. 3, we will describe the principles and properties of
the Adaptive Synchronization Protocol (ASP), which has been developed in the
CINEMA project [RBH94]. Finally, we will conclude with a brief summary.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-1996-04&engl=0}
}
@article {ART-1996-03,
author = {Kurt Rothermel and Tobias Helbig},
title = {{An Adaptive Protocol for Synchronizing Media Streams}},
journal = {ACM/Springer Multimedia Systems},
publisher = {ACM/Springer},
type = {Artikel in Zeitschrift},
month = {Januar},
year = {1996},
language = {Englisch},
cr-category = {H Information Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/ART-1996-03/ART-1996-03.ps},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {Stream synchronization is widely regarded as a fundamental problem in the field
of multimedia systems. Solutions to this problem can be divided into adaptive
and rigid mechanisms. While rigid mechanisms are based on worst-case
assumptions, adaptive ones monitor the underlying network and are able to adapt
themselves to changing network conditions. In this paper, we will present an
adaptive stream synchronization protocol. This protocol supports any kind of
distribution of the sources and sinks of the streams to be synchronized. It is
based on a buffer level control mechanism, allowing immediate corrections when
the danger of a buffer overflow or underflow is recognized. Moreover, the
proposed protocol is flexible enough to support a wide variety of
synchronization policies, which can be dynamically changed while
synchronization is in progress. Finally, the message overhead of this protocol
is low because control messages are only exchanged when network conditions
change.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-1996-03&engl=0}
}
@article {ART-1996-02,
author = {Kurt Rothermel and Tobias Helbig},
title = {{Clock Hierarchies: An Abstraction for Grouping and controlling Media Systems}},
journal = {IEEE Journal on Selected Areas in Communications - Synchronization Issues in Multimedia Communications, 1996},
address = {Stuttgart},
publisher = {Uni-Stuttgart},
volume = {14},
number = {1},
pages = {1--23},
type = {Artikel in Zeitschrift},
month = {Januar},
year = {1996},
keywords = {Distributed Multimedia System; System Services Interface; Stream Synchronization; Grouping},
language = {Englisch},
cr-category = {A General Literature},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/ART-1996-02/ART-1996-02.pdf,
ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/ART-1996-02/ART-1996-02.ps},
contact = {[rothermel,helbig]informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {Synchronization plays an important role in multimedia systems at various levels
of abstraction. In this paper, we propose a set of powerful abstractions for
controlling and synchronizing continuous media streams in distributed
environments. The proposed abstractions are based on a very general computation
model, which allows media streams to be processed (i.e. produced, consumed or
transformed) by arbitrarily structured networks of linked components. Further,
compound components can be composed of existing ones to provide higher levels
of abstractions. The clock abstraction is provided to control individual media
streams, i.e. streams can be started, paused or scaled by issuing the
appropriate clock operations. Clock hierarchies are used to hierarchically
group related streams, where each clock in the hierarchy identifies and
controls a certain (sub)group of streams. Control and synchronization
requirements can be expressed in a uniform manner by associating group members
with control or sync attributes. An important property of the concept of clock
hierarchies is that it can be combined in a natural way with component nesting.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-1996-02&engl=0}
}
@article {ART-1995-01,
author = {Tobias Helbig and Kurt Rothermel},
title = {{Synchronisation multimedialer Datenstr{\"o}me}},
journal = {it+ti - Informationstechnik und Technische Informatik 37 (1995) 4, pp. 18-25},
publisher = {(not available)},
pages = {18--25},
type = {Artikel in Zeitschrift},
month = {Januar},
year = {1995},
language = {Deutsch},
cr-category = {H Information Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {In multimedialen Anwendungen werden zeitabh{\"a}ngige, kontinuierliche Datenstr{\"o}me,
wie z.B. Audio und Video, {\"u}bertragen und verarbeitet. Der Entwurf und die
Steuerung solcher Anwendungen in einem verteilten System wird durch
Multimedia-Systemdienste unterst{\"u}tzt. Dabei f{\"a}llt dem Synchronisationsdienst
die Aufgabe zu, die Anwendungsanforderungen bez{\"u}glich der Pr{\"a}sentationsqualit{\"a}t
und der Synchronisation von zeitabh{\"a}ngigen Datenstr{\"o}men abzusichern. F{\"u}r diesen
Dienst beschreiben wir in diesem Papier eine Dienstschnittstelle und geben
einen {\"U}berblick {\"u}ber die Architektur und Protokolle seiner Realisierung. Es
wird gezeigt, wie verteilte Synchronisationsprotokolle den Fluss von
Dateneinheiten in verteilten Systemen entsprechend der Anwendungsanforderungen
koordinieren und somit die Voraussetzung f{\"u}r die zeitgerechte Verarbeitung
einzelner Dateneinheiten unter Kontrolle des Betriebssystems bilden.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-1995-01&engl=0}
}
@article {ART-1991-01,
author = {Ern{\"o} Kovacs and H. Fanderl},
title = {{Extension of the ISO norm ODA and DFR using the Example of an Hypertext Server}},
journal = {Hypertext / Hypermedia'91},
address = {Graz, Austria},
publisher = {Springer-Verlag},
series = {Informatik-Fachbericht},
volume = {427},
type = {Artikel in Zeitschrift},
month = {Januar},
year = {1991},
keywords = {ODA/ODIF; Hypertext; Partielle Dokumente},
language = {Englisch},
cr-category = {H Information Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {Die Dokumentenverarbeitung in offenen Systemen basiert auf internationalen
Normen f{\"u}r Dokumentenarchitektur und Kommunikation. Ein Beispiel f{\"u}r eine
normierte Dokumentenarchitektur ist die 'Open Document Architecture' (ODA).
Inwieweit ODA die Anforderungen eines in einem heterogenen Umfeld verteilten
Hypertext/Hypermedia Systems erf{\"u}llen kann, ist Inhalt dieses Beitrags. Dazu
werden die Konzepte, die die heutige ODA Norm bietet und Bestrebungen der
Standardisierungsgremien zur Architekturerweiterung untersucht. Dies resultiert
in ein erweitertes Schema f{\"u}r Dokumententeile, welches in Form eines Prototyps
auf seine Tauglichkeit hin {\"u}berpr{\"u}ft wird.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-1991-01&engl=0}
}
@inbook {INBOOK-2009-03,
author = {Stephan Schuhmann and Klaus Herrmann and Kurt Rothermel},
title = {{Selbstkonfiguration adaptiver Anwendungen in ubiquit{\"a}ren Systemen}},
series = {Basissoftware f{\"u}r drahtlose Ad-hoc- und Sensornetze},
address = {Karlsruhe},
publisher = {Universit{\"a}tsverlag Karlsruhe},
pages = {67--84},
type = {Beitrag in Buch},
month = {M{\"a}rz},
year = {2009},
language = {Deutsch},
cr-category = {C.2.4 Distributed Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Das Forschungsgebiet des Pervasive Computing hat in den letzten Jahren
zunehmend an Bedeutung gewonnen. Hauptziel ist die Integration von
Computertechnologie in Alltagsgegenst{\"a}nde und die Nutzung dieser hierdurch
elektronisch angereicherten Benutzerumgebung, ihrer Ger{\"a}te und Dienste f{\"u}r die
Ausf{\"u}hrung von Anwendungen. Daf{\"u}r m{\"u}ssen diese Anwendungen in die Lage versetzt
werden, sich dynamisch an wechselnde Umgebungen anzupassen, beispielsweise
durch Verlagerung ihrer Funktionalit{\"a}t zwischen Ger{\"a}ten. Bedingt durch
dynamische Umgebungen, Nutzermobilit{\"a}t sowie drahtlose
Kommunikationstechnologien ist die Entwicklung von Anwendungen f{\"u}r Pervasive
Computing Umgebungen hochkomplex. Daher wurden in diesem Projekt grundlegende
Konzepte und Algorithmen entwickelt, um eine automatisierte Nutzerunterst{\"u}tzung
in diesen Umgebungen zu erm{\"o}glichen. Hierbei lag der Schwerpunkt auf der
Entwicklung von Algorithmen zur Selbstkonfiguration von Anwendungen mittels
automatisierter Komposition und Adaption. Neben dynamischen, homogenen Ad Hoc
Umgebungen sollten au{\ss}erdem heterogene Umgebungen, in denen zus{\"a}tzlich
ressourcenstarke Infrastrukturger{\"a}te vorhanden sind, ber{\"u}cksichtigt werden, um
eine effiziente Ausf{\"u}hrung von Konfigurationen und Adaptionen auch in solchen
Umgebungen zu erm{\"o}glichen.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INBOOK-2009-03&engl=0}
}
@inbook {INBOOK-2008-11,
author = {Kurt Rothermel},
title = {{Kontextbezogene Systeme – die Welt im Computer modelliert}},
series = {Digitale Visionen},
publisher = {Springer Berlin Heidelberg},
pages = {31--42},
type = {Beitrag in Buch},
month = {April},
year = {2008},
isbn = {978-3-540-77021-3},
language = {Deutsch},
cr-category = {H.4 Information Systems Applications},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Ziel des Sonderforschungsbereichs 627 ``Nexus - Umgebungsmodelle f{\"u}r mobile
kontextbezogene Systeme'' ist die Erforschung von Methoden und Verfahren f{\"u}r die
Definition, die Verwaltung und die Nutzung von digitalen Umgebungsmodellen.
Existierende Informationsr{\"a}ume werden mit komplexen Modellen der realen Welt
verschr{\"a}nkt und erlauben so neuartige Anwendungen. Insbesondere die Klasse der
ortsbezogenen Anwendungen und aktuelle Forschungsgebiete wie das Ubiquitous
Computing k{\"o}nnen von solchen Umgebungsmodellen profitieren oder werden sogar
durch sie erst erm{\"o}glicht.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INBOOK-2008-11&engl=0}
}
@inbook {INBOOK-2007-04,
author = {Klaus Herrmann},
title = {{Selbstorganisierende Infrastrukturen f{\"u}r Ambient Services}},
series = {GI-Edition Lecture Notes in Informatics (LNI) - Ausgezeichnete Informatikdissertationen 2006},
publisher = {K{\"o}llen Verlag},
series = {GI-Edition Lecture Notes in Informatics (LNI)},
volume = {D-7},
pages = {109--118},
type = {Beitrag in Buch},
month = {Januar},
year = {2007},
keywords = {self-organization, replica placement, ambient intelligence, ambient services},
language = {Deutsch},
cr-category = {C.2.4 Distributed Systems},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INBOOK-2007-04/INBOOK-2007-04.pdf},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Die Vision von intelligenten Umgebungen (Ambient Intelligence - AmI) als neues
Paradigma f{\"u}r die Unterst{\"u}tzung mobiler Benutzer bei allt{\"a}glichen T{\"a}tigkeiten
r{\"u}ckt derzeit zunehmend in den Fokus Europ{\"a}ischer Forschungsaktivit{\"a}ten. Ein
hoher Grad an Autonomie auf Seiten der unterst{\"u}tzenden Software-Systeme ist
hierf{\"u}r eine unabdingbare Voraussetzung. Derartige Systeme m{\"u}ssen in der Lage
sein, sich selbst ohne steuernde Eingriffe von Benutzern an deren Aktivit{\"a}ten
und Verhalten anzupassen. Entsprechende Systeme sind derzeit jedoch weitgehend
unerforscht. Diese Arbeit stellt den ersten umfassenden Ansatz f{\"u}r eine
selbstorganisierende Plattform zur Unterst{\"u}tzung von so genannten Ambient
Services dar - Diensten, die es dem mobilen Benutzer gestatten, mit seiner
unmittelbaren Umgebung zu interagieren. Diese als Ad hoc Service Grid (ASG)
bezeichnete Plattform kann spontan in beliebigen Umgebungen (z.B.
Einkaufszentren, Baustellen, Messen, etc.) eingesetzt werden, um dort
entsprechende Dienste anzubieten. In der Arbeit schlagen wir zun{\"a}chst ein
Modell f{\"u}r eine entsprechende Infrastruktur aus spontan vernetzten
Rechnerknoten vor. Diese ist modular aufgebaut und im Einsatz flexibel
erweiterbar. Der eigentliche Fokus liegt jedoch auf der Entwicklung und
Evaluierung einer Reihe von Basis-Algorithmen und Protokollen f{\"u}r das
selbstorganisierte Betreiben dieser Infrastruktur. Hier konzentrieren wir uns
auf die Platzierung von Ambient Service-Instanzen, deren Auffinden (Discovery
und Lookup), und auf die Erhaltung der Konsistenz einer Gruppe verteilt
laufender Replikate eines solchen Dienstes. Diese Mechanismen legen zusammen
eine essenzielle Grundlage f{\"u}r die Weiterentwicklung intelligenter Umgebungen.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INBOOK-2007-04&engl=0}
}
@inbook {INBOOK-2007-01,
author = {J{\"o}rg H{\"a}hner and Christian Becker and Pedro Jos{\'e} Marr{\'o}n and Kurt Rothermel},
title = {{Drahtlose Sensornetze - Fenster zur Realwelt}},
series = {Die Informatisierung des Alltags},
address = {Berlin, Heidelberg},
publisher = {Springer-Verlag},
pages = {41--60},
type = {Beitrag in Buch},
month = {Juli},
year = {2007},
isbn = {978-3-540-71454-5},
keywords = {Sensornetze; Datenverwaltung; Konsistenz},
language = {Deutsch},
cr-category = {C.2 Computer-Communication Networks,
H.2 Database Management},
ee = {http://dx.doi.org/10.1007/978-3-540-71455-2_4},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Sensornetze stellen eine technische L{\"o}sung f{\"u}r die Erfassung und Verarbeitung
von Informationen der physischen Welt dar. Dabei handelt es sich um eine Menge
sogenannter Sensorknoten, die — meist drahtlos — miteinander kommunizieren
k{\"o}nnen. Sensorknoten sind miniaturisierte Computer, die — neben einem
Mikroprozessor und einer Kommunikationsschnittstelle — mit Sensoren
ausgestattet sind. Diese Sensoren erlauben es, physikalische Gr{\"o}{\ss}en in der
Umgebung des Knotens zu messen. Mit Hilfe des Mikroprozessors k{\"o}nnen diese
Messwerte verarbeitet und {\"u}ber die Kommunikationsschnittstelle an andere
Sensorknoten verschickt werden. In diesem Beitrag werden zun{\"a}chst verschiedene
Einsatz-gebiete von Sensornetzen vorgestellt. Danach werden technische
Eigenschaften von Sensornetzen anhand exemplarischer Sensorknoten diskutiert.
Neue wissen-schaftliche Herausforderungen werden beispielhaft anhand des
Gebiets der Daten-verwaltung in Sensornetzen vorgestellt.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INBOOK-2007-01&engl=0}
}
@inbook {INBOOK-2006-01,
author = {Kurt Rothermel},
title = {{Kontextbezogene Informationssysteme – von der Vision zur Anwendung}},
series = {Forschung st{\"a}rken - Produktion sichern},
publisher = {Springer-Verlag},
pages = {143--157},
type = {Beitrag in Buch},
month = {M{\"a}rz},
year = {2006},
language = {Deutsch},
cr-category = {H.4 Information Systems Applications},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Die rasant fortschreitende Entwicklung der drahtlosen Kommunikation, der
Computertechnologie sowie der Sensorik f{\"u}hrt zu mobilen Endger{\"a}ten und
„intelligenten“ Alltagsgegenst{\"a}nde, die in Kommunikationsnetze eingebunden sind
und {\"u}ber sensorische F{\"a}higkeiten verf{\"u}gen. Vor dem Hintergrund dieser
Entwicklungen ist es absehbar, dass in wenigen Jahren Milliarden von Sensoren
existieren werden, die kontinuierlich den Zustand der Realwelt erfassen und
kommunizieren. F{\"u}hrt man die sensorisch gewonnen Informationen in einem
r{\"a}umlichen Modell zusammen, so entsteht ein digitales Abbild der Realwelt, also
ein digitales Weltmodell, das analog zum heutigen Web einen globalen
Informati-onsraum darstellt. Das digitale Weltmodell kann Grundlage f{\"u}r ein
breites Spekt-rum so genanter kontextbezogener Anwendungen sein, welche in der
Lage sind, sich bei einer {\"A}nderung des Kontexts dynamisch anzupassen. In diesem
Beitrag wird der Begriff der kontextbezogenen Anwendung erl{\"a}utert und es werden
Anwendungen dieser Art am Beispiel existierender Systeme be-schrieben und
klassifiziert. Au{\ss}erdem wird die Vision, Kontextinformationen in Form digitaler
Weltmodelle zu verwalten, dargelegt und motiviert. Schlie{\ss}lich werden die sich
aus dieser Vision ergebenden wissenschaftlichen Fragestellungen diskutiert.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INBOOK-2006-01&engl=0}
}
@inbook {INBOOK-2004-09,
author = {Uwe Kubach and Christian Becker and Illya Stepanov and Jing Tian},
title = {{Simulation Model and Tool for Mobile Location Dependent Information Access}},
series = {Mobile Computing Handbook},
address = {New York},
publisher = {CRC Press},
type = {Beitrag in Buch},
month = {Juni},
year = {2004},
isbn = {0849319714},
language = {Englisch},
cr-category = {C.2.0 Computer-Communication Networks, General,
C.2.1 Network Architecture and Design,
C.2.4 Distributed Systems,
C.4 Performance of Systems,
I.6.3 Simulation and Modeling Applications,
H.2 Database Management},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INBOOK-2004-09&engl=0}
}
@inbook {INBOOK-2004-01,
author = {Silke Behling and Cora Burger and Martin Fromm and Melanie Schneider},
title = {{Grid-Interviews mit Notebook-Unterst{\"u}tzung}},
series = {Didaktik der Notebook-Universit{\"a}t},
address = {M{\"u}nster},
publisher = {Waxmann Verlag GmbH},
series = {Medien in der Wissenschaft},
type = {Beitrag in Buch},
month = {M{\"a}rz},
year = {2004},
keywords = {Notebook University; Didaktik; Grid-Interview; CSCL},
language = {Deutsch},
cr-category = {K.3.1 Computer Uses in Education},
ee = {http://www.campus-online.uni-stuttgart.de/nuss/},
contact = {arno.wacker@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Anhand des didaktischen Dreiecks, das alle Beziehungen zwischen Dozent -
Studierenden - Material darstellt, erl{\"a}utert der Beitrag die Erfahrungen, die
im Rahmen von Seminaren zur Grid-Interview-Technik in der Lehre zur P{\"a}dagogik
gemacht wurden. Speziell hervorgehoben wird dabei der Bedarf am
Online-Tutoring, bei dem Lehrende die Rechner von Lernenden fernsteuern und auf
diesem Weg Probleme beheben und Fragen kl{\"a}ren. W{\"a}hrend eine solche M{\"o}glichkeit
f{\"u}r fest vernetzte Rechner innerhalb eines Raumes bereits kommerziell zur
Verf{\"u}gung steht, stellt die Notebook-University mit ihren beliebig verteilten
Ger{\"a}ten hier neue Anforderungen, die erst durch neuere Forschungsergebnisse
ad{\"a}quat zu behandeln sind.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INBOOK-2004-01&engl=0}
}
@inbook {INBOOK-2001-02,
author = {Christian Maih{\"o}fer},
title = {{The Token Repository Service: A Universal and Scalable Mechanism for Constructing Multicast Acknowledgement Trees}},
series = {Multimedia Internet Broadcasting: Quality, Technology, and Interface},
publisher = {Springer-Verlag},
pages = {201--227},
type = {Beitrag in Buch},
month = {Januar},
year = {2001},
language = {Englisch},
cr-category = {C.2 Computer-Communication Networks},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INBOOK-2001-02/INBOOK-2001-02.pdf},
contact = {christian.maihoefer@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {Many new applications like groupware systems, news and file distribution or
audio and video systems are based on multicast as a prerequisite for
scalability. Many of these applications need a reliable multicast support,
which is realized in a scalable way by tree based multicast transport
protocols, where the receivers are organized in a so-called ACK tree. Tree
based approaches raise the problem of setting up and maintaining the ACK tree,
which is usually done by variations of the expanding ring search (ERS)
approach. In this paper we present an alternative approach for building up ACK
trees that is based on the concept of a distributed token repository service.
Our analysis and simulations show that our approach leads to a significantly
lower message overhead compared to ERS and results in better shaped ACK trees,
which has a positive effect on reliability and delay.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INBOOK-2001-02&engl=0}
}
@inbook {INBOOK-1999-02,
author = {L. Feldmann and V. Svjatnyi and V. Lapko and E.-D. Gilles and M. Zeitz and A. Reuter and K. Rothermel},
title = {{Parallele Simulationstechnik}},
series = {Problems of Simaulation and Computer Aided Design of Dynamic Systems. Collected Volume of Scientific Papers},
address = {Donetsk},
publisher = {Donetsk State Technical University},
type = {Beitrag in Buch},
month = {Januar},
year = {1999},
language = {Deutsch},
cr-category = {H Information Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {(not available)},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INBOOK-1999-02&engl=0}
}
@inbook {INBOOK-1999-01,
author = {Joachim Baumann and Fritz Hohl and Kurt Rothermel and Markus Strasser},
title = {{Mole - Concepts of a Mobile Agent System}},
series = {Mobiltiy - Processes, Computers and Agents},
publisher = {acm-press},
type = {Beitrag in Buch},
month = {Januar},
year = {1999},
language = {Englisch},
cr-category = {H Information Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {(not available)},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INBOOK-1999-01&engl=0}
}
@inbook {INBOOK-1998-01,
author = {K. Rothermel and M. Schwehm},
title = {{Mobile Agents}},
series = {Encyclopaedia for Computer Science and Technology},
address = {New York},
publisher = {M. Dekker Inc.},
type = {Beitrag in Buch},
month = {Januar},
year = {1998},
language = {Englisch},
cr-category = {H Information Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {(not available)},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INBOOK-1998-01&engl=0}
}
@proceedings {PROC-2009-02,
editor = {Kurt Rothermel and Dieter Fritsch and Wolfgang Blochinger and Frank D{\"u}rr},
title = {{Quality of Context -- Proceedings of the First International Workshop on Quality of Context (QuaCon 2009)}},
address = {Stuttgart, Germany},
publisher = {Springer},
institution = {Universit{\"a}t Stuttgart : Sonderforschungsbereich SFB 627 (Nexus: Umgebungsmodelle f{\"u}r mobile kontextbezogene Systeme), Germany},
series = {Lecture Notes in Computer Science},
volume = {5786},
pages = {184},
type = {Tagungsband},
month = {Juni},
year = {2009},
isbn = {978-3-642-04558-5},
keywords = {context-aware systems; location-based services; quality; context},
language = {Englisch},
cr-category = {H.2.8 Database Applications,
H.3.3 Information Search and Retrieval,
H.3.5 Online Information Services},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Anwendersoftware;
Universit{\"a}t Stuttgart, Institut f{\"u}r Photogrammetrie (ifp);
Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme;
Universit{\"a}t Stuttgart, Institut f{\"u}r Maschinelle Sprachverarbeitung},
abstract = {Advances in sensor technology, wireless communication, and mobile devices lead
to the proliferation of sensors in our physical environment. At the same time
detailed digital models of buildings, towns, or even the globe become widely
available. Integrating the huge amount of sensor data into spatial models
results in highly dynamic models of the real world, often called context
models.
A wide range of applications can substantially benefit from context models.
However, context data are inherently associated with uncertainty. In general,
quality of context information has to be taken into account by both context
management and applications. For example, the accuracy, completeness, and
trustworthiness of spatial context information such as street or building data
are very important for navigation and guidance systems.
QuaCon 2009 was the first international scientific meeting that specifically
focused on the different aspects of quality of context data. Research in
context management and, in particular, context quality, requires an
interdisciplinary approach. Therefore, the QuaCon workshop aimed to bring
together researchers from various fields to discuss approaches to context
quality and to make a consolidated contribution toward an integrated way of
treating this topic. We received 19 high-quality paper submissions by
researchers from Europe, USA, and Asia. The International Program Committee
selected 11 papers for presentation at the workshop. Additionally, five invited
contributions by internationally renowned experts in the field were included in
the workshop program. The presentations at the workshop showed many facets of
quality of context from different research fields including context data
management, spatial models, context reasoning, privacy, and system frameworks.
The lively discussions underlined the great interest in this topic and in
particular led to a deeper understanding of the relations between the various
aspects of quality of context.
The success of QuaCon 2009 was the result of a team effort. We are grateful to
the members of the Program Committee and the external reviewers for their
thorough and timely reviews as well as to the authors for their high-quality
submissions and interesting talks. We would like to extend special thanks to
our invited speakers for their excellent and inspiring keynotes. Finally, we
wish to thank all persons involved in the organization of the QuaCon 2009
workshop who did really a great job.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=PROC-2009-02&engl=0}
}
@proceedings {PROC-2006-02,
editor = {Pedro Jos{\'e} Marr{\'o}n and Thiemo Voigt and Christian Rohner},
title = {{Proceedings of the 2nd ACM Workshop on Real-World Wireless Sensor Networks}},
publisher = {ACM},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {1},
type = {Tagungsband},
month = {Juni},
year = {2006},
keywords = {ACM Workshop on Real-World Wireless Sensor Networks; REALWSN'06; Wireless Sensor Networks; Real-world Experiments; Deployments},
language = {Englisch},
cr-category = {C.3 Special-Purpose and Application-Based Systems,
C.2 Computer-Communication Networks},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Proceedings of the ACM Workshop on Real-World Wireless Sensor Networks
(REALWSN'06), held in conjunction with ACM MobiSys 2006 in Uppsala, Sweden.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=PROC-2006-02&engl=0}
}
@book {BOOK-2009-02,
editor = {Alejandro Buchmann and Boris Koldehofe},
title = {{IT-Information Technology}},
publisher = {Oldenbourg Verlag},
volume = {51},
number = {2009},
pages = {80},
type = {Buch},
month = {Oktober},
year = {2009},
doi = {10.1524/itit.2009.9058},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme;
Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme},
abstract = {This special issue on Complex Event Processing (CEP) intends to provide an
insight on the applications and principles as well as the evolution of CEP. The
selected articles from International and German researchers illustrate current
trends and challenges in designing powerful, scalable as well as secure event
processing systems.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=BOOK-2009-02&engl=0}
}
@book {BOOK-2008-03,
author = {Klaus Herrmann},
title = {{Self-Organizing Ambient Intelligence - Principles, Algorithms, and Protocols}},
publisher = {VDM Verlag Dr. M{\"u}ller},
pages = {276},
type = {Buch},
month = {April},
year = {2008},
isbn = {978-3-8364-9896-8},
language = {Englisch},
cr-category = {C.2.4 Distributed Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {In the last two decades, the advent of wireless networking technology and the
achievements in the miniaturization of electronic devices have set new trends
in distributed computing. This ultimately enables a new paradigm for embedding
mobile users in intelligent environments that support them in their
interactions with their local physical surrounding. This vision is called
Ambient Intelligence (AmI). There are still many challenges ahead on the way
towards the realization of AmI. One question that is central to the entire
concept is: How can we render AmI systems self-organizing such that they can
indeed disappear in our environment without creating a massive administrative
problem?
In this book, we propose a model for a dedicated AmI infrastructure that
supports the user in his interaction with his physical environment and with
external entities. This infrastructure is called Ad hoc Service Grid (ASG) and
provides wireless services in a decentralized and self-organizing fashion. We
identify three distinct problems associated with self-organized service
provisioning in the ASG model and propose algorithms and protocols that solve
them. The problem that is at the center of our work is the self-organized
replication and distribution of arbitrary services in an ASG. A set of
algorithms is presented that solves this problem in a completely distributed
way. The two other problems we tackle are the discovery and lookup of
dynamically distributed service replicas and the reconciliation among a dynamic
group of replicas. Together, the mechanisms we propose lay the foundation for a
general AmI software platform. We will derive the architecture of such a
Serviceware from these mechanisms. Detailed experimental results are presented
that show the validity of our concepts and identify ways for tailoring our
algorithms and protocols to the requirements of specific applications.
Furthermore, we propose a new general model and a classification methodology
for self-organizing software systems. We employ this model to evaluate our own
solutions.
The focus of the research work presented in this book is on the global-scale
interactions in an AmI system. We call this the macro-level of interactions to
separate it from the focus of most current research projects. These projects
concentrate more on adaptations at the micro-level, pertaining to the internal
structures of specific applications and services. Our work complements these
efforts by providing solutions for structuring AmI systems externally, for
example by distributing a group of service replicas within an ASG network.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=BOOK-2008-03&engl=0}
}
@book {BOOK-2006-03,
editor = {Pedro Jos{\'e} Marr{\'o}n and Daniel Minder and Embedded WiSeNts Consortium},
title = {{Embedded WiSeNts Research Roadmap}},
address = {Berlin},
publisher = {Logos Berlin},
pages = {190},
type = {Buch},
month = {November},
year = {2006},
isbn = {3-8325-1424-4},
keywords = {Cooperating Objects; Wireless Sensor Networks; Roadmap; State of the Art; Gap; Timeline; Roadblock; data-centric; market analysis},
language = {Englisch},
cr-category = {C.2.2 Network Protocols,
C.2.3 Network Operations,
C.2.4 Distributed Systems,
C.3 Special-Purpose and Application-Based Systems,
C.4 Performance of Systems,
I.2.9 Robotics,
J.2 Physical Sciences and Engineering,
J.3 Life and Medical Sciences,
J.7 Computers in Other Systems,
K.5.2 Legal Aspects of Computing Governmental Issues},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/BOOK-2006-03/BOOK-2006-03.pdf,
http://www.embedded-wisents.org},
contact = {The corresponding editor is pedro.marron@ipvs.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Wireless Sensor Networks are a canonical example of a wider field dealing with
Cooperating Objects that attempts to create the necessary technologies to make
Weiser's vision of the disappearing computer a reality. Cooperating Objects are
small computing devices equipped with wireless communication capabilities that
are able to cooperate and organise themselves autonomously into networks to
achieve a common task.
The book contains information about the research roadmap envisioned for
Cooperating Objects by the Embedded WiSeNts consortium and its associated
industrial and academic partners. The Embedded WiSeNts project started in
September 2004 as a Coordination Action funded by the European Commission under
IST/FP6 to create a series of studies on the state of the art of Cooperating
Objects and to devise a research roadmap to be used for the definition of
future research programs. This book is the final result of these two years of
work.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=BOOK-2006-03&engl=0}
}
@book {BOOK-2004-04,
author = {Christian Robert Becker},
title = {{System Support for Context-Aware Computing}},
address = {Stuttgart},
publisher = {Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Universit{\"a}t Stuttgart},
series = {Habilitationsschrift},
pages = {245},
type = {Buch},
month = {November},
year = {2004},
language = {Deutsch},
cr-category = {C.2.4 Distributed Systems},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
abstract = {Systemunterst{\"u}tzung f{\"u}r kontextbezogene Anwendungen
Zusammenfassung der Arbeit
System Support For Context-Aware Computing
Habilitationsschrift zur Erlangung der Venia Legendi in Informatik Angenommen
von der Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik Universit{\"a}t
Stuttgart
vorgelegt von Dr. phil. nat. Christian Robert Becker aus Hanau
Institut f{\"u}r Parallele und Verteilte Systeme Abteilung Verteilte Systeme
Universit{\"a}t Stuttgart
November 2004
Einleitung Die fortschreitende technologische Entwicklung im Bereich der
Sensortechnologie, der Miniaturisierung von eingebetteten Systemen und deren
Integration mit Sensorik und Kommunikationsf{\"a}higkeit erlauben das Erfassen von
Zust{\"a}nden der physischen Welt und deren Kommunikation. Der Einbezug solcher
Informationen in Softwaresysteme f{\"u}hrt zu kontextbezogenen Systemen, die ihre
Ausf{\"u}hrung auf Basis von Kontextinformationen adaptieren k{\"o}nnen. Beispiele
solcher Anwendungen sind: * Navigationswendungen: auf Basis von dynamischen
Informationen, wie Verkehrsinformationen, k{\"o}nnen bereits heutige
Navigationssysteme dynamische Anpassung von Routen vornehmen. Weitere
Parameter, durch die Navigationsanwendungen ihr Verhalten in Bezug auf den
Anwender ver{\"a}ndern k{\"o}nnen, sind Pr{\"a}ferenzen – beispielsweise f{\"u}r die Auswahl
eines Restaurants – die Aktivit{\"a}t eines Anwenders, um ma{\ss}geschneiderte
Benutzerschnittstellen f{\"u}r Fu{\ss}g{\"a}nger, Benutzer {\"o}ffentlicher Verkehrsmittel oder
Autofahrer anzubieten. Dar{\"u}ber hinaus k{\"o}nnen spezialisierte Navigationssysteme,
wie Touristenf{\"u}hrer oder die Unterst{\"u}tzung sehbehinderter Menschen, von
aktuellen Informationen der physischen Welt profitieren. * Instrumentierte
R{\"a}ume: diese Klasse von kontextbezogenen Anwendungen bietet durch die
Integration von eingebetteten Systemen und entsprechender Sensorik
Unterst{\"u}tzung f{\"u}r ma{\ss}geschneiderte Anwendungen. Ein Produktionsplanungssystem
in einer Fabrik kann beispielsweise die Position und den Wartungszustand von
Werkzeugen erfassen und somit sicherstellen, dass immer die ben{\"o}tigten
Werkzeuge f{\"u}r den Produktionsplanungsprozess vorgehalten werden. Weitere
Beispiele in dieser Klasse finden sich im Bereich so genannter „Smart
Environments“, in der R{\"a}ume auf bestimmte Anwendungsklassen ausgerichtet
werden. Beispiele sind die Unterst{\"u}tzung von Besprechungen und
Lehrveranstaltungen bei denen Anwendungen auf installierte Ger{\"a}te, wie
Projektoren, Besprechungstische mit Anzeige, und dynamisch in solche Umgebungen
eingebrachte Ger{\"a}te, wie mobile Enger{\"a}te von Anwendern, beispielsweise
Notebooks, verteilt werden. Dabei werden die Dienste und Informationen, die
sich aus der dynamischen Konstellation der installierten und eingebrachten
Ger{\"a}te ergeben, f{\"u}r die Ausf{\"u}hrung von Anwendungen einbezogen. * Annotationen:
im Gegensatz zu den vorangegangenen Beispielen, bei denen Anwendungen auf die
{\"A}nderungen der physischen Welt, beispielsweise durch Verkehrsinformationen oder
die {\"A}nderung in der Ausf{\"u}hrungsumgebung, reagieren, kann auch Information mit
Objekten der physischen Welt verkn{\"u}pft werden (d.h. diese Objekte werden
annotiert) und Anwender k{\"o}nnen so mit Informationen bedient werden. Beispiele
sind hier ortsbezogene Dienste, bei denen Geb{\"a}ude oder andere Orte mit
zus{\"a}tzlichen Informationen verkn{\"u}pft werden, die Anwender abrufen k{\"o}nnen. Aus
den oben genannten Beispielen ist ersichtlich, dass sich diese Anwendungen von
herk{\"o}mmlichen Anwendungen dadurch unterscheiden, dass sie ihre Ausf{\"u}hrung in
Abh{\"a}ngigkeit der physischen Welt ver{\"a}ndern. Dies dr{\"u}ckt sich in den folgenden
beiden Definitionen aus:
Definition Kontext Kontext ist die Information, die zur Charakterisierung der
Situation einer Entit{\"a}t herangezogen werden kann. Entit{\"a}ten sind Personen, Orte
oder Objekte, welche f{\"u}r das Verhalten von Anwendungen als relevant erachtet
werden. Dabei wird eine Entit{\"a}t selbst als Teil ihres Kontexts betrachtet.
Definition kontextbezogene Anwendungen Eine Anwendung ist kontextbezogen, wenn
ihr Verhalten durch Kontextinformationen beeinflusst wird.
Dabei k{\"o}nnen vier Klassen von kontextbezogenen Anwendungen unterschieden
werden: * Kontextbezogene Selektion: die Auswahl von Diensten oder
Informationen geschieht in Abh{\"a}ngigkeit des Kontexts, beispielsweise die
Selektion des n{\"a}chsten Druckers bezogen auf einen Anwender. * Kontextbezogene
Pr{\"a}sentation: die Darstellung einer Anwendung {\"a}ndert sich abh{\"a}ngig vom Kontext,
beispielsweise kann bei einer lauten Umgebung eine Audioausgabe auf eine
graphische Benutzeroberfl{\"a}che umschalten. * Kontextbezogene Aktion: in
Abh{\"a}ngigkeit von Kontextinformationen, wie dem Betreten eines Raums durch einen
Benutzer, wird eine Aktion, etwa das Einschalten des Lichts, ausgel{\"o}st. *
Annotation von Kontext: diese Klasse von Anwendungen erlaubt die Verkn{\"u}pfung
von Informationen mit Kontext, wie Orten oder Geb{\"a}uden, und den sp{\"a}teren
Zugriff auf diese Informationen {\"u}ber den Kontext. Klassifikation der
Systemunterst{\"u}tzung f{\"u}r kontextbezogene Systeme Die Klassifikation von
Systemunterst{\"u}tzung kontextbezogener Systeme soll anhand von zwei Dimensionen
geschehen. Die erste Dimension kennzeichnet das zugrunde liegende Systemmodell.
Dabei sind die m{\"o}glichen Auspr{\"a}gungen Infrastruktur oder ad hoc Systemmodelle.
Anwendungen in Infrastrukturbasierten Systemmodellen sind dadurch
gekennzeichnet, dass sie Zugriff auf Dienste und Informationen in der
Infrastruktur haben bzw. Vorkehrungen, wie das Vorabladen von Daten,
existieren, um Verbindungsabbr{\"u}che zur Infrastruktur abzufedern. Im Gegensatz
dazu sind ad hoc Systemmodelle dadurch gekennzeichnet, dass sie durch die
spontane Vernetzung mobiler Endger{\"a}te durch drahtlose Kommunikation gebildet
werden. H{\"a}ufige Partitionierungen des Netzwerkes und damit einhergehende
wechselnde Sichten auf die Informationen und Dienste, die einer Anwendung zur
Verf{\"u}gung stehen, sind Eigenschaften dieses Systemmodells. Die zweite Dimension
betrachtet die Unterst{\"u}tzung von Anwendungsadaptation. Dabei kann hier unter
Adaptation durch das System und Adaption durch die Anwendung unterschieden
werden.
Abbildung 1: Anpassung durch das System
Bei Adaption durch das System wird eine Anwendung in Form von nicht-adaptiven
Bl{\"o}cken spezifiziert und das System konfiguriert die Anwendung bei einem
Kontextwechsel entsprechend um (Abbildung 1). Im Gegensatz dazu, trifft bei
Adaption durch die Anwendung das Systems keine Entscheidung bez{\"u}glich der
Anwendungsadaption. Anwendungen greifen auf den Kontext typischerweise {\"u}ber
einen Dienst zu, der ein Kontextmodell verwaltet, und treffen ihre
Adaptationsentscheidungen (Abbildung 2) ohne Systemunterst{\"u}tzung, was mit einem
entsprechenden Mehraufwand bei der Konzeption und Programmierung der
Anwendungen verbunden ist.
Abbildung 2: Anpassung durch die Anwendung Zusammenfassung der Beitr{\"a}ge Die
Beitr{\"a}ge der vorliegenden Arbeit sollen im Folgenden den Klassen der
Systemunterst{\"u}tzung kontextbezogener System zugeordnet und diskutiert werden.
Die Einordnung geschieht hier entlang der Dimension der Systemunterst{\"u}tzung f{\"u}r
die Anwendungsadaptation. Adaption durch die Anwendung In dieser Klasse von
Systemunterst{\"u}tzung finden sich Dienste, die Kontextinformationen verwalten und
Anwendungen durch geeignete Schnittstellen verf{\"u}gbar machen. Die
Ortsbezogenheit von Kontextinformationen macht eine Organisation von
Kontextinformationen in Bezug auf ihre r{\"a}umliche Struktur notwendig. Kapitel 3
der vorliegenden Arbeit diskutiert zun{\"a}chst Eigenschaften von Koordinaten, wie
sie von Positionierungssystemen unterst{\"u}tzt werden. Aufgrund einer Analyse von
kontextbezogenen Anwendungen werden Anfragen nach Position, dem n{\"a}chsten
Nachbar und Objekten in einem Gebiet motiviert. Der Hauptbeitrag dieses
Kapitels liegt in der Klassifikation m{\"o}glicher Lokationsmodelle f{\"u}r symbolische
Koordinaten und eine Bewertung dieser Modelle in Hinblick auf ihre Eignung f{\"u}r
die o.g. Anfragen sowie des damit einhergehenden Modellierungsaufwands.
Symbolische Koordinaten zeichnen sich dadurch aus, dass sie – im Gegensatz zu
geometrischen Koordinaten - keine r{\"a}umlichen Bez{\"u}ge zwischen einzelnen
Koordinaten, wie eine Distanz, besitzen. Lokationsmodelle bilden r{\"a}umliche
Beziehungen zwischen symbolische Koordinaten ab und erlauben somit die
Bearbeitung von r{\"a}umlichen Anfragen. Der Beitrag dieses Kapitels kommt sowohl
infrastrukturbasierten wie auch ad hoc Systemen zu Gute. Kapitel 4 und 5 widmen
sich der Kontextverwaltung in ad hoc Systemen. In Kapitel 4 wird die
Usenet-on-the-Fly Anwendung als ein Beispiel f{\"u}r eine kontextbezogene Anwendung
in ad hoc Systemen vorgestellt. Diese Anwendung erlaubt es Benutzern, {\"a}hnlich
wie die Usenet-Anwendung im Internet, bestimmte Informationskan{\"a}le zu
abonnieren, Nachrichten zu lesen und zu schreiben. Die Verteilung der
Nachrichten zwischen den mobilen Endger{\"a}ten in dem ad hoc Netzwerk geschieht
{\"u}ber ein dreiphasiges Protokoll, in dem zun{\"a}chst nur Informationen {\"u}ber eine
Kennung von einem Knoten seinen Nachbarknoten angeboten werden. Nach einer
Nachfrage, werden diese Daten dann {\"u}bermittelt. Dies erlaubt die Verteilung von
Informationen in einem ad hoc Netzwerk, das sich durch h{\"a}ufige
Topologie{\"a}nderungen auszeichnet. Eine Analyse des Protokolls durch Simulationen
zeigt die Tragf{\"a}higkeit des Ansatzes. Kapitel 5 beschreibt eine Modifikation
dieses Protokolls, um den Nachrichtenaustausch in ad hoc Netzwerken mit
h{\"a}ufigerer Netzwerk-partitionierung zu unterst{\"u}tzen. Die Zustellung von
Informationen {\"u}ber Partitionsgrenzen hinweg bedeutet, dass Knoten diese
Informationen lokal vorhalten und wiederkehrend anbieten. Bei einer gr{\"o}{\ss}eren
Menge an Informationen bedeutet dies aber, dass die Gr{\"o}{\ss}e der
Anbieternachrichten steigt. Um diesem Problem zu begegnen wurde eine
Dreiteilung der Anbieternachrichten in Klassen eingef{\"u}hrt. Die erste Klasse
enth{\"a}lt Nachrichten bis zu einem gewissen Alter, das durch einen Schwellwert
bestimmt ist. Diese Nachrichten werden immer angeboten, da diese als aktuell
und somit f{\"u}r andere Knoten interessant erachtet werden. Der verbleibende Platz
in der Anbieternachricht wird f{\"u}r das Anbieten {\"a}lterer Nachrichten verwendet.
Die zweite Klasse beinhaltet {\"a}ltere Nachrichten, die aber von Knoten h{\"a}ufiger
nachgefragt werden und somit eine hohe Popularit{\"a}t besitzen. In der letzten
Klasse werden – nach unterschiedlichen Strategien, wie Round-Robin oder Zufall
- {\"a}ltere Nachrichten angeboten, um sicherzustellen, dass auch diese
Partitionsgrenzen {\"u}berwinden k{\"o}nnen. Wird eine Nachricht der letzten Klasse
nachgefragt, steigt deren Popularit{\"a}t und diese wechselt in die zweite Klasse
{\"u}ber. Die Leistungsf{\"a}higkeit des Protokolls wurde wiederum durch
Simulationsergebnisse gezeigt. Die Unterst{\"u}tzung durch Kontextinformationen f{\"u}r
Anwendungen, damit diese ihre Adaptionsentscheidung treffen k{\"o}nnen, setzt
voraus, dass Kontextinformationen in einem Dienst geeignet verwaltet und
zugreifbar gemacht werden. Die unterschiedlichen Ans{\"a}tze solche Dienste zu
realisieren und die Kontextinformationen zu strukturieren bedeuten allerdings,
dass Anwendungen hinsichtlich der verwendeten Kontextinformationen auf
kompatible Dienstanbieter beschr{\"a}nkt werden. Daher ist es w{\"u}nschenswert, dass
Zusammenschl{\"u}sse von unterschiedlichen Kontextanbietern in eine einheitliche
Struktur geschaffen werden, die Anwendungen einen einheitlichen Zugriff und
eine einheitliche Modellierung bieten. In Kapitel 6 wird {\"u}ber die Erfahrungen
einer Integration zweier Kontextmodelle, die als infrastrukturbasierte Dienste
realisiert sind, berichtet. Ausgehend von zwei Kontextdienste, der
Nexus-Plattform der Universit{\"a}t Stuttgart, und einem Kontextdienst f{\"u}r das
„Aware Home“ Projekt am Georgia Institute for Technology werden die
konzeptionellen Schritte f{\"u}r die Integration und die resultierende
Implementierung beschrieben. Der Aware Home Spatial Server (AHSS) des Aware
Home Projekts wurde aufgrund einer Analyse der Bed{\"u}rfnisse von Anwendungen in
diesem Projekt hin entworfen. Bedingt durch die organisatorische Struktur des
Projekts wurde die Festlegung einer einheitlichen Semantik der im AHSS
verwalteten Kontextinformationen verworfen. Die Abstimmung der Entwickler
erfolgt im Wesentlichen durch engen, pers{\"o}nlichen Kontakt. Die Struktur der
Kontextinformationen wurde auf Basis eines baumbasierten Lokationsmodells
vorgenommen, das f{\"u}r die Unterst{\"u}tzung von Nachbarschaftsanfragen weitere
Beziehungen zwischen Lokationen erlaubt. Die Speicherung erfolgte in einer
Datenbank mit Erweiterung f{\"u}r r{\"a}umliche Zugriffe und Anwendungen wurde eine
Schnittstelle {\"u}ber CORBA und das zugrunde liegende Internet Inter ORB Protokoll
(IIOP) angeboten. Im Gegensatz dazu hat das Nexus-Projekt eine offene Plattform
als Ziel, bei dem Kontextanbieter ihre Informationen frei integrieren k{\"o}nnen.
Eine F{\"o}deration bietet Klienten eine einheitliche Sicht auf die in der
Plattform verwalteten Kontextdienste. Die Integration beliebiger Kontextdienste
erfolgt auf Basis einer einheitlichen Modellierung von Kontextinformation durch
ein erweiterbares Klassenschema, das die Spezialisierung von einer gro{\ss}en
Anzahl von Basisklassen erlaubt. Eine XML-basierte Anfragesprache dient zur
Integration der Kontextdienste in die F{\"o}deration wie auch zur
Anfragebearbeitung von Klientenanfragen. Die Integration des AHSS in die
Nexus-Plattform erforderte die Einbettung der Kontextinformationen in das von
der Nexus-Plattform vorgegebene Klassenschema und die Umsetzung der
Nexus-Anfragesprache auf die Anfragebearbeitung des AHSS. Die Erfahrungen, die
aus dieser Einbettung gewonnen wurden, sind positiv. W{\"a}hrend Anwendungen im
Aware Home weiterhin die Kontextinformationen {\"u}ber den AHSS nutzen k{\"o}nnen, sind
diese {\"u}ber die Einbettungen f{\"u}r die Nexus-Anwendungen verf{\"u}gbar. Die Einbettung
in das Nexus-Klassenschema hat keine {\"A}nderung dieses Schemas erfordert, was als
Best{\"a}tigung der gew{\"a}hlten Klassenstruktur zu werten ist. Weiterhin ist durch
die Einbettungen es nun auch Nexus-Anwendungen m{\"o}glich auf die im AHSS
gespeicherten Kontextinformationen zuzugreifen. Die systematische Untersuchung
der Integration von Kontextinformationen und der Einbettung von
Kontextdiensten, wie dem AHSS, in die Nexus-Plattform hat eine {\"u}ber diese
beiden Projekte hinausgehende Bedeutung, da sie eine Untersuchung der Aufgaben
und Probleme der Dienst- und Informationsintegration im Bereich der
kontextbezogenen System darstellt und somit dem gesamten Bereich zu Gute kommt.
Adaption durch das System Bislang wurde die Klasse von Systemunterst{\"u}tzung f{\"u}r
kontextbezogenen Anwendungen betrachtet, die auf Basis von Kontextinformationen
ihr Verhalten adaptieren. Kapitel 7 bis 10 der vorliegenden Arbeit widmen sich
der Klasse der vom Systemunterst{\"u}tzung f{\"u}r vom System adaptierten
kontextbezogenen Anwendungen. Der Schwerpunkt liegt hierbei auf der
Unterst{\"u}tzung von Anwendungen basierend auf ad hoc Netzen. Solche Systeme
finden sich im Bereich des Peer-to-Peer Pervasive Computing, bei dem
Anwendungen auf Funktionalit{\"a}t, die in dem ad hoc Netz verf{\"u}gbar ist,
zur{\"u}ckgreifen k{\"o}nnen. Die Relevanz der Informationen und Dienste in einem ad
hoc Netz wird durch die N{\"a}he bestimmt, was letztlich dazu f{\"u}hrt, dass nur
Dienste und Information mit wenigen Zwischenknoten Entfernung in Betracht
gezogen werden. Durch die Charakteristika des zugrunde liegenden ad hoc Netzes
fluktuieren die einer Anwendung zur Verf{\"u}gung stehenden Dienste und
Informationen. Um dieser Dynamik zu begegnen ist die Unterst{\"u}tzung von
Anwendungsprogrammierern durch geeignete Systemsoftware notwendig.
Abbildung 3: Systemunterst{\"u}tzung in Peer-to-Peer Pervasive Computing
In Kapitel 7 werden die Anforderungen an Systemunterst{\"u}tzung in dem Gebiet des
Peer-to-Peer Pervasive Computing abgeleitet. Im wesentlichen zerfallen die
Anforderungen in einen anwendungsunabh{\"a}ngigen Bereich, der f{\"u}r die Etablierung
eines spontan vernetzten Funktionsverbunds in dem ad hoc Netzwerk zust{\"a}ndig
ist, und einem anwendungsabh{\"a}ngigen Bereich, der die Unterst{\"u}tzung der Adaption
von Anwendungen durch das System beinhaltet. Abbildung 3 zeigt die in Kapitel 8
und 9 beschriebene Systemunterst{\"u}tzung dieser beiden Bereiche. Die
Verteilungsinfrastruktur „BASE“, die in Kapitel 8 beschrieben wird, erlaubt die
automatische Etablierung spontaner Funktionsverb{\"u}nde durch geeignete
Dienstfindungsmechanismen und die flexible Nutzung von Transport- und
Interoperabilit{\"a}tsprotokollen. BASE beruht auf einem Mikrokern-Entwurf und kann
so selbst auf ressourcenarmen Ger{\"a}ten zur Ausf{\"u}hrung gebracht werden. Die
Nutzung von Ressourcen auf gr{\"o}{\ss}eren Ger{\"a}ten wird durch die Erweiterbarkeit des
Mikrokerns sichergestellt. Im Gegensatz zu bereits existierenden
Verteilungsinfrastrukturen erlaubt BASE die Trennung der Kommunikationsmodelle
von Anwendung und Interoperabilit{\"a}tsschicht. Dies erlaubt BASE, die
Interoperabilit{\"a}tsprotokolle w{\"a}hrend der Interaktion mit entfernten Diensten zu
wechseln und somit f{\"u}r die Anwendung transparent die Kommunikation zu
adaptieren. Ein Beispiel, wo dieses zum Einsatz kommt ist ein
Verbindungsabbruch beim Aussenden eines Dienstauftrages {\"u}ber eine
Infrarotschnittstelle. Steht allerdings noch eine Verbindung, beispielsweise
{\"u}ber eine Funkverbindung zur Verf{\"u}gung, wird diese von BASE f{\"u}r die Zustellung
des Ergebnisses benutzt. BASE stellt keine Anforderungen an die Struktur von
Anwendungen und bietet nur eine einfache Signalisierungsschnittstelle an, bei
denen Anwendungen die Verf{\"u}gbarkeit und Unverf{\"u}gbarkeit von Ressourcen
signalisiert bekommen. Das in Kapitel 9 vorgestellte Komponentensystem PCOM
basiert auf einem kontraktbasierten Anwendungsmodell. Kontrakte dienen zu
vollst{\"a}ndigen Beschreibung der Abh{\"a}ngigkeiten von Komponenten an andere
Komponenten aber auch an die zugrunde liegende Ausf{\"u}hrungsumgebung,
beispielsweise Speicher oder CPU Bedarf. Anwendungen werden als B{\"a}ume
beschrieben, deren Knoten Komponenten sind, die den Baum durch ihre
Abh{\"a}ngigkeiten aufspannen. Aufgrund dieser Informationen kann das
Laufzeitsystem eine Anwendung starten (was einem Sonderfall der Adaption
gleichkommt) oder adaptieren, sollten Komponenten vorliegen, die einen Kontrakt
besser erf{\"u}llen, oder aber genutzte Komponenten unverf{\"u}gbar werden. Das
Laufzeitsystem von PCOM basiert auf BASE und kann somit andere Laufzeitsysteme
in dem spontanen Funktionsverbund auffinden und die lokal verf{\"u}gbaren
Komponenten austauschen. Komponenten in PCOM m{\"u}ssen nicht adaptiv in Bezug auf
Kontextinformationen sein. PCOM f{\"a}llt in die Klasse der Systemunterst{\"u}tzung f{\"u}r
vom System adaptierten Anwendungen. Kapitel 10 berichtet von den Erfahrungen,
die bei der Portierung von BASE auf ein eingebettetes System und die Nutzung
von BASE als Basis von PCOM entstanden sind.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=BOOK-2004-04&engl=0}
}
@book {BOOK-1998-01,
author = {Kerstin Schneider (Hrsg.) and Hiltrud Betz and Cora Burger and Volker Claus and Waltraud Schweikhardt},
title = {{Die Informatik AG - Telekooperation.}},
address = {Stuttgart},
publisher = {B.G. Teubner-Verlag},
pages = {158},
type = {Buch},
month = {Januar},
year = {1998},
isbn = {3-519-12194-8},
keywords = {Studieninformation; Frauenf{\"o}rderung; gender; computer science},
language = {Deutsch},
cr-category = {K.3 Computers and Education},
ee = {http://www.informatik.uni-stuttgart.de/fakultaet/frauen/frauen.html,
http://medoc.informatik.uni-stuttgart.de/~medoc/},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Anwendersoftware (Prof. Reuter);
Universit{\"a}t Stuttgart, Institut f{\"u}r Informatik, Formale Konzepte;
Universit{\"a}t Stuttgart, Institut f{\"u}r Informatik, Programmiersprachen und {\"U}bersetzerbau;
Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme;
Universit{\"a}t Stuttgart, Institut f{\"u}r Informatik, Visualisierung und Interaktive Systeme},
abstract = {(not available)},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=BOOK-1998-01&engl=0}
}
@book {BOOK-1997-02,
author = {Cora Burger},
title = {{Groupware - Kooperationsunterst{\"u}tzung f{\"u}r Verteilte Anwendungen}},
address = {Heidelberg},
publisher = {dpunkt Verlag},
pages = {292},
type = {Buch},
month = {November},
year = {1997},
isbn = {3-920993-60-8},
language = {Deutsch},
cr-category = {H.3.4 Information Storage and Retrieval Systems and Software,
H.4.1 Office Automation,
H.4.3 Information Systems Applications Communications Applications,
H.5.3 Group and Organization Interfaces},
ee = {http://www.dpunkt.de/groupware,
http://www.informatik.uni-stuttgart.de/ipvr/vs/projekte/Festival/festival.html},
contact = {caburger@informatik.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {Werkzeuge, die eine rechnergest{\"u}tzte Form der Zusammenarbeit erm{\"o}glichen,
werden als Groupware bezeichnet. Hierzu z{\"a}hlen beispielsweise elektronische
Post, Terminplanungs- und Workflow-Management-Systeme, Konferenzsysteme oder
Mehrbenutzereditoren. Sie alle basieren auf Mechanismen verteilter Systeme.
Dieses Buch bietet eine aktuelle Einf{\"u}hrung in die Praxis rechnergest{\"u}tzter
Kooperation. Ein einfaches Modell illustriert die grundlegenden Konzepte und
unterschiedlichen Verfahren f{\"u}r kooperative Verarbeitung in verteilten Systemen
(Client-Server-Modell, Objekt- und Agentenmodell sowie Vermittlungstechniken).
Die Autorin gibt einen systematischen {\"U}berblick {\"u}ber existierende Groupware und
zeigt, wie diese Verfahren den Anforderungen einer Kooperationsunterst{\"u}tzung
gerecht werden. {\"U}bungen dienen dazu, die behandelten Themen zu vertiefen.
Anhand von Animationen, Tools zur Unterst{\"u}tzung der {\"U}bungen (BSCW, JDK, MICO,
MOLE) und WWW-Live-Links auf der beigef{\"u}gten CD k{\"o}nnen Erfahrungen im Umgang
mit den Basismechanismen und der Arbeitsweise der Werkzeuge erworben werden.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=BOOK-1997-02&engl=0}
}
@book {BOOK-1997-01,
author = {Kurt Rothermel and R. Popscu-Zeletin},
title = {{Mobile Agents, Proceedings of the First International Workshop, MA'97}},
publisher = {Springer-Verlag},
type = {Buch},
month = {M{\"a}rz},
year = {1997},
language = {Englisch},
cr-category = {A General Literature},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte H{\"o}chstleistungsrechner, Verteilte Systeme},
abstract = {Ohne Inhalt},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=BOOK-1997-01&engl=0}
}
