@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-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-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-2014-03,
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-2013-57,
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}
}
@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-2015-12,
author = {Viktor Avrutin and Christoph Dibak and Arianna Dal Forno and Ugo Merlone},
title = {{Dynamics of a 2D Piecewise Linear Braess Paradox Model: Effect of the Third Partition}},
journal = {International Journal of Bifurcation and Chaos},
publisher = {World Scientific},
volume = {25},
number = {11},
pages = {1530031--1530031},
type = {Artikel in Zeitschrift},
month = {Oktober},
year = {2015},
doi = {10.1142/S0218127415300311},
language = {Englisch},
cr-category = {G.0 Mathematics of Computing General},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Bildverstehen},
abstract = {In this work, we investigate the dynamics of a piecewise linear 2D
discontinuous map modeling a simple network showing the Braess paradox. This
paradox represents an example in which adding a new route to a specific
congested transportation network makes all the travelers worse off in terms of
their individual travel time. In the particular case in which the modeled
network corresponds to a binary choice situation, the map is defined on two
partitions and its dynamics has already been described. In the general case
corresponding to a ternary choice, a third partition appears leading to
significantly more complex bifurcation structures formed by border collision
bifurcations of stable cycles with points located in all three partitions.
Considering a map taking a constant value on one of the partitions, we provide
a first systematic description of possible dynamics for this case.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2015-12&engl=0}
}