@inproceedings {INPROC-2017-74,
author = {Frank Leymann and Uwe Breitenb{\"u}cher and Sebastian Wagner and Johannes Wettinger},
title = {{Native Cloud Applications: Why Monolithic Virtualization Is Not Their Foundation}},
booktitle = {Cloud Computing and Services Science},
publisher = {Springer International Publishing},
institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
pages = {16--40},
type = {Conference Paper},
month = {July},
year = {2017},
isbn = {978-3-319-62594-2},
language = {English},
cr-category = {K.6 Management of Computing and Information Systems,
D.2.12 Software Engineering Interoperability},
department = {University of Stuttgart, Institute of Architecture of Application Systems},
abstract = {Due to the current hype around cloud computing, the term `native cloud
application' becomes increasingly popular. It suggests an application to fully
benefit from all the advantages of cloud computing. Many users tend to consider
their applications as cloud native if the application is just bundled as a
monolithic virtual machine or container. Even though virtualization is
fundamental for implementing the cloud computing paradigm, a virtualized
application does not automatically cover all properties of a native cloud
application. In this work, which is an extension of a previous paper, we
propose a definition of a native cloud application by specifying the set of
characteristic architectural properties, which a native cloud application has
to provide. We demonstrate the importance of these properties by introducing a
typical scenario from current practice that moves an application to the cloud.
The identified properties and the scenario especially show why virtualization
alone is insufficient to build native cloud applications. We also outline how
native cloud applications respect the core principles of service-oriented
architectures, which are currently hyped a lot in the form of microservice
architectures. Finally, we discuss the management of native cloud applications
using container orchestration approaches as well as the cloud standard TOSCA.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2017-74&engl=1}
}
@inproceedings {INPROC-2017-53,
author = {Sebastian Wagner and Uwe Breitenb{\"u}cher and Oliver Kopp and Andreas Wei{\ss} and Frank Leymann},
title = {{Fostering the Reuse of TOSCA-based Applications by Merging BPEL Management Plans}},
booktitle = {Cloud Computing and Services Science: 6th International Conference (CLOSER 2016) - Revised Selected Papers},
publisher = {Springer International Publishing},
institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
series = {Communications in Computer and Information Science},
volume = {740},
pages = {232--254},
type = {Conference Paper},
month = {July},
year = {2017},
isbn = {978-3-319-62594-2},
doi = {10.1007/978-3-319-62594-2_12},
language = {English},
cr-category = {H.4.1 Office Automation},
department = {University of Stuttgart, Institute of Architecture of Application Systems},
abstract = {},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2017-53&engl=1}
}
@inproceedings {INPROC-2016-19,
author = {Frank Leymann and Christoph Fehling and Sebastian Wagner and Johannes Wettinger},
title = {{Native Cloud Applications: Why Virtual Machines, Images and Containers Miss the Point!}},
booktitle = {Proceedings of the 6th International Conference on Cloud Computing and Service Science (CLOSER 2016)},
address = {Rome},
publisher = {SciTePress},
institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
pages = {7--15},
type = {Conference Paper},
month = {April},
year = {2016},
keywords = {Cloud Computing; Virtualization; Cloud Migration; SOA; Microservices; Continuous Delivery},
language = {English},
cr-category = {D.2.9 Software Engineering Management,
D.2.11 Software Engineering Software Architectures,
K.6 Management of Computing and Information Systems,
H.4.1 Office Automation},
contact = {leymann@iaas.uni-stuttgart.de},
department = {University of Stuttgart, Institute of Architecture of Application Systems},
abstract = {Due to the current hype around cloud computing, the term {\^a}€śnative cloud
application{\^a}€ť becomes increasingly popular. It suggests an application to
fully benefit from all the advantages of cloud computing. Many users tend to
consider their applications as cloud native if the application is just bundled
in a virtual machine image or a container. Even though virtualization is
fundamental for implementing the cloud computing paradigm, a virtualized
application does not automatically cover all properties of a native cloud
application. In this work, we propose a definition of a native cloud
application by specifying the set of characteristic architectural properties,
which a native cloud application has to provide. We demonstrate the importance
of these properties by introducing a typical scenario from current practice
that moves an application to the cloud. The identified properties and the
scenario especially show why virtualization alone is insufficient to build
native cloud applications. Finally, we outline how native cloud applications
respect the core principles of service-oriented architectures, which are
currently hyped a lot in the form of microservice architectures.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2016-19&engl=1}
}
@inproceedings {INPROC-2016-08,
author = {Sebastian Wagner and Uwe Breitenb{\"u}cher and Frank Leymann},
title = {{A Method For Reusing TOSCA-based Applications and Management Plans}},
booktitle = {Proceedings of the 6th International Conference on Cloud Computing and Service Science (CLOSER 2016)},
address = {Rome},
publisher = {SciTePress},
institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
pages = {181--191},
type = {Conference Paper},
month = {April},
year = {2016},
language = {English},
cr-category = {D.2.9 Software Engineering Management,
K.6 Management of Computing and Information Systems,
H.4.1 Office Automation},
department = {University of Stuttgart, Institute of Architecture of Application Systems},
abstract = {The automated provisioning and management of Cloud applications is supported by
various general-purpose technologies that provide generic management
functionalities such as scaling components or automatically redeploying parts
of a Cloud application. However, if complex applications have to be managed,
these technologies reach their limits and individual, application-specific
processes must be created to automate the execution of holistic management
tasks that cannot be implemented in a generic manner. Unfortunately, creating
such processes from scratch is time-consuming, error-prone, and
knowledge-intensive, thus, leading to inefficient developments of new
applications. In this paper, we present an approach that tackles these issues
by enabling the usage of choreographies to systematically combine available
management workflows of existing application building blocks. Moreover, we show
how these choreographies can be merged into single, executable workflows in
order to enable their automated execution. To validate the approach, we apply
the concept to the choreography language BPEL4Chor and the Cloud standard
TOSCA. In addition, we extend the Cloud application management ecosystem
OpenTOSCA to support executing management choreographies.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2016-08&engl=1}
}
@inproceedings {INPROC-2015-25,
author = {Frank Steimle and Matthias Wieland and Bernhard Mitschang and Sebastian Wagner and Frank Leymann},
title = {{Design and Implementation Issues of a Secure Cloud-Based Health Data Management System}},
booktitle = {Proceedings of the 9th Symposium and Summer School On Service-Oriented Computing},
editor = {Johanna Barzen and Rania Khalaf and Frank Leymann and Bernhard Mitschang},
publisher = {IBM Research Report},
institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
series = {Technical Paper},
volume = {RC25564},
pages = {68--82},
type = {Conference Paper},
month = {December},
year = {2015},
keywords = {eHealth; mHealth; cloud data; data analysis; security},
language = {English},
cr-category = {C.2.4 Distributed Systems,
H.2.8 Database Applications,
J.3 Life and Medical Sciences},
ee = {http://domino.research.ibm.com/library/cyberdig.nsf/papers/656B934403848E8A85257F1D00695A63},
department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Applications of Parallel and Distributed Systems;
University of Stuttgart, Institute of Architecture of Application Systems},
abstract = {eHealth gains more and more interest since a lot of end-user devices which
support health data capturing are available. The captured data has to be
managed and securely stored, in order to access it from different devices and
to share it with other users such as physicians. The aim of the German-Greek
research project ECHO is to support the treatment of patients, who suffer from
Chronic Obstructive Pulmonary Disease (COPD), a chronic respiratory disease.
Usually the patients need to be examined by their physicians on a regular basis
due to their chronic condition. Since this is very time consuming and
expensive, we develop an eHealth system which allows the physician to monitor
patients conditions remotely, e.g., via smart phones. Therefore, a secure data
processing and sharing eHealth platform is required. In this paper we introduce
a health data model and a corresponding platform-architecture for the
management and analysis of the data provided by the patients. Furthermore, we
show how the security of the data is ensured and we explain how the platform
can be hosted in a cloud-based environment using the OASIS standard TOSCA,
which enables a self-contained and portable description and management of
cloud-services.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2015-25&engl=1}
}
@inproceedings {INPROC-2015-20,
author = {Sebastian Wagner and Oliver Kopp and Frank Leymann},
title = {{Choreography-based Consolidation of Interacting Processes Having Activity-based Loops}},
booktitle = {Proceedings of the 5th International Conference on Cloud Computing and Service Science (CLOSER 2015)},
address = {Stuttgart},
publisher = {SciTePress},
institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
pages = {284--296},
type = {Conference Paper},
month = {May},
year = {2015},
keywords = {BPEL; Choreography; Process Consolidation; Loops},
language = {English},
cr-category = {H.4.1 Office Automation},
contact = {sebastian.wagner@iaas.uni-stuttgart.de},
department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Applications of Parallel and Distributed Systems;
University of Stuttgart, Institute of Architecture of Application Systems},
abstract = {Choreographies describe the interaction between two or more parties. The
interaction behavior description might contain loops. In case two parties want
to merge their behavior to gain competitive advantage, the contained loop
constructs also have to be merged. This paper presents a language-independent
discussion on loop-structure pairing in choreographies and possible merging
strategies. Thereby, the focus is turned on loops grouping child activities to
be iterated. We show the feasibility of the merging strategies by applying them
to BPEL-based choreographies.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2015-20&engl=1}
}
@inproceedings {INPROC-2014-24,
author = {Florian Haupt and Frank Leymann and Alexander Nowak and Sebastian Wagner},
title = {{Lego4TOSCA: Composable Building Blocks for Cloud Applications}},
booktitle = {Proceedings of the 7th IEEE International Conference on Cloud Computing (CLOUD 2014)},
editor = {IEEE},
publisher = {IEEE},
institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
pages = {160--167},
type = {Conference Paper},
month = {July},
year = {2014},
isbn = {978-1-4799-5062-1},
doi = {10.1109/CLOUD.2014.31},
keywords = {Cloud; TOSCA},
language = {English},
cr-category = {D.2.11 Software Engineering Software Architectures},
contact = {florian.haupt@iaas.uni-stuttgart.de},
department = {University of Stuttgart, Institute of Architecture of Application Systems},
abstract = {The Topology and Orchestration Specification for Cloud Applications (TOSCA)
enables the description, provisioning, and management of complex cloud
applications in a portable way. TOSCA, therefore, provides a comprehensive yet
complex set of mechanisms that may hinder users from unleashing its power due
to misusing or neglecting parts of those mechanisms. TOSCA has just been
standardized and, although it seems to be highly adopted in industry, there is
a lack of systematic research of its features and capabilities. In this work we
discuss the design of basic building blocks for cloud applications, called node
types, and show how they can benefit from a deep integration with TOSCA. We
developed a generic architecture for the realization of TOSCA node types, show
an implementation of this architecture and validate it based on a sample cloud
application. Our work gives an insight into the capabilities of TOSCA with
respect to enable the creation of portable cloud services based on a set of
composable building blocks.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2014-24&engl=1}
}
@inproceedings {INPROC-2014-17,
author = {Sebastian Wagner and Oliver Kopp and Frank Leymann},
title = {{Choreography-based Consolidation of Multi-Instance BPEL Processes}},
booktitle = {Proceedings of the 4th International Conference on Cloud Computing and Services Science (CLOSER 2014);Barcelona, Spain, April 3-5, 2014.},
editor = {SciTePress},
address = {Barcelona},
publisher = {SciTePress},
institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
pages = {1--12},
type = {Conference Paper},
month = {April},
year = {2014},
keywords = {BPEL; Choreography; Process Consolidation; Multi-Instance Interactions},
language = {English},
cr-category = {H.4.1 Office Automation},
contact = {sebastian.wagner@iaas.uni-stuttgart.de},
department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Applications of Parallel and Distributed Systems;
University of Stuttgart, Institute of Architecture of Application Systems},
abstract = {Interaction behavior between processes of different organizational units such
as an enterprise and its suppliers can be modeled by choreographies. When
organizations decide, for instance, to gain more control about their suppliers
to minimize transaction costs, they may decide to insource these companies.
This especially includes the integration of the partner processes into the
organization’s processes. Existing works are able to merge single-instance BPEL
process interactions where each process model is only instantiated once during
choreography execution. However, there exist different interaction scenarios
where one process interacts with several instances of another process and where
the number of instances involved is not known at design time but determined
during runtime of the choreography. In this work we investigate these
interaction scenarios and extend the process consolidation approach in a way
that we can emulate the multi-instance interaction scenarios in the merged
process model.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2014-17&engl=1}
}
@inproceedings {INPROC-2013-45,
author = {Tobias Binz and Uwe Breitenb{\"u}cher and Florian Haupt and Oliver Kopp and Frank Leymann and Alexander Nowak and Sebastian Wagner},
title = {{OpenTOSCA - A Runtime for TOSCA-based Cloud Applications}},
booktitle = {Proceedings of 11th International Conference on Service-Oriented Computing (ICSOC'13)},
publisher = {Springer Berlin Heidelberg},
institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
series = {LNCS},
volume = {8274},
pages = {692--695},
type = {Demonstration},
month = {December},
year = {2013},
doi = {10.1007/978-3-642-45005-1_62},
keywords = {TOSCA; Cloud Applications; Automation; Management; Portability},
language = {English},
cr-category = {K.1 The Computer Industry,
K.6.4 System Management,
D.2.12 Software Engineering Interoperability},
contact = {a href=``http://www.iaas.uni-stuttgart.de/institut/mitarbeiter/binz''Tobias Binz/ a},
department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Applications of Parallel and Distributed Systems;
University of Stuttgart, Institute of Architecture of Application Systems},
abstract = {TOSCA is a new standard facilitating platform independent description of Cloud
applications. OpenTOSCA is a runtime for TOSCA-based Cloud applications. The
runtime enables fully automated plan-based deployment and management of
applications defined in the OASIS TOSCA packaging format CSAR. This paper
outlines the core concepts of TOSCA and provides a system overview on OpenTOSCA
by describing its modular and extensible architecture, as well as presenting
our prototypical implementation. We demonstrate the use of OpenTOSCA by
deploying and instantiating the school management and learning application
Moodle.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2013-45&engl=1}
}
@inproceedings {INPROC-2013-43,
author = {Tim Waizenegger and Matthias Wieland and Tobias Binz and Uwe Breitenb{\"u}cher and Florian Haupt and Oliver Kopp and Frank Leymann and Bernhard Mitschang and Alexander Nowak and Sebastian Wagner},
title = {{Policy4TOSCA: A Policy-Aware Cloud Service Provisioning Approach to Enable Secure Cloud Computing}},
booktitle = {On the Move to Meaningful Internet Systems: OTM 2013 Conferences},
editor = {Robert Meersman and Herve Panetto and Tharam Dillon and Johann Eder and Zohra Bellahsene and Norbert Ritter and Pieter De Leenheer and Dou Deijing},
address = {Heidelberg},
publisher = {Springer Berlin Heidelberg},
institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
series = {Lecture Notes in Computer Science (LNCS)},
volume = {8185},
pages = {360--376},
type = {Conference Paper},
month = {September},
year = {2013},
isbn = {978-3-642-41029-1},
doi = {10.1007/978-3-642-41030-7_26},
keywords = {Cloud Computing, TOSCA, Cloud Service, Cloud Management, Policy-Framework, Security, Green-IT, Sustainable Cloud Service},
language = {English},
cr-category = {D.2.7 Software Engineering Distribution, Maintenance, and Enhancement,
D.2.9 Software Engineering Management,
D.2.13 Software Engineering Reusable Software},
contact = {tim.waizenegger@informatik.uni-stuttgart.de},
department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Applications of Parallel and Distributed Systems;
University of Stuttgart, Institute of Architecture of Application Systems},
abstract = {With the growing adoption of Cloud Computing, automated deployment and
provisioning systems for Cloud applications are becoming more prevalent. They
help to reduce the onboarding costs for new customers as well as the financial
impact of managing Cloud Services by automating these previously manual tasks.
With the widespread use of such systems, the adoption of a common standard for
describing Cloud applications will provide a crucial advantage by enabling
reusable and portable applications. TOSCA, a newly published standard by OASIS
with broad industry participation provides this opportunity. Besides the
technical requirements of running and managing applications in the cloud,
non-functional requirements, like cost, security, and environmental issues, are
of special importance when moving towards the automated provisioning and
management of Cloud applications. In this paper we demonstrate how
non-functional requirements are defined in TOSCA using policies. We propose a
mechanism for automatic processing of these formal policy definitions in a
TOSCA runtime environment that we have developed based on the proposed
architecture of the TOSCA primer. In order to evaluate our approach, we present
prototypical implementations of security policies for encrypting databases and
for limiting the geographical location of the Cloud servers. We demonstrate how
our runtime environment is ensuring these policies and show how they affect the
deployment of the application.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2013-43&engl=1}
}
@inproceedings {INPROC-2013-08,
author = {Sebastian Wagner and Oliver Kopp and Frank Leymann},
title = {{Consolidation of Interacting BPEL Process Models with Fault Handlers}},
booktitle = {Proceedings of the 5th Central-European Workshop on Services and their Composition (ZEUS 2013)},
address = {Rostock},
publisher = {CEUR Workshop Proceedings},
institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
type = {Workshop Paper},
month = {February},
year = {2013},
keywords = {BPEL; Choreography; Process Consolidation},
language = {English},
cr-category = {H.4.1 Office Automation},
ee = {http://zeus-workshop.eu/2013/},
department = {University of Stuttgart, Institute of Architecture of Application Systems},
abstract = {The interaction behavior between processes of organizations and their suppliers
can be modeled by using choreographies. When an organization decides to gain
more control about their suppliers and to minimize transaction costs they may
decide to insource these companies. This also requires the integration of the
partner processes into the organization. In previous work we proposed an
approach to merge (consolidate) interacting BPEL process models of different
partners into a single process model by deriving control flow links between the
process models from their interaction specification. In this work we are
detailing this consolidation approach. Thereby, special attention is turned on
extending the consolidation operations in a way that process models with fault
handlers can be merged.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2013-08&engl=1}
}
@inproceedings {INPROC-2013-03,
author = {Sebastian Wagner and Dieter Roller and Oliver Kopp and Tobias Unger and Frank Leymann},
title = {{Performance Optimizations for Interacting Business Processes}},
booktitle = {Proceedings of the first IEEE International Conference on Cloud Engineering (IC2E 2013)},
publisher = {IEEE Computer Society},
institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
pages = {1--7},
type = {Conference Paper},
month = {March},
year = {2013},
doi = {10.1109/IC2E.2013.34},
keywords = {Workflow Engine; BPEL; Choreography; Performance Optimization; Process Merge; Green Computing},
language = {English},
cr-category = {H.4.1 Office Automation},
department = {University of Stuttgart, Institute of Architecture of Application Systems},
abstract = {Choreographies describe the interaction behavior of processes at design time: a
choreography defines when messages have to be exchanged between the involved
processes during their runtime. In the context of Web services and the de-facto
workflow language BPEL, SOAP is used to encode the messages. When complex
messages are exchanged between the processes, this can become costly and time
consuming with respect to the overall execution time of a choreography. In this
work, we suggest three different performance optimization techniques for
workflow engines to reduce the number of message exchanges between the
interacting processes and hence, to decrease the execution times and costs of
the choreographies: intra-engine transport, service request caching, and inline
execution. We describe how these techniques are implemented in a workflow
engine. Performance measurements are carried out to determine the performance
improvements that are achieved with each optimization technique. We further
show that the optimizations also affect the energy consumption of the workflow
engine.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2013-03&engl=1}
}
@inproceedings {INPROC-2012-48,
author = {Paul J. Kearney and David A. Sinclair and Sebastian Wagner},
title = {{Security Design Patterns in the MASTER Workbench}},
booktitle = {Proceedings of the First International Workshop on Cyberpatterns: Unifying Design Patterns with Security, Attack and Forensic Patterns},
address = {Abingdon, UK},
publisher = {Oxford Brookes University},
institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
pages = {65--69},
type = {Workshop Paper},
month = {July},
year = {2012},
keywords = {business process; design pattern; model-driven design; security},
language = {English},
cr-category = {H.4.1 Office Automation},
ee = {http://cms.brookes.ac.uk/staff/HongZhu/CyberPatterns2012/index.html},
department = {University of Stuttgart, Institute of Architecture of Application Systems},
abstract = {This paper describes pattern-related aspects of the prototype Protection and
Assessment Workbench developed as part of the MASTER EU 7th Framework
collaborative research project. The Workbench supports a model-driven design
process within the overall MASTER methodology. It includes a Protection and
Regulatory Model (PRM) tool that is a step towards turning the Workbench into
an ‘organisational memory’ for design practices that accumulates and improves
over time. PRMs are essentially control process design patterns that
incorporate proven strategies in a re-usable form, saving time and improving
quality and consistency.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2012-48&engl=1}
}
@inproceedings {INPROC-2012-44,
author = {Sebastian Wagner and Christoph Fehling and Dimka Karastoyanova and David Schumm},
title = {{State Propagation-based Monitoring of Business Transactions}},
booktitle = {Proceedings of the 2012 IEEE International Conference on Service-Oriented Computing and Applications},
publisher = {IEEE Xplore},
institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
type = {Conference Paper},
month = {December},
year = {2012},
doi = {10.1109/SOCA.2012.6449464},
keywords = {Business Transactions, Process View, BPEL, Process Merge, Process Split, Monitoring, State Propagation},
language = {English},
cr-category = {H.4.1 Office Automation},
department = {University of Stuttgart, Institute of Architecture of Application Systems},
abstract = {Business analysts want to monitor the status of their business goals in a
business-centric manner, without any knowledge of the actual implementation
artifacts that contribute achieving these goals. Business transactions are one
means to represent business goals and requirements. A business transaction is
typically implemented by a choreography of different parties contributing to
the accomplishment of the common agreement. To meet the constantly changing
requirements for all parties in a business transaction choreographies often
have to be adapted (e.g. change in the distribution on different execution
environments). The resulting challenge is that the execution state of a
choreography executed on several locations has to be propagated to the business
analyst to enable monitoring of (adapted) business transactions. For this
purpose we introduce a meta-model and state model of business transactions.
Based on these models, we introduce a two-stage monitoring approach involving
state propagation of the execution status of the adapted choreography to the
original choreography and from there to the business transaction.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2012-44&engl=1}
}
@inproceedings {INPROC-2012-10,
author = {Sebastian Wagner and Oliver Kopp and Frank Leymann},
title = {{Towards Verification of Process Merge Patterns with Allen’s Interval Algebra}},
booktitle = {Proceedings of the 4th Central-European Workshop on Services and their Composition (ZEUS 2012)},
address = {Bamberg},
publisher = {CEUR Workshop Proceedings},
institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
pages = {1--8},
type = {Workshop Paper},
month = {March},
year = {2012},
language = {English},
cr-category = {H.4.1 Office Automation},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2012-10/INPROC-2012-10.pdf,
http://zeus2012.pi.uni-bamberg.de/},
department = {University of Stuttgart, Institute of Architecture of Application Systems},
abstract = {Choreographies present how parties collaborate to achieve an agreed business
objective. When companies are bought, their processes have to be in-sourced.
Thereby, their part in a choreography has to be merged with the part of their
acquiring business partner. Merging patterns may be applied to merge
reoccurring activity combinations, such as send/receive. It has to be proven
that each merge patterns keeps the relations of the original activities of the
choreography. As a first step, we show by an example how the relations between
activities may be expressed using the Allen calculus. We show for merging a
synchronous message exchange, which relations have to be considered for
validating an implementation of that merge.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2012-10&engl=1}
}
@inproceedings {INPROC-2012-02,
author = {Alexander Nowak and Tobias Binz and Frank Leymann and Daniel Schleicher and David Schumm and Sebastian Wagner},
title = {{Ein Konzept zur Identifikation {\"o}kologisch nachhaltiger Verbesserungspotentiale unter B{\"u}rgerbeteiligung}},
booktitle = {Tagungsband der Multikonferenz Wirtschaftsinformatik 2012},
address = {Berlin},
publisher = {Gito Verlag},
institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
pages = {1559--1570},
type = {Conference Paper},
month = {February},
year = {2012},
isbn = {978-3-942183-63-5},
keywords = {Nachhaltigkeitsmanagement, Green IT, Pattern Identifikation, Green Patterns, B{\"u}rgerbeteiligung},
language = {German},
cr-category = {H.4.1 Office Automation},
ee = {http://mkwi2012.de/downloads/MKWI2012_Tagungsband.pdf},
contact = {alexander.nowak@iaas.uni-stuttgart.de},
department = {University of Stuttgart, Institute of Architecture of Application Systems},
abstract = {Die Optimierung von Abl{\"a}ufen zum Erhalt der Wettbewerbsf{\"a}higkeit ist ein fester
Bestandteil heutiger Organisationen. Die immer vielf{\"a}ltigeren Anforderungen an
Optimierungsvorhaben, sowie die steigende Komplexit{\"a}t der zu optimierenden
Problemstellungen erfordert zum einen die Erschlie{\ss}ung neuer Wissensquellen und
zum anderen die zielorientierte Nutzung geeigneter Verfahrensmuster aus
fr{\"u}heren Problemstellungen. In dieser Arbeit wird am Beispiel der
Identifikation {\"o}kologisch nachhaltiger Verbesserungspotentiale unter Nutzung
von B{\"u}rgerbeteiligungen gezeigt, wie soziale Aspekte innerhalb von
Optimierungsverfahren effizient eingesetzt und anschlie{\ss}end als strukturierte
Verfahrensmuster wiederverwendbar gemacht werden k{\"o}nnen.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2012-02&engl=1}
}
@inproceedings {INPROC-2011-65,
author = {Alexander Nowak and Frank Leymann and Daniel Schleicher and David Schumm and Sebastian Wagner},
title = {{Green Business Process Patterns}},
booktitle = {Proceedings of the 18th Conference on Pattern Languages of Programs, PLoP 2011},
publisher = {ACM},
institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
type = {Conference Paper},
month = {October},
year = {2011},
doi = {10.1145/2578903.2579144},
keywords = {Green IT; Green Patterns; Green Business Process Management; Environmental Impact},
language = {English},
cr-category = {H.4.1 Office Automation},
department = {University of Stuttgart, Institute of Architecture of Application Systems},
abstract = {To ensure their competitive advantage an increasing number of organizations
adopt business process management for design, automation, and analysis of their
business processes. In order to reduce cost, improve quality, save time, and
increase flexibility, techniques for business process improvement and
re-engineering are applied. Improving the environmental impact of a business
process is a new challenge organizations are faced with. However, current
approaches and techniques for business process optimization do not cover the
ecological dimension explicitly. In this paper, we propose patterns which
describe good solutions for green business process design to address this gap
from a business perspective. The patterns are described independently from
concrete business process modeling languages and execution environments in
order to provide a broad applicability of the patterns within different
scenarios. In addition to the patterns, we discuss the general usability of the
patterns based on different aspects relevant to an organization.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2011-65&engl=1}
}
@inproceedings {INPROC-2011-60,
author = {Oliver Kopp and Frank Leymann and Sebastian Wagner},
title = {{Modeling Choreographies: BPMN 2.0 versus BPEL-based Approaches}},
booktitle = {Enterprise Modelling and Information Systems Architectures - EMISA 2011},
publisher = {Gesellschaft f{\"u}r Informatik e.V. (GI)},
institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
series = {Lecture Notes in Informatics},
type = {Workshop Paper},
month = {September},
year = {2011},
language = {English},
cr-category = {H.4.1 Office Automation},
ee = {http://www.wiso.uni-hamburg.de/conferences/emisa2011/},
department = {University of Stuttgart, Institute of Architecture of Application Systems},
abstract = {Choreographies capture the collaboration aspects between two or more processes.
Explicit choreography notations have been included in the upcoming version 2.0
of the Business Process Model and Notation language (BPMN 2.0). This paper
presents a first evaluation of the choreography modeling capabilities of BPMN
2.0 and presents a summary of the evaluation of BPEL-based approaches. The
result is that BPMN 2.0 does not support reference passing and is tightly tied
to technical configurations.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2011-60&engl=1}
}
@inproceedings {INPROC-2011-58,
author = {Sebastian Wagner and Oliver Kopp and Frank Leymann},
title = {{Towards Choreography-based Process Distribution In The Cloud}},
booktitle = {Proceedings of the 2011 IEEE International Conference on Cloud Computing and Intelligence Systems},
address = {Bejing, China},
publisher = {IEEE Xplore},
institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
pages = {490--494},
type = {Conference Paper},
month = {September},
year = {2011},
doi = {10.1109/CCIS.2011.6045116},
language = {English},
cr-category = {H.4.1 Office Automation,
H.5.3 Group and Organization Interfaces},
contact = {sebastian.wagner@iaas.uni-stuttgart.de},
department = {University of Stuttgart, Institute of Architecture of Application Systems},
abstract = {Choreographies provide means to describe collaborations. Each partner runs its
own processes. To reduce the amount of data exchanged and to save resources,
part of the choreography can be run on a community cloud. We show how private
parts of a choreography can still be run on-premise and how non-private parts
can be merged to make use of the cloud infrastructure.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2011-58&engl=1}
}
@inproceedings {INPROC-2011-14,
author = {Oliver Kopp and Frank Leymann and Tobias Unger and Sebastian Wagner},
title = {{Towards The Essential Flow Model}},
booktitle = {Proceedings of the 3rd Central-European Workshop on Services and their Composition (ZEUS 2011)},
editor = {Daniel Eichhorn and Agnes Koschmider and Huayu Zhang},
publisher = {CEUR-WS.org},
institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
series = {CEUR Workshop Proceedings},
volume = {705},
pages = {26--33},
type = {Workshop Paper},
month = {March},
year = {2011},
language = {English},
cr-category = {H.4.1 Office Automation},
ee = {http://zeus2011.aifb.kit.edu/},
department = {University of Stuttgart, Institute of Architecture of Application Systems},
abstract = {Many of today's manufacturing projects are so complex that they cannot be
conducted only by one company anymore. Current approaches for modeling
inter-enterprise processes require an early decision on the way activities are
connected. The modeler has to decide between control flow and message flow.
This implies an early decision on the used IT-technology. We present a modeling
approach where this decision is postponed to a later modeling phase. This
enables modelers to concentrate on the essentials of the model.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2011-14&engl=1}
}
@inproceedings {INPROC-2010-13,
author = {Frank Leymann and Tobias Unger and Sebastian Wagner},
title = {{On designing a people-oriented constraint-based workflow language}},
booktitle = {Proceedings of the 2nd Central-European Workshop on Services and their Composition, ZEUS 2010, Berlin, Germany, February 25--26, 2010},
editor = {Christian Gierds and Jan S{\"u}rmeli},
publisher = {CEUR-WS.org},
institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
series = {CEUR Workshop Proceedings},
volume = {563},
pages = {25--31},
type = {Workshop Paper},
month = {March},
year = {2010},
language = {German},
cr-category = {H.4.1 Office Automation},
ee = {http://sunsite.informatik.rwth-aachen.de/Publications/CEUR-WS/Vol-563/,
http://ceur-ws.org/Vol-563/paper3.pdf},
contact = {unger@iaas.uni-stuttgart.de},
department = {University of Stuttgart, Institute of Architecture of Application Systems},
abstract = {The control-flow of business workflows is characterized by the strict execution
order of the activities that is already defined at design time. This
well-structured control-flow is for instance absolutely necessary if the
workflows have to be performed fully automatically. However, this rigidity is
not always appropriate for people-oriented workflows. Especially in scenarios
where real world processes are only semi-structured humans should have more
freedom to decide in which order they want to perform the activities. In this
paper, we suggest an approach to design people-oriented workflows via
constraints to make them more flexible.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2010-13&engl=1}
}
@inproceedings {INPROC-2010-102,
author = {Tobias Unger and Sebastian Wagner},
title = {{Collaboration Aspects of Human Tasks}},
booktitle = {Proceedings of the 1st International Workshop on Cross Enterprise Collaboration, People, and Work (CEC-PAW10)},
address = {Hoboken, NJ},
publisher = {-},
institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
type = {Workshop Paper},
month = {September},
year = {2010},
language = {English},
cr-category = {H.4.1 Office Automation},
contact = {unger@iaas.uni-stuttgart.de},
department = {University of Stuttgart, Institute of Architecture of Application Systems},
abstract = {Many of today's development and manufacturing projects are so complex that they
cannot be conducted only by one company anymore. Such collaborations are mostly
modeled and executed using business processes. Business processes are
increasingly controlled automatically by IT-systems, but they still consist of
many tasks that have to be performed by people. Collaborations using business
process are are widely discussed in the context of choreographies and
subprocesses. However, collaborations on human task level are discussed much
less. The goal of this work is to lay a foundation of a cross-organizational
federated task management infrastructure, which supports collaborations on task
level.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2010-102&engl=1}
}
@inproceedings {INPROC-2010-101,
author = {Tobias Unger and Hanna Eberle and Frank Leymann and Sebastian Wagner},
title = {{An Event-model for Constraint-based Person-centric Flows}},
booktitle = {Proceedings of the 2010 International Conference on Progress in Informatics and Computing (PIC-2010)},
publisher = {IEEE},
institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
pages = {927--932},
type = {Conference Paper},
month = {December},
year = {2010},
isbn = {978-1-4244-6788-4},
doi = {10.1109/PIC.2010.5687886},
language = {English},
cr-category = {H.4.1 Office Automation},
ee = {http://pic.sjtu.edu.cn,
http://ieeexplore.ieee.org/search/freesrchabstract.jsp?navigation=no&arnumber=5687886},
contact = {unger@iaas.uni-stuttgart.de},
department = {University of Stuttgart, Institute of Architecture of Application Systems},
abstract = {Over the past years research in pervasive computing has demonstrated the
potential of context-aware and proactive technologies for improving human work
performance and to ensure that people act compliant according to predefined
regulations. Human work can be structured into tasks, whereas a task is
representing an atomic human work entity. A person-centric flow is an
IT-representation of the flow of activities an individual person is performing.
For example the daily care schedule of a nurse can be understood as the
person-centric flow of the nurse. To be able to effectively guide a person in a
complex and highly dynamic work environment and to react on possible deviations
from the flow the supporting system is required to be aware of the state of the
person-centric-flow. Beside guidance the flow information can be utilized to
check compliance of a person’s flow with prescribed sequences of operation. In
this paper we propose a constraint-based workflow model for person-centric
flows and an event-model which can be used to inform applications about the
state of these flows.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2010-101&engl=1}
}
@article {ART-2016-26,
author = {Uwe Breitenb{\"u}cher and Christian Endres and K{\'a}lm{\'a}n K{\'e}pes and Oliver Kopp and Frank Leymann and Sebastian Wagner and Johannes Wettinger and Michael Zimmermann},
title = {{The OpenTOSCA Ecosystem - Concepts \& Tools}},
journal = {European Space project on Smart Systems, Big Data, Future Internet - Towards Serving the Grand Societal Challenges - Volume 1: EPS Rome 2016},
publisher = {SciTePress},
pages = {112--130},
type = {Article in Journal},
month = {December},
year = {2016},
isbn = {978-989-758-207-3},
doi = {10.5220/0007903201120130},
keywords = {TOSCA; OpenTOSCA; Orchestration; Management; Cloud},
language = {English},
cr-category = {D.2.2 Software Engineering Design Tools and Techniques,
D.2.9 Software Engineering Management},
department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Applications of Parallel and Distributed Systems;
University of Stuttgart, Institute of Architecture of Application Systems},
abstract = {Automating the provisioning and management of Cloud applications is one of the
most important issues in Cloud Computing. The Topology and Orchestration
Specification for Cloud Applications (TOSCA) is an OASIS standard for
describing Cloud applications and their management in a portable and
interoperable manner. TOSCA enables modeling the application's structure in the
form of topology models and employs the concept of executable management plans
to describe all required management functionality regarding the application. In
this paper, we give an overview of TOSCA and the OpenTOSCA Ecosystem, which is
an implementation of the TOSCA standard. The ecosystem consists of
standard-compliant tools that enable modeling application topology models and
automating the provisioning and management of the modeled applications.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2016-26&engl=1}
}
@article {ART-2016-19,
author = {Marina Bitsaki and Christos Koutras and George Koutras and Frank Leymann and Frank Steimle and Sebastian Wagner and Matthias Wieland},
title = {{ChronicOnline: Implementing a mHealth solution for monitoring and early alerting in chronic obstructive pulmonary disease}},
journal = {Health Informatics Journal},
publisher = {Sage Publications},
pages = {1--10},
type = {Article in Journal},
month = {April},
year = {2016},
doi = {10.1177/1460458216641480},
keywords = {chronic obstructive pulmonary disease; cloud computing; health services; mobile applications; monitoring},
language = {English},
cr-category = {C.2.4 Distributed Systems,
H.2.8 Database Applications,
J.3 Life and Medical Sciences},
ee = {http://jhi.sagepub.com/content/early/2016/04/16/1460458216641480.full.pdf+html},
department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Applications of Parallel and Distributed Systems;
University of Stuttgart, Institute of Architecture of Application Systems},
abstract = {Lack of time or economic difficulties prevent chronic obstructive pulmonary
disease patients from communicating regularly with their physicians, thus
inducing exacerbation of their chronic condition and possible hospitalization.
Enhancing Chronic patients{\^a}€™ Health Online proposes a new, sustainable and
innovative business model that provides at low cost and at significant savings
to the national health system, a preventive health service for chronic
obstructive pulmonary disease patients, by combining human medical expertise
with state-of-the-art online service delivery based on cloud computing,
service-oriented architecture, data analytics, and mobile applications. In this
article, we implement the frontend applications of the Enhancing Chronic
patients{\^a}€™ Health Online system and describe their functionality and the
interfaces available to the users.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2016-19&engl=1}
}
@article {ART-2016-18,
author = {Frank Steimle and Matthias Wieland and Bernhard Mitschang and Sebastian Wagner and Frank Leymann},
title = {{Extended provisioning, security and analysis techniques for the ECHO health data management system}},
journal = {Computing},
publisher = {Springer},
pages = {1--19},
type = {Article in Journal},
month = {October},
year = {2016},
doi = {10.1007/s00607-016-0523-8},
language = {English},
cr-category = {C.2.4 Distributed Systems,
H.2.8 Database Applications,
J.3 Life and Medical Sciences},
ee = {http://dx.doi.org/10.1007/s00607-016-0523-8},
department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Applications of Parallel and Distributed Systems},
abstract = {eHealth gains more and more interest since a lot of end-user devices supporting
health data capturing are available. The captured data has to be managed and
securely stored, in order to access it from different devices and share it with
other users such as physicians. The aim of the german-greek research project
ECHO is to support the treatment of patients, who suffer from chronic
obstructive pulmonary disease, a chronic respiratory disease. Usually the
patients need to be examined by their physicians on a regular basis due to
their chronic condition. Since this is very time consuming and expensive we
developed an eHealth system which allows the physician to monitor patients
condition remotely, e.g., via smart phones. This article is an extension of
previous work, where we introduced a health data model and an associated
platform-architecture for the management and analysis of the data provided by
the patients. There we have also shown how the security of the data is ensured
and we explained how the platform can be provided in a cloud-based environment
using the OASIS standard TOSCA, which enables a self-contained management of
cloud-services. In this article we provide a more detailed description about
the health data analysis, provisioning and security aspects of the eHealth
system.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2016-18&engl=1}
}
@article {ART-2013-03,
author = {Carlos Rodr{\'\i}guez and Daniel Schleicher and Florian Daniel and Fabio Casati and Frank Leymann and Sebastian Wagner},
title = {{SOA-enabled compliance management: instrumenting, assessing, and analyzing service-based business processes}},
journal = {Service Oriented Computing and Applications},
editor = {Springer},
publisher = {Springer},
pages = {1--18},
type = {Article in Journal},
month = {February},
year = {2013},
issn = {1863-2386},
issn = {1863-2394},
keywords = {Service-based compliance governance; Compliance assessment; Signaling instrumentation; Key indicators; Root cause analysis; Reporting dashboard},
language = {English},
cr-category = {H.4.1 Office Automation},
department = {University of Stuttgart, Institute of Architecture of Application Systems},
abstract = {Facilitating compliance management, that is, assisting a company’s management
in conforming to laws, regulations, standards, contracts, and policies, is a
hot but non-trivial task. The service-oriented architecture (SOA) has evolved
traditional, manual business practices into modern, service-based IT practices
that ease part of the problem: the systematic definition and execution of
business processes. This, in turn, facilitates the online monitoring of system
behaviors and the enforcement of allowed behaviors—all ingredients that can be
used to assist compliance management on the fly during process execution. In
this paper, instead of focusing on monitoring and runtime enforcement of rules
or constraints, we strive for an alternative approach to compliance management
in SOAs that aims at assessing and improving compliance. We propose two
ingredients: (i) a model and tool to design compliant service-based processes
and to instrument them in order to generate evidence of how they are executed
and (ii) a reporting and analysis suite to create awareness of a company’s
compliance state and to enable understanding why and where compliance
violations have occurred. Together, these ingredients result in an approach
that is close to how the real stakeholders—compliance experts and
auditors—actually assess the state of compliance in practice and that is less
intrusive than enforcing compliance.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2013-03&engl=1}
}
@article {ART-2012-03,
author = {Alexander Nowak and Tobias Binz and Christoph Fehling and Oliver Kopp and Frank Leymann and Sebastian Wagner},
title = {{Pattern-driven Green Adaptation of Process-based Applications and their Runtime Infrastructure}},
journal = {Computing},
publisher = {Springer Wien},
pages = {463--487},
type = {Article in Journal},
month = {February},
year = {2012},
doi = {10.1007/s00607-012-0188-x},
keywords = {Green Business Process Pattern, Cloud Pattern, Green IT, TOSCA, Adaptation of Applications, Ecological Sustainable Business Processes},
language = {English},
cr-category = {H.4.1 Office Automation},
department = {University of Stuttgart, Institute of Architecture of Application Systems},
abstract = {Business Processes are a key aspect of modern organization. In recent years,
business process management and optimization has been applied to different
cross-cutting concerns such as security, compliance, or Green IT, for example.
Based on the ecological characteristics of a business process, proper
environmentally sustainable adaptation strategies can be chosen to improve the
total environmental impact of the business process. We use ecological
sustainable adaptation strategies that are described as Green Business Process
Patterns. The application of such a Green Business Process Pattern, however,
affects the business process layer, the application component and the
infrastructure layer. This implies that changes in the application
infrastructure also need to be considered. Hence, we use best practices of
cloud application architectures which are described as Cloud Patterns. To guide
developers through the adaptation process we propose a pattern-based approach
in this work. We correlate Cloud Patterns relevant for sustainable business
processes to Green Business Process Patterns and organize them within a
classification. To provide concrete implementation support we further annotate
these Cloud Patterns to application component models that are described with
the Topology and Orchestration Specification for Cloud Applications (TOSCA).
Using these annotations, we describe a method that provides the means to
optimize business processes based on Green Business Process Patterns through
adapting the implementation of application components with concrete TOSCA
implementation models.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2012-03&engl=1}
}