@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 = {University of Stuttgart : Collaborative Research Center SFB 627 (Nexus: World Models for Mobile Context-Based Systems), Germany},
   pages = {132--143},
   type = {Workshop Paper},
   month = {June},
   year = {2009},
   keywords = {uncertainty; inconsistency; trust; processing model},
   language = {English},
   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 = {University of Stuttgart, Institute of Parallel and Distributed Systems, Distributed Systems;
                  University of Stuttgart, Institute of Parallel and Distributed Systems, Applications of Parallel and Distributed Systems},
   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=1}
}

@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 = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   series = {Lecture Notes in Computer Science},
   volume = {5872},
   pages = {98--107},
   type = {Workshop Paper},
   month = {November},
   year = {2009},
   language = {German},
   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 = {University of Stuttgart, Institute of Parallel and Distributed Systems, Distributed Systems},
   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=1}
}

@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 = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {42--61},
   type = {Conference Paper},
   month = {November},
   year = {2009},
   language = {English},
   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 = {University of Stuttgart, Institute of Parallel and Distributed Systems, Distributed Systems},
   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=1}
}

@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 = {University of Stuttgart : Collaborative Research Center SFB 627 (Nexus: World Models for Mobile Context-Based Systems), Germany},
   pages = {1--10},
   type = {Conference Paper},
   month = {June},
   year = {2009},
   language = {English},
   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 = {University of Stuttgart, Institute of Parallel and Distributed Systems, Distributed Systems},
   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=1}
}

@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 = {University of Stuttgart : Collaborative Research Center SFB 627 (Nexus: World Models for Mobile Context-Based Systems), Germany},
   pages = {1--12},
   type = {Workshop Paper},
   month = {June},
   year = {2009},
   keywords = {data uncertainty; position information; position accuracy; spatial queries},
   language = {English},
   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 = {University of Stuttgart, Institute for Natural Language Processing;
                  University of Stuttgart, Institute of Parallel and Distributed Systems, Distributed Systems},
   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=1}
}

@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 = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {405--412},
   type = {Conference Paper},
   month = {July},
   year = {2009},
   doi = {10.1109/ICWS.2009.82},
   isbn = {978-0-7695-3709-2},
   keywords = {Business Process Management; BPM; BPEL; Enforcement},
   language = {English},
   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 = {University of Stuttgart, Institute of Architecture of Application Systems;
                  University of Stuttgart, Institute of Parallel and Distributed Systems, Distributed Systems},
   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=1}
}

@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 = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {1--6},
   type = {Conference Paper},
   month = {August},
   year = {2009},
   language = {English},
   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 = {University of Stuttgart, Institute of Parallel and Distributed Systems, Distributed Systems},
   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=1}
}

@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 = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {1--12},
   type = {Conference Paper},
   month = {June},
   year = {2009},
   language = {English},
   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 = {University of Stuttgart, Institute of Parallel and Distributed Systems, Distributed Systems},
   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=1}
}

@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 = {University of Stuttgart, Faculty of Computer Science, Germany},
   pages = {613--617},
   type = {Workshop Paper},
   month = {June},
   year = {2009},
   doi = {10.1145/1582379.1582512},
   language = {English},
   cr-category = {C.2.1 Network Architecture and Design,
                   C.2.4 Distributed Systems},
   department = {University of Stuttgart, Institute of Parallel and Distributed High-Performance Systems, Distributed Systems},
   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=1}
}

@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 = {University of Stuttgart : Collaborative Research Center SFB 627 (Nexus: World Models for Mobile Context-Based Systems), Germany},
   pages = {1--6},
   type = {Conference Paper},
   month = {June},
   year = {2009},
   language = {English},
   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 = {University of Stuttgart, Institute of Parallel and Distributed Systems, Distributed Systems},
   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=1}
}

@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 = {University of Stuttgart : Collaborative Research Center SFB 627 (Nexus: World Models for Mobile Context-Based Systems), Germany},
   pages = {1--10},
   type = {Conference Paper},
   month = {May},
   year = {2009},
   keywords = {ad-hoc; mobile; RFID-sensor; urban sensing},
   language = {English},
   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 = {University of Stuttgart, Institute of Parallel and Distributed Systems, Distributed Systems},
   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=1}
}

@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 = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {1--2},
   type = {Workshop Paper},
   month = {June},
   year = {2009},
   language = {English},
   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 = {University of Stuttgart, Institute of Parallel and Distributed Systems, Distributed Systems},
   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=1}
}

@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 = {University of Stuttgart : Collaborative Research Center SFB 627 (Nexus: World Models for Mobile Context-Based Systems), Germany},
   pages = {1--4},
   type = {Conference Paper},
   month = {March},
   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 = {English},
   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 = {University of Stuttgart, Institute of Parallel and Distributed Systems, Distributed Systems;
                  University of Stuttgart, Institute of Architecture of Application Systems;
                  University of Stuttgart, Institute of Parallel and Distributed Systems, Applications of Parallel and Distributed Systems},
   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=1}
}

@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 = {University of Stuttgart : Collaborative Research Center SFB 627 (Nexus: World Models for Mobile Context-Based Systems), Germany},
   pages = {1--10},
   type = {Conference Paper},
   month = {March},
   year = {2009},
   keywords = {Remote trajectory simplification; tracking; dead reckoning; moving objects database; MOD; line simplification},
   language = {English},
   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 = {University of Stuttgart, Institute of Parallel and Distributed Systems, Distributed Systems},
   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=1}
}

@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 = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   series = {Electronic Communications of the EASST},
   volume = {17},
   pages = {1--6},
   type = {Workshop Paper},
   month = {March},
   year = {2009},
   issn = {1863-2122},
   keywords = {Global Sensor Networks, Wireless Sensor Networks, Predictors},
   language = {English},
   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 = {University of Stuttgart, Institute of Parallel and Distributed Systems, Distributed Systems},
   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=1}
}

@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 = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   type = {Conference Paper},
   month = {January},
   year = {2009},
   doi = {10.1007/978-3-540-92666-5_13},
   language = {English},
   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 = {University of Stuttgart, Institute of Parallel and Distributed Systems, Distributed Systems},
   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=1}
}

@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 = {Article in Journal},
   month = {November},
   year = {2009},
   doi = {10.1145/1614379.1614388},
   keywords = {Wireless sensor network; Coordination; Energy; Lifetime goal; Programming abstraction},
   language = {English},
   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 = {University of Stuttgart, Institute of Parallel and Distributed Systems, Distributed Systems},
   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=1}
}

@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 = {Article in Journal},
   month = {April},
   year = {2009},
   language = {English},
   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 = {University of Stuttgart, Institute of Parallel and Distributed Systems, Distributed Systems},
   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=1}
}

@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 = {Article in Journal},
   month = {January},
   year = {2009},
   doi = {10.1007/s10723-008-9114-z},
   language = {English},
   cr-category = {C.2.1 Network Architecture and Design,
                   C.2.2 Network Protocols,
                   C.2.4 Distributed Systems,
                   C.2.6 Internetworking},
   department = {University of Stuttgart, Institute of Parallel and Distributed High-Performance Systems, Distributed Systems},
   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=1}
}

@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 = {Article in Journal},
   month = {October},
   year = {2009},
   language = {English},
   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 = {University of Stuttgart, Institute of Parallel and Distributed Systems, Distributed Systems},
   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=1}
}

@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 = {Article in Journal},
   month = {October},
   year = {2009},
   language = {German},
   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 = {University of Stuttgart, Institute of Parallel and Distributed Systems, Distributed Systems},
   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=1}
}

@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 = {Article in Book},
   month = {March},
   year = {2009},
   language = {German},
   cr-category = {C.2.4 Distributed Systems},
   department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Distributed Systems},
   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=1}
}

@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 = {University of Stuttgart : Collaborative Research Center SFB 627 (Nexus: World Models for Mobile Context-Based Systems), Germany},
   series = {Lecture Notes in Computer Science},
   volume = {5786},
   pages = {184},
   type = {Proceedings},
   month = {June},
   year = {2009},
   isbn = {978-3-642-04558-5},
   keywords = {context-aware systems; location-based services; quality; context},
   language = {English},
   cr-category = {H.2.8 Database Applications,
                   H.3.3 Information Search and Retrieval,
                   H.3.5 Online Information Services},
   department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Applications of Parallel and Distributed Systems;
                  Universit{\"a}t Stuttgart, Institut f{\"u}r Photogrammetrie (ifp);
                  University of Stuttgart, Institute of Parallel and Distributed Systems, Distributed Systems;
                  University of Stuttgart, Institute for Natural Language Processing},
   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=1}
}

@book {BOOK-2009-02,
   editor = {Alejandro Buchmann and Boris Koldehofe},
   title = {{IT-Information Technology}},
   publisher = {Oldenbourg Verlag},
   volume = {51},
   number = {2009},
   pages = {80},
   type = {Book},
   month = {October},
   year = {2009},
   doi = {10.1524/itit.2009.9058},
   language = {English},
   cr-category = {C.2.4 Distributed Systems},
   department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Distributed Systems;
                  University of Stuttgart, Institute of Parallel and Distributed Systems},
   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=1}
}