@inproceedings {INPROC-2014-95,
   author = {Simon Gansel and Stephan Schnitzer and Ahmad Gilbeau-Hammoud and Viktor Friesen and Frank D{\"u}rr and Kurt Rothermel and Christian Maih{\"o}fer},
   title = {{An access control concept for novel automotive HMI systems}},
   booktitle = {Proceedings of the 19th ACM symposium on Access control models and technologies, 2014, London, Ontario, Canada.},
   publisher = {ACM},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {17--28},
   type = {Conference Paper},
   month = {June},
   year = {2014},
   isbn = {978-1-4503-2939-2},
   doi = {10.1145/2613087.2613104},
   keywords = {Access Control; State-based Model; Automotive; Windows},
   language = {English},
   cr-category = {D.4.6 Operating Systems Security and Protection,
                   H.5.2 Information Interfaces and Presentation User Interfaces},
   ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2014-95/INPROC-2014-95.pdf,
      http://dl.acm.org/citation.cfm?id=2613104},
   department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Distributed Systems},
   abstract = {The relevance of graphical functions in vehicular applications has increased
      significantly during the few last years. Modern cars are equipped with multiple
      displays used by different applications such as speedometer or navigation
      system. However, so far applications are restricted to using dedicated
      displays. In order to increase flexibility, the requirement of sharing displays
      between applications has emerged. Sharing displays leads to safety and security
      concerns since safety-critical applications as the dashboard warning lights
      share the same displays with uncritical or untrusted applications like the
      navigation system or third-party applications. To guarantee the safe and secure
      sharing of displays, we present a formal model for defining and controlling the
      access to display areas in this paper. We prove the validity of this model, and
      present a proof-of-concept implementation to demonstrate the feasibility of our
      concept.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2014-95&engl=1}
}

@inproceedings {INPROC-2014-94,
   author = {Stephan Schnitzer and Simon Gansel and Frank D{\"u}rr and Kurt Rothermel},
   title = {{Concepts for execution time prediction of 3D GPU rendering}},
   booktitle = {9th IEEE International Symposium on Industrial Embedded Systems (SIES), 2014, pp.160-169, 18-20 June 2014},
   publisher = {IEEE},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {160--169},
   type = {Conference Paper},
   month = {June},
   year = {2014},
   isbn = {10.1109/SIES.2014.6871200},
   keywords = {3D-rendering; GPU-scheduling; embedded systems; execution time prediction; real-time},
   language = {English},
   cr-category = {H.5.2 Information Interfaces and Presentation User Interfaces,
                   I.3.m Computer Graphics Miscellaneous},
   ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2014-94/INPROC-2014-94.pdf,
      http://dx.doi.org/10.1109/SIES.2014.6871200},
   department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Distributed Systems},
   abstract = {The relevance of graphical functions in vehicular applications has increased
      significantly during the last years. Modern cars are equipped with multiple
      displays used by different applications such as speedometer, navigation system,
      or media players. The recent trend towards hardware consolidation to reduce
      hardware cost, installation space, and energy consumption, causes graphical 3D
      applications of different safety-criticality to share a single GPU. This
      requires effective real-time GPU scheduling concepts to ensure safety and
      isolation for 3D rendering. Since current GPUs are not preemptible, a
      deadline-based scheduler must know the GPU execution time of GPU commands in
      advance. In this work, we present a novel framework to measure and predict the
      execution time of GPU commands using OpenGL ES 2.0. We present prediction
      models for the main GPU commands relevant for 3D rendering, namely, FLUSH,
      CLEAR, and DRAW. For the DRAW command we propose to use the 3D bounding box of
      the rendered model and apply the vertex shader projection to heuristically
      estimate the number of fragments rendered. We finally present the
      implementation and evaluation of our framework, which demonstrates its
      feasibility and shows that good prediction accuracy can be achieved. In our
      evaluation using realistic scenarios the absolute prediction error of the DRAW
      command did not exceed 260 µs.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2014-94&engl=1}
}

@inproceedings {INPROC-2014-78,
   author = {Florian Berg and Frank D{\"u}rr and Kurt Rothermel},
   title = {{Optimal Predictive Code Offloading}},
   booktitle = {Proceedings of the 11th International Conference on Mobile and Ubiquitous Systems: Computing, Networking and Services},
   publisher = {IEEE Computer Society},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {1--10},
   type = {Conference Paper},
   month = {December},
   year = {2014},
   doi = {10.4108/icst.mobiquitous.2014.258023},
   keywords = {Code Offloading; Markov chain; Link quality},
   language = {English},
   cr-category = {C.2.4 Distributed Systems},
   ee = {http://dl.acm.org/citation.cfm?id=2692985},
   contact = {Florian.Berg@ipvs.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Distributed Systems},
   abstract = {Modern mobile devices like smart phones and tablets are equipped with powerful
      processing and memory resources, enabling resource-intensive mobile
      applications such as high-end mobile games. The main limitation, however,
      remains the energy resource. To improve the energy efficiency, code offloading
      has been proposed, which offloads code to remote servers and transfers the
      results back to the mobile device. Although several approaches have shown that
      code offloading improves energy efficiency significantly in general, they
      largely neglect the adverse effects of network disconnections. Therefore, we
      have proposed the concept of preemptive code offloading to improve energy
      efficiency also under link failures. It transmits so-called safe-points between
      server and mobile device during remote execution, enabling the re-use of
      partial remote results after link failures. In this paper, we improve our basic
      preemptive code offloading approach by optimizing the time when to generate and
      transmit safe-points to minimize the communication overhead and maximize energy
      efficiency. To find the optimal safe-point schedule, we use a predictive
      approach that predicts the mobile link quality in order to send safe-points
      before network disconnections. Moreover, we consider additional deadline
      constraints for code execution to ensure a minimal responsiveness of offloaded
      applications despite link failures. Our evaluation results show that energy
      efficiency can be improved significantly using our predictive offloading
      approach.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2014-78&engl=1}
}

@inproceedings {INPROC-2014-74,
   author = {Ruben Mayer and Boris Koldehofe and Kurt Rothermel},
   title = {{Meeting Predictable Buffer Limits in the Parallel Execution of Event Processing Operators}},
   booktitle = {Proceedings of the 2014 IEEE International Conference on Big Data, BigData '14},
   publisher = {IEEE},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {402--411},
   type = {Conference Paper},
   month = {October},
   year = {2014},
   keywords = {Complex Event Processing, Stream Processing, Data Parallelization, Self-Adaptation, Quality of Service},
   language = {English},
   cr-category = {C.2.4 Distributed Systems,
                   C.4 Performance of Systems},
   ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2014-74/INPROC-2014-74.pdf},
   department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Distributed Systems},
   abstract = {Complex Event Processing (CEP) systems enable applications to react to
      live-situations by detecting event patterns (complex events) in data streams.
      With the increasing number of data sources and the increasing volume at which
      data is produced, parallelization of event detection is becoming of tremendous
      importance to limit the time events need to be buffered before they actually
      can be processed by an event detector—named event processing operator. In this
      paper, we propose a pattern-sensitive partitioning model for data streams that
      is capable of achieving a high degree of parallelism for event patterns which
      formerly could only be consistently detected in a sequential manner or at a low
      parallelization degree. Moreover, we propose methods to dynamically adapt the
      parallelization degree to limit the buffering imposed on event detection in the
      presence of dynamic changes to the workload. Extensive evaluations of the
      system behavior show that the proposed partitioning model allows for a high
      degree of parallelism and that the proposed adaptation methods are able to meet
      the buffering level for event detection under high and dynamic workloads.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2014-74&engl=1}
}

@inproceedings {INPROC-2014-67,
   author = {Muhammad Adnan Tariq and Boris Koldehofe and Sukanya Bhowmik and Kurt Rothermel},
   title = {{PLEROMA: A SDN-based High Performance Publish/Subscribe Middleware}},
   booktitle = {To appear in Proceedings of the ACM/IFIP/USENIX Middleware Conference},
   publisher = {ACM press.},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   type = {Conference Paper},
   month = {December},
   year = {2014},
   doi = {10.1145/2663165.2663338},
   keywords = {Content-based Routing, Publish/Subscribe, Software-defined Networking, Network Virtualization},
   language = {English},
   cr-category = {C.2.1 Network Architecture and Design,
                   C.2.4 Distributed Systems,
                   D.2.11 Software Engineering Software Architectures},
   ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2014-67/INPROC-2014-67.pdf},
   department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Distributed Systems},
   abstract = {With the increasing popularity of Software-defined networks (SDN), TCAM memory
      of switches can be directly accessed by a publish/subscribe middleware to
      perform filtering operations at low latency. This way two important
      requirements for a publish/subscribe middleware can be fulfilled: namely
      bandwidth efficiency and line-rate performance in forwarding messages between
      producers and consumers. Nevertheless, it is challenging to sustain line-rate
      performance in the presence of dynamic changes in the interest of producers and
      consumers. In this paper, we propose and evaluate the PLEROMA middleware to
      realize publish/subscribe at line-rate and bandwidth efficiently in SDN.
      PLEROMA offers methods to efficiently reconfigure a deployed topology in the
      presence of dynamic subscriptions and advertisements. Furthermore, PLEROMA
      ensures interoperability and independent reconfiguration of multiple controlled
      SDN networks.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2014-67&engl=1}
}

@inproceedings {INPROC-2014-57,
   author = {David Richard Sch{\"a}fer and Santiago G{\'o}mez S{\'a}ez and Thomas Bach and Vasilios Andrikopoulos and Muhammad Adnan Tariq},
   title = {{Towards Ensuring High Availability in Collective Adaptive Systems}},
   booktitle = {Proceedings of the First International Workshop of Business Processes in Collective Adaptive Systems: BPCAS'14; Eindhoven, Netherlands, September 8, 2014},
   publisher = {Springer},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   type = {Workshop Paper},
   month = {September},
   year = {2014},
   keywords = {workflows; high availability; service discovery; process fragment injection},
   language = {English},
   cr-category = {D.2.0 Software Engineering General,
                   D.2.11 Software Engineering Software Architectures,
                   D.2.12 Software Engineering Interoperability,
                   C.2.4 Distributed Systems,
                   C.4 Performance of Systems},
   ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2014-57/INPROC-2014-57.pdf},
   contact = {david.schaefer@ipvs.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems;
                  University of Stuttgart, Institute of Parallel and Distributed Systems, Distributed Systems},
   abstract = {Collective Adaptive Systems support the interaction and adaptation of virtual
      and physical entities towards achieving common objectives. For these systems,
      several challenges at the modeling, provisioning, and execution phases arise.
      In this position paper, we define the necessary underpinning concepts and
      identify requirements towards ensuring high availability in such systems. More
      specifically, based on a scenario from the EU Project ALLOW Ensembles, we
      identify the necessary requirements and derive an architectural approach that
      aims at ensuring high availability by combining active workflow replication,
      service selection, and dynamic compensation techniques.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2014-57&engl=1}
}

@inproceedings {INPROC-2014-55,
   author = {Thomas Kohler and Jan-Philipp Stegh{\"o}fer and D{\'\i}dac Busquets and Jeremy Pitt},
   title = {{The Value of Fairness: Trade-offs in Repeated Dynamic Resource Allocation}},
   booktitle = {Proceedings of the 2014 IEEE Eighth International Conference on Self-Adaptive and Self-Organizing Systems (SASO 2014), London, UK},
   publisher = {IEEE Computer Society},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {1--10},
   type = {Conference Paper},
   month = {September},
   year = {2014},
   doi = {10.1109/SASO.2014.12},
   isbn = {978-1-4799-5367-7},
   keywords = {artificial intelligence; distributive justice; electronic institution; fairness; multi-agent system; allocation},
   language = {English},
   cr-category = {I.2.11 Distributed Artificial Intelligence},
   ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2014-55/INPROC-2014-55.pdf,
      http://dx.doi.org/10.1109/SASO.2014.12},
   contact = {thomas.kohler@ipvs.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Distributed Systems},
   abstract = {Resource allocation problems are an important part of many distributed
      autonomous systems. In sensor networks, they determine which nodes get to use
      the communication links, in SmartGrid applications they decree which electric
      vehicle batteries are loaded, and in autonomous power management they select
      which generators produce the power required to satisfy the overall load. These
      cases have been considered in the literature before under the aspect of demand
      satisfaction: how well can distributed algorithms with local knowledge
      approximate the best allocation. A factor that has been ignored, however, is
      fairness: how fair is the resource allocation and - in extension - the
      distribution of revenue, wear, or recovery time.
      
      In this paper, we bring together previously disjoint approaches on dynamic
      distributed resource allocation and on fairness in electronic institutions. We
      show that fair allocations based on Ostrom's principles and on Rescher's canons
      of distributive justice create value in repeated resource allocations. We apply
      the scheme to solve the multi-objective problem of distributing load to
      generators fairly based on demands made by the individual generators. Our
      evaluation shows that a fair distribution increases satisfaction of the
      individual agents while reducing the hazard of optimising the problem in the
      short-term at the cost of long-term robustness and stability.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2014-55&engl=1}
}

@inproceedings {INPROC-2014-54,
   author = {Christoph Dibak and Boris Koldehofe},
   title = {{Towards Quality-aware Simulations on Mobile Devices}},
   booktitle = {Proceedings of the 44. Jahrestagung der Gesellschaft f{\"u}r Informatik e.V. (GI) (Informatik 2014)},
   publisher = {Gesellschaft f{\"u}r Informatik (GI)},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   series = {Lecture Notes in Informatics (LNI)},
   type = {Workshop Paper},
   month = {September},
   year = {2014},
   language = {English},
   cr-category = {C.2.4 Distributed Systems,
                   G.1.8 Partial Differential Equations},
   ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2014-54/INPROC-2014-54.pdf,
      http://www.gi.de/service/publikationen/lni},
   department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Distributed Systems},
   abstract = {Numerical simulations are import for analyzing Big Data and realizing
      applications in the Internet of Things. Running numerical simulations on mobile
      devices makes analyzing and reasoning about Big Data ubiquitous. However,
      mobile devices are limited in energy and compute resources, and connectivity to
      a dedicated infrastructure like a cloud cannot always be assured. Therefore, we
      propose to run the simulation on a distributed environment consisting of a
      mobile device and the cloud. This environment has a number of constraints for
      compute and network resources that need to be considered for providing
      simulation results in time and with high quality. In this paper we propose an
      architecture for mobile simulations and list challenges for realizing them.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2014-54&engl=1}
}

@inproceedings {INPROC-2014-32,
   author = {Florian Berg and Frank D{\"u}rr and Kurt Rothermel},
   title = {{Increasing the Efficiency and Responsiveness of Mobile Applications with Preemptable Code Offloading}},
   booktitle = {Proceedings of the 3rd IEEE International Conference on Mobile Services: MS'14; Anchorage, Alaska, USA, June 27 - July 2, 2014},
   publisher = {IEEE Computer Society},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {76--83},
   type = {Conference Paper},
   month = {June},
   year = {2014},
   doi = {10.1109/MobServ.2014.20},
   keywords = {Distributed Systems, Code Offloading, Safe-points, Mobile Cloud Computing, Efficiency, Responsiveness},
   language = {English},
   cr-category = {C.2.4 Distributed Systems},
   ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2014-32/INPROC-2014-32.pdf,
      http://dx.doi.org/10.1109/MobServ.2014.20},
   contact = {Florian.Berg@ipvs.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Distributed Systems},
   abstract = {Mobile applications are getting more and more sophisticated and demanding.
      Although the processing, memory, and storage resources of mobile devices are
      constantly increasing to enable such resource-demanding mobile applications,
      battery capacity is still the main limiting factor. To solve this problem,
      mobile code offloading approaches can be used to offload parts of a mobile
      application to remote servers and utilize the resources of cloud services. In
      this paper, we propose a novel code offloading approach that makes code
      offloading robust against communication link failures, which are still a major
      problem of mobile systems. To this end, we propose preemptable code offloading.
      It allows for interrupting the offloading process and continuing the remote
      execution locally after a link failure, without abandoning the complete result
      calculated remotely so far. The basic idea of our approach is to create
      safe-points of the remote execution and transmit these intermediate results
      back to the mobile device. After a link failure, the mobile device can now
      continue execution from the last transmitted safe-point. Although safe-points
      induce communication and energy overhead, our evaluations show that using an
      optimized safe-point schedule this overhead quickly pays off under link
      failures. Besides reducing the overall energy consumption significantly,
      responsiveness also benefits from safe-points by meeting given execution
      deadlines after link failures.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2014-32&engl=1}
}

@inproceedings {INPROC-2014-31,
   author = {Beate Ottenw{\"a}lder and Boris Koldehofe and Kurt Rothermel and Kirak Hong and Umakishore Ramachandran},
   title = {{RECEP: Selection-based Reuse for Distributed Complex Event Processing}},
   booktitle = {Proceedings of the 8th ACM International Conference on Distributed Event-Based Systems (DEBS 2014)},
   publisher = {ACM},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {59--70},
   type = {Conference Paper},
   month = {May},
   year = {2014},
   doi = {10.1145/2611286.2611297},
   keywords = {mobility; complex event processing; query optimization},
   language = {English},
   cr-category = {C.2.1 Network Architecture and Design,
                   C.2.4 Distributed Systems},
   ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2014-31/INPROC-2014-31.pdf},
   department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Distributed Systems},
   abstract = {An appealing use case of complex event processing (CEP) systems is for mobile
      users to react in real-time to events in their environment, e.g., to the
      occurrence of a dangerous situation such as an accident. Maintaining mobile CEP
      systems is highly resource intensive since in many cases events need to be
      detected in a consumer-centric manner to ensure low latency event detection and
      high quality of results. In this paper we propose the RECEP system to increase
      the scalability of mobile CEP systems. In the presence of mobile users with
      partially overlapping interest, the RECEP system offers methods to efficiently
      reuse computations and this way reduces the resource requirements of mobile
      CEP. Since reuse of computations happens with respect to well defined quality
      metrics, RECEP can be easily tailored to specific mobile applications and
      maximize the resource savings for their desired quality in terms of precision
      and recall of the processed events from the user's environment.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2014-31&engl=1}
}

@inproceedings {INPROC-2014-29,
   author = {David Richard Sch{\"a}fer and Thomas Bach and Muhammad Adnan Tariq and Kurt Rothermel},
   title = {{Increasing Availability of Workflows Executing in a Pervasive Environment}},
   booktitle = {Proceedings of the 2014 IEEE International Conference on Services Computing},
   address = {Anchorage, AK, USA},
   publisher = {IEEE Computer Society},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {717--724},
   type = {Conference Paper},
   month = {June},
   year = {2014},
   doi = {10.1109/SCC.2014.98},
   isbn = {978-1-4799-5066-9/14},
   language = {English},
   cr-category = {C.2.4 Distributed Systems,
                   C.4 Performance of Systems},
   ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2014-29/INPROC-2014-29.pdf,
      http://dx.doi.org/10.1109/SCC.2014.98},
   department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Distributed Systems},
   abstract = {Workflows have gained enormous importance to organize and manage business
      processes. With the recent advent of smartphones and mobile applications,
      traditional business process management is shifting. Now, long-running business
      processes (workflows) have to be executed in large-scale distributed and
      pervasive environments. Due to the heterogeneity and high dynamicity of such
      environments, they are vulnerable to frequent communication and device failures
      and, thus, impose new requirements on the execution of workflows. To increase
      the availability, we concurrently executed restructured replicas of workflows
      on multiple nodes. We developed techniques to generate differently structured
      replicas and propose a metric that identifies the set of replicas that ensures
      the highest availability during execution. Finally, we presented a distributed
      algorithm to coordinate and synchronize the concurrent execution of the
      identified replicas while maintaining the original workflow semantics. Our
      methods approximately double the availability during execution, while our
      generation techniques produce almost optimal replicas over a hundred times
      faster.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2014-29&engl=1}
}

@inproceedings {INPROC-2014-26,
   author = {Andreas Benzing and Boris Koldehofe and Kurt Rothermel},
   title = {{Bandwidth-Minimized Distribution of Measurements in Global Sensor Networks}},
   booktitle = {In Proceedings of the 14th IFIP International Conference on Distributed Applications and Interoperable Systems (DAIS 2014)},
   publisher = {Springer-Verlag},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   series = {Lecture Notes in Computer Science},
   volume = {8460},
   pages = {156--170},
   type = {Conference Paper},
   month = {June},
   year = {2014},
   doi = {10.1007/978-3-662-43352-2_13},
   keywords = {Data Streams; Global Sensor Networks; Optimization},
   language = {English},
   cr-category = {C.2.4 Distributed Systems},
   ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2014-26/INPROC-2014-26.pdf,
      http://link.springer.com/chapter/10.1007/978-3-662-43352-2_13},
   department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Distributed Systems},
   abstract = {Global sensor networks (GSN) allow applications to integrate huge amounts of
      data using real-time streams from virtually anywhere. Queries to a GSN offer
      many degrees of freedom, e.g. the resolution and the geographic origin of data,
      and scaling optimization of data streams to many applications is highly
      challenging. Existing solutions hence either limit the flexibility with
      additional constraints or ignore the characteristics of sensor streams where
      data points are produced synchronously. In this paper, we present a new
      approach to bandwidth-minimized distribution of real-time sensor streams in a
      GSN. Using a distributed index structure, we partition queries for bandwidth
      management and quickly identify overlapping queries. Based on this information,
      our relay strategy determines an optimized distribution structure which
      minimizes traffic while being adaptive to changing conditions. Simulations show
      that total traffic and user perceived delay can be reduced by more than 50\%.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2014-26&engl=1}
}

@inproceedings {INPROC-2014-03,
   author = {Damian Philipp and Patrick Baier and Christoph Dibak and Frank D{\"u}rr and Kurt Rothermel and Susanne Becker and Michael Peter and Dieter Fritsch},
   title = {{MapGENIE: Grammar-enhanced Indoor Map Construction from Crowd-sourced Data}},
   booktitle = {Proceedings of the 12th IEEE International Conference on Pervasive Computing and Communications (PerCom 2014)},
   address = {Budapest, Hungary},
   publisher = {IEEE Computer Society Conference Publishing Services},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {139--147},
   type = {Conference Paper},
   month = {March},
   year = {2014},
   doi = {10.1109/PerCom.2014.6813954},
   keywords = {Public Sensing; Opportunistic Sensing; Indoor Mapping; Map Reconstruction; IMU; Grammar},
   language = {English},
   cr-category = {C.2.4 Distributed Systems},
   ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2014-03/INPROC-2014-03.pdf,
      http://dx.doi.org/10.1109/PerCom.2014.6813954},
   contact = {damian.philipp@ipvs.uni-stuttgart.de patrick.baier@ipvs.uni-stuttgart.de christoph.dibak@ipvs.uni-stuttgart.de frank.duerr@ipvs.uni-stuttgart.de susanne.becker@ifp.uni-stuttgart.de michael.peter@ifp.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Distributed Systems},
   abstract = {While location-based services are already well established in outdoor
      scenarios, they are still not available in indoor environments. The reason for
      this can be found in two open problems: First, there is still no off-the-shelf
      indoor positioning system for mobile devices and, second, indoor maps are not
      publicly available for most buildings. While there is an extensive body of work
      on the first problem, the efficient creation of indoor maps remains an open
      challenge.
      
      We tackle the indoor mapping challenge in our MapGENIE approach that
      automatically derives indoor maps from traces collected by pedestrians moving
      around in a building. Since the trace data is collected in the background from
      the pedestrians' mobile devices, MapGENIE avoids the labor-intensive task of
      traditional indoor map creation and increases the efficiency of indoor mapping.
      To enhance the map building process, MapGENIE leverages exterior information
      about the building and uses grammars to encode structural information about the
      building. Hence, in contrast to existing work, our approach works without any
      user interaction and only needs a small amount of traces to derive the indoor
      map of a building. To demonstrate the performance of MapGENIE, we implemented
      our system using Android and a foot-mounted IMU to collect traces from
      volunteers. We show that using our grammar approach, compared to a purely
      trace-based approach we can identify up to four times as many rooms in a
      building while at the same time achieving a consistently lower error in the
      size of detected rooms.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2014-03&engl=1}
}

@article {ART-2014-07,
   author = {Beate Ottenw{\"a}lder and Boris Koldehofe and Kurt Rothermel and Kirak Hong and David Lillethun and Umakishore Ramachandran},
   title = {{MCEP: A Mobility-Aware Complex Event Processing System}},
   journal = {ACM Transactions Internet Technology},
   editor = {Munindar P. Singh},
   publisher = {ACM},
   volume = {14},
   number = {1},
   pages = {1--24},
   type = {Article in Journal},
   month = {August},
   year = {2014},
   issn = {1533-5399 EISSN:1557-6051},
   keywords = {Mobility, complex event processing, migration, moving range queries},
   language = {English},
   cr-category = {C.2.1 Network Architecture and Design,
                   C.2.4 Distributed Systems},
   ee = {http://doi.acm.org/10.1145/2633688},
   department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Distributed Systems},
   abstract = {With the proliferation of mobile devices and sensors, complex event processing
      (CEP) is becoming increasingly important to scalably detect situations in real
      time. Current CEP systems are not capable of dealing efficiently with highly
      dynamic mobile consumers whose interests change with their location. We
      introduce the distributed mobile CEP (MCEP) system which automatically adapts
      the processing of events according to a consumer's location. MCEP significantly
      reduces latency, network utilization, and processing overhead by providing
      on-demand and opportunistic adaptation algorithms to dynamically assign event
      streams and computing resources to operators of the MCEP system.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2014-07&engl=1}
}

@article {ART-2014-03,
   author = {Marius Wernke and Pavel Skvortsov and Frank D{\"u}rr and Kurt Rothermel},
   title = {{A Classification of Location Privacy Attacks and Approaches}},
   journal = {Personal and Ubiquitous Computing (Special Issue on Security and Trust in Context-Aware Systems)},
   publisher = {Springer London},
   volume = {18},
   number = {1},
   pages = {163--175},
   type = {Article in Journal},
   month = {January},
   year = {2014},
   issn = {1617-4909},
   doi = {10.1007/s00779-012-0633-z},
   keywords = {location-based services; location privacy; adversary; attack; classification; location privacy approaches},
   language = {English},
   cr-category = {C.2.4 Distributed Systems,
                   H.3.5 Online Information Services},
   ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/ART-2014-03/ART-2014-03.pdf,
      http://link.springer.com/article/10.1007%2Fs00779-012-0633-z,
      http://www.priloc.de},
   department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Distributed Systems},
   abstract = {In recent years, location-based services have become very popular, mainly
      driven by the availability of modern mobile devices with integrated position
      sensors. Prominent examples are points of interest finders or geo-social
      networks like Facebook Places, Qype, Loopt. Because these services access
      private position information, location privacy concepts become mandatory in
      order to ensure that users accept these services.
      
      Many different concepts and approaches for the protection of location privacy
      have been described in the literature. These approaches differ with respect to
      the protected information and their effectiveness against different attacks.
      The goal of this paper is to assess the applicability and effectiveness of
      location privacy approaches systematically. We first identify different
      protection goals, namely, personal information (user identity), spatial
      information (user position), and temporal information (identity/position +
      time). Secondly, we give an overview of basic principles and existing
      approaches to protect these privacy goals. In a third step, we classify
      possible attacks. Finally, we analyzed existing approaches with respect to
      their protection goals and their ability to resists the introduced attacks.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2014-03&engl=1}
}

@article {ART-2014-01,
   author = {Muhammad Adnan Tariq and Boris Koldehofe and Kurt Rothermel},
   title = {{Securing Broker-Less Publish/Subscribe Systems using Identity-Based Encryption}},
   journal = {IEEE Transactions on Parallel and Distributed Systems},
   address = {Los Alamitos, CA, USA},
   publisher = {IEEE Computer Society},
   volume = {25},
   number = {2},
   pages = {518--528},
   type = {Article in Journal},
   month = {February},
   year = {2014},
   doi = {10.1109/TPDS.2013.256},
   issn = {1045-9219},
   keywords = {Identity-based encryption; Routing; Servers; Subscriptions; Distributed Systems; Security and Privacy Protection},
   language = {English},
   cr-category = {C.2.4 Distributed Systems},
   ee = {http://dx.doi.org/10.1109/TPDS.2013.256,
      http://doi.ieeecomputersociety.org/10.1109/TPDS.2013.256,
      http://www.computer.org/cms/Computer.org/dl/trans/td/2014/02/extras/ttd2014020518s.pdf},
   department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Distributed Systems},
   abstract = {The provisioning of basic security mechanisms such as authentication and
      confidentiality is highly challenging in a content-based publish/subscribe
      system. Authentication of publishers and subscribers is difficult to achieve
      due to the loose coupling of publishers and subscribers. Likewise,
      confidentiality of events and subscriptions conflicts with content-based
      routing. This article presents a novel approach to provide confidentiality and
      authentication in a broker-less content-based publish-subscribe system. The
      authentication of publishers and subscribers as well as confidentiality of
      events is ensured, by adapting the pairing-based cryptography mechanisms, to
      the needs of a publish/subscribe system. Furthermore, an algorithm to cluster
      subscribers according to their subscriptions preserves a weak notion of
      subscription confidentiality. In addition to our previous work, this article
      contributes i) use of searchable encryption to enable efficient routing of
      encrypted events, ii) Multi-credential routing a new event dissemination
      strategy to strengthen the weak subscription confidentiality, and iii) thorough
      analysis of different attacks on subscription confidentiality. The overall
      approach provides fine grained key management and the cost for encryption,
      decryption and routing is in the order of subscribed attributes. Moreover, the
      evaluations show that providing security is affordable w.r.t. i) throughput of
      the proposed cryptographic primitives, and ii) delays incurred during the
      construction of the publish/subscribe overlay and the event dissemination.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2014-01&engl=1}
}