Sebastian Feld, M.Sc.

Sebastian Feld, M.Sc.

Lehrstuhl für Mobile und Verteilte Systeme

Ludwig-Maximilians-Universität München, Institut für Informatik

Oettingenstraße 67
80538 München

Raum E 008

Telefon: +49 89 / 2180-9421

Fax: +49 89 / 2180-9148

Mail: sebastian.feld@ifi.lmu.de

Aufgabengebiet

Route Planning and Navigation
Alternative Route Graphs
Time Series and Trajectories
Computational Geometry and Graph Theory

Sprechstunde

auf Anfrage

Abschlussarbeiten

Bei Interesse an einer Abschlussarbeit in meinem Themengebiet könnt ihr euch gerne bei mir melden. Ihr findet unten eine Liste von aktuell ausgeschriebenen Abschlussarbeiten, die aber nicht zwingend vollständig sein muss. Falls ihr eigene Ideen habt und glaubt, dass man sie mit meinem Themengebiet verbinden kann, so könnt ihr euch auch gerne melden. Die Ausarbeitungssprache ist grundsätzlich in Deutsch.
Stand: April 2017

Aktuell ausgeschriebene Abschlussarbeiten

  • Quality Metrics for Alternative Routes in Constrained Free Space Scenarios
  • Segmenting Trajectories in Constrained Free Space Scenarios Using Bayesian Surprise
  • Identifying Structures in Buildings Using Approximated Environment Features
  • Length (& Diversity) Estimation and Calculation of Loopless Alternative Routes

Zugeteilte Abschlussarbeiten

  • Network Function Virtualization – eine Taxonomie
  • Concept and Implementation of a Workflow Monitoring Tool for Big Data Processes
  • Routensynthese in Straßennetzen basierend auf Freihandzeichnungen
  • Candidate Sets For Alternative Routes in Constrained Free Space Scenarios
  • Nutzung von Isochronen zur Findung alternativer Routen in Indoor-Szenarien
  • Effiziente Annäherung von Eigenschaften räumlicher Wahrnehmung
  • Erkennung von Raumeingängen in Indoor-Navigations-Szenarien anhand von Isovisten
  • Datenanalyse von Probe-Request Aufzeichnungen zur Bestimmung von Archetypen
  • Template-basierte Bewertung von Eigengewichtsübungen mithilfe von Sensordaten

Abgeschlossene Arbeiten

  • Trajektorienvergleich ohne Alignment
  • Automatische Erkennung von Wegekreuzungen in Gebäuden mithilfe von Isovists
  • Skalierbarkeit der IT-Sicherheit am Beispiel eines globalen Finanzdienstleisters
  • Navigation in Gebäuden
  • Geräteübergreifende Benutzeridentifikation
  • Segmentierung von Pfaden in Gebäuden zur Analyse des Ähnlichkeitsverhaltens
  • Kontextsensitives Routing für ein informationszentrisches hybrides Radionetzwerk
  • Analyse des Einflusses von Merkmalskombinationen auf die Erstellung archetypischer Routen
  • Vergleich und Analyse menschlicher und algorithmischer Routenwahl in Gebäuden
  • Kartenbasierte Eigenschaften archetypischer Routen
  • Sensorbasierte Kollisionsanalyse stationärer Objekte
  • Routing mit polygonalen Sperren
  • Weiterentwicklung eines Benutzerinterfaces für Fahrzeugführer zur Anzeige des bevorstehenden Verhaltens von Lichtzeichensignalanlagen durch Integration eines Verfahrens zur Fahrtrichtungsvorhersage
  • Hindernis-getriebener Ansatz zur Ermittlung azyklischer Routen in Gebäudeplänen
  • Microscopic Traffic Estimation for Green Wave Routing
  • Performanceanalyse dynamischer, auf Schaltzeitprognosen für Lichtsignalanlagen basierender Routingalgorithmus auf dem Münchener Verkehrsnetz
  • Konzeption und Implementierung eines Plateau-Algorithmus zur Ermittlung von alternativen Routen in Gebäuden
  • Kompression von Routen mittels Persistenz
  • Annäherung des kürzesten homotopen Pfades mittels Kurvenglättung
  • Erweiterung der Privatsphäre-schonenden Routenplanung für kontinuierliche Positions-Updates
  • Implementierung und Evaluation verschiedener Karten-Darstellungen für ein Framework zur Ermittlung alternativer Routen
  • Konzeption und Implementierung eines Penalty-Algorithmus für Indoor-Szenarien
  • Klassifizierung und Sortierung von alternativen Routen in Gebäudeplänen
  • Indizierung von Trajektorien ohne Alignment
  • Archetypal Analysis in Indoor Navigation Scenarios
  • Dynamisches Routing im Straßennetz unter Einbeziehung von Schaltzeitprognosen für Lichtsignalanlagen
  • Konzeptionierung einer Geo-Social-Media-Platform für die Mobile Edge
  • Verfahren zur Distanzmessung zwischen Trajektorien
  • Lastoptimierung in Mobilfunknetzen durch Mobile-Edge-Computing am Beispiel eines Videokonferenzsystems

Publikationen

2016

  • M. T. Beck, S. Feld, C. Linnhhoff-Popien, and U. Pützschler, "Mobile Edge Computing," Informatik-Spektrum, vol. 39, iss. 2, pp. 108-114, 2016.
    [BibTeX] [Download PDF]
    @Article{Beck2016Mobile,
    Title = {Mobile Edge Computing},
    Author = {Michael Till Beck and Sebastian Feld and Claudia Linnhhoff-Popien and Uwe Pützschler},
    Journal = {Informatik-Spektrum},
    Year = {2016},
    Number = {2},
    Pages = {108-114},
    Volume = {39},
    Owner = {mbeck},
    Timestamp = {2016.04.29},
    Url = {http://rd.springer.com/article/10.1007/s00287-016-0957-6}
    }
  • A. Ebert, S. Feld, and F. Dorfmeister, "Segmented and Directional Impact Detection for Parked Vehicles using Mobile Devices," in 23rd International Conference on Systems, Signals and Image Processing (IWSSIP 2016), 2016.
    [BibTeX]
    @InProceedings{ebert2016segmented,
    Title = {Segmented and Directional Impact Detection for Parked Vehicles using Mobile Devices},
    Author = {André Ebert and Sebastian Feld and Florian Dorfmeister},
    Booktitle = {23rd International Conference on Systems, Signals and Image Processing (IWSSIP 2016)},
    Year = {2016},
    Publisher = {IEEE},
    Owner = {aebert},
    Timestamp = {2016.07.01}
    }
  • S. Feld, C. Linnhhoff-Popien, and R. Göttmann, "Wo bleibt die Sehnsucht nach dem Neuen?," Informatik-Spektrum, vol. 39, iss. 2, pp. 105-107, 2016.
    [BibTeX] [Download PDF]
    @Article{Feld2016Wo,
    Title = {Wo bleibt die Sehnsucht nach dem Neuen?},
    Author = {Sebastian Feld and Claudia Linnhhoff-Popien and Rainer Göttmann},
    Journal = {Informatik-Spektrum},
    Year = {2016},
    Number = {2},
    Pages = {105-107},
    Volume = {39},
    Owner = {sfeld},
    Timestamp = {2016.04.29},
    Url = {http://rd.springer.com/article/10.1007/s00287-016-0959-4}
    }
  • S. Feld, H. Lyu, and A. Keler, "Identifying Divergent Building Structures Using Fuzzy Clustering of Isovist Features," in Accepted at the 13th International Conference on Location-Based Services (LBS 2016), 2016.
    [BibTeX]
    @InProceedings{feld2016identifying,
    Title = {Identifying Divergent Building Structures Using Fuzzy Clustering of Isovist Features},
    Author = {Sebastian Feld and Hao Lyu and Andreas Keler},
    Booktitle = {Accepted at the 13th International Conference on Location-Based Services (LBS 2016)},
    Year = {2016},
    Owner = {sfeld}
    }
  • S. Feld, M. Schönfeld, and M. Werner, "Traversing Bitcoin’s P2P network: Insights into the structure of a decentralized currency," International Journal of Computational Science and Engineering (IJCSE), Special Issue on Security and Trust Issues in Peer-to-Peer Networks, vol. 13, iss. 2, pp. 122-131, 2016.
    [BibTeX] [Abstract] [Download PDF]
    Bitcoin has become increasingly important for several years. While being declared dead in the meantime, it got a boost in 2011. The exchange rate increased from \$14 in January 2013 up to \$240 in April 2013 and even \$900 in early 2014. Lots of existing work addresses the analysis of the publicly available transaction graph. There are evaluations of the user's anonymity and privacy, but no proper measurements of the underlying network. In this paper, we present novel insights about Bitcoin's peer-to-peer network, with a focus on its distribution among distinct autonomous systems. The resilience of the Bitcoin ecosystem, the unambiguousness of the blockchain in use, the propagation and verification of transaction blocks, but also the anonymity of Bitcoin's users depend on the structure of the global peer-to-peer network. Our work is the first thorough analysis of Bitcoin's underlying peer-to-peer network, especially with regard to its distribution at the autonomous system level. We traversed Bitcoin's peer-to-peer network in a protocol-compliant manner and made statements about the size of the accessible network and the number of clients. This information is useful when modelling the probability of attacks against the user's privacy or other aspects. Further, we investigated the distribution of the peer-to-peer network on autonomous systems. The concrete form has an impact on the above-mentioned topics, such as vitality, resilience or privacy. Finally, we analysed the mechanism to announce known peers. It turns out that Bitcoin's peer announcement is not well distributed, affecting information propagation.
    @Article{bitcoinjournal,
    Title = {Traversing Bitcoin’s P2P network: Insights into the structure of a decentralized currency},
    Author = {Sebastian Feld and Mirco Schönfeld and Martin Werner},
    Journal = {International Journal of Computational Science and Engineering (IJCSE), Special Issue on Security and Trust Issues in Peer-to-Peer Networks},
    Year = {2016},
    Number = {2},
    Pages = {122-131},
    Volume = {13},
    Abstract = {Bitcoin has become increasingly important for several years. While being declared dead in the meantime, it got a boost in 2011. The exchange rate increased from \$14 in January 2013 up to \$240 in April 2013 and even \$900 in early 2014. Lots of existing work addresses the analysis of the publicly available transaction graph. There are evaluations of the user's anonymity and privacy, but no proper measurements of the underlying network. In this paper, we present novel insights about Bitcoin's peer-to-peer network, with a focus on its distribution among distinct autonomous systems. The resilience of the Bitcoin ecosystem, the unambiguousness of the blockchain in use, the propagation and verification of transaction blocks, but also the anonymity of Bitcoin's users depend on the structure of the global peer-to-peer network. Our work is the first thorough analysis of Bitcoin's underlying peer-to-peer network, especially with regard to its distribution at the autonomous system level. We traversed Bitcoin's peer-to-peer network in a protocol-compliant manner and made statements about the size of the accessible network and the number of clients. This information is useful when modelling the probability of attacks against the user's privacy or other aspects. Further, we investigated the distribution of the peer-to-peer network on autonomous systems. The concrete form has an impact on the above-mentioned topics, such as vitality, resilience or privacy. Finally, we analysed the mechanism to announce known peers. It turns out that Bitcoin's peer announcement is not well distributed, affecting information propagation.},
    Owner = {sfeld},
    Url = {http://www.inderscience.com/offer.php?id=78441}
    }
  • S. Feld, M. Werner, and C. Linnhoff-Popien, "Approximated Environment Features With Application to Trajectory Annotation," in Accepted at the 6th IEEE Symposium Series on Computational Intelligence (IEEE SSCI 2016), 2016.
    [BibTeX]
    @InProceedings{feld2016approximated,
    Title = {Approximated Environment Features With Application to Trajectory Annotation},
    Author = {Sebastian Feld and Martin Werner and Claudia Linnhoff-Popien},
    Booktitle = {Accepted at the 6th IEEE Symposium Series on Computational Intelligence (IEEE SSCI 2016)},
    Year = {2016},
    Owner = {sfeld}
    }
  • S. Feld, M. Werner, and C. Linnhoff-Popien, "Criteria for Selecting Small Sets of Alternative Routes in Free Space Scenarios," in Accepted at the 13th International Conference on Location-Based Services (LBS 2016), 2016.
    [BibTeX]
    @InProceedings{feld2016criteria,
    Title = {Criteria for Selecting Small Sets of Alternative Routes in Free Space Scenarios},
    Author = {Sebastian Feld and Martin Werner and Claudia Linnhoff-Popien},
    Booktitle = {Accepted at the 13th International Conference on Location-Based Services (LBS 2016)},
    Year = {2016},
    Owner = {sfeld}
    }

2015

  • M. Beck, S. Feld, and T. Schimper, "Vom Zugangs- zum Dienstanbieter: Wie Mobilfunkprovider das Internet der Zukunft mitgestalten können," in Marktplätze im Umbruch - Digitale Strategien fuer Services im Mobilen Internet, C. Linnhoff-Popien, M. Zaddach, and A. Grahl, Eds., Springer Berlin Heidelberg, 2015, pp. 123-131.
    [BibTeX] [Abstract]
    Dieser Beitrag beleuchtet, inwieweit sich Mobilfunkprovider in den letzten Jahren zu Infrastrukturprovidern gewandelt haben, die primär Datenvolumen an externe Dienste weiterleiten, an denen sie selbst finanziell nicht beteiligt sind. Am Beispiel der Mobile Edge Computing Technologie wird erörtert, wie diesem Trend entgegengewirkt werden kann und der Wandel vom Infrastrukturprovider hin zum Dienstanbieter gelingen kann.
    @InCollection{marktplaetzebuch,
    Title = {Vom Zugangs- zum Dienstanbieter: Wie Mobilfunkprovider das Internet der Zukunft mitgestalten können},
    Author = {Michael Beck and Sebastian Feld and Thomas Schimper},
    Booktitle = {Marktplätze im Umbruch - Digitale Strategien fuer Services im Mobilen Internet},
    Publisher = {Springer Berlin Heidelberg},
    Year = {2015},
    Editor = {Claudia Linnhoff-Popien and Michael Zaddach and Andreas Grahl},
    Pages = {123-131},
    Series = {Xpert.press},
    Abstract = {Dieser Beitrag beleuchtet, inwieweit sich Mobilfunkprovider in den letzten Jahren zu Infrastrukturprovidern gewandelt haben, die primär Datenvolumen an externe Dienste weiterleiten, an denen sie selbst finanziell nicht beteiligt sind. Am Beispiel der Mobile Edge Computing Technologie wird erörtert, wie diesem Trend entgegengewirkt werden kann und der Wandel vom Infrastrukturprovider hin zum Dienstanbieter gelingen kann.},
    Owner = {mbeck}
    }
  • M. T. Beck, S. Feld, A. Fichtner, C. Linnhoff-Popien, and T. Schimper, "ME-VoLTE: Network Functions for Energy-Efficient Video Transcoding at the Mobile Edge," in 18th International Conference on Intelligence in Next Generation Networks (ICIN 2015), 2015, pp. 38-44. doi:http://dx.doi.org/10.1109/ICIN.2015.7073804
    [BibTeX] [Abstract]
    Encoding multimedia streams of video calls is a very compute-intense task that significantly decreases battery lifetime of mobile phones. This paper introduces an approach to reduce power consumption of mobile phones by offloading video encoding efforts from mobile devices to external services. These services are hosted on servers co-located with cellular base stations. The paper describes how these services are integrated into the existing mobile network architecture and presents a communication protocol for negotiating offloading settings. First measurement results indicate that power consumption of mobile devices is reduced by approximately 13\%.
    @InProceedings{mecsip,
    Title = {ME-VoLTE: Network Functions for Energy-Efficient Video Transcoding at the Mobile Edge},
    Author = {Michae Till Beck and Sebastian Feld and Andreas Fichtner and Claudia Linnhoff-Popien and Thomas Schimper},
    Booktitle = {18th International Conference on Intelligence in Next Generation Networks (ICIN 2015)},
    Year = {2015},
    Pages = {38-44},
    Publisher = {IEEE},
    Abstract = {Encoding multimedia streams of video calls is a very compute-intense task that significantly decreases battery lifetime of mobile phones. This paper introduces an approach to reduce power consumption of mobile phones by offloading video encoding efforts from mobile devices to external services. These services are hosted on servers co-located with cellular base stations. The paper describes how these services are integrated into the existing mobile network architecture and presents a communication protocol for negotiating offloading settings. First measurement results indicate that power consumption of mobile devices is reduced by approximately 13\%.},
    Doi = {http://dx.doi.org/10.1109/ICIN.2015.7073804},
    Owner = {mbeck}
    }
  • A. Ebert, S. Feld, and M. Werner, "Nuanced Collision Detection for Parked Vehicles," in 12. GI/ITG KuVS Fachgespräch Ortsbezogene Anwendungen und Dienste (LBAS 2015), 2015.
    [BibTeX]
    @InProceedings{collisiondetection15,
    Title = {Nuanced Collision Detection for Parked Vehicles},
    Author = {André Ebert and Sebastian Feld and Martin Werner},
    Booktitle = {12. GI/ITG KuVS Fachgespräch Ortsbezogene Anwendungen und Dienste (LBAS 2015)},
    Year = {2015},
    Owner = {aebert}
    }
  • S. Feld, "Scoring of Alternative Routes Using Implicit Building Topologies," in Science and Information Conference (SAI 2015), 2015, pp. 329-336.
    [BibTeX] [Abstract]
    Currently navigation in indoor scenarios enjoys a highly increasing popularity. Besides that, there are numerous applications that utilize alternatives to a particular path. Think of a navigation system that proposes a mall's visitor three different routes: the fastest, a route passing restaurants, and a route traversing shops. Thus, the visitor is able to choose a route by personal preference or experience. Further users of alternative routes can be fire fighters, mobile robots, or nonplayer characters in video games. In contrast to navigation in road networks, there are several challenges to solve in indoor scenarios. First, the creation of alternative routes is not much discussed in literature. Second, due to the high degree of freedom there is a large number of alternative routes possible regarding a reference path. Third, there is no proper understanding of how to measure the meaningfulness or quality of an alternative route. This paper is a step towards the evaluation of alternative routes in indoor navigation scenarios and has got two main contributions. First, we propose to use the term congestion probability as a first common understanding to estimate the meaningfulness of alternative routes inside buildings. Most of the indoor use cases are looking for routes that either seek or avoid crowded areas - at least as one of multiple criteria. Additionally, we propose to score alternative routes based on a local and a global perception. The paper's second contribution is an algorithm that scores a set of alternative routes based on an ordinary floor plan. Thus, it compares a formerly non-valuated set of routes and creates a ranking regarding the congestion probability. Basically, the algorithm is based on the assumption that points on a map, that are frequently located on shortest paths, will also be frequently traversed. Due to the lack of appropriate data sets we discuss the algorithm's results in detail by means of four different indoor scenarios.
    @InProceedings{feld2015scoring,
    Title = {Scoring of Alternative Routes Using Implicit Building Topologies},
    Author = {Sebastian Feld},
    Booktitle = {Science and Information Conference (SAI 2015)},
    Year = {2015},
    Organization = {The Science and Information (SAI) Organization Limited},
    Pages = {329-336},
    Publisher = {IEEE},
    Abstract = {Currently navigation in indoor scenarios enjoys a highly increasing popularity. Besides that, there are numerous applications that utilize alternatives to a particular path. Think of a navigation system that proposes a mall's visitor three different routes: the fastest, a route passing restaurants, and a route traversing shops. Thus, the visitor is able to choose a route by personal preference or experience. Further users of alternative routes can be fire fighters, mobile robots, or nonplayer characters in video games. In contrast to navigation in road networks, there are several challenges to solve in indoor scenarios. First, the creation of alternative routes is not much discussed in literature. Second, due to the high degree of freedom there is a large number of alternative routes possible regarding a reference path. Third, there is no proper understanding of how to measure the meaningfulness or quality of an alternative route. This paper is a step towards the evaluation of alternative routes in indoor navigation scenarios and has got two main contributions. First, we propose to use the term congestion probability as a first common understanding to estimate the meaningfulness of alternative routes inside buildings. Most of the indoor use cases are looking for routes that either seek or avoid crowded areas - at least as one of multiple criteria. Additionally, we propose to score alternative routes based on a local and a global perception. The paper's second contribution is an algorithm that scores a set of alternative routes based on an ordinary floor plan. Thus, it compares a formerly non-valuated set of routes and creates a ranking regarding the congestion probability. Basically, the algorithm is based on the assumption that points on a map, that are frequently located on shortest paths, will also be frequently traversed. Due to the lack of appropriate data sets we discuss the algorithm's results in detail by means of four different indoor scenarios.},
    Owner = {sfeld}
    }
  • S. Feld, M. Werner, M. Schönfeld, and S. Hasler, "Archetypes of Alternative Routes in Buildings," in 6th International Conference on Indoor Positioning and Indoor Navigation (IPIN 2015), 2015, pp. 1-10.
    [BibTeX] [Abstract]
    Alternative routes have found many applications in navigation scenarios. However, alternative routes have only been introduced recently for the indoor space due to the complexity of these environments. Furthermore, the number of alternative routes in buildings can be quite high. With this paper, we propose to organize sets of alternative routes by employing archetypal analysis on a feature space representation of routes and show results in which a set of hundreds of routes between the same start and end point has been compressed to only a few obviously different archetypal routes. Additionally, the framework allows for comparing routes with archetypes and with each other. This comparison does not reveal spatial similarity alone, but rather a measure of routes' similarity representing their inherent semantic character.
    @InProceedings{feld2015archetypes,
    Title = {Archetypes of Alternative Routes in Buildings},
    Author = {Sebastian Feld and Martin Werner and Mirco Schönfeld and Stefanie Hasler},
    Booktitle = {6th International Conference on Indoor Positioning and Indoor Navigation (IPIN 2015)},
    Year = {2015},
    Pages = {1-10},
    Abstract = {Alternative routes have found many applications in navigation scenarios. However, alternative routes have only been introduced recently for the indoor space due to the complexity of these environments. Furthermore, the number of alternative routes in buildings can be quite high. With this paper, we propose to organize sets of alternative routes by employing archetypal analysis on a feature space representation of routes and show results in which a set of hundreds of routes between the same start and end point has been compressed to only a few obviously different archetypal routes. Additionally, the framework allows for comparing routes with archetypes and with each other. This comparison does not reveal spatial similarity alone, but rather a measure of routes' similarity representing their inherent semantic character.},
    Owner = {sebastian},
    Timestamp = {2015.12.01}
    }
  • V. Protschky, S. Feld, and M. Wälischmiller, "Traffic Signal Adaptive Routing," in IEEE 18th International Conference on Intelligent Transportation Systems (ITSC 2015), 2015, pp. 450-456.
    [BibTeX] [Abstract]
    The knowledge of future Signal Phase and Timing information (SPaT) of traffic lights ahead enables a vast number of driving assistance functions, such as Green Light Optimal Speed Control (GLOSA), Red Light Duration Advisory (RLDA) or Traffic Signal Adaptive routing (TSA routing). The purpose of TSA routing is to reduce the travel time by choosing a route that is possibly longer than the shortest one but has less red lights. Whereas GLOSA and RLDA are quite easy to implement from a scientific point of view, TSA routing presents a certain challenge: first of all, TSA routing necessitates predictions on future signal states on a wider look in the future than GLOSA and RLDA, a possible reason why this field of research still seems rather unexplored. Second, there are still many unresolved issues, such as the inadequacy of graphs for TSA-routing, or proper traffic load estimations. In this paper, we present a fully functioning model for TSA routing on the basis of our forgoing research on the prediction of future signal states and address the question of practical usability by evaluating our model under realistic conditions. We analyze, among other things, the impact of partial knowledge on traffic light's future signal states and the impact of different traffic loads on TSA routes by means of a test field in Munich, Germany. We describe necessary modifications of the underlying transportation network's graph structure and shortest path routing algorithm to allow routing under consideration of future signal states of traffic lights. We show that, albeit there are many erratic aspects in traffic and signal states, TSA routing still reaches a significant travel time gain over usual routing in our test field.
    @InProceedings{protschky2015traffic,
    Title = {Traffic Signal Adaptive Routing},
    Author = {Valentin Protschky and Sebastian Feld and Michael Wälischmiller},
    Booktitle = {IEEE 18th International Conference on Intelligent Transportation Systems (ITSC 2015)},
    Year = {2015},
    Pages = {450-456},
    Abstract = {The knowledge of future Signal Phase and Timing information (SPaT) of traffic lights ahead enables a vast number of driving assistance functions, such as Green Light Optimal Speed Control (GLOSA), Red Light Duration Advisory (RLDA) or Traffic Signal Adaptive routing (TSA routing). The purpose of TSA routing is to reduce the travel time by choosing a route that is possibly longer than the shortest one but has less red lights. Whereas GLOSA and RLDA are quite easy to implement from a scientific point of view, TSA routing presents a certain challenge: first of all, TSA routing necessitates predictions on future signal states on a wider look in the future than GLOSA and RLDA, a possible reason why this field of research still seems rather unexplored. Second, there are still many unresolved issues, such as the inadequacy of graphs for TSA-routing, or proper traffic load estimations. In this paper, we present a fully functioning model for TSA routing on the basis of our forgoing research on the prediction of future signal states and address the question of practical usability by evaluating our model under realistic conditions. We analyze, among other things, the impact of partial knowledge on traffic light's future signal states and the impact of different traffic loads on TSA routes by means of a test field in Munich, Germany. We describe necessary modifications of the underlying transportation network's graph structure and shortest path routing algorithm to allow routing under consideration of future signal states of traffic lights. We show that, albeit there are many erratic aspects in traffic and signal states, TSA routing still reaches a significant travel time gain over usual routing in our test field.},
    Owner = {vprotschky}
    }

2014

  • M. T. Beck, M. Werner, S. Feld, and T. Schimper, "Mobile Edge Computing: A taxonomy," in 6h International Conference on Advances in Future Internet (AFIN 2014), 2014, pp. 48-54.
    [BibTeX] [Abstract]
    Mobile Edge Computing proposes co-locating computing and storage resources at base stations of cellular networks. It is seen as a promising technique to alleviate utilization of the mobile core and to reduce latency for mobile end users. Due to the fact that Mobile Edge Computing is a novel approach not yet deployed in real-life networks, recent work discusses merely general and non-technical ideas and concepts. This paper introduces a taxonomy for Mobile Edge Computing applications and analyzes chances and limitations from a technical point of view. Application types which profit from edge deployment are identified and discussed. Furthermore, these applications are systematically classified based on technical metrics.
    @InProceedings{mectaxonomy,
    Title = {Mobile Edge Computing: A taxonomy},
    Author = {Michael Till Beck and Martin Werner and Sebastian Feld and Thomas Schimper},
    Booktitle = {6h International Conference on Advances in Future Internet (AFIN 2014)},
    Year = {2014},
    Pages = {48-54},
    Publisher = {IARIA},
    Abstract = {Mobile Edge Computing proposes co-locating computing and storage resources at base stations of cellular networks. It is seen as a promising technique to alleviate utilization of the mobile core and to reduce latency for mobile end users. Due to the fact that Mobile Edge Computing is a novel approach not yet deployed in real-life networks, recent work discusses merely general and non-technical ideas and concepts. This paper introduces a taxonomy for Mobile Edge Computing applications and analyzes chances and limitations from a technical point of view. Application types which profit from edge deployment are identified and discussed. Furthermore, these applications are systematically classified based on technical metrics.},
    Keywords = {Edge Deployment, Cellular Networks, Classification},
    Owner = {mbeck}
    }
  • F. Dorfmeister, S. Feld, and C. Linnhoff-Popien, "ALPACA: A Decentralized, Privacy-Centric and Context-Aware Framework for the Dissemination of Context Information," International Journal On Advances in Intelligent Systems, vol. 7, iss. 1 and 2, pp. 223-236, 2014.
    [BibTeX] [Abstract]
    With the ongoing rise of smartphones as everyday mobile devices and their steadily increasing amount of sensing and communication capabilities, we are on the brink of a subtle, widespread adoption of context-aware computing techniques into our daily lives. Focusing on functionality and performance, the majority of existing architectures for managing context information typically deploy central components for collecting, analyzing and distributing its users' up-to-date data. However, preservation of users' privacy needs remains a crucial factor for such systems' acceptableness. Inspired by existing works on privacy in context-aware applications and the authors' beliefs in the necessity to put users back in control, this article adopts a privacy-centric perspective and presents ALPACA: A novel approach for modeling and managing a user's rich context information in a user-centric and privacy-preserving way fit for a multitude of different usage scenarios. To this end, this article offers a general conceptual mapping of a user's privacy needs to distinct layers. Based on this conceptualization we introduce a privacy-centric approach for modeling this information. Additionally, we propose a context-aware mechanism for the definition of context-dependent release triggers in order to enable fine-grained control over the disclosure of sensitive information. Finally, we present the components of the proposed system architecture, explain how they interact with each other and discuss how our framework can be integrated into a modern mobile operating system.
    @Article{dorfmeister2014alpaca,
    Title = {ALPACA: A Decentralized, Privacy-Centric and Context-Aware Framework for the Dissemination of Context Information},
    Author = {Florian Dorfmeister and Sebastian Feld and Claudia Linnhoff-Popien},
    Journal = {International Journal On Advances in Intelligent Systems},
    Year = {2014},
    Number = {1 and 2},
    Pages = {223-236},
    Volume = {7},
    Abstract = {With the ongoing rise of smartphones as everyday mobile devices and their steadily increasing amount of sensing and communication capabilities, we are on the brink of a subtle, widespread adoption of context-aware computing techniques into our daily lives. Focusing on functionality and performance, the majority of existing architectures for managing context information typically deploy central components for collecting, analyzing and distributing its users' up-to-date data. However, preservation of users' privacy needs remains a crucial factor for such systems' acceptableness. Inspired by existing works on privacy in context-aware applications and the authors' beliefs in the necessity to put users back in control, this article adopts a privacy-centric perspective and presents ALPACA: A novel approach for modeling and managing a user's rich context information in a user-centric and privacy-preserving way fit for a multitude of different usage scenarios. To this end, this article offers a general conceptual mapping of a user's privacy needs to distinct layers. Based on this conceptualization we introduce a privacy-centric approach for modeling this information. Additionally, we propose a context-aware mechanism for the definition of context-dependent release triggers in order to enable fine-grained control over the disclosure of sensitive information. Finally, we present the components of the proposed system architecture, explain how they interact with each other and discuss how our framework can be integrated into a modern mobile operating system.},
    Owner = {fdorfmeister}
    }
  • S. Feld, M. Schönfeld, and M. Werner, "Analyzing the Deployment of Bitcoin's P2P Network under an AS-level Perspective," in 5th International Conference on Ambient Systems, Networks and Technologies (ANT 2014) and 4th International Conference on Sustainable Energy Information Technology (SEIT 2014), 2014, pp. 1121-1126.
    [BibTeX] [Abstract] [Download PDF]
    Bitcoin has become increasingly important in recent years. The exchange rate raised from \$14 in January 2013 up to \$240 in April 2013 and even \$900 in early 2014. In this paper, we present novel insights about Bitcoin's peer-to-peer (P2P) network with a special focus on its distribution among distinct autonomous systems. We traversed Bitcoin's P2P network in a protocol-compliant manner and collected information about the network size, the number of clients, and the network distribution among autonomous systems. Our findings lead to conclusions about the resilience of the Bitcoin ecosystem, the unambiguousness of the blockchain in use, and the propagation and verification of transaction blocks.
    @InProceedings{bitcoin,
    Title = {Analyzing the Deployment of Bitcoin's P2P Network under an AS-level Perspective},
    Author = {Sebastian Feld and Mirco Schönfeld and Martin Werner},
    Booktitle = {5th International Conference on Ambient Systems, Networks and Technologies (ANT 2014) and 4th International Conference on Sustainable Energy Information Technology (SEIT 2014)},
    Year = {2014},
    Pages = {1121-1126},
    Abstract = {Bitcoin has become increasingly important in recent years. The exchange rate raised from \$14 in January 2013 up to \$240 in April 2013 and even \$900 in early 2014. In this paper, we present novel insights about Bitcoin's peer-to-peer (P2P) network with a special focus on its distribution among distinct autonomous systems. We traversed Bitcoin's P2P network in a protocol-compliant manner and collected information about the network size, the number of clients, and the network distribution among autonomous systems. Our findings lead to conclusions about the resilience of the Bitcoin ecosystem, the unambiguousness of the blockchain in use, and the propagation and verification of transaction blocks.},
    File = {pdf?md5=2a5efb534e0d4dc1e12ba9b4157ae4c9&pid=1-s2.0-S187705091400742X-main.pdf:http\://www.sciencedirect.com/science/article/pii/S187705091400742X/pdf?md5=2a5efb534e0d4dc1e12ba9b4157ae4c9&pid=1-s2.0-S187705091400742X-main.pdf:PDF},
    Owner = {sfeld},
    Url = {http://www.sciencedirect.com/science/article/pii/S187705091400742X}
    }
  • S. Feld and M. Werner, "Compression of GPS tracks Using Map Information," in 11. GI/ITG KuVS Fachgespräch Ortsbezogene Anwendungen und Dienste (LBAS 2014), 2014, pp. 103-114.
    [BibTeX] [Abstract]
    With this paper, we propose a novel semantic compression scheme for GPS trajectories which exploits map knowledge for data reduction. Therefore, the compression is integrated into a simple map matching scheme and shows superior performance with respect to the compression ratio. In contrast to other compression schemes including compressed GPX files, a lot of information about a trajectory can be readily extracted from the given representation and a uniformly sampled representative can be easily calculated for advanced trajectory comparison. We provide a detailed analysis of the approach as well as preliminary results on performance and feasibility of this approach in typical urban mobility scenarios.
    @InProceedings{feld2014compression,
    Title = {Compression of GPS tracks Using Map Information},
    Author = {Sebastian Feld and Martin Werner},
    Booktitle = {11. GI/ITG KuVS Fachgespräch Ortsbezogene Anwendungen und Dienste (LBAS 2014)},
    Year = {2014},
    Pages = {103-114},
    Abstract = {With this paper, we propose a novel semantic compression scheme for GPS trajectories which exploits map knowledge for data reduction. Therefore, the compression is integrated into a simple map matching scheme and shows superior performance with respect to the compression ratio. In contrast to other compression schemes including compressed GPX files, a lot of information about a trajectory can be readily extracted from the given representation and a uniformly sampled representative can be easily calculated for advanced trajectory comparison. We provide a detailed analysis of the approach as well as preliminary results on performance and feasibility of this approach in typical urban mobility scenarios.},
    Owner = {sfeld}
    }
  • C. Marouane, M. Maier, S. Feld, and M. Werner, "Visual Positioning Systems - An Extension to MoVIPS," in 5th International Conference on Indoor Positioning and Indoor Navigation (IPIN 2014), 2014, pp. 95-104.
    [BibTeX] [Abstract]
    Due to the increasing popularity of location-based services, the need for reliable and cost-effective indoor positioning methods is rising. As an alternative to radio-based localization methods, in 2011, we introduced MoVIPS (Mobile Visual Indoor Positioning System), which is based on the idea to extract visual feature points from a query image and compare them to those of previously collected geo-referenced images. The general feasibility of positioning by SURF points on a conventional smartphone was already shown in our previous work. However, the system still faced several shortcomings concerning real-world usage such as request times being too high and distance estimation being unreliable because of the employed estimation method not being rotation invariant. In this paper, three extensions are presented that improve the practical applicability of MoVIPS. To speed up request times, both a dead reckoning approach (based on step counting using the accelerometer) and an orientation estimation (based on the smartphone's compass) are introduced to filter relevant images from the database and thus to reduce the amount of images to compare the query image to. Furthermore, the vectors of the SURF points are quantized. For this purpose, clusters are calculated from all SURF points from the database. As a result, each image can be represented by a histogram of cluster frequencies, which can be compared with each other a lot more efficiently. The third extension is an improvement of the distance estimation method, which uses the matched feature points of an image to perform a perspective transformation and to determine the actual position with the aid of the transformation matrix. Employing the first extension, request times are reduced by 84\% percent. The quantization of the SURF points reduces the search time by a factor of 1000. Finally, the distance estimation is now rotation invariant and enables a better position correction.
    @InProceedings{marouane2014visual,
    Title = {Visual Positioning Systems - An Extension to MoVIPS},
    Author = {Chadly Marouane and Marco Maier and Sebastian Feld and Martin Werner},
    Booktitle = {5th International Conference on Indoor Positioning and Indoor Navigation (IPIN 2014)},
    Year = {2014},
    Pages = {95-104},
    Abstract = {Due to the increasing popularity of location-based services, the need for reliable and cost-effective indoor positioning methods is rising. As an alternative to radio-based localization methods, in 2011, we introduced MoVIPS (Mobile Visual Indoor Positioning System), which is based on the idea to extract visual feature points from a query image and compare them to those of previously collected geo-referenced images. The general feasibility of positioning by SURF points on a conventional smartphone was already shown in our previous work. However, the system still faced several shortcomings concerning real-world usage such as request times being too high and distance estimation being unreliable because of the employed estimation method not being rotation invariant. In this paper, three extensions are presented that improve the practical applicability of MoVIPS. To speed up request times, both a dead reckoning approach (based on step counting using the accelerometer) and an orientation estimation (based on the smartphone's compass) are introduced to filter relevant images from the database and thus to reduce the amount of images to compare the query image to. Furthermore, the vectors of the SURF points are quantized. For this purpose, clusters are calculated from all SURF points from the database. As a result, each image can be represented by a histogram of cluster frequencies, which can be compared with each other a lot more efficiently. The third extension is an improvement of the distance estimation method, which uses the matched feature points of an image to perform a perspective transformation and to determine the actual position with the aid of the transformation matrix. Employing the first extension, request times are reduced by 84\% percent. The quantization of the SURF points reduces the search time by a factor of 1000. Finally, the distance estimation is now rotation invariant and enables a better position correction.},
    Owner = {cmarouane}
    }
  • M. Werner and S. Feld, "Homotopy and Alternative Routes in Indoor Navigation Scenarios," in 5th International Conference on Indoor Positioning and Indoor Navigation (IPIN 2014), 2014, pp. 230-238.
    [BibTeX] [Abstract]
    There are lots of innovative use cases possible that build on a shortest route between two locations together with a set of alternatives that are highly different yet short. Imagine, for example, a complicated building like an airport, where passengers can consult a computer terminal to get navigation advices to a desired goal. By scanning the boarding card the calculation of alternatives can be made context-sensitive. Based on gender, amount of time, or shopping preferences, for example, the terminal can display different routes regarding floors traversed, or shops and restaurants passed. Furthermore, the building operator can control the presentation of alternatives in order to influence visitor flows in real time. Therefore, we propose to use the topological concept of homotopy in order to decide if two routes should be considered equivalent or alternative. Basically, the homotopy relation identifies equivalence classes. We propose that a representative of an equivalence class is an alternative regarding another equivalence class. We concatenate the two routes in question and thus, create a polygon. If there is an obstacle inside, the routes are non-homotopic and we consider them as proper alternatives. For this situation, we propose two fundamentally different approaches that are able to find alternative routes with respect to homotopy. The input is a building plan in form of an occupancy grid. Bitmaps allow for fast calculation of the homotopy relation and can be generated from almost any type of environmental model. The first approach aims for enumerating routes that have to visit a special supporting point. This concatenation of two shortest paths leads to alternatives very fast. The second approach is orthogonal to that in the sense that it generates alternatives roughly ordered by their length. Finally, we evaluate and discuss the approaches' feasibility based on different metrics in several scenarios.­­­­­­­­
    @InProceedings{werner2014homotopy,
    Title = {Homotopy and Alternative Routes in Indoor Navigation Scenarios},
    Author = {Martin Werner and Sebastian Feld},
    Booktitle = {5th International Conference on Indoor Positioning and Indoor Navigation (IPIN 2014)},
    Year = {2014},
    Pages = {230-238},
    Abstract = {There are lots of innovative use cases possible that build on a shortest route between two locations together with a set of alternatives that are highly different yet short. Imagine, for example, a complicated building like an airport, where passengers can consult a computer terminal to get navigation advices to a desired goal. By scanning the boarding card the calculation of alternatives can be made context-sensitive. Based on gender, amount of time, or shopping preferences, for example, the terminal can display different routes regarding floors traversed, or shops and restaurants passed. Furthermore, the building operator can control the presentation of alternatives in order to influence visitor flows in real time. Therefore, we propose to use the topological concept of homotopy in order to decide if two routes should be considered equivalent or alternative. Basically, the homotopy relation identifies equivalence classes. We propose that a representative of an equivalence class is an alternative regarding another equivalence class. We concatenate the two routes in question and thus, create a polygon. If there is an obstacle inside, the routes are non-homotopic and we consider them as proper alternatives. For this situation, we propose two fundamentally different approaches that are able to find alternative routes with respect to homotopy. The input is a building plan in form of an occupancy grid. Bitmaps allow for fast calculation of the homotopy relation and can be generated from almost any type of environmental model. The first approach aims for enumerating routes that have to visit a special supporting point. This concatenation of two shortest paths leads to alternatives very fast. The second approach is orthogonal to that in the sense that it generates alternatives roughly ordered by their length. Finally, we evaluate and discuss the approaches' feasibility based on different metrics in several scenarios.­­­­­­­­},
    Owner = {mwerner}
    }
  • K. Wiesner, S. Feld, F. Dorfmeister, and C. Linnhoff-Popien, "Right to Silence: Establishing Map-based Silent Zones for Participatory Sensing," in IEEE 9th International Conference on Intelligent Sensors, Sensor Networks and Information Processing (IEEE ISSNIP 2014), 2014, pp. 339-344.
    [BibTeX] [Abstract]
    Participatory sensing tries to create cost-effective, large-scale sensing systems by leveraging sensors embedded in mobile devices. One major challenge in these systems is to protect the users' privacy, since users will not contribute data if their privacy is jeopardized. Especially location data needs to be protected if it is likely to reveal information about the users' identities. A common solution is the blinding out approach that creates so-called ban zones in which location data is not published. Thereby, a user's important places, e.g., her home or workplace, can be concealed. However, ban zones of a fixed size are not able to guarantee any particular level of privacy. For instance, a ban zone that is large enough to conceal a user's home in a large city might be too small in a less populated area. For this reason, we propose an approach for dynamic map-based blinding out: The boundaries of our privacy zones, called Silent Zones, are determined in such way that at least k buildings are located within this zone. Thus, our approach adapts to the habitat density and we can guarantee k-anonymity in terms of surrounding buildings. In this paper, we present two new algorithms for creating Silent Zones and evaluate their performance. Our results show that especially in worst case scenarios, i.e., in sparsely populated areas, our approach outperforms standard ban zones and guarantees the specified privacy level.
    @InProceedings{silentzones,
    Title = {Right to Silence: Establishing Map-based Silent Zones for Participatory Sensing},
    Author = {Kevin Wiesner and Sebastian Feld and Florian Dorfmeister and Claudia Linnhoff-Popien},
    Booktitle = {IEEE 9th International Conference on Intelligent Sensors, Sensor Networks and Information Processing (IEEE ISSNIP 2014)},
    Year = {2014},
    Pages = {339-344},
    Abstract = {Participatory sensing tries to create cost-effective, large-scale sensing systems by leveraging sensors embedded in mobile devices. One major challenge in these systems is to protect the users' privacy, since users will not contribute data if their privacy is jeopardized. Especially location data needs to be protected if it is likely to reveal information about the users' identities. A common solution is the blinding out approach that creates so-called ban zones in which location data is not published. Thereby, a user's important places, e.g., her home or workplace, can be concealed. However, ban zones of a fixed size are not able to guarantee any particular level of privacy. For instance, a ban zone that is large enough to conceal a user's home in a large city might be too small in a less populated area. For this reason, we propose an approach for dynamic map-based blinding out: The boundaries of our privacy zones, called Silent Zones, are determined in such way that at least k buildings are located within this zone. Thus, our approach adapts to the habitat density and we can guarantee k-anonymity in terms of surrounding buildings. In this paper, we present two new algorithms for creating Silent Zones and evaluate their performance. Our results show that especially in worst case scenarios, i.e., in sparsely populated areas, our approach outperforms standard ban zones and guarantees the specified privacy level.},
    Owner = {kwiesner}
    }

2013

  • F. Dorfmeister, S. Feld, C. Linnhoff-Popien, and S. A. W. Verclas, "Privacy-Centric Modeling and Management of Context Information," in 6th International Conference on Advances in Human oriented and Personalized Mechanisms, Technologies, and Services (CENTRIC 2013), 2013, pp. 92-97.
    [BibTeX] [Abstract]
    Context-aware computing has been an intensively researched topic for years already. Consequently, there exists a plethora of usage scenarios for context-aware applications as well as several approaches for the modeling and management of a user's context information, many of which focus on the efficient and scalable distribution of the latter. With the ongoing rise of smartphones as everyday mobile devices and their steadily increasing amount of sensing and communication capabilities, we finally find ourselves at the edge towards a widespread usage of these techniques. However, apart from technical issues such as how to reliably determine a user’s current context, privacy still remains a crucial factor for these systems’ acceptance rate. Therefore, inspired by earlier works on privacy in context-aware computing and the authors’ beliefs in the necessity to put users in control, this paper presents a novel approach for modeling and managing a mobile user’s context information in a user-centric and privacy-preserving way. To this end, this work’s contribution is twofold: First, based on widely recognized requirements for privacy in context-aware applications, we propose a privacy-centric context model which allows for an intuitive and context-dependent definition of a user’s privacy preferences, directly integrating privacy aspects into the context model itself. Second, we present a generic and flexible architecture for the management and distribution of context information in a privacy-preserving way fit for a multitude of different usage scenarios.
    @InProceedings{dorfmeister2013privacy,
    Title = {Privacy-Centric Modeling and Management of Context Information},
    Author = {Florian Dorfmeister and Sebastian Feld and Claudia Linnhoff-Popien and Stephan A. W. Verclas},
    Booktitle = {6th International Conference on Advances in Human oriented and Personalized Mechanisms, Technologies, and Services (CENTRIC 2013)},
    Year = {2013},
    Pages = {92-97},
    Abstract = {Context-aware computing has been an intensively researched topic for years already. Consequently, there exists a plethora of usage scenarios for context-aware applications as well as several approaches for the modeling and management of a user's context information, many of which focus on the efficient and scalable distribution of the latter. With the ongoing rise of smartphones as everyday mobile devices and their steadily increasing amount of sensing and communication capabilities, we finally find ourselves at the edge towards a widespread usage of these techniques. However, apart from technical issues such as how to reliably determine a user’s current context, privacy still remains a crucial factor for these systems’ acceptance rate. Therefore, inspired by earlier works on privacy in context-aware computing and the authors’ beliefs in the necessity to put users in control, this paper presents a novel approach for modeling and managing a mobile user’s context information in a user-centric and privacy-preserving way. To this end, this work’s contribution is twofold: First, based on widely recognized requirements for privacy in context-aware applications, we propose a privacy-centric context model which allows for an intuitive and context-dependent definition of a user’s privacy preferences, directly integrating privacy aspects into the context model itself. Second, we present a generic and flexible architecture for the management and distribution of context information in a privacy-preserving way fit for a multitude of different usage scenarios.},
    Owner = {fdorfmeister}
    }
  • S. Feld and M. Werner, "Efficient Path Planning Involving Equivalent Places," in 10. GI/ITG KuVS Fachgespräch Ortsbezogene Anwendungen und Dienste (LBAS 2013), 2013, pp. 13-22.
    [BibTeX] [Abstract]
    This paper investigates a complication of the classical Traveling Salesman Problem, which arises due to multiple points of interest with functional equivalence. While the classical Traveling Salesman Problem tries to find a shortest tour visiting each point in a set exactly once, we consider the challenge of finding the shortest tour visiting each point of a given set exactly once and exactly one additional point out of a different set of equivalent places. The insertion of a gas station to a traveling salesman problem provides an example. With this paper, we investigate and analyze different algorithms to solve this complex problem by reducing it to the solution of a set of classic Traveling Salesman Problems. Furthermore, we provide an efficient tradeoff between the size of the set of traditional problems still to be solved and the expected error of the algorithm.
    @InProceedings{equivalentplan,
    Title = {Efficient Path Planning Involving Equivalent Places},
    Author = {Sebastian Feld and Martin Werner},
    Booktitle = {10. GI/ITG KuVS Fachgespräch Ortsbezogene Anwendungen und Dienste (LBAS 2013)},
    Year = {2013},
    Pages = {13-22},
    Publisher = {Logos Verlag Berlin},
    Abstract = {This paper investigates a complication of the classical Traveling Salesman Problem, which arises due to multiple points of interest with functional equivalence. While the classical Traveling Salesman Problem tries to find a shortest tour visiting each point in a set exactly once, we consider the challenge of finding the shortest tour visiting each point of a given set exactly once and exactly one additional point out of a different set of equivalent places. The insertion of a gas station to a traveling salesman problem provides an example. With this paper, we investigate and analyze different algorithms to solve this complex problem by reducing it to the solution of a set of classic Traveling Salesman Problems. Furthermore, we provide an efficient tradeoff between the size of the set of traditional problems still to be solved and the expected error of the algorithm.},
    Owner = {sfeld}
    }
  • K. Wiesner and S. Feld, "Energy-efficient Tasking in Participatory Sensing Systems," in 10. GI/ITG KuVS Fachgespräch Ortsbezogene Anwendungen und Dienste (LBAS 2013), 2013, pp. 127-136.
    [BibTeX] [Abstract]
    By leveraging sensors embedded in mobile devices, participatory sensing tries to create large-scale sensing systems. One major challenge in these participatory sensing networks is the problem of distributing sensing tasks in an energy-efficient manner. A large portion of energy is typically consumed for the exchange of tasks between the tasking server and the mobile devices, as well as for the position monitoring needed to detect whether a user is situated within the tasking area. In this paper, we mainly focus on reducing energy for receiving and monitoring tasks on the client side. We propose an energy-efficient task distribution and monitoring concept for participatory sensing systems and evaluate it by means of simulation.
    @InProceedings{taskingpsn,
    Title = {Energy-efficient Tasking in Participatory Sensing Systems},
    Author = {Kevin Wiesner and Sebastian Feld},
    Booktitle = {10. GI/ITG KuVS Fachgespräch Ortsbezogene Anwendungen und Dienste (LBAS 2013)},
    Year = {2013},
    Pages = {127-136},
    Publisher = {Logos Verlag Berlin},
    Abstract = {By leveraging sensors embedded in mobile devices, participatory sensing tries to create large-scale sensing systems. One major challenge in these participatory sensing networks is the problem of distributing sensing tasks in an energy-efficient manner. A large portion of energy is typically consumed for the exchange of tasks between the tasking server and the mobile devices, as well as for the position monitoring needed to detect whether a user is situated within the tasking area. In this paper, we mainly focus on reducing energy for receiving and monitoring tasks on the client side. We propose an energy-efficient task distribution and monitoring concept for participatory sensing systems and evaluate it by means of simulation.},
    Owner = {kwiesner}
    }