Dr. Martin Werner

Dr. Martin Werner

Lehrstuhl für Mobile und Verteilte Systeme

Ludwig-Maximilians-Universität München,

Institut für Informatik

Oettingenstraße 67
80538 München

Raum E 011 (alt D0.11)

Telefon: +49 89 / 2180-9127

Fax: +49 89 / 2180-99 9127

Mail: martin.werner@ifi.lmu.de

Aufgabengebiet

Indoor-Positioning
Indoor-Location-Based Services
Security and Privacy in Location Based Services
Ubiquitous Computing

Sprechstunde:
auf Anfrage

Publikationen

2016

  • 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}
    }
  • E. J. Hoffmann, M. Werner, and L. Schauer, "Indoor Navigation Using Virtual Anchor Points," in European Navigation Conference (ENC 2016), 2016.
    [BibTeX] [Download PDF]
    @InProceedings{hoffmann2016indoor,
    Title = {Indoor Navigation Using Virtual Anchor Points},
    Author = {Eike Jens Hoffmann and Martin Werner and Lorenz Schauer},
    Booktitle = {European Navigation Conference (ENC 2016)},
    Year = {2016},
    Owner = {ehoffmann},
    Timestamp = {2016.07.28},
    Url = {http://www.martinwerner.de/preprint/VAP.pdf}
    }
  • M. Werner, C. Hahn, and L. Schauer, "DeepMoVIPS: Visual Indoor Positioning Using Transfer Learning," in 7th International Conference on Indoor Positioning and Indoor Navigation (IPIN 2016), 2016.
    [BibTeX]
    @InProceedings{werner2016deepmovips,
    Title = {DeepMoVIPS: Visual Indoor Positioning Using Transfer Learning},
    Author = {Martin Werner and Carsten Hahn and Lorenz Schauer},
    Booktitle = {7th International Conference on Indoor Positioning and Indoor Navigation (IPIN 2016)},
    Year = {2016},
    Owner = {mwerner}
    }
  • M. Werner and M. Kiermeier, "A Low-Dimensional Feature Vector Representation for Alignment-Free Spatial Trajectory Analysis," in Proceedings of the 5th ACM SIGSPATIAL International Workshop on Mobile Geographic Information Systems (MobiGIS'16), 2016.
    [BibTeX]
    @InProceedings{AlignmentFree,
    Title = {A Low-Dimensional Feature Vector Representation for Alignment-Free Spatial Trajectory Analysis},
    Author = {Martin Werner and Marie Kiermeier},
    Booktitle = {Proceedings of the 5th ACM SIGSPATIAL International Workshop on Mobile Geographic Information Systems (MobiGIS'16)},
    Year = {2016},
    Owner = {mwerner},
    Timestamp = {2016.11.17}
    }

2015

  • 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}
    }
  • A. Ebert, C. Marouane, B. Rott, and M. Werner, "KeyPocket - Improving Security and Usability for Provider Independent Login Architectures with Mobile Devices," in EAI 11th International Conference on Security and Privacy in Communication Networks (SecureComm 2015), 2015.
    [BibTeX]
    @InProceedings{keypocket15,
    Title = {KeyPocket - Improving Security and Usability for Provider Independent Login Architectures with Mobile Devices},
    Author = {André Ebert and Chadly Marouane and Benno Rott and Martin Werner},
    Booktitle = {EAI 11th International Conference on Security and Privacy in Communication Networks (SecureComm 2015)},
    Year = {2015},
    Publisher = {EAI},
    Owner = {aebert},
    Timestamp = {2015.09.30}
    }
  • 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}
    }
  • L. Schauer and M. Werner, "Kunden-Monitoring im stationären Handel," 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. 73-82.
    [BibTeX] [Download PDF]
    @InCollection{schauer15kunden,
    Title = {Kunden-Monitoring im stationären Handel},
    Author = {Lorenz Schauer and Martin Werner},
    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 = {73-82},
    Series = {Xpert.press},
    Owner = {lschauer},
    Timestamp = {2015.09.28},
    Url = {http://link.springer.com/chapter/10.1007/978-3-662-43782-7_10}
    }
  • L. Schauer and M. Werner, "Analyzing Pedestrian Flows Based on Wi-Fi and Bluetooth Captures," EAI Endorsed Transactions on Ubiquitous Environments, vol. 15, iss. 4, 2015. doi:10.4108/ue.1.4.e4
    [BibTeX] [Download PDF]
    @Article{schauer15analyzing,
    Title = {Analyzing Pedestrian Flows Based on Wi-Fi and Bluetooth Captures},
    Author = {Lorenz Schauer and Martin Werner},
    Journal = {EAI Endorsed Transactions on Ubiquitous Environments},
    Year = {2015},
    Month = {5},
    Number = {4},
    Volume = {15},
    Doi = {10.4108/ue.1.4.e4},
    Keywords = {crowd density, pedestrian flow, tracking, Wi-Fi probes, Bluetooth},
    Owner = {lschauer},
    Timestamp = {2015.07.10},
    Url = {http://www.eudl.eu/pdf/10.4108/ue.1.4.e4}
    }
  • L. Schauer and M. Werner, "Clustering of Inertial Indoor Positioning Data," in 1st KuVS Expert Talk on Localization, 2015.
    [BibTeX] [Download PDF]
    @InProceedings{schauer15clustering,
    Title = {Clustering of Inertial Indoor Positioning Data},
    Author = {Lorenz Schauer and Martin Werner},
    Booktitle = {1st KuVS Expert Talk on Localization},
    Year = {2015},
    Owner = {lschauer},
    Timestamp = {2015.07.10},
    Url = {http://www.cip.ifi.lmu.de/~schauer/publications/ClusteringIndoor.pdf}
    }
  • M. Schönfeld, M. Werner, C. Linnhoff-Popien, and A. Erk, "Towards a Privacy-Preserving Hybrid Radio Network: Design and Open Challenges," in 15th International Conference on Innovations for Community Services (I4CS 2015), 2015, pp. 1-6.
    [BibTeX] [Download PDF]
    @InProceedings{RadioNetwork,
    Title = {Towards a Privacy-Preserving Hybrid Radio Network: Design and Open Challenges},
    Author = {Mirco Schönfeld and Martin Werner and Claudia Linnhoff-Popien and Alexander Erk},
    Booktitle = {15th International Conference on Innovations for Community Services (I4CS 2015)},
    Year = {2015},
    Pages = {1-6},
    Owner = {mschönfeld},
    Timestamp = {2015.08.06},
    Url = {http://publications.mircoschoenfeld.de/2015-RadioNetwork.pdf}
    }
  • M. Werner, F. Dorfmeister, and M. Schönfeld, "AMBIENCE: A Context-Centric Online Social Network," in Accepted for Inclusion in the 12th Workshop on Positioning, Navigation and Communications (WPNC 2015), 2015.
    [BibTeX] [Download PDF]
    @InProceedings{ambience,
    Title = {AMBIENCE: A Context-Centric Online Social Network},
    Author = {Martin Werner and Florian Dorfmeister and Mirco Schönfeld},
    Booktitle = {Accepted for Inclusion in the 12th Workshop on Positioning, Navigation and Communications (WPNC 2015)},
    Year = {2015},
    Publisher = {IEEE},
    File = {2015-Ambience.pdf:http\://publications.mircoschoenfeld.de/2015-Ambience.pdf:PDF},
    Url = {http://publications.mircoschoenfeld.de/2015-Ambience.pdf}
    }
  • M. Werner and M. Schönfeld, "The Gaussian Bloom Filter," in 20th International Conference on Database Systems for Advanced Applications (DASFAA 2015), 2015, pp. 191-206.
    [BibTeX]
    @InProceedings{gaussianbloom,
    Title = {The Gaussian Bloom Filter},
    Author = {Martin Werner and Mirco Schönfeld},
    Booktitle = {20th International Conference on Database Systems for Advanced Applications (DASFAA 2015)},
    Year = {2015},
    Pages = {191-206}
    }

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}
    }
  • 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}
    }
  • L. Schauer, M. Werner, and P. Marcus, "Estimating Crowd Densities and Pedestrian Flows Using Wi-Fi and Bluetooth," in 11th International Conference on Mobile and Ubiquitous Systems: Computing, Networking and Services (Mobiquitous 2014), 2014, pp. 171-177.
    [BibTeX] [Download PDF]
    @InProceedings{schaflow14,
    Title = {Estimating Crowd Densities and Pedestrian Flows Using Wi-Fi and Bluetooth},
    Author = {Lorenz Schauer and Martin Werner and Philipp Marcus},
    Booktitle = {11th International Conference on Mobile and Ubiquitous Systems: Computing, Networking and Services (Mobiquitous 2014)},
    Year = {2014},
    Pages = {171-177},
    Owner = {lschauer},
    Url = {http://www.cip.ifi.lmu.de/~schauer/publications/estimatingCrowds.pdf}
    }
  • M. Schönfeld and M. Werner, "Distributed Privacy-Preserving Mean Estimation," in 2nd International Conference on Privacy and Security in Mobile Systems (PRISMS 2014), 2014, pp. 1-8.
    [BibTeX] [Abstract] [Download PDF]
    Due to the rise of mobile computing and smartphones, a lot of information about groups has become accessible. This information shall often be kept secret. Hence distributed algorithms for privacy-preserving distribution estimation are needed. Most research currently focuses on privacy in a database, where a single entity has collected the secret information and privacy is ensured between query results and the database. In fully distributed systems such as sensor networks it is often infeasible to move the data towards a central entity for processing. Instead, distributed algorithms are needed. With this paper we propose a fully distributed, privacy-friendly, consensus-based approach. In our approach all nodes cooperate to generate a sufficiently random obfuscation of their secret values until the estimated and obfuscated values of the individual nodes can be safely published. Then the calculations can be done on this replacement containing only non-secret values but recovering some aspects (mean, standard deviation) of the original distribution.
    @InProceedings{distributedmeanestim,
    Title = {Distributed Privacy-Preserving Mean Estimation},
    Author = {Mirco Schönfeld and Martin Werner},
    Booktitle = {2nd International Conference on Privacy and Security in Mobile Systems (PRISMS 2014)},
    Year = {2014},
    Pages = {1-8},
    Publisher = {IEEE},
    Abstract = {Due to the rise of mobile computing and smartphones, a lot of information about groups has become accessible. This information shall often be kept secret. Hence distributed algorithms for privacy-preserving distribution estimation are needed. Most research currently focuses on privacy in a database, where a single entity has collected the secret information and privacy is ensured between query results and the database. In fully distributed systems such as sensor networks it is often infeasible to move the data towards a central entity for processing. Instead, distributed algorithms are needed. With this paper we propose a fully distributed, privacy-friendly, consensus-based approach. In our approach all nodes cooperate to generate a sufficiently random obfuscation of their secret values until the estimated and obfuscated values of the individual nodes can be safely published. Then the calculations can be done on this replacement containing only non-secret values but recovering some aspects (mean, standard deviation) of the original distribution.},
    File = {2014-DistrPrivPresMeanEstim.pdf:http\://publications.mircoschoenfeld.de/2014-DistrPrivPresMeanEstim.pdf:PDF},
    Keywords = {Mobile Systems; Privacy; Distributed Privacy;},
    Url = {http://publications.mircoschoenfeld.de/2014-DistrPrivPresMeanEstim.pdf}
    }
  • 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}
    }
  • M. Werner, L. Schauer, and A. Scharf, "Reliable Trajectory Classification Using Wi-Fi Signal Strength in Indoor Scenarios," in 2014 IEEE/ION Position Location and Navigation Symposium (PLANS 2014), 2014, pp. 663-670.
    [BibTeX] [Download PDF]
    @InProceedings{reliabletrajectory,
    Title = {Reliable Trajectory Classification Using Wi-Fi Signal Strength in Indoor Scenarios},
    Author = {Martin Werner and Lorenz Schauer and Andreas Scharf},
    Booktitle = {2014 IEEE/ION Position Location and Navigation Symposium (PLANS 2014)},
    Year = {2014},
    Pages = {663-670},
    Url = {http://trajectorycomputing.com/datasets/reliable-trajectory-classification-using-wi-fi-signal-strength-indoor-scenarios/}
    }

2013

  • 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}
    }
  • P. Marcus, M. Kessel, and M. Werner, "Dynamic Nearest Neighbors and Online Error Estimation for SMARTPOS," International Journal On Advances in Internet Technology, vol. 6, iss. 1 and 2, pp. 1-11, 2013.
    [BibTeX] [Download PDF]
    @Article{13MarKesWer,
    Title = {Dynamic Nearest Neighbors and Online Error Estimation for SMARTPOS},
    Author = {Philipp Marcus and Moritz Kessel and Martin Werner},
    Journal = {International Journal On Advances in Internet Technology},
    Year = {2013},
    Number = {1 and 2},
    Pages = {1-11},
    Volume = {6},
    Owner = {pmarcus},
    Url = {http://www.thinkmind.org/download.php?articleid=inttech_v6_n12_2013_1}
    }
  • M. Schönfeld and M. Werner, "Node Wake-Up via OVSF-Coded Bloom Filters in Wireless Sensor Networks," in 5th International Conference on Ad Hoc Networks (ADHOCNETS 2013), 2013.
    [BibTeX] [Abstract] [Download PDF]
    Interest dissemination in constrained environments such as wireless sensor networks utilizes Bloom filters commonly. A Bloom filter is a probabilistic data structure of fixed length, which can be used to encode the set of sensor nodes to be awake. In this way an application can disseminate interest in specific sensor nodes by broadcasting the Bloom filter throughout the complete wireless sensor network. The probabilistic nature of a Bloom filter induces false positives, that is some sensor nodes will be awake without the application having interest in their sensor values. As the interest is often depending on location such as in adaptive sampling applications, we present a novel method to encode both interest and possible location of information into one probabilistic data structure simultaneously. While our algorithm is able to encode any kind of tree-structured information into a fixed length bit array we exemplify its use through a wireless sensor network. In comparison to traditional Bloom encoding techniques we are able to reduce the overall number of false positives and furthermore reduce the average distance of false positives from the next true positive of the same interest. In our example this helps to reduce the overall energy consumption of the sensor network by only requesting sensor nodes that are likely to store the requested information.
    @InProceedings{bloomwakeup,
    Title = {Node Wake-Up via OVSF-Coded Bloom Filters in Wireless Sensor Networks},
    Author = {Mirco Schönfeld and Martin Werner},
    Booktitle = {5th International Conference on Ad Hoc Networks (ADHOCNETS 2013)},
    Year = {2013},
    Abstract = {Interest dissemination in constrained environments such as wireless sensor networks utilizes Bloom filters commonly. A Bloom filter is a probabilistic data structure of fixed length, which can be used to encode the set of sensor nodes to be awake. In this way an application can disseminate interest in specific sensor nodes by broadcasting the Bloom filter throughout the complete wireless sensor network. The probabilistic nature of a Bloom filter induces false positives, that is some sensor nodes will be awake without the application having interest in their sensor values. As the interest is often depending on location such as in adaptive sampling applications, we present a novel method to encode both interest and possible location of information into one probabilistic data structure simultaneously. While our algorithm is able to encode any kind of tree-structured information into a fixed length bit array we exemplify its use through a wireless sensor network. In comparison to traditional Bloom encoding techniques we are able to reduce the overall number of false positives and furthermore reduce the average distance of false positives from the next true positive of the same interest. In our example this helps to reduce the overall energy consumption of the sensor network by only requesting sensor nodes that are likely to store the requested information.},
    File = {2013-HierarchicalHashing.pdf:http\://publications.mircoschoenfeld.de/2013-HierarchicalHashing.pdf:PDF},
    Url = {http://publications.mircoschoenfeld.de/2013-HierarchicalHashing.pdf}
    }

2012

  • M. Kessel and M. Werner, "Automated WLAN Calibration with a Backtracking Particle Filter," in International Conference on Indoor Positioning and Indoor Navigation (IPIN 2012), 2012, pp. 1-10.
    [BibTeX] [Download PDF]
    @InProceedings{kessel2012ipin,
    Title = {Automated WLAN Calibration with a Backtracking Particle Filter},
    Author = {Moritz Kessel and Martin Werner},
    Booktitle = {International Conference on Indoor Positioning and Indoor Navigation (IPIN 2012)},
    Year = {2012},
    Pages = {1-10},
    Publisher = {IEEE},
    Url = {http://dx.doi.org/10.1109/IPIN.2012.6418907}
    }
  • M. Kessel, M. Werner, and C. Linnhhoff, "Compass and WLAN Integration for Indoor Tracking on Mobile Phones," in 6th International Conference on Mobile Ubiquitous Computing, Systems, Services and Technologies (UBICOMM 2012), 2012.
    [BibTeX] [Download PDF]
    @InProceedings{ubicomm2012,
    Title = {Compass and WLAN Integration for Indoor Tracking on Mobile Phones},
    Author = {Moritz Kessel and Martin Werner and Claudia Linnhhoff},
    Booktitle = {6th International Conference on Mobile Ubiquitous Computing, Systems, Services and Technologies (UBICOMM 2012)},
    Year = {2012},
    Url = {http://www.thinkmind.org/index.php?view=article&articleid=ubicomm_2012_1_10_10041}
    }
  • J. Preis, M. Kessel, M. Werner, and C. Linnhoff-Popien, "Gait Recognition with Kinect," in 1st International Workshop on Kinect in Pervasive Computing, 2012, pp. 28-36.
    [BibTeX] [Download PDF]
    @InProceedings{gaitkinect,
    Title = {Gait Recognition with Kinect},
    Author = {Johannes Preis and Moritz Kessel and Martin Werner and Claudia Linnhoff-Popien},
    Booktitle = {1st International Workshop on Kinect in Pervasive Computing},
    Year = {2012},
    Pages = {28-36},
    Url = {http://noggnogg.com/pervasivekinect/wp-content/uploads/2012/06/Preis_GaitRecognition.pdf}
    }
  • C. Scheuermann, M. Werner, M. Kessel, C. Linnhoff-Popien, and S. A. W. Verclas, "Evaluation of Barcode Decoding Performance using ZXING Library," in 2nd Workshop on Smart Mobile Applications (SmartApps 2012), 2012.
    [BibTeX] [Download PDF]
    @InProceedings{zxingeval,
    Title = {Evaluation of Barcode Decoding Performance using ZXING Library},
    Author = {Constantin Scheuermann and Martin Werner and Moritz Kessel and Claudia Linnhoff-Popien and Stephan A. W. Verclas},
    Booktitle = {2nd Workshop on Smart Mobile Applications (SmartApps 2012)},
    Year = {2012},
    Url = {http://www.mobile.ifi.uni-muenchen.de/aktuelles/smartapps2012/smartapps12_barcodes.pdf}
    }
  • M. Schönfeld, M. Werner, and F. Dorfmeister, "Location-based Access Control Providing One-Time Passwords Through 2D Barcodes," in 9. GI/ITG KuVS Fachgespräch Ortsbezogene Anwendungen und Dienste, 2012, pp. 165-168.
    [BibTeX] [Abstract] [Download PDF]
    Location-based Access Control often relies a location proof, which ensures that a specific user is at a specific location. These locations are most often inferred from measurements. As a consequence, such systems are never trustworthy. An attacker can simply fake sensor measurements or even sensor data in absence of a trusted measurement module. Moreover, the measurement data is typically stable over time at a fixed location and can thus be replayed at later times. With this paper, we propose a system, which can provide functionality for a location proof, which does not rely on measurements and does not suffer from replay attacks. Therefore, a self-contained system is generating signed one-time passwords and communicates them via 2D barcodes for authentication of camera-enabled devices being in a specific location.
    @InProceedings{qrcodelocationproof,
    Title = {Location-based Access Control Providing One-Time Passwords Through 2D Barcodes},
    Author = {Mirco Schönfeld and Martin Werner and Florian Dorfmeister},
    Booktitle = {9. GI/ITG KuVS Fachgespräch Ortsbezogene Anwendungen und Dienste},
    Year = {2012},
    Pages = {165-168},
    Abstract = {Location-based Access Control often relies a location proof, which ensures that a specific user is at a specific location. These locations are most often inferred from measurements. As a consequence, such systems are never trustworthy. An attacker can simply fake sensor measurements or even sensor data in absence of a trusted measurement module. Moreover, the measurement data is typically stable over time at a fixed location and can thus be replayed at later times. With this paper, we propose a system, which can provide functionality for a location proof, which does not rely on measurements and does not suffer from replay attacks. Therefore, a self-contained system is generating signed one-time passwords and communicates them via 2D barcodes for authentication of camera-enabled devices being in a specific location.},
    File = {2012-LBAC.pdf:http\://publications.mircoschoenfeld.de/2012-LBAC.pdf:PDF},
    Url = {http://publications.mircoschoenfeld.de/2012-LBAC.pdf}
    }
  • M. Werner, Ubiquitous Navigation: Skalierbare ortsbezogene Dienste in Gebäuden, Logos Verlag Berlin, 2012.
    [BibTeX] [Download PDF]
    @Book{dissertation,
    Title = {Ubiquitous Navigation: Skalierbare ortsbezogene Dienste in Gebäuden},
    Author = {Martin Werner},
    Publisher = {Logos Verlag Berlin},
    Year = {2012},
    ISBN = {978-3-8325-3226-0},
    Url = {http://www.logos-verlag.de/cgi-bin/buch/isbn/3226}
    }
  • M. Werner, M. Kessel, F. Gschwandtner, M. Dürr, K. Wiesner, and T. Mair, "Technologische Herausforderungen für kontextsensitive Geschäftsanwendungen," in Smart Mobile Apps: Mit Business-Apps ins Zeitalter mobiler Geschäftsprozesse, Springer, 2012. doi:10.1007/978-3-642-22259-7_19
    [BibTeX] [Download PDF]
    @InCollection{werner2012technologische,
    Title = {Technologische Herausforderungen für kontextsensitive Geschäftsanwendungen},
    Author = {Martin Werner and Moritz Kessel and Florian Gschwandtner and Michael Dürr and Kevin Wiesner and Thomas Mair},
    Booktitle = {Smart Mobile Apps: Mit Business-Apps ins Zeitalter mobiler Geschäftsprozesse},
    Publisher = {Springer},
    Year = {2012},
    Doi = {10.1007/978-3-642-22259-7_19},
    Url = {http://dx.doi.org/10.1007/978-3-642-22259-7_19}
    }
  • M. Werner and M. Schönfeld, "DualCodes: Backward-Compatible Multi-Layer 2D-Barcodes," in 9th Annual International Conference on Mobile and Ubiquitous Systems: Computing, Networking and Services (MOBIQUITOUS 2012), 2012, pp. 25-36.
    [BibTeX] [Abstract] [Download PDF]
    Matrix codes enable a coupling between virtual and physical worlds for ubiquitous computing applications. With this paper, we propose a technique, which can be used to increase the amount of information contained in a matrix barcode in a backward compatible way. This enables applications to fully utilize the wide spread of QR Codes or Data Matrix Codes for service discovery or basic service, while being able to transmit much more information during one scan for advanced applications. We present the approach, explain difficulties in decoding typical camera images, a simulatory evaluation of decoding performance, and application examples.
    @InProceedings{dualcodes,
    Title = {DualCodes: Backward-Compatible Multi-Layer 2D-Barcodes},
    Author = {Martin Werner and Mirco Schönfeld},
    Booktitle = {9th Annual International Conference on Mobile and Ubiquitous Systems: Computing, Networking and Services (MOBIQUITOUS 2012)},
    Year = {2012},
    Pages = {25-36},
    Abstract = {Matrix codes enable a coupling between virtual and physical worlds for ubiquitous computing applications. With this paper, we propose a technique, which can be used to increase the amount of information contained in a matrix barcode in a backward compatible way. This enables applications to fully utilize the wide spread of QR Codes or Data Matrix Codes for service discovery or basic service, while being able to transmit much more information during one scan for advanced applications. We present the approach, explain difficulties in decoding typical camera images, a simulatory evaluation of decoding performance, and application examples.},
    File = {2012-DualCodes.pdf:http\://publications.mircoschoenfeld.de/2012-DualCodes.pdf:PDF},
    Url = {http://www.springer.com/computer/communication+networks/book/978-3-642-40237-1}
    }

2011

  • M. Duchon, A. Paulus, and M. Werner, "Mobile Anwendung zur Routenplanung mit öffentlichen Verkehrsmitteln basierend auf OpenStreetMap-Daten," in Tagungsband der Anwenderkonferenz für Freie und Open Source Software für Geoinformationssysteme (FOSSGIS 2011), 2011.
    [BibTeX] [Download PDF]
    @InProceedings{routeopnv,
    Title = {Mobile Anwendung zur Routenplanung mit öffentlichen Verkehrsmitteln basierend auf OpenStreetMap-Daten},
    Author = {Markus Duchon and Andreas Paulus and Martin Werner},
    Booktitle = {Tagungsband der Anwenderkonferenz für Freie und Open Source Software für Geoinformationssysteme (FOSSGIS 2011)},
    Year = {2011},
    Url = {https://www.legato.net/download/attachments/2555944/2011_FOSSGIS_Tagungsband.pdf}
    }
  • W. Heidrich, M. Schulze, M. Kessel, and M. Werner, "Robustes Map-Matching hoch aufgelöster, fahrzeugbasierter GPS-Tracks," in 8. GI/KuVS-Fachgespräches "Ortsbezogene Anwendungen und Dienste", 2011.
    [BibTeX] [Download PDF]
    @InProceedings{mapmatch,
    Title = {Robustes Map-Matching hoch aufgelöster, fahrzeugbasierter GPS-Tracks},
    Author = {Wolf Heidrich and Martin Schulze and Moritz Kessel and Martin Werner},
    Booktitle = {8. GI/KuVS-Fachgespräches "Ortsbezogene Anwendungen und Dienste"},
    Year = {2011},
    Url = {http://www.logos-verlag.de/cgi-bin/buch/isbn/3041}
    }
  • M. Kessel and M. Werner, "SMARTPOS: Accurate and Precise Indoor Positioning on Mobile Phones," in 1st International Conference on Mobile Services, Resources, and Users (MOBILITY 2011), 2011, pp. 158-163.
    [BibTeX] [Download PDF]
    @InProceedings{kessel2011smartpos,
    Title = {SMARTPOS: Accurate and Precise Indoor Positioning on Mobile Phones},
    Author = {Moritz Kessel and Martin Werner},
    Booktitle = {1st International Conference on Mobile Services, Resources, and Users (MOBILITY 2011)},
    Year = {2011},
    Pages = {158-163},
    Url = {http://www.thinkmind.org/index.php?view=article&articleid=mobility_2011_8_10_40203}
    }
  • M. Werner, "Selection and Ordering of Points-of-Interest in Large-Scale Indoor Navigation Systems," in IEEE 35th Annual Computer Software and Applications Conference (COMPSAC 2011), 2011, pp. 504-509. doi:10.1109/COMPSAC.2011.71
    [BibTeX] [Download PDF]
    @InProceedings{6032388,
    Title = {Selection and Ordering of Points-of-Interest in Large-Scale Indoor Navigation Systems},
    Author = {Martin Werner},
    Booktitle = {IEEE 35th Annual Computer Software and Applications Conference (COMPSAC 2011)},
    Year = {2011},
    Pages = {504 -509},
    Doi = {10.1109/COMPSAC.2011.71},
    Url = {http://dx.doi.org/10.1109/COMPSAC.2011.71}
    }
  • M. Werner, "Datenschutz in ortsbasierten Diensten," digma: Zeitschrift für Datenrecht und Informationssicherheit, vol. 11, iss. 2, pp. 54-59, 2011.
    [BibTeX] [Download PDF]
    @Article{datenschutz,
    Title = {Datenschutz in ortsbasierten Diensten},
    Author = {Martin Werner},
    Journal = {digma: Zeitschrift für Datenrecht und Informationssicherheit},
    Year = {2011},
    Number = {2},
    Pages = {54 - 59},
    Volume = {11},
    Publisher = {Schulthess Juristische Medien AG},
    Url = {http://www.schulthess.com}
    }
  • M. Werner, "Simulation WLAN-basierter Indoor-Positionierung unter Verwendung von CAD-Plänen," in 8. GI/KuVS-Fachgespräches "Ortsbezogene Anwendungen und Dienste", 2011.
    [BibTeX] [Download PDF]
    @InProceedings{indoorsim,
    Title = {Simulation WLAN-basierter Indoor-Positionierung unter Verwendung von CAD-Plänen},
    Author = {Martin Werner},
    Booktitle = {8. GI/KuVS-Fachgespräches "Ortsbezogene Anwendungen und Dienste"},
    Year = {2011},
    Url = {http://www.logos-verlag.de/cgi-bin/buch/isbn/3041}
    }
  • M. Werner, "Privacy-protected communication for location-based services," Security and Communication Networks, 2011. doi:10.1002/sec.330
    [BibTeX] [Download PDF]
    @Article{ppcomm,
    Title = {Privacy-protected communication for location-based services},
    Author = {Werner, Martin},
    Journal = {Security and Communication Networks},
    Year = {2011},
    Doi = {10.1002/sec.330},
    ISSN = {1939-0122},
    Keywords = {location-based services, privacy},
    Owner = {mwerner},
    Publisher = {John Wiley \& Sons, Ltd},
    Timestamp = {2011.05.13},
    Url = {http://dx.doi.org/10.1002/sec.330}
    }
  • M. Werner, "Efficiently Using Bitmap Floorplans for Indoor Navigation on Mobile Phones," in 7th International Conference on Wireless and Mobile Communications (ICWMC 2011), 2011, pp. 225-230.
    [BibTeX] [Download PDF]
    @InProceedings{werner2011efficiently,
    Title = {Efficiently Using Bitmap Floorplans for Indoor Navigation on Mobile Phones},
    Author = {Werner, Martin},
    Booktitle = {7th International Conference on Wireless and Mobile Communications (ICWMC 2011)},
    Year = {2011},
    Pages = {225-230},
    Url = {http://www.thinkmind.org/index.php?view=article&articleid=icwmc_2011_10_40_20064}
    }
  • M. Werner, M. Kessel, and C. Marouane, "Indoor positioning using smartphone camera," in International Conference on Indoor Positioning and Indoor Navigation (IPIN 2011), 2011, pp. 1-6. doi:10.1109/IPIN.2011.6071954
    [BibTeX] [Download PDF]
    @InProceedings{werner2011indoor,
    Title = {Indoor positioning using smartphone camera},
    Author = {Martin Werner and Moritz Kessel and Chadly Marouane},
    Booktitle = {International Conference on Indoor Positioning and Indoor Navigation (IPIN 2011)},
    Year = {2011},
    Pages = {1-6},
    Publisher = {IEEE},
    Doi = {10.1109/IPIN.2011.6071954},
    Url = {http://dx.doi.org/10.1109/IPIN.2011.6071954}
    }

2010

  • M. Dürr, M. Werner, and M. Maier, "Re-Socializing Online Social Networks," in 2010 IEEE/ACM International Conference on Green Computing and Communications (GreenCom 2010) & International Conference on Cyber, Physical and Social Computing (CPSCom 2010), 2010, pp. 786-791. doi:10.1109/GreenCom-CPSCom.2010.18
    [BibTeX] [Download PDF]
    @InProceedings{resocial,
    Title = {Re-Socializing Online Social Networks},
    Author = {Michael Dürr and Martin Werner and Marco Maier},
    Booktitle = {2010 IEEE/ACM International Conference on Green Computing and Communications (GreenCom 2010) \& International Conference on Cyber, Physical and Social Computing (CPSCom 2010)},
    Year = {2010},
    Month = {Dec.},
    Pages = {786 -791},
    Doi = {10.1109/GreenCom-CPSCom.2010.18},
    Url = {http://dx.doi.org/10.1109/GreenCom-CPSCom.2010.18}
    }
  • M. Werner, "A Privacy-Enabled Architecture for Location-Based Services," in Security and Privacy in Mobile Information and Communication Systems, Springer Berlin Heidelberg, 2010, vol. 47, pp. 80-90.
    [BibTeX] [Download PDF]
    @InCollection{privacyarchitecture,
    Title = {A Privacy-Enabled Architecture for Location-Based Services},
    Author = {Martin Werner},
    Booktitle = {Security and Privacy in Mobile Information and Communication Systems},
    Publisher = {Springer Berlin Heidelberg},
    Year = {2010},
    Pages = {80-90},
    Series = {Lecture Notes of the Institute for Computer Sciences, Social Informatics and Telecommunications Engineering},
    Volume = {47},
    Affiliation = {Institute for Informatics of LMU, Mobile and Distributed Systems Group, Munich, Germany},
    ISBN = {978-3-642-17502-2},
    Keyword = {Computer Science},
    Url = {http://dx.doi.org/10.1007/978-3-642-17502-2_7}
    }
  • M. Werner and M. Kessel, "Organisation of Indoor Navigation data from a data query perspective," in Ubiquitous Positioning Indoor Navigation and Location Based Service (UPINLBS 2010), 2010. doi:10.1109/UPINLBS.2010.5653981
    [BibTeX] [Abstract] [Download PDF]
    Indoor Navigation is becoming a more and more important topic. It is a key tool for the integration of disabled people into environments which they are not familiar with. With this paper we want to address the problem of indoor navigation being much more complex than outdoor navigation with a thorough modelling of queries which a indoor navigation GIS database shall be able to answer quickly and present an organisation of indoor navigation data tailored to scalable and flexible indoor navigation.
    @InProceedings{indoororga,
    Title = {Organisation of Indoor Navigation data from a data query perspective},
    Author = {Martin Werner and Moritz Kessel},
    Booktitle = {Ubiquitous Positioning Indoor Navigation and Location Based Service (UPINLBS 2010)},
    Year = {2010},
    Abstract = {Indoor Navigation is becoming a more and more important topic. It is a key tool for the integration of disabled people into environments which they are not familiar with. With this paper we want to address the problem of indoor navigation being much more complex than outdoor navigation with a thorough modelling of queries which a indoor navigation GIS database shall be able to answer quickly and present an organisation of indoor navigation data tailored to scalable and flexible indoor navigation.},
    Doi = {10.1109/UPINLBS.2010.5653981},
    Url = {http://dx.doi.org/10.1109/UPINLBS.2010.5653981}
    }
  • M. Werner, S. A. W. Verclas, and C. Linnhoff-Popien, "A Workflow Definition Language for Business Integration of Mobile Devices," in Mobile Wireless Middleware, Operating Systems, and Applications, Springer Berlin Heidelberg, 2010, vol. 48, pp. 353-362.
    [BibTeX] [Download PDF]
    @InCollection{Werner2010,
    Title = {A Workflow Definition Language for Business Integration of Mobile Devices},
    Author = {Martin Werner and Stephan A. W. Verclas and Claudia Linnhoff-Popien},
    Booktitle = {Mobile Wireless Middleware, Operating Systems, and Applications},
    Publisher = {Springer Berlin Heidelberg},
    Year = {2010},
    Pages = {353-362},
    Series = {Lecture Notes of the Institute for Computer Sciences, Social Informatics and Telecommunications Engineering},
    Volume = {48},
    Affiliation = {Mobile and Distributed Systems Group, Ludwig-Maximilians University, Munich, Germany},
    ISBN = {978-3-642-17758-3},
    Keyword = {Computer Science},
    Url = {http://dx.doi.org/10.1007/978-3-642-17758-3_27}
    }