Location- and Context-Awareness: Third International Symposium, LoCA 2007, Oberpfaffenhofen, Germany, September 20-21, 2007. Proceedings PDF
Preview Location- and Context-Awareness: Third International Symposium, LoCA 2007, Oberpfaffenhofen, Germany, September 20-21, 2007. Proceedings
Lecture Notes in Computer Science 4718 CommencedPublicationin1973 FoundingandFormerSeriesEditors: GerhardGoos,JurisHartmanis,andJanvanLeeuwen EditorialBoard DavidHutchison LancasterUniversity,UK TakeoKanade CarnegieMellonUniversity,Pittsburgh,PA,USA JosefKittler UniversityofSurrey,Guildford,UK JonM.Kleinberg CornellUniversity,Ithaca,NY,USA FriedemannMattern ETHZurich,Switzerland JohnC.Mitchell StanfordUniversity,CA,USA MoniNaor WeizmannInstituteofScience,Rehovot,Israel OscarNierstrasz UniversityofBern,Switzerland C.PanduRangan IndianInstituteofTechnology,Madras,India BernhardSteffen UniversityofDortmund,Germany MadhuSudan MassachusettsInstituteofTechnology,MA,USA DemetriTerzopoulos UniversityofCalifornia,LosAngeles,CA,USA DougTygar UniversityofCalifornia,Berkeley,CA,USA MosheY.Vardi RiceUniversity,Houston,TX,USA GerhardWeikum Max-PlanckInstituteofComputerScience,Saarbruecken,Germany Jeffrey Hightower Bernt Schiele Thomas Strang (Eds.) Location- and Context-Awareness Third International Symposium, LoCA 2007 Oberpfaffenhofen, Germany, September 20-21, 2007 Proceedings 1 3 VolumeEditors JeffreyHightower IntelResearchSeattle 1100NE45thSt.,Seattle,WA98105,USA E-mail:[email protected] BerntSchiele TUDarmstadt ComputerScienceDepartment Hochschulstrasse10,64289Darmstadt,Germany E-mail:[email protected] ThomasStrang GermanAerospaceCenter InstituteofCommunicationsandNavigation 82234Wessling/Oberpfaffenhofen,Germany E-mail:[email protected] and DigitalEnterpriseResearchInstitute(DERI) UniversityofInnsbruck,6020Innsbruck,Austria LibraryofCongressControlNumber:2007934918 CRSubjectClassification(1998):H.3,H.4,C.2,H.5,K.8 LNCSSublibrary:SL3–InformationSystemsandApplication,incl.Internet/Web andHCI ISSN 0302-9743 ISBN-10 3-540-75159-9SpringerBerlinHeidelbergNewYork ISBN-13 978-3-540-75159-5SpringerBerlinHeidelbergNewYork Thisworkissubjecttocopyright.Allrightsarereserved,whetherthewholeorpartofthematerialis concerned,specificallytherightsoftranslation,reprinting,re-useofillustrations,recitation,broadcasting, reproductiononmicrofilmsorinanyotherway,andstorageindatabanks.Duplicationofthispublication orpartsthereofispermittedonlyundertheprovisionsoftheGermanCopyrightLawofSeptember9,1965, initscurrentversion,andpermissionforusemustalwaysbeobtainedfromSpringer.Violationsareliable toprosecutionundertheGermanCopyrightLaw. SpringerisapartofSpringerScience+BusinessMedia springer.com ©Springer-VerlagBerlinHeidelberg2007 PrintedinGermany Typesetting:Camera-readybyauthor,dataconversionbyScientificPublishingServices,Chennai,India Printedonacid-freepaper SPIN:12162987 06/3180 543210 Preface These proceedings contain the papers presented at the 3rd International Sym- posium on Location- and Context-Awareness in September of 2007. Computinghasbecomemobile,wireless,andportable.Therangeofcontexts encountered while sitting at a desk working on a computer is very limited com- pared to the large variety of situations experienced away from the desktop. For computingtoberelevantandusefulintheseemergingsituations,computerswill need to take advantage of users location, activities, goals, abilities, preferences, interruptibility, affordances, and surroundings. With this contextual awareness, we can expect computers to deliver information, services, and entertainment in a way that maximizes convenience and minimizes intrusion. This symposium presented research aimed at sensing, inferring, and using location and context data in ways that help the user. Developing awareness in- volvesresearchinsensing,inference,datarepresentation,anddesign.Wesought technical papers describing original, previously unpublished research results in- cluding: – Sensing location and context – Inference techniques for context from low-level sensor data – Privacy and sharing of location and context information – User studies of location- and context-aware systems Our call for papers resulted in 55 submissions, each of which was assigned to members of our Program Committee. After reviews and e-mail discussions, we selected 17 papers for publication in these proceedings. We extend a sincere thank you to all the authors who submitted papers, to the 33 hard-working members of our Program Committee, and to our external reviewers. September 2007 Jeffrey Hightower Bernt Schiele Thomas Strang Organization Program Committee Gregory Abowd Georgia Tech Witold Abramowicz Poznan University of Economics Alessandro Acquisti CMU Michael Beigl TU Braunschweig Carlos Bento University of Coimbra Gaetano Borriello University of Washington Jim Crowley INRIA, France Eyal de Lara University of Toronto Anind Dey CMU Alois Ferscha University of Linz Hans Gellersen Lancaster University Robert Harle University of Cambridge Mike Hazas Lancaster University Jaga Indulska University of Queensland Minkyong Kim IBM Research John Krumm Microsoft Research Reto Krummenacher DERI Innsbruck Anthony LaMarca Intel Research Marc Langheinrich ETH Zurich Claudia Linnhoff-Popien LMU Munich Paul Lukowicz University of Passau Max Mu¨hlha¨user TU Darmstadt Kurt Partridge PARC Shwetak Patel Georgia Tech Alex Pentland MIT Matt Reynolds ThingMagic Inc. Kay Roemer ETH Zurich Chris Schmandt MIT Albrecht Schmidt Fraunhofer IAIS and University of Bonn Tim Sohn UC San Diego Hiroyuki Tarumi Kagawa University Alex Varshavsky University of Toronto Andy Wilson Microsoft Research External Reviewers Mohammed Al-Loulah Lancaster University Philippe Golle PARC VIII Organization Sponsoring Institutions German Aerospace Center (DLR) Intel Table of Contents WiFi Location Technology Bootstrapping a Location Service Through Geocoded Postal Addresses....................................................... 1 Gayathri Chandrasekaran, Mesut Ali Ergin, Marco Gruteser, and Richard P. Martin Deployment, Calibration, and Measurement Factors for Position Errors in 802.11-BasedIndoor Positioning Systems ......................... 17 Thomas King, Thomas Haenselmann, and Wolfgang Effelsberg LifeTag: WiFi-Based Continuous Location Logging for Life Pattern Analysis ........................................................ 35 Jun Rekimoto, Takashi Miyaki, and Takaaki Ishizawa Activity and Situational Awareness Scalable Recognition of Daily Activities with Wearable Sensors ........ 50 Taˆm Hu`ynh, Ulf Blanke, and Bernt Schiele Information Overlay for Camera Phones in Indoor Environments....... 68 Harlan Hile and Gaetano Borriello SocialMotion: Measuring the Hidden Social Life of a Building.......... 85 Christopher R. Wren, Yuri A. Ivanov, Ishwinder Kaur, Darren Leigh, and Jonathan Westhues Taxonomy, Architectures, and a Broader Perspective A Unified Semantics Space Model.................................. 103 Juan Ye, Lorcan Coyle, Simon Dobson, and Paddy Nixon Federation and Sharing in the Context Marketplace .................. 121 Carsten Pils, Ioanna Roussaki, Tom Pfeifer, Nicolas Liampotis, and Nikos Kalatzis A Taxonomy for Radio Location Fingerprinting...................... 139 Mikkel Baun Kjærgaard The Meaning of Place Inferring the Everyday Task Capabilities of Locations ................ 157 Patricia Shanahan and William G. Griswold X Table of Contents The Whereabouts Diary .......................................... 175 Gabriella Castelli, Marco Mamei, and Alberto Rosi Adaptive Learning of Semantic Locations and Routes................. 193 Keshu Zhang, Haifeng Li, Kari Torkkola, and Mike Gardner Radio Issues in Location Technology Signal Dragging: Effects of Terminal Movement on War-Driving in CDMA/WCDMA Networks ....................................... 211 Daehyung Jo, Jeongkeun Lee, Semun Lee, Taejoon Ha, Taekyoung Kwon, and Yanghee Choi Modeling and Optimizing Positional Accuracy Based on Hyperbolic Geometry for the Adaptive Radio Interferometric Positioning System... 228 Hao-ji Wu, Ho-lin Chang, Chuang-wen You, Hao-hua Chu, and Polly Huang New Approaches to Location Estimation Inferring Position Knowledge from Location Predicates ............... 245 J¨org Roth Preserving Anonymity in Indoor Location System by Context Sensing and Camera-BasedTracking....................................... 263 Takeshi Iwamoto, Arei Kobayashi, and Satoshi Nishiyama Localizing Tags Using Mobile Infrastructure......................... 279 Ying Zhang, Kurt Partridge, and Jim Reich Author Index.................................................. 297 Bootstrapping a Location Service Through Geocoded Postal Addresses Gayathri Chandrasekaran, Mesut Ali Ergin, Marco Gruteser, and Richard P. Martin WINLAB,Electrical and Computer Engineering Department Rutgers, The StateUniversity of New Jersey North Brunswick, NJ 08902-3390 {chandrga,ergin,gruteser}@winlab.rutgers.edu, [email protected] Abstract. Weanalyzethefeasibility ofboostrappingalocation service through geocoded postal addresses rather than the common wardriving technique. A location service that contains the MAC addresses and ge- ographic position of wireless LAN access points enables positioning ser- vices for WLAN devices and location-aware networking protocols. This work thus compares the accuracy of access point position estimates ob- tained based on RF signal strengths readings (wardriving) with the ac- curacyofthegeocodedpostaladdress.Theresultsshowsimilaraccuracy for geocoding in comparison to typical wardriving studies, with signif- icantly reduced effort if postal addresses of access point positions are known. 1 Introduction WiFi localization promises to complement satellite positioning in two key ar- eas that frequently experience poor satellite coverage,indoor environments and urban canyons. Wide area WiFi localization techniques as provided by Place Lab[1]orcommercialproviders[2],however,relyonalocationservicethatpro- vides geographic position of third-party WiFi access points identified by their MAC address. Obtaining the data to initialize and subsequently maintain the records of such a location service requires significanteffort. Typically, data is collected via wardriving, whereby a vehicle sweeps the area of interest and recording period- ically its position and the signal strength of nearby access points (the vehicle candetermineitspositionwithaGlobalPositioningSystemreceiver).Fromthis dataset, the position of access points can then be estimated using a number of heuristics such as position of maximum signal strength, or centroidof all access pointsightings.1Thisprocessisinaccurate[4]anditislaborious,sinceitrequires physically driving a vehicle through the road network in the intended coverage area.It needs to be repeatedperiodically to update the dataset,since ownersof access points upgrade their hardware (resulting in a change of MAC address), 1 SeeWigle.net [3] for example wardriving datasets. J.Hightower,B.Schiele,andT.Strang(Eds.): LoCA2007,LNCS4718,pp. 1–16,2007. (cid:2)c Springer-VerlagBerlinHeidelberg2007 2 G. Chandrasekaran et al. or move with the access point to a different geographic location. To reduce this updating effort [5] proposes self-mapping, wherein users of the location service contribute updates to its records. Still, bootstrapping a location service to the point where it is useful for early adopters is necessary. This paper studies the feasibility ofan alternate method, initializing location service records through geocoded postal addresses. This approach is motivated by the realization that large Internet service providers already maintain a di- rectory of postal addresses (i.e., billing addresses) and could easily add MAC addresses to these records.To evaluate this approach,we compare the accuracy of access point position estimates obtained through wardriving with those from postal address geocoding. Specifically, we study the effect of building and road densities, wardriving road coverage,and geocoding databases on these results. The remainder of this paper is organized as follows. The terms and metrics are introduced in section 2. The methodology is described in detail in section 3. Section4describestheresultsandsection5hasdiscussionsrelatedtheideaspre- sented.TherelatedworkissummarizedinSection6.Finally,section7concludes the paper. 2 Terms and Metrics In this section, we define the various terms and metrics used in the paper. Defi- nitions are as follows: – Actual Location of the AP:ItisthegeographiclocationwheretheAPis physically installed. This was found using the Orthophoto-based geocoding explained in the next section. – Full Coverage War-Driving Location of the AP: It is the geographic location of the AP reported by war driving through both the main and side roads.TheinferenceofthelocationoftheAPinthis experimentisbasedon the location at which the strongest SNR was received. Full Coverage War Driving Error is then defined as the Euclidean distance between the actual location of the AP and the full coverage war driving location of the AP, measured in feet. – Main Road War-Driving Location of the AP: It is the geographic location of the AP reported by war driving only through the main roads. Main Road War-Driving Error is then defined as the Euclidean distance betweentheactuallocationoftheAPandthemainroadwardrivinglocation of the AP, measured in feet. – Postal Address Geocoded Location of the AP: It is the geographic location of the AP reportedby geocoding the postal address of the building inwhichtheAPisinstalled.Postal Address Geocoding Error isthendefined as the Euclidean distance between the actual location of the AP and the postal address geocoded location of the AP, measured in feet.
The list of books you might like
