Vishnu Shankar Tiwari

Fair Isaac Corporation

Bangalore

A Faster Way To Establish Trip

Similarity

Presenter Title, Group Company

India Conference on Geo-spatial Technologies & Applications, April 12-13, 2012

Motivation

Location Data organized as trips are used in :

Route Prediction

Mining travel patterns

Vehicle turn prediction

Network routing algorithms for QOS

Resource prediction in Grid computing

Trip and Trip Segmentation

Location Data : Log of triplet

<(xt0,yt0,t0),(xt1,yt1,t1)….. (xtn,ytn,tn)>

Traveling from location A to B and after time δt again B to A are two trips

Traveling from location A to B and after time δt from B to C are two trips

Trip is sequence (by time) of consecutive location points

(Pi,ti) for 1<i<=n

Trip of a vehicle : <vid, Ps, Ts, Pe, Te> (Ps, Pe : start, end positions; Ts, Te: start, end times respectively).

Two Trips T1, T2 of a vehicle are said to be consecutive if

PS(T2) = Pe(T1) and Ts(T2) > Te(T1) and (Ts(T2) – Te(T1)) > t

Road Network Graph

Some utility are available like

OSM2PO - http://osm2po.de/

Problems???????

Road Network Graph

No nodes placed at important places…only at junctions.

Traveler may terminate a trip at important places like hospital, restaurant etc

Road Network Graph

Undershoot and

Overshoots

Conversion of Trips to Network-edges

Map-Matching refers to associating location data to spatial features

It is not same as Map Comparison

Conversion of Trips to Map-edges

Conversion of Trips to Map-edges

Conversion of Trips to Map-edges

Storage Space Comparison

Similarity Between Trips

Two Trips

T1<ex1,ex2,……exn>

T2<ey1,ey2,……eyn>

are said to be similar if

ST(T1,T2)≥ dthreshold

where

ST (X,Y)=max(length(X),length(Y))-LD(X,Y)

Where LD is Levenshtein’s Distance.

Agglometric Clustering Trip1: 17619, 17617, 17615, 17613, 17611, 176090

Trip2: 17619, 17617, 17615, 17613, 17611, 32195, 32197

Trip3: 17617, 31961, 32167, 32165, 32163, 32063, 32061

Trip4: 32255, 32253, 17617, 17615, 31933, 31935, 31937

Trip5: 32255, 32253, 17617, 17615, 31933, 31935, 32265

Running Time Comparison

Tools and Technologies

For all the experiments we used open source tools and technologies.

GPS Data

-Microsoft Geolife trajectories (http://research.microsoft.com/en-us/downloads/b16d359d-

d164-469e-9fd4-daa38f2b2e13/)

-Data collected by us in Mumbai Area

Map Data- Open street Maps (OSM)

-www.openstreetmap.org

-http://cloudmade.com

Database- Postgres, Postgis

Visualization- Geoserver

All implementations done in java

References [1] Yue,Y, Zhuang,Y,Li,Q, Mao,Q, Mining time-dependent attractive areas and movement patterns from taxi trajectory data, 2009 17th International Conference

on Geoinformatics, Fairfax, VA, ISBN: 978-1-4244-4562-2,Aug 2009

[2] Froehlich,j., Krumm,j.,Route Prediction from Trip Observations,SAE 2008-01-0201

[3] Doherty,A.R, Gurrin,C., Jones, G.J.F., Smeaton,A.F., Retrievl of similar Travel Routes Using GPS Tracklog Place Names, SIGIR GIR‘06, August 10,2006, Seattle, USA.

[4] Bernstein,D., and Kornhauser,A., ―An Introduction to Map Matching for Personal Navigation Assistants‖, Technical report, New Jersey TIDE Center Technical Report,1996.

[5] White, C.E., Bernstein, D., Kornhauser, A.L. ,2000, Some map matching algorithms for personal navigation assistants. Transportation Research Part C 8, 91-108.

[6] Greenfeld,J.S, ―Matching GPS Observations to Locations on a Digital Map‖, In proceedings of the 81st Annual Meeting of the Transportation Research Board, Wasington D. C, 2002.

[7] Zhou,j., Golledge,R., A Three-step General Map Matching Method in the GIS Environment: Travel/Transportation Study Perspective, International Journal of Geographical Information System, Vol. X, No. X, Month 2006, xxx–xxx

[8] http://research.microsoft.com/e-us/projects/geolife/

[9] Alnoor, L. and Martinez, R. B. 1996. "Automated derivation of high accuracy road centerlines thiessen polygons technique," in ESRI User Conference Proceedings, London, England.

[10] Lou,Y., Xie,X., Zhang,C., Wang,W., Zheng,Y., Huang,Y., Map-Matching for Low-Sampling-Rate GPS Trajectories , ACM GIS '09 , November 4-6, 2009. Seattle, WA, USA (c) 2009 ACM ISBN 978-1-60558-649-6/09/11...$10.00

[11] Quddus, Mohammed A. , Noland, Robert,B., Ochieng, Washington Y.(2006) 'A High Accuracy Fuzzy Logic BasedMap Matching Algorithm for Road Transport', Journal of Intelligent Transportation Systems, 10: 3, 103 — 115

[12] Yin, H, Wolfson,O, A Weight-based Map Matching Method in Moving Objects Databases, SSDBM '04 Proceedings of the 16th International Conference on Scientific and Statistical Database Management IEEE Computer Society Washington, DC, USA ©2004, ISBN:0-7695-2146-0

[13] Kipp Jones, Ling Liu, Farshid Alizadeh-Shabdiz,”Improving Wireless Positioning with Look-ahead Map-Matching”,Proceeding MOBIQUITOUS '07 Proceedings of the 2007 Fourth Annual International Conference on Mobile and Ubiquitous Systems: Networking&Services (MobiQuitous)

[14] http://staffwww.dcs.shef.ac.uk/people/sam.chapman@k-now.co.uk/stringmetrics.html

THANK YOU

Presenter 1 Contact # email@email.com

India Conference on Geo-spatial Technologies & Applications, April 12-13, 2012