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Landmark-Based - PowerPoint Presentation

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Landmark-Based - PPT Presentation

User Location Inference in Social Media Yuto Yamaguchi Toshiyuki Amagasa and Hiroyuki Kitagawa University of Tsukuba 131008 COSN 2013 Yuto Yamaguchi 1 locationrelated information ID: 328227

cosn yuto 2013 yamaguchi yuto cosn yamaguchi 2013 landmark location users mixture user landmarks boston centrality distribution based constraint weight recall followers

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Slide1

Landmark-Based User Location Inferencein Social Media

Yuto Yamaguchi†, Toshiyuki Amagasa†and Hiroyuki Kitagawa††University of Tsukuba

13/10/08

COSN 2013 - Yuto Yamaguchi

1Slide2

location-related information

13/10/08

COSN 2013 - Yuto Yamaguchi

2

Eating seafood !!!

I’m at Logan airport

Profile

Residence: Tokyo, Japan

COSN @ northeastern Slide3

applicationsVarious Researches using Home Locations

Outbreak Modeling [Poul+, ICWSM’12]Real-World Event Detection [Sakaki+, WWW’12]Analyzing Disasters [Mandel+, LSM’12]Other Useful ApplicationsLocation-aware Recommender

[Levandoski+, ICDE’12]Merketing

, AdsDisaster Warning

13/10/08

COSN 2013 - Yuto Yamaguchi

3Slide4

our ProblemLocation profiles are not available for …

76% of Twitter users [Cheng et al., CIKM’10]94% of Facebook users [Backstrom et al., WWW’10]This reduces opportunities of location information                User Home Location Inference

13/10/08

COSN 2013 - Yuto Yamaguchi

4Slide5

User home location inferenceContent-Based Approaches

[Cheng et al., CIKM’10][Kinsella et al., SMUC’11][Chandra et al., SocialCom’11]Graph-Based Approaches[Backstrom et al., WWW’10][

Sadilek et al., WSDM’12][

Jurgens, ICWSM’13]

13/10/08

COSN 2013 - Yuto Yamaguchi

5

Our focusSlide6

graph-based approach (1/2)Basic Idea

13/10/08COSN 2013 - Yuto Yamaguchi6

Boston

Boston

Boston

Chicago

New York

Boston

?

friendsSlide7

graph-based approach (2/2)Closeness Assumption

13/10/08COSN 2013 - Yuto Yamaguchi7

F

riends

Not friends

Spatially close

Spatially distant

Really close

?

60% are 100km distantSlide8

concentration assumption13/10/08

COSN 2013 - Yuto Yamaguchi8

Boston

Boston

?

LANDMARK

Unknown

NY

ChicagoSlide9

landmarks         

13/10/089COSN 2013 - Yuto YamaguchiSlide10

requirementsSmall Dispersion

Large Centrality13/10/08COSN 2013 - Yuto Yamaguchi

10Slide11

examples in twitter13/10/08

COSN 2013 - Yuto Yamaguchi11Slide12

Landmarks mapping13/10/08

COSN 2013 - Yuto Yamaguchi12

Red: all usersBlue: landmarksSlide13

proposed method    

13/10/0813COSN 2013 - Yuto YamaguchiSlide14

OverviewProbabilistic Model

Modeling 13/10/08COSN 2013 - Yuto Yamaguchi

14

Each user has his/her

location distribution

Location inference =

Selecting the location with

the largest probability density

location set

LANDMARK MIXTURE MODELSlide15

Dominance DistributionSpatial distribution of followers’ home locations

Modeled as Gaussian Landmarks have small covariances

 many followers at the center

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15

latitude

longitude

many

followers

few

followersSlide16

Landmark Mixture Model (LMM)13/10/08

COSN 2013 - Yuto Yamaguchi16

I

nference

target user

follow

Landmark

Non-landmark

Non-landmark

Dominance

distribution

Mixture

weight

Large weight for landmarkSlide17

mixture weights13/10/08

COSN 2013 - Yuto Yamaguchi17

Proportional to centrality

Landmark

Non-landmark

Large mixture weight

Small

mixture weightSlide18

Confidence ConstraintIf the distribution does not have a clear peak,

we should not infer the location of that user13/10/08COSN 2013 - Yuto Yamaguchi18

 High precision

but

low recallSlide19

Centrality ConstraintWe can reduce the cost by

ignoring non-landmarks13/10/08COSN 2013 - Yuto Yamaguchi19

 low cost

but

low recall

I

nference

target user

follow

Landmark

Non-landmark

Non-landmarkSlide20

experiments         

13/10/0820COSN 2013 - Yuto YamaguchiSlide21

DatasetTwitter dataset provided by [Li et al., KDD’12]

3M users in the U.S.285M follow edgesGeocode their location profiles for ground truth465K users (15%)  labeled usersTest set

46K users (10% of labeled users)

13/10/08

COSN 2013 - Yuto Yamaguchi

21Slide22

performance comparison13/10/08

COSN 2013 - Yuto Yamaguchi22

Compared three methodsLMM: our method

UDI: [Li+, KDD’12]

Naïve: Spatial medianSlide23

effect of Confidence constraint13/10/08

COSN 2013 - Yuto Yamaguchi23

p0

We can adjust the trade-off between precision and recallSlide24

effect of centrality constraint13/10/08

COSN 2013 - Yuto Yamaguchi24

c0

We can adjust the trade-off between cost and recallSlide25

ConclusionIntroduced the

concentration assumptioninstead of widely-used closeness assumptionThere exist landmarksProposed landmark mixture modelOutperforms the state-of-the-art methodConfidence / Centrality constraintFuture work

Other application of landmarks

Recommending landmarks or their tweets

13/10/08

COSN 2013 - Yuto Yamaguchi

25