Social Mining & Big Data Analy1cs
Big Data, Human Mobility & Migra4on
h4p://www.sobigdata.eu/
Roberto Trasar1 roberto.trasar1@is1.cnr.it
Social Mining & Big Data Analy1cs Big Data, Human Mobility & - - PowerPoint PPT Presentation
Social Mining & Big Data Analy1cs Big Data, Human Mobility & Migra4on Roberto Trasar1 roberto.trasar1@is1.cnr.it h4p://www.sobigdata.eu/ Moving Object data (Vehicles) Call Detail Records (Phone data) Social Networks geo-located data
Social Mining & Big Data Analy1cs
Big Data, Human Mobility & Migra4on
h4p://www.sobigdata.eu/
Roberto Trasar1 roberto.trasar1@is1.cnr.it
n Moving object and trajectory data mining has many important, real-world applications driven by the real need
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Ecological analysis (e.g., animal scientists)
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Weather forecast
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Traffic control
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Location-based services
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Homeland security (e.g., border monitoring)
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Law enforcement (e.g., video surveillance)
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…
Algorithms Models
Individual Behaviors Collec1ve Mobility Global Models
G y m Hospital Restaura nta
P>(a)
Tij ∝ pop2
i popj(popi + sij)(popi + sij + popj)
raw trajectory data basic trajectory patterns derived models
semantics
Analyzing the collec1ve behavior
Urban Mobility Atlas http://kdd.isti.cnr.it/uma2/
Flows of vehicles to the two airports
Vehicles of the sample have been re-scaled using ACI data of the
circula1ng vehicle fleet.
1 2 3 4 O/D Community Discovery
A user-centric view of mobility data
Mobility Data Mining methods automatically extract relevant episodes: locations and movements.
user’s personal loca+ons, i.e., the places
any kind of ac1vity.
set of observa1ons defining the personal loca1ons.
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characterized by the trajectories that start and end in the user’s personal loca1ons.
their similarity.
representa1ve trajectory, named rou+ne.
profile Pu, is an abstrac1on in 1me and space of the systema1c movements of a user.
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Graph abstraction based
movements (edges)
Trip Features Length Dura1on Time Interval Average Speed Network Features centrality clustering coefficient average path length predictability entropy hubbiness degree betweenness volume edge weight flow per loca1on
Radius of gyration k-radius of gyra4on
the characteristic distance traveled by individuals the radius computed on the k most visited locations
K=4
The movements between the K loca1ons cannot represent the user All the mobility of the user can be represented by the movements between the K loca1ons Two different and separated behaviors
Individual Call Profile and Classifica4on
123643 Cell12 24/06/2015 14:05 123643 Cell12 24/06/2015 18:13 123643 Cell15 25/06/2015 11:05 123643 Cell15 25/06/2015 20:42 123643 Cell11 25/06/2015 21:05 123643 Cell12 26/06/2015 10:01 …. t1 = [00:00-08:00) t2 = [8:00-19:00) t3 = [19:00-24:00)
A condensed representa1on of the user’s phone calls: Individual Call profile (ICP). It is used to classify his behavior.
Modelling individuals to discover correla1ons and pa4erns among the collec1vity
– If the user is following one of her rou1nes, she will con1nue to do so – Otherwise, check if other users’rou1nes fit the actual trip, and use them now predic1on
– Rou1ne containment – A driver can pick up an
– Nodes = users – Edges = pairs of users with matching rou1nes
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passenger driver
PDE
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< 5% SOV
Detec4ng Events – Example of Piazza San Pietro
Characterizing “Padre Pio’s” Event
Event Day afer Mean day - Week 5 Mean day - Week 6
From area N. 2 3 4 5
Day afer
1 From area N. 1 2 3 4 5
Event
partners, in various languages, with geoloca1on
news ar1cles.
world (country to country, 2012).
Sen1ment on migra1on topics: Percep1on of the Mediterranean Refugee Crisis
Sen4ment on migra4on topics: Percep4on of the Mediterranean Refugee Crisis
migra1on in Twi4er?
rela1on to the refugee crisis?
affected by the phenomenon?
by the migra1on flow?
large tweet collec1ons by extrac1ng and crossing informa1on about the following three dimensions: – Time – Space
– Sen1ment
and loca1ons in 1me
Posi1ve Hashtags Nega1ve Hashtags Posi1ve Tweets Nega1ve Tweets Posi1ve Users Nega1ve Users
Enrich hashtag seeds from #-tag co-occurrence
Ini1al seeds
#refugeeswelcome #refugessnotwelcome
Sen4ment on migra4on topics: Percep4on of the Mediterranean Refugee Crisis
European country men4ons
AT-HU border
Flow shif to Croa1a
News about Syria Terrorist a4ack in Nigeria
Africa & Middle East country men4ons
September 4 (death of Alan Kurdi, borders between AT HU, Germany welcomes refugees).
– bars show the number of polarized posi1ve and nega1ve users by city
h4p://www.sobigdata.eu/