NUS - VASuTool

VAST 2008 Challenge
Mini Challenge 3: Cell Phone Calls

Authors and Affiliations:

Chidansh Bhatt, National University of Singapore, chidansh@comp.nus.edu.sg  [PRIMARY contact]
Dhaval Patel, National University of Singapore, dhaval@comp.nus.edu.sg [PRIMARY contact]
Mohan Kankanhalli, National University of Singapore, mohan@comp.nus.edu.sg
Wynne Hsu, National University of Singapore, whsu@comp.nus.edu.sg
Lee Mong Li, National University of Singapore, leeml@comp.nus.edu.sg

Student team: YES  

Supervisors : [Mohan Kankanhalli, Wynne Hsu, Lee Mong Li]

Tool(s):

We preprocess data using Matlab programs. The outcome of programs gives files as input to GraphViz tool  (http://www.graphviz.org/). Graphviz is open source graph visualization software. Graph visualization is a way of representing structural information as diagrams of abstract graphs and networks. We have provided required matlab files to reproduce the result. Generated images which we use for analysis are available here. (1) Catalano Network: Hierarchical View  ( We use different color for node at different level of hierarchy in the network for better Visualization. The Required dot file is available here to run on GraphViz. ) (2) Interaction with core group members: 200

Two Page Summary: NO

ANSWERS:

---

Phone-1: What is the Catalano/Vidro social network, as reflected in the cell phone call data, at the end of the time period

PhoneNodes.txt

PhoneLinks.txt

We derive at above results considering the given hint of head Ferdinando Catalano being ID 200. To verify these we tried to find the node from which we can traverse maximum number of links in the given phone links network and it turn out that taking root of such network as ID 200 gives us maximum traversed links network. Thus we have confidence that node 200 is head of network. Among adjacent nodes to 200 we found ID 1 having link to maximum incoming and outgoing calls with unique IDs and thus we consider him as coordinator. The ID 5 receives maximum calls from 200 and talk more frequently so ID 5 is consider as brother. ID 2 and ID 97 looks of same person Juan Vidro from their interaction within core group and ID 3 and 137 of Jorge Vidro. It looks like Ferdinando Catalano stays in middle part of Island and brother at top part of Island and ID 97 ( Juan Vidro) at lower part of island. Interestingly their most frequent tower of calls are the places from where the migrant boats also launched to the US.

---

Phone-2  Characterize the changes in the Catalano/Vidro social structure over the ten day period.

Detailed Answer:

As expected the catalano/vidro structure looks like chain of stars. These chain of stars represents the people with importance in the network where star pattern takes palce. The found Catalano/Vidro social structure based on cell phone towers structure over 10 days period shows that on 8th day some event happened at location of tower 22. For this location of catalano/vidro network activity the main in charge is ID 97 ( Juan Vidro). It looks like the cell network mainly shown the pattern before some event to happen on 8th day at this location. As after the 8th day the interaction among the main people of network is not much but it is more active before 8th day. As it looks like Ferdinando Catalano  mainly stays at location of tower 29 and ID 97 ( Juan Vidro) also remains at location of tower 22.