Beijing University of Posts
VAST 2008 Challenge
Mini Challenge 3: Cell Phone Calls
Authors and
Affiliations:
Qi Ye,
Tian Zhu,
Deyong hu,
Student team: YES
faculty advisor:
Bin Wu,
Bai Wang,
Tool(s):
In order to combine the
analysis of geographic information and link relationships, we developed a tool called
GeoTemporalNet based on the framework called JSNVA. GeoTemporalNet is composed of two major parts, one part is used to show the
geographical information in the grid on the panel and the other part is used to
show the structure of different networks. JSNVA (Java Straight-line
drawing Network Visual Analysis framework) is a software framework JSNVA for
network visual analysis in different applications. JSNVA has a clear
architecture and supports a more systematic way of implementing different
straight-line graph drawing algorithms which show different networks on
different views. JSNVA can be used as a front-end for visualization and a
back-end for analysis in applications, and it can be customized for different
applications. The paper of more details about JSNVA will be published in
ADMA2008. Based on JSNVA, the data in GeoTemporalNet’s applications are stored in a
graph structure as nodes and edges, and if there are relations between two
nodes there will be an edge. The information in nodes and edges can be stored
and achieved by different keys, such as time,
position, names et al.
In this mini
challenge, we just use the graph data structure to record the relationships of different people as shown in the video. Both the time information and position
information of each people are stored in these nodes. In this challenge, we mainly use the force directed layout algorithm to show the social
network. By using this tool users can not
only get the temporal information of all people’s positions in the building
dynamically but also the evacuation trace of each person statically.
Phone-1: What is the Catalano/Vidro social
network, as reflected in the cell phone call data, at the end of the time
period
Figure 1 the Catalano/Vidro social network
In this challenge we try to find the social network by the egocentric networks of certain
persons whose IDs are 200 and 300, as shown in figure 1.
We find that there are two groups of
people who coordinate high-level in the social network and communicate with a
lot of people. One group is the people who communicate with 200, and their IDs are 1, 2, 3 and 5. The other group is the people who have the equal positions in this social network with the people in the first group.
The IDs of these people in the second group are 309, 392, 360 and 306. All the people in the second group communicate with the person whose ID is 300. At last
we use the egocentric networks of 200 and 300 to
detect the social network in this island. We get the
network by detecting the network whose roots are 200 and
Phone-2 Characterize the changes in the Catalano/Vidro social structure over the ten day period.
Detailed Answer:
We believe that the person whose ID is 200 is Ferdinando
Catalano and the person whose ID is 5 must be his brother Estaban
Catalano. As the person whose ID is 200 have communicated with 6 persons and
the person whose ID is 5 have communicated with him most frequently. They have communicated for 14 times, 15183 seconds during these 10 days. The person whose ID is 3 the second
one who communicated with Ferdinando Catalano most
frequently, while they had communicated for 8 times, 8520 seconds. So we believe that the person whose ID is 5 must be Estaban Catalano. We use the page-rank algorithm to find
the people’s centrality in the social network, and the size of vertices in
these figures show their importance. As David Vidro
coordinates high-level Paraiso activities and
communications, we find that the person whose ID is 0 communicated with all the important people who communicated with 200. He also
communicated with the persons in the second group whose IDs are 306 and 309, as
shown in figure 2. We also guess that the persons whose IDs are 1 and 2 may be
Juan Vidro and Jorge Vidro. The one whose ID is 0 should be David Vidro.
Figure 2 the neighbors of 0
By visualizing the calling behaviors of the people in the video, we find out
that the structure of the social network changed greatly on the 8th day. The people who communicated with 1, 2, 3 and 5 changed to communicated with 309, 392, 360 and 306.
In order to find out all the persons who share the common neighbors, we set each person’s neighbors as a set
and use Jaccard Coefficient to get the similarity of
any two nodes’ neighbor set. The
coefficient of 1 and 54 nodes is 0.75; the coefficient of 5 and 306 nodes is
also 0.68; the coefficient of 3 and 360 nodes is also 0.6; the coefficient of 2
and 397 nodes is 0.59.
Figue 3 (A ) shows the social network of the first 7 days,
and figure 3 (B ) shows the
social network of the last 3 days. The green nodes are the ones in both social
networks. Figure 4 shows the social network by using
combing the common nodes in figure 3 (A) and (B) in the third level. We find out
these persons who communicate with 200 seldom communicate with others. While the people whose IDs are 309, 392, 360 and 306 take the place of these people in the social network.
Figure 3 the temporal social network (A) the first 7 days (B) the last 3 days
Figure 4 the
social network combined by the common nodes in figure 3 (A) and (B)