introduction to complex systems and social network analysis
DESCRIPTION
This Presentation was prepared by Arif Khan for the Seminar on Introduction to complex systems and social network analysis on 05/03/14 (Wednesday) Organized by BRAC University CSE Department in collaboration with BRAC University Computer Club (BUCC).TRANSCRIPT
Introduction to Complex Systems and Social Network Analysis
Arif KhanComplex Systems Research Centre
The University of Sydney
Lecturer (on leave)Department of CSE, BRAC University
This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.
What is Social Networks
• Relationship between Social Entities
A B
CD
Nodes are Entities/ActorsCan be people, organization, countries
Edges are relationshipCan be Friendship, Transaction, Trust, Relationship
Some Social Network
• Migratory Bird Network
Some Social Networks• Relationship network in a U.S. high school. Girls are pink, boys
are blue
Some Social Network
• Ingredients Network
Why Social Network Analysis?
• Because our choice/behavior has social context, we are influenced by others
Some Research Facts
• Relationships are mostly mutual. If you like me, I will like you.
A B
• Friend of my friend will eventually be my Friend
A B
C
Some Research Facts
• Making and Maintaining friendship is costly.• Average person can maintain only 150
intimate relationship.• So this friendship network is hardly possible.
Some Research Facts
• This is a small world. On average each person of world has a friendship distance of 6
• There are on average 3.74 people in between any two facebook users.
Complex System
• Social Networks are one type of Complex System, they have all the properties discussed above.
• Complex Systems– Have large number of actors/nodes– Changes over time– They are resilient.
Centrality: finding important Nodes
• Degree Centrality
A B
C
D
E
I am So popular!!
A B
C
D
E
I am social,
I love
everyone!!
B has high in-Degree
B has high out-Degree
Centrality: finding important Nodes
• Betweenness Centrality‘A’ has high Betweenness centralityIt can control Information, can control business,Can manipulate information
Centrality: finding important Nodes
• Closeness centralityI may not have
lots of friend. But I have powerful
friend, enough for me
High (not highest) closeness centrality
Example of SNA software (Gephi)
• Analyze my Facebook network• <OPEN GEPHI outside>
Social Network Analysis as CSE perspective
• Developing efficient algorithms (graph algorithm, approximation algorithm)
• Developing efficient graph/mathematical models of real world Social Networks
• Developing data mining software, centrality measures
• And many more…
If you are interested…
• This is relative new research area.• Almost all universities have research centers
related to Social Network analysis, complex system, data mining etc.
• Complete the online course (FREE!) from www.coursera.org/course/sna
THANK YOU
Questions?
Important Links: www.coursera.org/course/snaMy Mail: [email protected]
Pictures taken from various sources, may be copyrighted. Used for Educational purpose only