Sun et. al., ICDM 2005

This a Paper discussed in Social Media Analysis 10-802 in Spring 2010.

Citation

Neighborhood Formation and Anomaly Detection in Bipartite Graphs, Jimeng Sun, Huiming Qu, Deepayan Chakrabarti, Christos Faloutsos, ICDM 2005

Online version

Neighborhood Formation and Anomaly Detection in Bipartite Graphs

Summary

This paper poses two interesting social problems on bipartite graph named Neighborhood formation and Anomaly detection. They also propose solutions based on Random walk with restart.

The experimented on 3 real world social graphs Conference-Author dataset, Author-Paper dataset and IMDB dataset

Evaluation

They evaluate their methods by asking following 4 questions :

 - Does NF find out meaningful neighborhoods?
 - How close is Approximate NF to exact NF?
 - Can AD detect injected anomalies?
 - How much time these methods take to run on graphs of varying sizes?

Discussion

This paper poses two important social problems related to bipartite social graphs and explained how those problems can be solved efficiently using random walks.

They also claim that the neighborhoods over nodes can represent personalized clusters depending on different perspectives.

During presentation one of the audiences raised question about is anomaly detection in this paper similar to betweenness of edges defined in Kleinber's text as discussed in Class Meeting for 10-802 01/26/2010. I think they are similar. In the texbook they propose, detecting edges with high betweenness and using them to partition the graph. In this paper they first try to create neighbourhood partitions based on random walk prbabilities and which as a by product gives us nodes and edges with high betweenness value.

Related papers

There has been a lot of work on anomaly detection in graphs.

• The paper by Moonesinghe and Tan ICTAI06 finds the clusters of outlier objects by doing random walk on the weighted graph.
• The paper by Aggarwal SIGMOD 2001 proposes techniques for projecting high dimensional data on lower dimensions to detect outliers.

Study plan

• Article:Bipartite graph:[1]
• Article:Anomaly detection:[2]
• Paper:Topic sensitive pagerank:[3]
  • Paper:The PageRank Citation Ranking: Bringing Order to the Web:[4]
• Paper:Multilevel k-way Partitioning Scheme for Irregular Graphs:[5]