Visual Mining of Epidemic Networks

We show how an interactive graph visualization method based on maximal modularity clustering can be used to explore a large epidemic network. The visual representation is used to display statistical tests results that expose the relations between the propagation of HIV in a sexual contact network and the sexual orientation of the patients.Comment: 8 page

How Do Social Interaction Networks Influence Peer Impressions Formation? A Case Study

Part 1: Open Source Visualization and ReportingInternational audienceDue to their lack of physical interaction, Free and Open Source Software (FOSS) participants form impressions of their teammates largely based on sociotechnical mechanisms including: code commits, code reviews, mailing-lists, and bug comments. These mechanisms may have different effects on peer impression formation. This paper describes a social network analysis of the WikiMedia project to determine which type of interaction has the most favorable characteristics for impressions formation. The results suggest that due to lower centralization, high interactivity, and high degree of interactions between participants, the code review interactions have the most favorable characteristics to support impression formation among FOSS participants

Are Crossings Important for Drawing Large Graphs?

Abstract. Reducing the number of edge crossings is considered one of the most important graph drawing aesthetics. While real-world graphs tend to be large and dense, most of the earlier work on evaluating the impact of edge crossings utilizes relatively small graphs that are manually generated and manipulated. We study the effect on task performance of increased edge crossings in automatically generated layouts for graphs, from different datasets, with different sizes, and with different densities. The results indicate that increasing the number of crossings negatively impacts accuracy and performance time and that impact is significant for small graphs but not significant for large graphs. We also quantitatively evaluate the impact of edge crossings on crossing angles and stress in automatically constructed graph layouts. We find a moderate correlation between minimizing stress and the minimizing the number of crossings.