Wednesday September 19th, 2018 | Leave a comment Speaker Dr. Tiphaine Viard, postdoctral researcher at Riken AIP, Tokyo Date 9/20 (木) 13:00- Location 東京工業大学大岡山キャンパス 西8号館W棟W1008 / W1008, 10th floor, West wing, West 8 building, Tokyo Tech Ookayama Abstract Graph theory provides a language for studying the structure of relations, and it is often used to study interactions over time too. However, it poorly captures the both temporal and structural nature of interactions, that calls for a dedicated formalism. In this talk, we present a generalization of graph concepts in order to cope with both aspects in a consistent way. We start with elementary concepts like density, clusters, or paths, and derive from them more advanced concepts like cliques, degrees, clustering coefficients, or connected components. We obtain a language to directly deal with interactions over time, similar to the language provided by graphs to deal with relations. This formalism is self-consistent: usual relations between different concepts are preserved. It is also consistent with graph theory: graph concepts are special cases of the ones we introduce. This makes it easy to generalize higher-level objects such as quotient graphs, line graphs, k-cores, and centralities. We will present some applications of this formalism, in particular the analysis of email exchanges and face-to-face contacts. Slide Dr. Tiphaine Viard kindly shared her slide that she used for her talk. Related information Stream Graphs and Link Streams for the Modeling of Interactions over Time: a revised version to appear in the Social Networks Analysis and Mining journal. Analysis of the temporal and structural features of threads in a mailing-list: presented at the 7th international workshop on Complex Networks, 2016. GitHub project