Issue No. 06 - June (2010 vol. 32)

ISSN: 0162-8828

pp: 1112-1126

DOI Bookmark: http://doi.ieeecomputersociety.org/10.1109/TPAMI.2009.78

Amin Mantrach , IRIDIA—CoDE—Université Libre de Bruxelles, Brussels

Marco Saerens , ISYS/LSM, Université Catholique de Louvain, Louvain-la-Neuve

Masashi Shimbo , Nara Institute of Technology and Science, Takayama

Luh Yen , ISYS/LSM, Université Catholique de Louvain, Louvain-la-Neuve

Kevin Francoisse , ISYS/LSM, Université Catholique de Louvain, Louvain-la-Neuve

Jerome Callut , ISYS/LSM, Université Catholique de Louvain, Louvain-la-Neuve

ABSTRACT

This work introduces a link-based covariance measure between the nodes of a weighted directed graph, where a cost is associated with each arc. To this end, a probability distribution on the (usually infinite) countable set of paths through the graph is defined by minimizing the total expected cost between all pairs of nodes while fixing the total relative entropy spread in the graph. This results in a Boltzmann distribution on the set of paths such that long (high-cost) paths occur with a low probability while short (low-cost) paths occur with a high probability. The sum-over-paths (SoP) covariance measure between nodes is then defined according to this probability distribution: two nodes are considered as highly correlated if they often co-occur together on the same—preferably short—paths. The resulting covariance matrix between nodes (say n nodes in total) is a Gram matrix and therefore defines a valid kernel on the graph. It is obtained by inverting an n\times n matrix depending on the costs assigned to the arcs. In the same spirit, a betweenness score is also defined, measuring the expected number of times a node occurs on a path. The proposed measures could be used for various graph mining tasks such as computing betweenness centrality, semi-supervised classification of nodes, visualization, etc., as shown in Section 7.

INDEX TERMS

Graph mining, kernel on a graph, shortest path, correlation measure, betweenness measure, resistance distance, commute time distance, biased random walk, semi-supervised classification.

CITATION

Amin Mantrach, Marco Saerens, Masashi Shimbo, Luh Yen, Kevin Francoisse, Jerome Callut, "The Sum-over-Paths Covariance Kernel: A Novel Covariance Measure between Nodes of a Directed Graph",

*IEEE Transactions on Pattern Analysis & Machine Intelligence*, vol. 32, no. , pp. 1112-1126, June 2010, doi:10.1109/TPAMI.2009.78SEARCH