2007/03/31 by Gergely Palla, Illés J Farkas, Illes J. Farkas +6 · 3 citations
Biochemistry, Genetics and Molecular Biology · Mathematics · Physics and Astronomy · #Bioinformatics and Genomic Networks #Complex Network Analysis Techniques #Graph theory and applications #cond-mat.stat-mech #physics.bio-ph #physics.comp-ph #physics.soc-ph
paper · pdf · doi:10.1088/1367-2630/9/6/186
published as New J. Phys. 9, 186 (2007) · 21 pages, 10 figures, version 2: added two paragaphs
arxiv created 2007/06/12 · openalex publication_date 2007/06/28 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/01
A search technique locating network modules, i.e. internally densely connected groups of nodes in directed networks is introduced by extending the clique percolation method originally proposed for undirected networks. After giving a suitable definition for directed modules we investigate their percolation transition in the Erdős–Rényi graph both analytically and numerically. We also analyse four real-world directed networks, including Google's own web-pages, an email network, a word association graph and the transcriptional regulatory network of the yeast Saccharomyces cerevisiae . The obtained directed modules are validated by additional information available for the nodes. We find that directed modules of real-world graphs inherently overlap and the investigated networks can be classified into two major groups in terms of the overlaps between the modules. Accordingly, in the word-association network and Google's web-pages, overlaps are likely to contain in-hubs, whereas the modules in the email and transcriptional regulatory network tend to overlap via out-hubs.