Discovering bipartite substructure in directed networks

Taylor, Alan and Vass, J. Keith and Higham, Desmond J. (2011) Discovering bipartite substructure in directed networks. LMS Journal of Computation and Mathematics, 14. pp. 72-86.

[img]
Preview
PDF
P101.pdf
Preprint

Download (1MB)| Preview

    Abstract

    Bipartivity is an important network concept that can be applied to nodes, edges and communities. Here we focus on directed networks and look for subnetworks made up of two distinct groups of nodes, connected by “one-way” links. We show that a spectral approach can be used to find hidden substructure of this form. Theoretical support is given for the idealised case where there is limited overlap between subnetworks. Numerical experiments show that the approach is robust to spurious and missing edges. A key application of this work is in the analysis of high-throughput gene expression data, and we give an example where a biologically meaningful directed bipartite subnetwork is found from a cancer microarray dataset.