Triangulation heuristics for bn2o networks

Abstract

A BN2O network is a Bayesian network having the structure of a bipartite graph with all edges directed from one part (the top level) toward the other (the bottom level) and where all conditional probability tables are noisy-or gates. In order to perform efficient inference, graphical transformations of these networks are performed. The efficiency of inference is proportional to the total table size of tables corresponding to the cliques of the triangulated graph. Therefore in order to get efficient inference it is desirable to have small cliques in the triangulated graph. We analyze existing heuristic triangulation methods applicable to BN2O networks after transformations using parent divorcing and tensor rank-one decomposition and suggest several modifications. Both theoretical and experimental results confirm that tensor rank-one decomposition yields better results than parent divorcing in randomly generated BN2O networks that we tested. © 2009 Springer Berlin Heidelberg.