Constrained Independent Component Analysis of DNA Microarray Signals
Xuejun Liao, Lawrence Carin · 2004
In this paper we examine the use of user-defined constraints in the independent component analysis (ICA) model of DNA microarray signals (gene expression levels). The extracted constrained ICA model is used to define the functional gemonic unit (FGU). Two kinds of constraints are constructed, one on the FGU membership function defining the degree to which each gene is included in a FGU, the other on the FGU expression levels in the various experiments considered. The simulation results show that, proper constraints can be designed to build feasible regions that guide the constrained ICA to find the true FGUs, which may not be found by the unconstrained ICA.