Parameter Optimization in Hierarchical Structures

Abstract

The genetic-algorithm-based method described in this paper can be used to identify a parameter set whose value defines the gene regulation circuit. To demonstrate the effectiveness of the approach we choose Drosophila segmentation processes. In the processes, we search the parameter set of diffusion constant and transcription ratio of each gene. The characteristics of convergence were also investigated in order to find out how to improve the method. The results suggest that (1) when the gene regulatory network is hierarchically structured, genetic algorithm optimize the upstream parameters earlier than that of downstream in the hierarchy structure, (2) some gene network has smooth concave error surface with no local minima, and (3) the method can be used to test appropriateness of the basic model assumed.