On the issue of separability for problem decomposition in cooperative neuro-evolution

Cooperative coevolution divides an optimisation problem into subcomponents and employs evolutionary algorithms for evolving them. Problem decomposition has been a major issue in using cooperative coevolution for neuro-evolution. Efficient problem decomposition methods group interacting variables into the same subcomponents. It is important to find out which problem decomposition methods efficiently group subcomponents and the behaviour of neural network during training in terms of the interaction among the synapses. In this paper, the interdependencies among the synapses are analysed and a problem decomposition method is introduced for feedforward neural networks on pattern classification problems. We show that the neural network training problem is partially separable and that the level of interdependencies changes during the learning process. The results confirm that the proposed problem decomposition method has improved performance compared to its counterparts.