Constructive learning of recurrent neural network

Recurrent neural networks are a natural model for learning and predicting temporal signals.In addition simple recurrent networks have been shown to be both theoretically and experimentally capable of learning finite state automata. However it is difficult to determine what is the minimal neural network structure for a particular automation. Using a large recurrent network, which would be versatile in theory in practice proves to be very difficult to train. Constructive or destructive recurrent methods might offer a solution to this problem. We prove that one current method. Recurrent cascade correlation has fundamental limitations in representation and thus in its learning capabilities. We give a preliminary approach on how to get around these limitation by devising a ″Simple″ constructive training method that adds neurons during training while still preserving the powerful fully recurrent structure. Through simulations we show that such a method can learn many types of regular grammars that the Recurrent Cascade Correlation method is unable to learn.