1 Introduction
The Radial Basis Function (RBF) network has been extensively applied to a lot of applications such as pattern recognition, image processing, and time series forecasting because it allows the independent tuning of RBF network parameters and sufficiency of using one layer of neural network to establish input-output mapping[12]. In general, the complexity of the RBF network increases when the net's input size increases. Moreover, the noise and the irrelevant components itn the inputs will degrade the generation performance of RBF networks as well.