Nonlinear Time Series Forecast Using Radial Basis Function Neural NetworksThe projects supported by National Natural Science Foundation of China (Grant No. 60074020) and the Doctoral Foundation of the Chinese Education Commission (Grant No. 90203008)

In the research of using Radial Basis Function Neural Network (RBF NN) forecasting nonlinear time series, we investigate how the different clusterings affect the process of learning and forecasting. We find that ?-means clustering is very suitable. In order to increase the precision we introduce a nonlinear feedback term to escape from the local minima of energy, then we use the model to forecast the nonlinear time series which are produced by Mackey-Glass equation and stocks. By selecting the ?-means clustering and the suitable feedback term, much better forecasting results are obtained.