In the second step, an RBFNN is developed to model the residuals from the ARMA model.The final forecast value combines both outputs of ARMA model and RBFNN.

• 采用ARMA模型对汽车销量趋势进行初步线性预测，利用RBF神经网络对线性预测的残差建模，得到非线性预测，两部分预测输出和为总的预测值。