It has smooth effect on data, this effect that make the result not to follow statistical rule of data, if we do not clear smooth effect, it will effect strictlyy edict precise.

• 它对参数有一种光滑效应，这种光滑效应使结果有模糊化倾向，不能严格遵从参数的统计规律，若不将这些光滑效应加以消除，则会对预测精度有严重影响。