periodical changes

• 周期变化

periodical changes的用法和样例：

例句

1. Considering the effects of the outside factor and the periodic change of the predictand, the multivariate mixed threshold regression model with periodic components is developed.
   摘要在综合考虑预测对象的周期变化和前期外部因子的共同作用后，给出带有周期分量的多元混合门限回归模型。