Variances used for data generation in the simulation study based on the SUMA model.

denotes the variance of the shared multiplicative error (εSM), and the variance of the unshared multiplicative error (εUM,i). See Fig 3 for a graphical depictions of scenario realizations.分别表示共享乘性误差（εSM）与非共享乘性误差（εUM,i）的方差。场景实现的图形化展示详见图3。