Longitudinal data is typical related data, and it is desirable to choose correct data variance structure since the correct structure affects the efficiency of estimation.
纵向数据为典型的相关数据，数据方差结构选择的正确与否直接影响估计的效率。
2
The generalized variance ratio is a measure of efficiency.
广义方差比是一个效率度量。
3
The experiments results shown that the effect of rotational speed variance on the desalination and its efficiency wer. e obvious under same experiment condition.