However the analysis of both location and dispersion effects in unreplicated factorial experiments with censored data has not been studied widely . hamada and wu ( 1991 ) proposed a iterated method to estimate location effect under the condition of homogeneity of variances Hamada和wu ( 1991 )给出了此条件下鉴别和估计位置效应的迭代算法，但由于其模型假定各试验点同方差，因此不能分析散度效应。
