摘要
设Ａ和Ｂ均为矩阵，符号Ａ＾－表示Ａ的“减”的广义逆，λｉ（Ａ）表示方阵Ａ的第ｉ大特征根，ｔｒ（Ａ）表示方阵Ａ的“逆”，ＡＢ表示矩阵Ａ和Ｂ的Ｋｒｏｎｅｃｋｅｒ积，Ａ表示Ａ按行拉直Ａ≥Ｂ或Ａ＞Ｂ表示Ａ－Ｂ对称且半定或正定，符号″Ｍ→Ｎ”表示可由命题Ｍ推导出命题Ｎ，″→Ｎ”表示命题Ｍ和Ｎ等价。
In this paper, we give eight diffinitions for admissibility from diffrent form on multivariate regression coefficient under multivariate linear model with known covariance matrix, we prove that they are identical in the class of homogenous linear estimates,but they can be divided into three identical subclasses in the class of nonhomogeneous linear estimates.
