【摘要】 关于S2NS阵和广义逆符号唯一阵,有人给出了一个实矩阵是S2NS阵(或广义逆符号唯一阵)且其逆(或广义逆)非正的特征刻画,在此提出了以上问题的一个反问题,即给定一个符号模式矩阵N(非正),是否存在S2NS阵(或广义逆符号唯一阵)A使其逆(或广义逆)等于N,并且给出了这个问题的特征刻画.更多还原

【Abstract】 A real matrix A is said to have a signed generalized inverse(or signed GI),if the sign pattern of its generalized inverse is uniquely determined by the sign pattern of A.This paper presents an imvestigation of some corresponding problems and a complete characterization is obtained about the nonpositive sign pattern matrices N which satisfy the following condition: there exists a real matrix A that has a signed generalized inverse and sgn(A+)=N.更多还原