Ela a Note on the Positive Semidefinite Minimum Rank of a Sign Pattern Matrix
نویسندگان
چکیده
is called the sign pattern of A, where sgn(x) = −1, 0, 1 when x <,=, > 0 respectively. A matrix with −1, 0, 1 entries is also called a sign pattern matrix. The concept of sign pattern matrix first appeared in Paul A. Samuelson’s book [24], and it was related to the stability problem in economic models. Later on, additional applications for the sign pattern matrix have been found. Since the 1990s, the sign pattern matrix has been an important research topic in combinatorial matrix theory. The interested readers many refer to [12] and the bibliography therein.
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