منابع مشابه
Perfect 0 , + 1 Matrices *
Perfect graphs and perfect 0,l matrices are well studied in the literature. Here we introduce perfect 0, f 1 matrices. Our main result is a characterization of these matrices in terms of a family of perfect 0,l matrices. 0 Elsevim Science Inc., 1997 * This work was supported in part by NSF grants DMI-9424348 and DMS-9509581, and by ONR grant NOOO14-89-J-1063. LINEAR ALGEBRA AND ITS APPLZCATIONS...
متن کاملOn perfect 0, +/- 1 matrices,
Perfect 0,±1 matrices were introduced recently in [5] as a generalization of the well-studied class of perfect 0, 1 matrices. In this paper we provide a characterization of perfect 0,±1 matrices in terms of an associated perfect graph which one can build in O(nm) time, where m × n is the size of the matrix. We also obtain an algorithm of the same time complexity, for testing the irreducibility ...
متن کامل(0, ±1) Ideal Matrices
A (0; 1) matrix A is said to be ideal if all the vertices of the polytope Q(A) = fx : Ax 1; 0 x 1g are integral. The issue of nding a satisfactory characterization of those matrices which are minimally non-ideal is a well known open problem. An outstanding result toward the solution of this problem, due to Alfred Lehman, is the description of crucial properties of minimally non-ideal matrices. ...
متن کاملTotally Nonnegative (0, 1)-Matrices
We investigate (0, 1)-matrices which are totally nonnegative and therefore which have all of their eigenvalues equal to nonnegative real numbers. Such matrices are characterized by four forbidden submatrices (of orders 2 and 3). We show that the maximum number of 0s in an irreducible (0, 1)-matrix of order n is (n − 1) and characterize those matrices with this number of 0s. We also show that th...
متن کاملBalanced 0-1 Matrices I. Decomposition
A 0, \1 matrix is balanced if, in every square submatrix with two nonzero entries per row and column, the sum of the entries is a multiple of four. This paper extends the decomposition of balanced 0, 1 matrices obtained by Conforti, Cornue jols, and Rao (1999, J. Combin. Theory Ser. B 77, 292 406) to the class of balanced 0, \1 matrices. As a consequence, we obtain a polynomial time algorithm f...
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ژورنال
عنوان ژورنال: Linear Algebra and its Applications
سال: 1997
ISSN: 0024-3795
DOI: 10.1016/s0024-3795(96)00773-2