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Showing papers on "Circulant matrix published in 1975"


Journal ArticleDOI
TL;DR: In this paper, it was shown that if q is a prime power then there exists a circulant weighing matrix of order q2 + q + 1 with q2 nonzero elements per row and column.
Abstract: It is shown that if q is a prime power then there exists a circulant weighing matrix of order q2 + q + 1 with q2 nonzero elements per row and column.This result allows the bound N to be lowered in the theorem of Geramita and Wallis that “given a square integer k there exists an integer N dependent on k such that weighing matrices of weight k and order n and orthogonal designs (1, k) of order 2n exist for every n > N”.

33 citations



Journal ArticleDOI
TL;DR: The incidence matrix of a (v, k, λ) configuration is used to construct a ( 2v, v) and a (2v + 2, v + 1) self-dual code and if the incidence matrix is a circulant, the codes obtained are quasi-cyclic and extended quasi-cycles, respectively.
Abstract: The incidence matrix of a (v, k, λ) configuration is used to construct a (2v, v) and a (2v + 2, v + 1) self-dual code. If the incidence matrix is a circulant, the codes obtained are quasi-cyclic and extended quasi-cyclic, respectively. The weight distributions of some codes of this type are obtained.

16 citations


Journal ArticleDOI
TL;DR: In this paper, the authors investigated the matrix equation A2 =dI+λJ, where A is a rational circulant, and a necessary and sufficient condition is given for the existence of matrices A satisfying the equation, when such matrices exist, the construction and enumeration of solutions are given explicitly.

15 citations


Journal ArticleDOI

5 citations



Journal ArticleDOI
01 Sep 1975
TL;DR: In this article, the Lagrange-Sylvester (LS) theorem is used to simplify the reduction of matrix functions without explicit use of the LS theorem and of the characteristic roots.
Abstract: Straightforward reduction of matrix functions without explicit use of the Lagrange-Sylvester (LS) theorem and of the characteristic roots is achieved by expansions in terms of Lucas polynomials. Use of the LS theorem within the framework of the Lucas polynomial method and, furthermore, of circulant matrices leads to substantial simplifications.

2 citations