Buscar
Mostrando ítems 1-10 de 35
Artículo
Algebra Structures on the Comparison of the Reduced Bar Construction and the Reduced W-Construction
(Taylor and Francis, 2009)
For a simplicial augmented algebra K, Eilenberg–Mac Lane constructed a chain map . They proved that g is a reduction (homology isomorphism) and conjectured that it is also the injection of a contraction (special homotopy ...
Artículo
Generalized Hadamard full propelinear codes
(Springer, 2021)
Codes from generalized Hadamard matrices have already been introduced. Here we deal with these codes when the generalized Hadamard matrices are cocyclic. As a consequence, a new class of codes that we call generalized ...
Artículo
Boolean Functions and Permanents of Sylvester Hadamard Matrices
(MDPI, 2021-01-17)
One of the fastest known general techniques for computing permanents is Ryser’s formula. On this note, we show that this formula over Sylvester Hadamard matrices of order 2m, Hm, can be carried out by enumerating m-variable ...
Artículo
Self-Dual codes from (−1,1)-matrices of skew symmetric type
(Cornell University, 2013)
Previously, self-dual codes have been constructed from weighing matrices, and in particular from conference matrices (skew and symmetric). In this paper, codes constructed from matrices of skew symmetric type whose ...
Artículo
On Cocyclic Hadamard Matrices over Goethals-Seidel Loops
(MDPI, 2020)
About twenty-five years ago, Horadam and de Launey introduced the cocyclic development of designs, from which the notion of cocyclic Hadamard matrices developed over a group was readily derived. Much more recently, it ...
Artículo
A Mixed Heuristic for Generating Cocyclic Hadamard Matrices
(Springer, 2018)
A way of generating cocyclic Hadamard matrices is described, which combines a new heuristic, coming from a novel notion of fitness, and a peculiar local search, defined as a constraint satisfaction problem. Calculations ...
Artículo
On an inequivalence criterion for cocyclic Hadamard matrices
(Springer, 2010)
Given two Hadamard matrices of the same order, it can be quite difficult to decide whether or not they are equivalent. There are some criteria to determine Hadamard inequivalence. Among them, one of the most commonly ...
Artículo
On D4t-Cocyclic Hadamard Matrices
(Wiley, 2016)
In this paper, we describe some necessary and sufficient conditions for a set of coboundaries to yield a cocyclic Hadamard matrix over the dihedral group D4t. Using this characterization, new classification results for ...
Artículo
Determinants of (–1,1)-matrices of the skew-symmetric type: a cocyclic approach
(Walter de Gruyter GmbH, 2015)
An n by n skew-symmetric type (−1, 1)-matrix K = [ki,j ] has 1’s on the main diagonal and ±1’s elsewhere with ki,j = −kj,i. The largest possible determinant of such a matrix K is an interesting problem. The literature ...
Artículo
On p-minimal homological models of twisted tensor products of elementary complexes localised over a prime
(American Mathematical Society, 1999)
In this paper, working over Z(p) and using algebra perturbation results from [18], p-minimal homological models of twisted tensor products (TTPs) of Cartan’s elementary complexes are obtained. Moreover, making use of the ...