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Mostrando ítems 1-10 de 54
Ponencia
On the computability of the p-local homology of twisted cartesian products of Eilenberg-Mac Lane spaces
(Universidade do Minho, 1997)
Working in the framework of the Simplicial Topology, a method for calculating the p-local homology of a twisted cartesian product X( , m, , 0, n) = K( ,m)× K( 0, n) of Eilenberg-Mac Lane spaces is given. The chief ...
Ponencia
Error correcting codes from quasi-Hadamard matrices
(Springer, 2007)
Levenshtein described in [5] a method for constructing error correcting codes which meet the Plotkin bounds, provided suitable Ha- damard matrices exist. Uncertainty about the existence of Hadamard matrices on all orders ...
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 ...
Ponencia
Homological perturbation theory and computability of Hochschild and cyclic homologies of CDGAs
(Diffiety Institute of the Russian Academy of Natural Sciences, 1997)
We establish an algorithm computing the homology of commutative differential graded algebras (briefly, CDGAs). The main tool in this approach is given by the Homological Perturbation Theory particularized for the algebra ...
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 ...