search of hadamard matrices by turyn sequences

In this paper we study the Hadamard matrices and some algorithms to generate them. We review some theoretical aspects about Hadamard's conjecture, which asserts that every positive integer multiple of 4 is a Hadamard number. Then we describe the methods of Kronecker, Sylvester, Paley, Williamso...

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Autor Principal: Piza Volio, Eduardo
Formato: Artículo
Idioma: Español
Publicado: 2015
Acceso en línea: http://revistas.ucr.ac.cr/index.php/matematica/article/view/2094
http://hdl.handle.net/10669/12995
Sumario: In this paper we study the Hadamard matrices and some algorithms to generate them. We review some theoretical aspects about Hadamard's conjecture, which asserts that every positive integer multiple of 4 is a Hadamard number. Then we describe the methods of Kronecker, Sylvester, Paley, Williamson, Goethals-Seidel, Cooper- Wallis, Baumert-Hall, Ehlich and supplementary dierence sets. Subsequently we settle the Hadamard sieve: 668 is lowest order for which is unknown if there exist an Hadamard matrix. Finally we propose a simulated annealing algorithms as alternative to nd Hadamard matrices from Turyn sequences. We found excellent solutions with this search method.