Sphere Packings
Mostrando 1-8 de 8 artigos, teses e dissertações.
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1. Reticulados algébricos : abordagem matricial e simulações / Algebraic lattices : matrix approach and simulations
Neste trabalho abordamos a construção de reticulados usando propriedades da Teoria Algébrica dos Números. Enfocamos a construção de alguns reticulados com características especiais, conhecidos na literatura, via reticulados ideais, através de uma abordagem matricial e algorítmica...Observação: O resumo, na íntegra, poderá ser visualizado no text
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 15/06/2012
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2. Codigos esfericos em toros planares / Spherical codes on flat torus
Spherical codes in Euclidean spaces are finite sets of points on the surface of a multidimensional sphere and have been widely studied in connection with the signal transmission over a Gaussian channel. For this purpose one fundamental issue is to maximize the minimum distance between two code points, what is strongly related to the more general problem of s
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 21/07/2009
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3. The density of lattice sphere packings / A densidade de empacotamentos esfericos em reticulados
This dissertation addresses the lattice theory with focus on packing density, which has many applications and allows to establish interesting connections between topics of linear algebra, calculus of several variables and discrete geometry. The first chapter is an introduction to the main concepts and properties of lattices. In the second chapter we discuss
Publicado em: 2009
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4. Reticulados e codigos / Lattices and codes
We approach here some problems related to minimizing the error probability in signals transmission over Gaussian and Rayleigh channels. Algebraic ideal lattice theory is used to construct rotations of the n-dimensional integer lattice via cyclotomic fields. This construction allows to evaluate the minimum product distance of the lattice, parameter which cont
Publicado em: 2008
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5. A turbulent bed contactor: energetic efficiency for particle collection
Particle collection experiments were conducted in a fluidizing irrigated bed to evaluate the performance of mobile packings: 38 x 50 mm plain oblate spheroids 38 mm ID plain spheres and alternative perforated spheres with a 38 mm ID and 10% and 25% free areas were used as fluidizing media in a 0.264 m diameter and 1.20 m high turbulent bed contactor (TBC). P
Brazilian Journal of Chemical Engineering. Publicado em: 2007-03
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6. From binary codes to lattices and spherical codes / De codigos binarios a reticulados e codigos esfericos
In this work it is presented through examples a connection between inary codes, lattices and spherical codes. A brief introduction to coding theory, properties and examples is included in the first chapter. In Chapter 2 lattices are approached with focus on the quotient of lattices, graphs on flat tori and connections with circulant graphs. An introduction t
Publicado em: 2007
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7. Spherical codes with cyclic symmetries / Codigos esfericos com simetrias ciclicas
Euclidean spherical codes with symmetries are orbits of finite orthogonal matrix groups. These codes are also known as group codes. ln this work, the commutative group codes in even dimensions are viewed on flat tori, which are submanifolds of the sphere. Also, if the matrix group is cyclic, the generated code lies on a knot which wraps around a torus. If th
Publicado em: 2006
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8. Uma contribuição a classe dos codigos geometricamente uniformes
In this research we present extensions oí code constructions whose codes belong to the class oí geometrically uniíorm codes. We consider two characterizations oí signal sets matched to groups. The first characterization is derived írom a noncommutative group which is the semidirect product oí a commutative group by a cyclic group oí even order. The se
Publicado em: 1996