Spherical Harmonics
Mostrando 1-8 de 8 artigos, teses e dissertações.
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1. Controle da diretividade sonora no espaço tridimensional por um arranjo esférico compacto de alto-falantes / Sound directivity control in a 3-D space by a compact spherical loudspeaker array
O controle angular da radiação sonora pode ser obtido utilizando um arranjo compacto de alto-falantes independentemente programáveis operando na mesma faixa de frequência. Geralmente, os alto-falantes são dispostos sobre uma estrutura de formato esférico seguindo a geometria de um sólido de Platão a fim de se obter uma configuração altamente simét
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 22/02/2010
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2. Aproximação na esfera por uma soma com pesos de harmônicos esféricos / Approximation on the sphere by weighted sums of spherical harmonics
The subject of this work is to study approximation on the sphere by weighted sums of spherical harmonics. We present necessary and sufficient conditions on the weights for convergence in both, the continuous and the Lp cases. We analyse the convergence rates of the approximation processes using a modulus of smoothness related to the strong Laplace- Beltrami
Publicado em: 2007
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3. Diferentes noções de diferenciabilidade para funções definidas na esfera / Different notions of differentiability for functions defined on the sphere
In this work we study different notions of differentiability for functions defined on the unit sphere S^n-1 of R^n, n>=2. With respect to the usual derivative, we find necessary and/or sufficient conditions in order that a function be differentiable up to a fixed order. As for the other two, the strong Laplace-Beltrami derivative and the weak derivative, we
Publicado em: 2007
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4. Utilização de redes neurais na determinação de modelos geoidais / Using artificial neural network to obtain geoid models.
Applying data from EGM96 geopotential model, gravimetric, GPS and geometric leveling data and using spherical harmonics and FFT as techniques of geoidal determination, this thesis has the goal to find a fast alternative tool to define a geoidal undulation model considering precision and a small effort to estimate important parameters to obtain the mentioned
Publicado em: 2003
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5. Preliminary representation of world population by spherical harmonics.
The geographical arrangement of people on the surface of the earth is approximated by a mathematical equation of 361 terms. This is a convenient form for comparison with other distributions and for use in global change studies, and it has other advantages, but it must be considered preliminary because of data limitations.
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6. Fourier analysis on the Heisenberg group
We obtain a usable characterization of the (group) Fourier transform of 𝒮(Hn) (Schwartz space on the Heisenberg group). The characterization involves writing elements of [Formula: see text] as asymptotic series in Planck's constant. In the process, we derive a new “discrete” version of spherical harmonics, and elucidate the theory of group contraction
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7. An L2 form of Bernstein's inequality
Suppose P is a pth degree real polynomial function in n variables and f=PǀSn-1 is the restriction of P to the unit sphere Sn-1 in Rn. Bernstein's inequality asserts that ([unk]0kf)2 + p2([unk]0k-1f)2 ≤ p2k ∥f∥∞2, where k ≥ 1 and differentiation is with respect to arc length θ along any geodesic in Sn-1. We find the constant corresponding to p2k w
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8. Pattern formation in icosahedral virus capsids: the papova viruses and Nudaurelia capensis beta virus.
The capsids of the spherical viruses all show underlying icosahedral symmetry, yet they differ markedly in capsomere shape and in capsomere position and orientation. The capsid patterns presented by the capsomere shapes, positions, and orientations of three viruses (papilloma, SV40, and N beta V) have been generated dynamically through a bottom-up procedure