Hamilton Jacobi Equations
Mostrando 1-12 de 12 artigos, teses e dissertações.
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1. Analytical Solution for Optimal Low-Thrust Limited-Power Transfers Between Non-Coplanar Coaxial Orbits
ABSTRACT: In this paper, an analytical solution for time-fixed optimal low-thrust limited-power transfers (no rendezvous) between elliptic coaxial non-coplanar orbits in an inverse-square force field is presented. Two particular classes of maneuvers are related to such transfers: maneuvers with change in the inclination of the orbital plane and maneuvers wit
J. Aerosp. Technol. Manag.. Publicado em: 03/05/2018
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2. A função hipergeométrica e o pêndulo simples / The hypergeometric function and the simple pendulum
Este trabalho tem por objetivo modelar e resolver, matematicamente, um problema físico conhecido como pêndulo simples. Discutimos, como caso particular, as chamadas oscilações de pequena amplitude, isto é, uma aproximação que nos leva a mostrar que o período de oscilação é proporcional à raiz quadrada do quociente entre o comprimento do pêndulo
Publicado em: 2011
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3. Controle H-infinito não linear e a equação de Hamilton Jacobi-Isaacs. / Nonlinear H-infinity control and the Hamilton-Jacobi-Isaacs equation.
O objetivo desta tese é investigar aspectos práticos que facilitem a aplicação da teoria de controle H1 não linear em projetos de sistemas de controle. A primeira contribuição deste trabalho é a proposta do uso de funções ponderação com dinâmica no projeto de controladores H1 não lineares. Essas funções são usadas no projeto de controladores
Publicado em: 2008
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4. "Implementation of Level Set Method for computing curves and surfaces motion" / "Implementação numérica do método Level Set para propagação de curvas e superfícies"
Nesta dissertação de Mestrado será apresentada uma poderosa técnica numérica, conhecida como método Level Set, capaz de simular e analisar movimentos de curvas em diferentes cenários físicos. Tal método - formulado por Osher e Sethian [1] - está sedimentado na seguinte idéia: representar uma determinada curva (ou superfície) Γ como a curva d
Publicado em: 2004
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5. Sobre a modelagem e dinamica de estruturas flexiveis de rastreamento (pequenas e grandes deflexões)
In this work two models are developed to slewing flexible structures with just one link: a model considering small deflections and a model considering great deflections. For both models, the Extended Hamilton s PrincipIe is utilized so one can obtain the goveming euqations o fmotion. This equations are then nondimensionalized so one can obtain a smalI nondim
Publicado em: 1997
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6. Fast methods for the Eikonal and related Hamilton– Jacobi equations on unstructured meshes
The Fast Marching Method is a numerical algorithm for solving the Eikonal equation on a rectangular orthogonal mesh in O(M log M) steps, where M is the total number of grid points. The scheme relies on an upwind finite difference approximation to the gradient and a resulting causality relationship that lends itself to a Dijkstra-like programming approach. In
The National Academy of Sciences.
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7. Ordered upwind methods for static Hamilton–Jacobi equations
We introduce a family of fast ordered upwind methods for approximating solutions to a wide class of static Hamilton–Jacobi equations with Dirichlet boundary conditions. Standard techniques often rely on iteration to converge to the solution of a discretized version of the partial differential equation. Our fast methods avoid iteration through a carefu
The National Academy of Sciences.
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8. An O(N log N) algorithm for shape modeling.
We present a shape-recovery technique in two dimensions and three dimensions with specific applications in modeling anatomical shapes from medical images. This algorithm models extremely corrugated structures like the brain, is topologically adaptable, and runs in O(N log N) time, where N is the total number of points in the domain. Our technique is based on
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9. A Biological Least-Action Principle for the Ecological Model of Volterra-Lotka
The conservative model of Volterra for more-than-two predator-prey species is shown to be generated as extremals that minimize a definable Lagrange-Hamilton integral involving half the species and their rates of change. This least-action formulation differs from that derived two generations ago by Volterra, since his involves twice the number of phase variab
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10. Fast-phase space computation of multiple arrivals
We present a fast, general computational technique for computing the phase-space solution of static Hamilton–Jacobi equations. Starting with the Liouville formulation of the characteristic equations, we derive “Escape Equations” which are static, time-independent Eulerian PDEs. They represent all arrivals to the given boundary from all possible startin
The National Academy of Sciences.
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11. Numerical computation of diffusion on a surface
We present a numerical method for computing diffusive transport on a surface derived from image data. Our underlying discretization method uses a Cartesian grid embedded boundary method for computing the volume transport in a region consisting of all points a small distance from the surface. We obtain a representation of this region from image data by using
National Academy of Sciences.
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12. A fast marching level set method for monotonically advancing fronts.
A fast marching level set method is presented for monotonically advancing fronts, which leads to an extremely fast scheme for solving the Eikonal equation. Level set methods are numerical techniques for computing the position of propagating fronts. They rely on an initial value partial differential equation for a propagating level set function and use techni