Steepest Descent
Mostrando 13-20 de 20 artigos, teses e dissertações.
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13. Numerical computation of optimal low-thrust limited-power trajectories - Transfers between coplanar circular orbits
An algorithm based on gradient techniques, proposed in a companion paper, is applied to numerical analysis of optimal low-thrust limited-power trajectories for simple transfer (no rendezvous) between coplanar circular orbits in a central Newtonian gravity field. The proposed algorithm combines the main positive characteristics of two well-known methods in op
Journal of the Brazilian Society of Mechanical Sciences and Engineering. Publicado em: 2005-06
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14. On the convergence properties of the projected gradient method for convex optimization
When applied to an unconstrained minimization problem with a convex objective, the steepest descent method has stronger convergence properties than in the noncovex case: the whole sequence converges to an optimal solution under the only hypothesis of existence of minimizers (i.e. without assuming e.g. boundedness of the level sets). In this paper we look at
Computational & Applied Mathematics. Publicado em: 2003
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15. Desenvolvimento e analise de novos algoritmos preditivos para equalização cega
In this work, the blind equalization of a communication channel will be considered. The work will focus on the discussion of blind equalization techniques that are based on linear prediction theory. These are called predictive techniques for blind equalization. Firstly, the need for an equalizer in a communication system will be discussed, as well as the adv
Publicado em: 1997
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16. PROGRAMAÇÃO HIPERBÓLICA EM VARIÁVEIS 0-1 E OTIMIZAÇÃO DE CONSULTAS A BANCOS DE DADOS BIBLIOGRAFICOS / HIPERBOLIC PROGRAMMING IN 0-1 VARIABLES AND BIBLIOGRAPHIC DATABASES SEARCH OPTIMIZATION
In this work we study the solution of problems arising in the field of queries optimization in information retrieval from classical databases, through their formulation as mathematical problems in 0-1 variables. The first problem studied is the hyperbolic programming problem in 0-1 variables, for which we developed exact linear-time algorithms. The second pr
Publicado em: 1988
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17. Calculation of the Reaction Cross Section from a Rate Constant by the Method of Steepest-Descent
The reaction cross section of a bimolecular reaction has been calculated from the corresponding rate constant by the inverse Laplace transform. In carrying out the inverse Laplace transform, the method of steepest-descent has been used. As applications, the reaction cross sections for the rate constant of k(T) = k′ Tne-E0/kT and for the rate constant of th
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18. An extension of the steepest descent method for Riemann-Hilbert problems: The small dispersion limit of the Korteweg-de Vries (KdV) equation
This paper extends the steepest descent method for Riemann-Hilbert problems introduced by Deift and Zhou in a critical new way. We present, in particular, an algorithm, to obtain the support of the Riemann-Hilbert problem for leading asymptotics. Applying this extended method to small dispersion KdV (Korteweg-de Vries) equation, we (i) recover the varia
The National Academy of Sciences.
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19. Equilibrium and stability code for a diffuse plasma
A computer code to investigate the equilibrium and stability of a diffuse plasma in three dimensions is described that generalizes earlier work on a sharp free boundary model. Toroidal equilibria of a plasma are determined by considering paths of steepest descent associated with a new version of the variational principle of magnetohydrodynamics that involves
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20. An analysis of neural receptive field plasticity by point process adaptive filtering
Neural receptive fields are plastic: with experience, neurons in many brain regions change their spiking responses to relevant stimuli. Analysis of receptive field plasticity from experimental measurements is crucial for understanding how neural systems adapt their representations of relevant biological information. Current analysis methods using histogram e
The National Academy of Sciences.