The computation of lower-bound dynamic buckling loads of imperfection sensitive systems is examined under step load of infinite duration. An extended system based on the energy criterion for establishing the lower-bou...
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The computation of lower-bound dynamic buckling loads of imperfection sensitive systems is examined under step load of infinite duration. An extended system based on the energy criterion for establishing the lower-bound dynamic buckling loads without solving the highly nonlinear initial-value problems is proposed. The newly introduced scaling parameters are nonsingular solutions to the extended system;thus, standard methods can be used to compute them. Using the extended system, one can directly obtain the lower-bound dynamic buckling loads without tracing the postbuckling equilibrium paths. An efficient implementation of Newton's method for solving the extended system is presented, and numerical examples are given.
In this paper new global optimization algorithms are proposed for solving problems where the objective function is univariate and has Lipschitzean first derivatives. To solve this problem, smooth auxiliary functions, ...
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In this paper new global optimization algorithms are proposed for solving problems where the objective function is univariate and has Lipschitzean first derivatives. To solve this problem, smooth auxiliary functions, which are adaptively improved during the course of the search, are constructed. Three new algorithms are introduced: the first used the exact a priori known Lipschitz constant for derivatives;the second, when this constant is unknown, estimates it during the course of the search and finally, the last method uses neither the exact global Lipschitz constant nor its estimate but instead adaptively estimates the local Lipschitz constants in different sectors of the search region during the course of optimization. Convergence conditions of the methods are investigated from a general viewpoint and some numerical results are also given. (C) 1998 The Mathematical Programming Society, Inc. Published by Elsevier Science B.V.
The paper presents the novel principle on constructing a new class of highly parallel fast stable numerical algorithms of linear algebra. In accordance with suggested principle the parallel modifications of classic Gr...
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ISBN:
(纸本)0819427438
The paper presents the novel principle on constructing a new class of highly parallel fast stable numerical algorithms of linear algebra. In accordance with suggested principle the parallel modifications of classic Gran-Shmidt algorithm and the conjugate directions' algorithm are developed. The modified algorithms have super-linear convergence rate: the sufficient number of iterations is proportional to effective rank of linear algebraic system. Also they have high numerical stability supported by easy controlled parallel cross-feedbacks. The new algorithms provide for high computing density in distributed processors and proposed for using in area of multidimensional data stream real-time processing.
C++ templates are already recognized as a powerful linguistic mechanism, whose usefulness transcends the realization of traditional generic containers. In the same venue, this paper reports on a somewhat surprising ap...
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ISBN:
(纸本)1880446936
C++ templates are already recognized as a powerful linguistic mechanism, whose usefulness transcends the realization of traditional generic containers. In the same venue, this paper reports on a somewhat surprising application of templates-for computing the symbolic derivative of expression. Specifically, we describe a software package based on templates, called SEMT, which allows the programmer to create symbolic expressions, substitute variables in them, and compute their derivatives. SEMT is unique in that these manipulations are all done at compile time. In other words, SEMT effectively coerces the compiler to do symbolic computation as part of the compilation process. Beyond the theoretical interest, SEMT can be practically applied in the efficient, generic and easy to use implementation of many numerical algorithms.
Two algorithms are proposed for evaluating the rank of an arbitrary polynomial matrix. They rely upon constant matrix rank evaluations and therefore are more reliable than already existing elementary polynomial operat...
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Two algorithms are proposed for evaluating the rank of an arbitrary polynomial matrix. They rely upon constant matrix rank evaluations and therefore are more reliable than already existing elementary polynomial operations techniques. Some applications are mentioned, such as polynomial null-space extraction or conditions of existence of solutions to matrix polynomial equations arising in control problems. Deux algorithmes sont proposés pour évaluer le rang d'une matrice polynomiale quelconque. Ils sont basés sur des évaluations de rangs de matrices constantes et sont donc plus fiables que les techniques déjà existantes d'opérations polynomiales élémentaires. Quelques applications sont mentionnées, comme l'extraction du noyau polynomial ou des conditions d'existence de solutions aux équations polynomiales matricielles provenant de problèmes de commande.
A GPS-based power transmission line tester, in which the time tag of GPS is used as the synchronization signal, is developed practically to realize the online measurement of power system parameters. The principles of ...
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ISBN:
(纸本)0780344952
A GPS-based power transmission line tester, in which the time tag of GPS is used as the synchronization signal, is developed practically to realize the online measurement of power system parameters. The principles of the new measurement scheme are reviewed in the first part of the paper. The hardware and numerical algorithms are then presented in details, followed by experimental results.
A pragmatic approach is proposed in order to perform simplification of a complex non-linear model of a full-vehicle with the purpose of active suspension design. It relies upon two stages : numerical linearisation of ...
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A pragmatic approach is proposed in order to perform simplification of a complex non-linear model of a full-vehicle with the purpose of active suspension design. It relies upon two stages : numerical linearisation of the non-linear model around an equilibrium point, and order reduction of the linear representation. The emphasis is put on the fact that, as the objective is control design, it is necessary to involve the control law into the simplification process. This is done in an iterative way, since, initially, no controller is available.
A new method for the synthesis of compensators which solve the disturbance rejection problem (either by state feedback or by output feedback) is presented. This method, based on structural and geometric approaches, pr...
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A new method for the synthesis of compensators which solve the disturbance rejection problem (either by state feedback or by output feedback) is presented. This method, based on structural and geometric approaches, provides solutions to the problem with the minimal number of unassignable poles (i.e. poles that are fixed due to the fact that this particular problem is been solved). Moreover, all the poles that remain assignable are relocated to values selected by a non expert user, without any required knowledge of the proposed programs. Une nouvelle méthode de synthèse de compensateurs solutions du problème du rejet de perturbation, soit par retour d'état soit par retour de mesure, est proposée. Cette méthode, basée sur les approches géométrique et structurelle, permet de résoudre le problème (s'il est soluble) avec le minimum de pôles imposés par cette résolution. De plus tous les autres pôles sont placés aux valeurs indiquées par un utilisateur non expert de ces méthodes.
Linear Control Theory problems such as those of pole assignment by state, output feedback (centralised or decentralised), and zero assignment by input, or output squaring down may be reduced to a standard common probl...
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Linear Control Theory problems such as those of pole assignment by state, output feedback (centralised or decentralised), and zero assignment by input, or output squaring down may be reduced to a standard common problem known as the Determinantal assignment Problem (DAP) Giannakopoulos (1985). The aim of this paper is to develop and compare optimization algorithms for the computation of solutions of DAP. The developed numerical approaches may be used as a basis of a design technique centered around the frequency assignment problems.
In this paper a new class of multidimensional global optimization algorithms (called "divide the best" algorithms) is proposed. The class unifies and generalizes the classes of the characteristic methods and...
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