共查询到20条相似文献，搜索用时 31 毫秒
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In this paper, a numerical method for solving the optimal control (OC) problems is presented. The method is enlightened by the Chebyshev-Legendre (CL) method for solving the partial differential equations (PDEs). The Legen-dre expansions are used to approximate both the control and the state functions. The constraints are discretized over the Chebyshev-Gauss-Lobatto (CGL) collocation points. A Legendre technique is used to approximate the integral involved in the performance index. The OC problem is changed into an equivalent nonlinear programming problem which is directly solved. The fast Legendre transform is employed to reduce the computation time. Several further illustrative examples demonstrate the efficiency of the proposed method. 相似文献
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李宝凤 《唐山师范学院学报》2014,(2):1-6
给出了基于 Bernstein多项式求解分数阶微分方程的配置方法。首先,在 Bernstein级数的截断式中用tα（0〈α〈1）代替t得到分数阶Bernstein级数截断式,采用Caputo分数阶导数构建分数阶Bernstein级数截断式的矩阵形式。其次,把方程中的每一项用分数阶Bernstein级数截断式转换成矩阵形式,选取配置点,得到相应于非线性代数方程的基本矩阵方程。最后得到由条件矩阵形式和基本矩阵方程构成的新方程组,其解给出了截断项为N的近似解,同时给出了基于残余函数的误差分析。举例说明了这种方法的有效性和可行性。 相似文献
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INC Mustafa 《浙江大学学报(A卷英文版)》2005,6(10):1058-1064
INTRODUCTION The decomposition method was introduced by Adomian(1989;1994)in the1980’s for solving linear and nonlinear functional equations(algebraic,dif-ferential,partial differential equations(PDEs)and systems,integral,differential-delay,integro-differen-tial equations,etc.)(Adomian,1989;1994;Guellal and Cherruault,1995;Adomian et al.,1996;Laffez and Abbaoui,1996;Ndour et al.,1996;Guellal et al.,1997;Abbaoui and Cherruault,1999;Adjedj,1999).This method leads to computable,accurat… 相似文献
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从两点到三点到m点再到无穷多点,对常微分方程边值问题的研究最早始于牛顿和莱布尼茨建立微积分的最初阶段。这些常微分方程多点边值问题也常常被称为常微分方程非局部问题。讨论阶数为q∈（1,2）的非线性分数阶微分方程四点非局部边值问题,借助Ascoli—Arzela定理,首先利用压缩映射原理得到解的唯一性,其次利用Krasnoselskii不动点定理得到四点边值问题至少存在一个解,并且举例验证。 相似文献
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LIU Xin 《浙江大学学报(A卷英文版)》2006,7(6):1061-1067
INTRODUCTION Meshfree methods are increasingly becoming popular as they are effective for dealing with com-putational mechanics problems including both solid and fluid problems. Most of various approaches proposed in (Liu, 2002) are based on Galerkin form (weak form) which need background meshes for numerical integrations, and are actually not truly meshfree methods. Other approaches are based on collocation form (strong form), such as finite point method (FPM) (Onate et al., 1996), ra… 相似文献
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A spectral method based on the Legendre polynomials for solving Helmholz equations was proposed. With an explicit formula for the Legendre polynomials in terms of arbitrary order of their derivatives, the successive integration of the Legendre polynomials was represented by the Legendre polynomials. Then the method was formulized for secondorder differential equations in one dimension and two dimensions. Numerical results indicate that the suggested method is significantly accurate and in satisfactory agreement with the exact solution. 相似文献
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黄正达 《浙江大学学报(A卷英文版)》2003,4(1):80-85
A judgment criterion to guarantee a point to be a Chen's approximate zero of Newton method for solving nonlinear equation
is sought by dominating sequence techniques. The criterion is based on the fact that the dominating function may have only
one simple positive zero; assuming that the operator is weak Lipschitz continuous, which is much more relaxed and can be checked
much more easily than Lipschitz continuous in practice. It is demonstrated that a Chen's approximate zero may not be a Smale's
approximate zero. The error estimate obtained indicated the convergent order when we use |f(x)|<ε to stop computation in software. The result can also be applied for solving partial derivative and integration equations.
Project supported by the Special Funds for Major State Basic Research (973) Program(No. 19990328) and the National Natural
Science Foundation of China(No. 10271112), and Y. C. Tang Disciplinary Development Fund of Zhejiang University, China 相似文献
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刘立山 《黄冈师范学院学报》2001,21(3):52-54
利用一个新的比较结果和Moench不动点定理，研究了Banach空间非线性混合型微分－积分方程初值问题整体解的存在性，作为应用，得到了两类三阶方程混合边值问题的整体解。 相似文献
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1 IntroductionThenonlinearconstrainedoptimizationproblemisaveryimportantmathematicalprogrammingprob lem .Ithasbeenstudiedextensively ,andmanyalgo rithmsforsolvingthis problemhasbeen pro posed[1,2 ] .Mostalgorithmsforsolvingthenonlinearcon strainedoptimization problemislocallyconvergent ,suchastheNewtonmethod ,theBFGSmethodandtheSQPmethod ,etc .Toovercomethisdrawback ,manyextendediterativemethodshavebeendevel oped .Forexample ,theNewtonmethodincorporatedwiththelinesearch[1] andhomotopymeth… 相似文献
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As a basic mathematical structure,the system of inequalities over symmetric cones and its solution can provide an effective method for solving the startup problem of interior point method which is used to solve many optimization problems.In this paper,a non-interior continuation algorithm is proposed for solving the system of inequalities under the order induced by a symmetric cone.It is shown that the proposed algorithm is globally convergent and well-defined.Moreover,it can start from any point and only needs to solve one system of linear equations at most at each iteration.Under suitable assumptions,global linear and local quadratic convergence is established with Euclidean Jordan algebras.Numerical results indicate that the algorithm is efficient.The systems of random linear inequalities were tested over the second-order cones with sizes of 10,100,,1 000 respectively and the problems of each size were generated randomly for 10 times.The average iterative numbers show that the proposed algorithm can generate a solution at one step for solving the given linear class of problems with random initializations.It seems possible that the continuation algorithm can solve larger scale systems of linear inequalities over the secondorder cones quickly.Moreover,a system of nonlinear inequalities was also tested over Cartesian product of two simple second-order cones,and numerical results indicate that the proposed algorithm can deal with the nonlinear cases. 相似文献
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将边界积分方程的等价变分形式与径向基点插值法相结合,提出了Galerkin径向边界点法.由于径向基点插值法构造的形函数具有Delta函数性质,因此边界条件可以很方便地得到满足;该法也能保持变分问题的对称性和正定性.数值算例验证了该方法的有效性. 相似文献
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姚庆六 《周口师范学院学报》2008,25(5)
研究了非线性Sturm-Liouville边值问题{(p(t)u'(t))' f(t,u(t),u(t))=0,0＜t＜1,au(0)-bp(0)u,(0)=A,cu(1) dp(1)u'(1)=B.的可解性,允许非线性项f(t,u,v)在t=0和t=1处奇异.利用相关线性问题的Green函数将此问题转化为一个积分方程.利用Leray-Schauder不动点定理证明了一个新的存在定理.该定理表明只要非线性项在某个有界集合上的"高度"的积分是适当的此问题就有一个解. 相似文献
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探讨应用Wavelet-Galerkin方法求解一维波动方程的初边值问题,通过修改边界上的小波函数,得到满足齐次边界条件的有限区域的小波基,用Wavelet-Galerkin方法离散微分方程后,得到一个确定小波系数的线性方程组,此方程组的系数矩阵在一维情况下是一个带状矩阵,且其中还有许多小的元素,其逆矩阵有类似的性质.数值实验表明,小波为求解微分方程提供了一个新的强有力的工具,用它来求解方程得到的小波近似解能很好地满足各种边界条件,且解的精度可以通过增加小波函数或增加尺度而得到提高. 相似文献
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求解非线性互补问题的一种方法是将其转化为非光滑方程组。本文通过引进一个基于Fischer-Burmeister函数的光滑NCP函数[8],建立了求解P0函数非线性互补问题的一个新的光滑牛顿算法。这个算法在每步迭代中只需要解一个光滑方程且不要求给出具体光滑因子下降的过程。在一定的条件下,证明了该算法的全局收敛性。数值试验表明该算法是有效的. 相似文献
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姚庆六 《周口师范学院学报》2004,21(2):11-14
考察了一类二阶非线性常微分方程的Dirichlet边值问题的存在性. 在非线性项线性增长的情况下,利用Leray-Schauder不动点定理获得了若干新的存在性结论. 相似文献
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杨刘 《安徽教育学院学报》2011,29(3):8-10
利用一个新的不动点定理考虑一类二阶三点边值问题正解的存在性,给出了正解存在的充分条件,所得结论不同于已有文献取得的结果。文中构造实例解释了结果的应用性。 相似文献
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应用Green函数将分数微分方程边值问题转化为积分方程的方法讨论分数阶微分方程边值问题正解的存在性.研究非线性分数阶微分方程的两点边值问题,主要工具是锥上的Krasnosel'skii不动点定理.结果表明:只要非线性项在某些有界集合上的"高度"是适当的,该问题有n个正解(n是一个任意给定的正整数). 相似文献
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戚仕硕 《商丘师范学院学报》1996,(Z1)
本文采用单调迭代技术研究了Ｂａｎａｃｈ空间中形如ｘ（４）＝ｆ（ｔ，ｘ，ｘ＇，ｘ＂，ｘ），ｘ＇（ａ）＝Ａ，ｘ＂（ａ）＝Ｂ，ｘ（ａ）＝Ｃ，ｘ（ｂ）＝ｘ０的四阶非线性微分方程两点边值问题，并首次得到关于最大解与最小解的存在性定理。 相似文献
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钱树华 《宁夏师范学院学报》2006,27(3):38-41
本文针对非线性方程组的求解问题提出一种混合算法,将方程组转换成一个优化问题.利用优化问题的非线性共轭梯度法与混沌优化方法相结合,提出了一种新的混合优化算法.该算法能使非线性共轭梯度法跳出局部最优,最终获得全局最优.通过对算法的收敛性的证明及数值分析,结果表明该算法是有效的. 相似文献