共查询到20条相似文献,搜索用时 125 毫秒
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首先对空中加油问题进行了分析,提取了相关性质,在此基础上建立了问题的递推模型.根据该模型,提出了一种启发式搜索算法.该算法计算复杂度低,适用性好.对应于辅机是否可以多次起飞,该算法分为两子算法.对这两种不同情况下的具体问题,设计了相关的优化函数.所有算法都在计算机中运行,并得到了相应结果.值得指出的是,提出的启发式搜索算法十分高效.对于问题1和问题2,该算法所得解是约束条件下的最优调度策略.对于问题3,问题4,问题5,该算法所得解逼近最优调度策略. 相似文献
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基于遗传算法的大学课程表问题研究 总被引:3,自引:0,他引:3
课程表问题是时间表问题之一 ,也是 NP难问题 .根据大学授课形式的特点建立了大学课程表问题的数学模型 ,给出了求解该问题的遗传算法 .根据模型和大学课程表问题的特点设计了一种全新的编码 ,提出了一种新形式的交叉方式 .实验结果表明该方法是可行和有效的 . 相似文献
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讨论了一类具有超抛物型方程的反应扩散问题.首先,证明了比较定理.其次,构造了形式渐近解.然后,利用微分不等式方法,研究了问题解的存在、唯一性和渐近性态.最后得到了原问题解的渐近展开式. 相似文献
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研究了一类变系数椭圆方程的柯西问题,这类问题出现在很多实际问题领域.由于问题的不适定性,不可能通过经典的数值方法来求解上述问题,必须引入正则化手段.采用了一种修正吉洪诺夫正则化方法来求解上述问题.在一种先验和一种后验参数选取准则下,分别获得了问题的误差估计.数值例子进一步显示方法是稳定有效的. 相似文献
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文[6]中,F.Qi提出了一个未解决的不等式问题.本文给出了此问题的答案和进一步的拓广,同时也得到了该问题的反向不等式. 相似文献
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研究的是自主招生的面试安排问题.它与一个经典问题(Steiner System问题)有很紧密的联系.首先我们形式化地提出了这个问题,并针对问题提出了3种算法.值得一提的是,我们提出的同余构造算法在时间复杂度较低的情况下,具有很高的近似比(强于FPTAS).对于文理分科的情况,我们同样在形式化地提出问题之后,给出了相应的算法.我们编写程序实现了所述的算法. 相似文献
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K. Malanowski 《Journal of Optimization Theory and Applications》1987,53(3):429-449
A family of optimal control problems for discrete systems that depend on a real parameter is considered. The problems are strongly convex and subject to state and control constraints. Some regularity conditions are imposed on the constraints.The control problems are reformulated as mathematical programming problems. It is shown that both the primal and dual optimal variables for these problems are right-differentiable functions of a parameter. The right-derivatives are characterized as solutions to auxiliary quadratic control problems. Conditions of continuous differentiability are discussed, and some estimates of the rate of convergence of the difference quotients to the respective derivatives are given. 相似文献
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We propose general variational inclusion problems which are slightly different from corresponding problems considered in several recent papers in the literature and show that they are advantageous. Sufficient conditions for the solution existence are established. As applications we derive consequences for several special cases of variational inclusion problems, quasioptimization problems, equilibrium problems and implicit variational inequalities and show that they improve the results of some recent existing papers. 相似文献
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本文中,我们首先给出了一类混合似变分不等式问题.接着,在Banach空间中研究了它的解的存在性和唯一性.最后,讨论了混合似变分不等式问题的扰动问题,并证明了扰动问题的解的存在唯一性定理. 相似文献
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纺织材料设计反问题是数学物理反问题的一个新领域,也被称为应用数学与计算数学的一个分支.综述纺织材料设计反问题的来源、数学归结,并基于服装的热湿舒适性、压力舒适性提出了设计反问题,给出了反问题解的定义,综述了求解纺织材料设计反问题的数值算法,列举了若干具有挑战的研究课题. 相似文献
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凸二次规划问题逆问题的模型与解法 总被引:1,自引:0,他引:1
本文分别考虑带非负约束和不带大量负约束凸二次规划问题逆问题。首先得到各个逆问题的数学模型,然后对不同的模型给出不同的求解方法。 相似文献
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D. Mitrovi? 《Journal of Mathematical Analysis and Applications》2006,313(1):98-119
A priori estimates for elliptic linear Dirichlet problems are revisited and precisely determined. Such estimates are used for the analysis of Dirichlet problems with singular coefficients and data. Elliptic Dirichlet problems with singularities are reformulated in appropriate generalized function algebras and uniquely solved. 相似文献
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Hölder continuity and uniqueness of the solutions of general multivalued vector quasiequilibrium problems in metric spaces are established. The results are shown to be extensions of recent ones for equilibrium problems with some improvements. Applications in quasivariational inequalities, vector quasioptimization and traffic network problems are provided as examples for others in various optimization—related problems. 相似文献
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This work is a survey of results for ill-posed Cauchy problems for PDEs of the author with co-authors starting from 1991. A universal method of the regularization of these problems is presented here. Even though the idea of this method was previously discussed for specific problems, a universal approach of this paper was not discussed, at least in detail. This approach consists in constructing of such Tikhonov functionals which are generated by unbounded linear operators of those PDEs. The approach is quite general one, since it is applicable to all PDE operators for which Carleman estimates are valid. Three main types of operators of the second order are among them: elliptic, parabolic and hyperbolic ones. The key idea is that convergence rates of minimizers are established using Carleman estimates. Generalizations to nonlinear inverse problems, such as problems of reconstructions of obstacles and coefficient inverse problems are also feasible. 相似文献
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This paper presents a review of the optimization problems for control processes described by ordinary differential equations and of the variational methods for solving these problems. The following cases are studied: problems with constraints on the controls or the coordinates, problems described by equations with discontinuous right-hand sides, problems with functionals depending on intermediate coordinates, and problems with given discontinuities in the coordinates. Variational problems of synthesis of optimal systems are also discussed. The method of solution is based on the multiplier rule and the Weierstrass necessary condition for the strong minimum of a functional. In some cases, the Legendre-Clebsch necessary condition for the weak minimum of a functional is used. 相似文献
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The initial-irregular oblique derivative boundary value problems for linear and nondivergence parabolic complex equations
of second order in multiply connected domains are dealt with, where the coefficients of equations are measurable. Firstly
the uniqueness of solutions for the above problems is introduced, and then somea priori estimates of solutions for the problems are given. By using the above estimates and the Leray-Schauder theorem, the existence
of solutions of the initial-boundary value problems can be proved. The results are generalizations of corresponding theorems
in literature.
Project supported by the National Natural Science Foundation of China (Grant No. 19671006). 相似文献