关于Lax-Milgram定理和Cea定理的一个注记

本文研究抽象变分问题（不必要求具有强制性）的Galerhin方法，利用泛函分析理论证明了：若变分问题的Galerkin逼近问题存在唯一解，那么它本身的解存在唯一且可由Galerhin逼近解无限逼近的充要条件是其Galerkin逼近格式具有某种稳定性．此结果是对Lax-Milgram定理和Cea定理的补充，可以应用于不必具有强制性的变分问题．     

三维种群生态动力系统的参数识别

研究具有反应一扩散现象的三维种群生态动力系统的参数识别问题，依该系统正问题解的性质，建立了参数识别的数学模型；论证了系统正问题解关于待识别参数的连续依赖性与参数识别问题最优解的存在性。     

具有年龄结构的线性周期种群动力系统的最优收获控制问题

研究一类具有年龄结构的线性周期种群动力系统的最优收获控制问题,即讨论了具有周期的生死率和周期变化的收获项的Lotka Mckendrick模型.利用Mazur's定理,作者证明了控制问题最优解的存在性,同时借助于法锥概念,还得到了控制问题最优解存在的必要条件。最后，在适当的假设下，得到了最优控制问题的唯一解。该文的结论推广了某些已有的结果.      

一类非线性积分微分方程的初边值问题

本文讨论下列初边值问题整体经典解的存在性：该问题所描述的是一类具有非线性粘弹性的粘弹性杆的非线性振动，在一定条件下，我们证明了该问题整体经典解的存在唯一性。     

拟合模糊观测数据的线性回归模型

本文讨论了实验观测数据为一般模糊数的线性最优拟合问题，通过定义模糊数空间中的距离，建立了模糊数空间到模糊数空间的回归模型，证明了最小二乘问题的解与其正则方程组的解的一致性，进而由正则方程组导出了问题的显式解。本模型的计算简便，具有实用价值。     

半导体技术中数学模型的渐近分析

本文在非平衡状态下，研究了具有Dirichlet边界条件的稳态半导体模型的解的渐近性态。首先，对N维半导体模型，结合解在L^∞和H^1空间一致有界性，论证了奇异摄动问题的解的极限满足相应的退化问题且在H^1中弱收敛。然后，对一维半导体模型，进一步证明了解在H^1中强收敛。     

带随机过程的随机规划问题最优解过程的平稳性与马氏性

证明了带随机过程的随机规划问题其最优争集中至少存在一列最优解均为可测的随机过程；且如果问题中的随机过程具有平稳性与马氏性，则此时间问题的最优解过程亦具有相应的特性。     

一类非线性双曲偶合方程组广义解的存在性

本文考虑了具有形式ｎ的弱偶合双曲守恒方程组广义解的存在性问题．极大值原理导出了粘性解Ｌ∞模先验估计，关于单个守恒律简化的补偿列紧方法给出了粘性解的收敛性，即广义解的存在性．     

幂律流体边界层方程的近似解析解和壁摩擦因数的近似值

对幂率流体层流平板边界层的解析解进行了研究。对该问题提供了Adomian分解方法并且推导出了问题的级数形式的近似解析解，该近似解析解具有快速收敛性和易于计算性。对不同的幂率给出了方程的近似解析解和相应的壁摩擦因数近似值，最后对近似解所推出结果和所得壁摩擦因数与文献中的数值解进行了比较验证，证实了该文提出的解析近似方法的准确性和可靠性，说明了该近似解能够应用于提供所研究问题的壁摩擦因数。     

基于GA的一类Fuzzy资源非线性规划问题的模型

本文建立了一类连续型Ｆｕｚｚｙ资源约束非线性规划问题的模型ＦＲＮＬＰ。基于ｆｕｚｚｙ最优解集和最优决策集，提出了求解ＦＲＮＬＰ模型的精确最优解和满意解的方法，最后研究并讨论了具有惩罚因子的ｆｕｚｚｙ资源约束非线性规划问题，并针对一个实例进行了分析。     

非线性特征值问题的二次近似方法

本文研究求解非线性特征值问题的数值方法.基于矩阵值函数的二次近似,将非线性特征值问题转化为二次特征值问题,提出了求解非线性特征值问题的逐次二次近似方法,分析了该方法的收敛性.结合求解二次特征值问题的Arnoldi方法和Jacobi-Davidson方法,给出求解非线性特征值问题的一些二次近似方法.数值结果表明本文所给算法是有效的.     

Quasi-Newton Methods for Nonlinear Least Squares Focusing on Curvatures

A new quasi-Newton method for nonlinear least squares problems is proposed. Two advantages of the method are accomplished by utilizing special geometrical properties in the problem class. First, fast convergence is established for well-conditioned problems by interpolating both the current and the previous step in each iteration. Second, high accuracy is achieved for certain difficult problems, such as ill-conditioned problems and problems with large curvatures in the tangent space. Numerical results for artificial problems and standard test problems are presented and discussed.     

Differential sensitivity of solutions of convex constrained optimal control problems for discrete systems

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.     

The solution existence of general variational inclusion problems

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.     

Global and Local Search Algorithms for Concave Cost Transshipment Problems

Traditionally, the minimum cost transshipment problems have been simplified as linear cost problems, which are not practical in real applications. Recently, some advanced local search algorithms have been developed that can directly solve concave cost bipartite network problems. However, they are not applicable to general transshipment problems. Moreover, the effectiveness of these modified local search algorithms for solving general concave cost transshipment problems is doubtful. In this research, we propose a global search algorithm for solving concave cost transshipment problems. Effecient methods for encoding, generating initial populations, selection, crossover and mutation are proposed, according to the problem characteristics. To evaluate the effectiveness of the proposed global search algorithm, four advanced local search algorithms based on the threshold accepting algorithm, the great deluge algorithm, and the tabu search algorithm, are also developed and are used for comparison purpose. To assist with the comparison of the proposed algorithms, a randomized network generator is designed to produce test problems. All the tests are performed on a personal computer. The results indicate that the proposed global search algorithm is more effective than the four advanced local algorithms, for solving concave cost transshipment problems.     

Towards global bilevel dynamic optimization

The global solution of bilevel dynamic optimization problems is discussed. An overview of a deterministic algorithm for bilevel programs with nonconvex functions participating is given, followed by a summary of deterministic algorithms for the global solution of optimization problems with nonlinear ordinary differential equations embedded. Improved formulations for scenario-integrated optimization are proposed as bilevel dynamic optimization problems. Solution procedures for some of the problems are given, while for others open challenges are discussed. Illustrative examples are given.     

Necessary optimality conditions for Stackelberg problems

First-order necessary optimality conditions are derived for a class of two-level Stackelberg problems in which the followers' lower-level problems are convex programs with unique solutions. To this purpose, generalized Jacobians of the marginal maps corresponding to followers' problems are estimated. As illustrative examples, two discretized optimum design problems with elliptic variational inequalities are investigated. The theoretical results may be used also for the numerical solution of the Stackelberg problems considered by nondifferentiable optimization methods.Communicated by M. Simaan     

半无限规划问题的一个有效解法

1．引言在计算机辅助设计和工程设计中,经常遇到下面的两类优化问题1,2］．1．无约束半无限极大极小问题．其中外x）二——x。。Im。x。。。Yi夕（x;N）这里J二（】,2,·,｝对任何7E八岁：R－xR”。＋R是连续可微的函数,X是R”。中的一个紧子集,且VYj）一O,这里问h）表示X体积．2．约束半无限代化问题．其中I一（1,2,·．小记L二《0｝UI对任何jCL冲’（x）一max。。。Yi夕（x,yi）·这里拉：PX＊n＋R是连续可微函数,X是”。中的一个紧子集,且NU）一0·注．设Y（Z,一二切EyW一叫卜4．今后对本文用到的紧子集地做…     

Helly’s Principle and Its Application to an Infinite-Horizon Optimal Control Problem

In this paper, a numerical method is presented to solve singularly-perturbed two-point boundary-value problems for second-order ordinary differential equations with a discontinuous source term. First, an asymptotic expansion approximation of the solution of the boundary-value problem is constructed using the basic ideas of the well-known WKB perturbation method. Then, some initial-value problems and terminal-value problems are constructed such that their solutions are the terms of this asymptotic expansion. These initial-value problems and terminal-value problems are singularly-perturbed problems and therefore fitted mesh method (Shishkin mesh) are used to solve these problems. Necessary error estimates are derived and examples are provided to illustrate the method.     

一类混合似变分不等式问题解的存在唯一性

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．