带梯度障碍的抛物型变分不等式解的存在性唯一性和正则性

本文讨论带梯度障碍的抛物型变分不等式解的存在性、唯一性和正则性问题．通过证明一类带梯度障碍的问题的求解等价于解某个双边障碍的问题，并利用双边障碍问题解的存在性、唯一性和正则性，得到了带梯度障碍的问题的相应结果．这一方法将有助于对具有梯度约束的非线性以及完全非线性抛物型方程解的正则性的研究．     

半无界空间上的拟线性抛物型方程解的Blow—up现象

本文研究了拟线性抛物型方程的初边值问题在无界区域D上的全局解存在性问题和局部解的Blow-up问题．利用上、下解方法，并借助Green函数，给出了问题（I）全局解的存在性条件，也给出了局部解发生Blow－up现象的条件     

一类新型的广义向量拟均衡问题

提出一类新的广义向量拟均衡问题，并得到解的存在性定理．用于证明向量变分不等式和向量优化问题的解的存在性．     

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．     

目标属性为真假值函数的多目标决策问题解的存在性与求解方法

本文建立了一类目标属性为真假值函数的多目标决策模型，定义了相应有效解、弱有效解与最优解．并在此基础上，对有效解与弱有效解的存在性、求解等问题进行了探讨．     

关于向量最优化问题的ε-有效解的几点注记

本文讨论了向量最优化问题的ε-有效解的存在性和标量化．同时引进了ε-真有效解的概念，在锥-次类凸的假设条件下，建立了这种解的一个标量化定理．     

带有单模糊映射的一般变分不等式解的存在性

众所周知，在各种变分不等式问题中，解的存在性是最基础也是最重要的问题之一．本文的目的是在Hilbert空间中研究带有单模糊映射的一般变分不等式解的存在性．此外，还讨论了几种特殊情况．     

半导体物理中的一个两点边值问题

本文研究了在半导体流的区域提纯过程中提出的两点边值问题解的存在性，我们用上、下解方法和Ｓｓｈａｕｄｅｒ不动点定理证明了如果Ｑ＝２Ａ３Ｒｅ，其中Ａ是表面速率，Ｒｅ是Ｒｅｙｎｏｌｄｓ数，则当０ Ｑ １２．６８时，该问题有解． 对［１］的结果（０ Ｑ＜８．５１时，此问题的解存在）进行了重要的改进．     

一阶带参数的时滞微分方程的边值问题

本文利用上下解和单调迭代法，讨论了带参数的一阶时滞微分方程的边值问题，获得了这类问题极值解的存在性定理．     

一类二阶隐式微分方程的可解性

本文关注如下的二阶隐式微分方程f（t，u（t），u″（t））=0，a．e．t∈（O，1），边值条件为u（0）=u（1）=0．利用上下解方法和迭代技巧研究了该问题的可解性并得到了一些解的存在性结果．     

方程utt-△u-△ut-△utt=f(u)的初边值问题

本文研究一类四阶非线性耗散、色散波动方程的初边值问题｛ｕｔｔ－△ｕ－△ｕｔ－△ｕｔｔ＝ｆ（ｕ）,ｕ│ｔ＝０＝ｕ０（ｘ）,ｕｔ│ｔ＝０＝ｕ１（ｘ）,ｕ│эΩ＝０,得到了问题整体强解的存在性和唯一性,并在一定条件下,研究了解的渐近性质和ｂｌｏｗ ｕｐ现象。     

关于线性互补问题解的存在性

讨论线性互补问题解的存在性。证明关于解的唯一性定理。用反例表明:对于线性互补问题解的存在性,"M是半正定矩阵"既不是充分条件,也不是必要条件。     

<Emphasis Type="Italic">p</Emphasis>-Medians and Multi-Medians

The classical p-median problem is discussed, together with methods for its solution. The multi-median problem, a generalization of the p-median problem in which more than one type of facility is allowed, is introduced and methods of solution developed. Numerical results are presented.     

一类非线性三阶三点边值问题的解和正解

考察了一类含有一阶和二阶导数的非线性三阶三点边值问题的解和正解.通过构造适当的Banach空间并且利用相应的积分方程建立了两个存在定理.主要结论表明,只要非线性项在其定义域的某个子集上的"高度"是适当的,该问题存在一个解或者正解.     

广义Kuramoto-Sivashinsky型方程初值问题光滑整体解的存在性与破裂性

本文用积分估计和不动点原理证明了一类广义Kuramoto-Sivashinsky型方程初值问题光滑整体解的存在唯一性,并在不同情况下讨论了解的破裂性,并给出了导致破裂性的充分条件.     

On the Oseen–Brinkman flow around an $$$$-dimensional solid obstacle

The purpose of this paper is to develop a layer potential analysis in order to show the well-posedness result of a transmission problem for the Oseen and Brinkman systems in open sets in \({\mathbb R}^m\) (\(m\in \{2,3\}\)) with compact Lipschitz boundaries and around a lower dimensional solid obstacle, when the boundary data belong to some \(L^q\)-spaces. If \(m=3\) or if the Brinkman system is given on bounded open set then there exists a solution of the transmission problem for arbitrary data. If \(m=2\) and the Brinkman system is given on exterior open set then necessary and sufficient conditions for the existence of a solution of the transmission problem are stated. A solution of the transmission problem is not unique. All solutions of the problem are found.     

Test problem construction for linear bilevel programming problems

A method of constructing test problems for linear bilevel programming problems is presented. The method selects a vertex of the feasible region, far away from the solution of the relaxed linear programming problem, as the global solution of the bilevel problem. A predetermined number of constraints are systematically selected to be assigned to the lower problem. The proposed method requires only local vertex search and solutions to linear programs.     

An Iterative Method for Finding the Least Solution to the Tensor Complementarity Problem

In this paper, we are concerned with finding the least solution to the tensor complementarity problem. When the involved tensor is strongly monotone, we present a way to estimate the nonzero elements of the solution in a successive manner. The procedure for identifying the nonzero elements of the solution gives rise to an iterative method of solving the tensor complementarity problem. In each iteration, we obtain an iterate by solving a lower-dimensional tensor equation. After finitely many iterations, the method terminates with a solution to the problem. Moreover, the sequence generated by the method is monotonically convergent to the least solution to the problem. We then extend this idea for general case and propose a sequential mathematical programming method for finding the least solution to the problem. Since the least solution to the tensor complementarity problem is the sparsest solution to the problem, the method can be regarded as an extension of a recent result by Luo et al. (Optim Lett 11:471–482, 2017). Our limited numerical results show that the method can be used to solve the tensor complementarity problem efficiently.     

Analysis and numerical solution of a Riemann-Liouville fractional derivative two-point boundary value problem

A two-point boundary value problem is considered on the interval [0, 1], where the leading term in the differential operator is a Riemann-Liouville fractional derivative of order 2 ? δ with 0 < δ < 1. It is shown that any solution of such a problem can be expressed in terms of solutions to two associated weakly singular Volterra integral equations of the second kind. As a consequence, existence and uniqueness of a solution to the boundary value problem are proved, the structure of this solution is elucidated, and sharp bounds on its derivatives (in terms of the parameter δ) are derived. These results show that in general the first-order derivative of the solution will blow up at x = 0, so accurate numerical solution of this class of problems is not straightforward. The reformulation of the boundary problem in terms of Volterra integral equations enables the construction of two distinct numerical methods for its solution, both based on piecewise-polynomial collocation. Convergence rates for these methods are proved and numerical results are presented to demonstrate their performance.     

A Variational Principle with Applications in Finite Elements

One of the difficulties which arise when finite element methodsare applied to the solution of fourth order differential equationsvia the Rayleigh–Ritz method is that compatible basisfunctions are required to have continuous derivatives acrossthe interelement boundaries. In this paper a method is proposedwhich requires only continuity of the basis functions acrossthe inter-element boundaries. A perturbed variational problem containing a parameter is proposed.The solution of the original problem is the leading term inan asymptotic expansion, in powers of ^–1, for the solutionof the perturbed problem. When is taken large enough, an approximationto the solution of the perturbed problem is therefore an approximationto the solution of the original problem. As numerical examples the problems of a clamped elastic plateunder a central point load and under a uniform load are examined.