锥上的半线性方程正解的存在性定理及其应用

在不要求正规锥的条件下,利用A-proper半线性算子的不动点指数性质,本文给出了半线性方程正解的存在性结果.作为应用,我们获得了二阶m点共振边值问题正解的存在性.     

具有分数阶导数的积分边值问题正解的存在性

本文研究一类具有分数阶导数的积分边值问题正解的存在性,利用锥拉伸与压缩不动点定理和Leggett-Williams不动点定理,得到该问题至少存在1个正解和3个正解的存在性条件.并给出两个例子来说明结果的有效性.     

具有相对论作用的奇异微分方程周期正解的存在性

本文考虑一类具有相对论作用的奇异微分方程周期正解存在性问题. 运用Mawhin重合度延拓定理得到周期解存在性相关结果. 为了验证结果的正确性, 我们给出相关的例子和数值模拟. 所得结论丰富并补充已有文献的相关结论.     

二阶非线性时滞微分方程的多个正解

在这篇文章中,我们探讨了非线性边值问题正解的存在性.给出的主要结果证明了边值问题两个正解的存在性.结论的证明使用了一个锥上的不动点定理.为了说明定理的正确性,我们最后给出了一个例子.     

具有Strum—Liouville边界条件的四阶奇异超线性微分方程正解的存在性和不存在性

本文给出Strum-Liouville边界条件下的一类四阶奇异超线性微分方程其C2[0,1]正解存在的充分必要条件和C3[0,1]正解存在的充分条件和必要条件.结果可用于判断给定的边值问题其正解的存在性与不存在性.     

双锥不动点定理及其在非线性边值问题中的应用

本文研究了具可变号非线性项的非线性边值问题的正解存在性,推广了Krasnoselskii不动点定理,得到了新的锥上不动点定理,并应用这些定理给出这类边值问题正解的存在性.     

具p-Laplacian算子分数阶微分方程边值问题正解的存在唯一性

本文运用非紧性测度,给出了一类具p-Laplacian算子分数阶微分方程边值问题正解的存在性与唯一性.最后,用一个例子阐述我们的主要结果.     

时间测度上二阶非线性边值问题的解

利用Avery-Henderson不动点定理,讨论了时间测度链上一类非线性边值问题正解的存在性,并在一定条件下得到两个正解的存在性结果,继而利用Legget-Williams不动点定理将其两个正解推广到三个解的情况,同时利用一种等价转化,给出二阶非线性边值问题格林函数的求法,使其求法一般化.     

一类带p-Laplacian算子分数阶微分方程边值问题的正解

本文应用凸锥上的不动点定理,讨论了一类带p-Laplacian算子分数阶微分方程边值问题的正解的存在性,分别得到了这类边值问题至少存在一个正解和多个正解的充分条件.最后,给出了两个具体的例子.     

一类具有交叉扩散的捕食模型非常数正解的存在性

研究了一类具有扩散和交叉扩散项的Holling-Tanner捕食-食饵模型.首先利用最大值原理和Harnack不等式给出正解的先验估计,进一步利用度理论得到非常数正解的存在性与不存在性,从而给出非常数正解存在的充分条件.     

An iterative method for split variational inclusion problem and fixed point problem for a nonexpansive mapping

In this paper, we introduce and study an iterative method to approximate a common solution of split variational inclusion problem and fixed point problem for a nonexpansive mapping in real Hilbert spaces. Further, we prove that the sequences generated by the proposed iterative method converge strongly to a common solution of split variational inclusion problem and fixed point problem for a nonexpansive mapping which is the unique solution of the variational inequality problem. The results presented in this paper are the supplement, extension and generalization of the previously known results in this area.     

Iterative approximation of a common solution of a split equilibrium problem,a variational inequality problem and a fixed point problem

In this paper, we introduce an iterative method to approximate a common solution of a split equilibrium problem, a variational inequality problem and a fixed point problem for a nonexpansive mapping in real Hilbert spaces. We prove that the sequences generated by the iterative scheme converge strongly to a common solution of the split equilibrium problem, the variational inequality problem and the fixed point problem for a nonexpansive mapping. The results presented in this paper extend and generalize many previously known results in this research area.     

On the treatment of free boundary problems with the heat equation via optimal control

In this paper we consider a free boundary problem of general type for the heat equation in one space dimension. We formulate this problem as an optimal control problem and derive necessary conditions for a solution of it. In order to compute a solution of the control problem, we apply the projection-gradient-method. Simple numerical examples illustrate the results.     

Stability of Rothe difference scheme for the reverse parabolic problem with integral boundary condition

In this paper, we study the approximation of reverse parabolic problem with integral boundary condition. The Rothe difference scheme for an approximate solution of reverse problem is discussed. We establish stability and coercive stability estimates for the solution of the Rothe difference scheme. In sequel, we investigate the first order of accuracy difference scheme for approximation of boundary value problem for multidimensional reverse parabolic equation and obtain stability estimates for its solution. Finally, we give numerical results together with an explanation on the realization in one- and two-dimensional test examples.     

锥度量空间中基于Ekeland变分原理的向量均衡问题的解的存在性

本文研究了向量均衡问题.利用在锥度量空间中给出的Ekeland变分原理,我们推导了向量均衡问题解的存在性定理.本文的结论是新的并推广了相关文献中的结论.     

Optimality properties of speed optimization for a vessel operating with time window constraint

We consider speed optimization for a vessel that has to arrive at every port along its voyage within a time window at each port. The objective of the problem is to minimize the vessel’s bunker fuel cost given that fuel consumption rate is a convex function of speed. The intent of this paper is to establish the optimality properties for this problem and show that a solution with such properties (which we refer to as a good solution) is unique and optimal. The optimality properties established in this paper facilitate the proof of exactness for existing and future algorithms, as one needs only to show that the solution provided by an algorithm satisfies the definition of a good solution. As an illustration, we show how we can apply our results to prove the exactness of an existing algorithm in literature. Our work contributes to the understanding of the problem’s optimality structure, which will provide intuition for development of algorithms for this problem.     

Properties and least‐squares problems for row extended matrices

In this paper, we discuss basic properties, a least‐squares problem for row extended matrices and the associated approximation problem. First, we obtain their basic properties by applying their particular structure. Then we derive a general representation of the solutions to the least‐squares problem, and we obtain an expression for the solution to the associated approximation problem. Finally, we provide a perturbation analysis and a perturbation bound for the best approximate solution. The results are illustrated by numerical examples. Copyright © 2009 John Wiley & Sons, Ltd.     

Minimum Norm Solution to the Absolute Value Equation in the Convex Case

In this paper, we give an algorithm to compute the minimum norm solution to the absolute value equation (AVE) in a special case. We show that this solution can be obtained from theorems of the alternative and a useful characterization of solution sets of convex quadratic programs. By using an exterior penalty method, this problem can be reduced to an unconstrained minimization problem with once differentiable convex objective function. Also, we propose a quasi-Newton method for solving unconstrained optimization problem. Computational results show that convergence to high accuracy often occurs in just a few iterations.     

Modelling and control of natural convection in canned foods

In this paper we study mathematically an industrial problemrelated to sterilization processes involving heat transfer bynatural convection. We give results of existence and regularityfor the solution of this problem. We recast the whole problemas an optimal control problem with pointwise constraints onthe state and the control in order to ensure the reduction ofmicroorganism concentration and the retention of nutrients,and to save energy. Finally, we give results on existence ofthe optimal solution and optimality conditions for its characterization.     

Convergence analysis of Tikhonov-type regularization algorithms for multiobjective optimization problems

In this paper, we introduce a vector-valued Tikhonov-type regularization algorithm for an extended-valued multiobjective optimization problem. Under some mild conditions, we prove that any sequence generated by this algorithm converges to a weak Pareto optimal solution of the multiobjective optimization problem. Our results improve and generalize some known results.