区间动力系统稳定性分析

本文研究了泛区间动力系统的稳定性,并由此给出了区间矩阵稳定的充要条件和离散区间动力系统稳定的充要条件.本文的分析方法具有普遍意义,适于一大类区间分析问题,包括区间时滞系统,灰色控制系统,区间分布参数系统等.     

时滞脉冲切换神经网络的鲁棒指数稳定性

本文研究具有时间滞后和脉冲效应的切换区间细胞神经网络的鲁棒指数稳定性.利用M-矩阵的性质和平均驻留时间方法,研究了时滞切换脉冲神经网络在参数扰动和限制切换下的指数稳定性,并得到确保系统全局指数稳定的充分条件.得到的结论是显式结构,有利于实际工程应用.     

时标动力方程的稳定性分析

近来，一种称之为时标动力系统的新理论得到了蓬勃的发展. 该文给出并建立了时标动力系统的各种稳定性概念和Lyapunov稳定性准则(稳定, 一致稳定, 渐近稳定, 指数渐近稳定等等).     

非线性离散动力系统的某些定性性质

证明了一致指数稳定的非线性离散动力系统Lyapunov函数的存在性．由此证明非线性离散动力系统一致指数稳定等价于其线性化系统的一致指数稳定．     

区间动力系统的离散稳定性

本文获得了一般非对称区间动力系统的离散稳定的充分判据，改进了文[3，5]的有关结果．     

具时滞Kolmogorov系统的强区间稳定性与部分稳定性

通过得用区间动力系统的稳定性理论和构造适当的Ｌｙａｐｕｎｏｖ科学家函，我们讨论了具离散时滞Ｋｏｌｍｏｇｏｒｏｖ生态系统的渐近性，分别获得了该系统强稳定、部分稳定的充分条件。     

一类带有捕食者阶段结构的滞后型捕食食饵模型的Hopf分支

本文研究了一类带有阶段结构和Ho1lingⅢ型滞后函数响应的捕食食饵模型的稳定性和Hopf分支的问题.利用微分动力系统的标准型和中心流形定理,获得了内平衡点局部稳定和周期解的方向性,推广了文献[4]所得出的结论.     

一类区间随机分布时滞系统的p-阶矩指数稳定性

研究了一类区间随机分布时滞系统的p-阶矩指数稳定性问题.利用分布时滞转化为点时滞方法和区间矩阵的分解技术,得到了该系统p-阶矩指数稳定的时滞依赖的稳定性判据.通过数值例子说明了所得判据的有效性和实用性.     

一类带有捕食者阶段结构的滞后型捕食食饵模型的Hopf分支（英文）

本文研究了一类带有阶段结构和Ho1lingⅢ型滞后函数响应的捕食食饵模型的稳定性和Hopf分支的问题.利用微分动力系统的标准型和中心流形定理,获得了内平衡点局部稳定和周期解的方向性,推广了文献[4]所得出的结论.     

几类离散动力系统的渐近行为

对于高阶线性差分方程稳定和渐近稳定最新的Хусаинов和Никифорова(1999)定理给出了新的完整、严谨、简洁的证明, 并推广到允许系数变号的线性系统和两类非线性离散动力系统. 用推广的结果来分析高阶区间线性差分方程的鲁棒稳定性及鲁棒稳定度, 且应用到离散控制系统的镇定问题的分析.     

Matrix representations of Sturm‐Liouville problems with coupled eigenparameter‐dependent boundary conditions and transmission conditions

We study matrix representations of Sturm‐Liouville problems with coupled eigenparameter‐dependent boundary conditions and transmission conditions. Meanwhile, given any matrix eigenvalue problem with coupled eigenparameter‐dependent boundary conditions and transmission conditions, we construct a class of Sturm‐Liouville problems with given boundary conditions and transmission conditions such that they have the same eigenvalues.     

两邻接B样条曲面的G1连续条件

本文得到了非均匀重内节点邻接B样条曲面间G1连续的充要条件 ,给出了一类G1连续的充分条件 ;基于对B样条曲线参数连续性的分析 ,本文着重给出了这类充分条件成立的内在约束 ,即对公共边界控制顶点的约束条件 .     

Generalized boundary conditions on representative volume elements and their use in determining the effective material properties

We discuss generalized boundary conditions for representative volume elements (RVE), which include the classical boundary conditions as special cases. From the generalization, stochastic boundary conditions are derived. These allows to adjust the the stiffness of the boundary conditions smoothly between the extremal cases of homogeneous strain and homogeneous stress boundary conditions. We found that it needs to be distinguished between the resistance of the boundary conditions against homogeneous and inhomogeneous RVE deformation. The stochastic BC can combine the moderate stiffness of the well known periodic boundary conditions with the high resistance against localization of the homogeneous strain boundary conditions. (© 2013 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim)     

集值优化问题的高阶最优性条件(借助Studniarski导数)(英文)

本文研究的是约束集值优化问题的高价最优性条件.首先通过借助集值映射的Stud-niarski导数和严格局部有效性,讨论了集值优化问题的高阶必要条件和充分条件.对于充分条件,初始空间必须是有限维的.其次在初始空间和目标空间是有限维的以及集值映射是m阶稳定的条件下,也得到了此约束集值优化问题的高阶最优性条件.     

多目标半定规划的最优性条件及对偶理论

在不变凸的假设下来讨论多目标半定规划的最优性条件、对偶理论以及非凸半定规划的最优性条件．首先给出了非凸半定规划的一个KKT条件成立的充分必要条件, 并利用此定理证明了其最优性必要条件．其次讨论了多目标半定规划的最优性必要条件、充分条件, 并对其建立Wolfe对偶模型, 证明了弱对偶定理和强对偶定理．     

非全局Lipschitz条件下随机延迟微分方程Euler方法的收敛性

大多数随机延迟微分方程数值解的结果是在全局Lipschitz条件下获得的.许多延迟方程不满足全局Lipschitz条件,研究非全局Lipschitz条件下的数值解的性质,具有重要的意义.本文证明了漂移系数满足单边Lipschitz条件和多项式增长条件,扩散系数满足全局Lipschitz条件的一类随机延迟微分方程的Eul...     

Immersed Interface Finite Element Methods for Elasticity Interface Problems with Non-Homogeneous Jump Conditions

<正>In this paper,a class of new immersed interface finite element methods (IIFEM) is developed to solve elasticity interface problems with homogeneous and non-homogeneous jump conditions in two dimensions.Simple non-body-fitted meshes are used.For homogeneous jump conditions,both non-conforming and conforming basis functions are constructed in such a way that they satisfy the natural jump conditions. For non-homogeneous jump conditions,a pair of functions that satisfy the same non-homogeneous jump conditions are constructed using a level-set representation of the interface.With such a pair of functions,the discontinuities across the interface in the solution and flux are removed;and an equivalent elasticity interface problem with homogeneous jump conditions is formulated.Numerical examples are presented to demonstrate that such methods have second order convergence.     

Constraint Qualifications in Nonsmooth Multiobjective Optimization

For an inequality constrained nonsmooth multiobjective optimization problem involving locally Lipschitz functions, stronger KT-type necessary conditions and KT necessary conditions (which in the continuously differentiable case reduce respectively to the stronger KT conditions studied recently by Maeda and the usual KT conditions) are derived for efficiency and weak efficiency under several constraint qualifications. Stimulated by the stronger KT-type conditions, the notion of core of the convex hull of the union of finitely many convex sets is introduced. As main tool in the derivation of the necessary conditions, a theorem of the alternatives and a core separation theorem are also developed which are respectively extensions of the Motzkin transposition theorem and the Tucker theorem.     

On strong and weak second-order necessary optimality conditions for nonlinear programming

Second-order necessary optimality conditions play an important role in optimization theory. This is explained by the fact that most numerical optimization algorithms reduce to finding stationary points satisfying first-order necessary optimality conditions. As a rule, optimization problems, especially the high dimensional ones, have a lot of stationary points so one has to use second-order necessary optimality conditions to exclude nonoptimal points. These conditions are closely related to second-order constraint qualifications, which guarantee the validity of second-order necessary optimality conditions. In this paper, strong and weak second-order necessary optimality conditions are considered and their validity proved under so-called critical regularity condition at local minimizers.     

Degenerate boundary conditions for the diffusion operator

We describe all degenerate two-point boundary conditions possible in a homogeneous spectral problem for the diffusion operator. We show that the case in which the characteristic determinant is identically zero is impossible for the nonsymmetric diffusion operator and that the only possible degenerate boundary conditions are the Cauchy conditions. For the symmetric diffusion operator, the characteristic determinant is zero if and only if the boundary conditions are falsely periodic boundary conditions; the characteristic determinant is identically a nonzero constant if and only if the boundary conditions are generalized Cauchy conditions.