时滞抛物方程组振动的充要条件

本文研究了一类时滞抛物微分方程组在齐次Neumann边界条件下解的振动性,用平均值技巧和Green公式把时滞抛物方程组的振动问题转化为泛函微分方程组的振动问题,获得了判别其所有解振动的一个易于验证的充要条件,并举出实例对主要结果进行阐明.     

中立型向量双曲偏微分方程的H-振动性

本文研究了一类中立型向量双曲偏微分方程边值问题的振动性.利用Domslak引进的H-振动的概念及内积降维的方法,将多维振动问题化为一维泛函微分不等式正解的不存在性问题,获得了该类边值问题在Dirichlet边界条件下所有解H-振动的若干新的充分条件,其中H是Rm中的单位向量.     

轴向运动梁的横向振动分析

论述了轴向运动梁横向振动问题以及研究轴向运动梁横向振动问题的方法,指出对轴向运动梁横向振动问题研究中存在的一些错误并进行了更正.针对一端可看作固定边界条件的轴向运动悬臂梁,基于连续体的模态叠加法,推导出含自重效应的轴向运动梁动力响应的计算公式,进行实例计算,并对计算结果进行了详细的讨论,得出影响轴向运动梁振动响应的因素主要有速度和运动方向.     

悬索桥竖向自由振动的传递矩阵解

该文将传递矩阵方法引入悬索桥竖向自由振动求解.首先,提出了悬索桥竖向自由振动微分方程的求解方法,由此求解方法可直接得到结构自由振动解析式.在此基础上,得出了悬索桥竖向自由振动分析的传递矩阵.应用此方法,该文研究了等截面悬索桥及变截面悬索桥竖向自由振动问题.研究结果表明,传递矩阵法能高效地进行悬索桥竖向自由振动分析,并对变截面问题的处理有独特的优势.研究工作对悬索桥在方案设计阶段的动力学分析有一定的参考价值和借鉴意义.     

脉冲向量时滞抛物型方程的H-振动性

研究一类脉冲向量时滞抛物型偏微分方程的振动性,借助Domslak引进的H-振动的概念及内积降维的方法,将多维振动问题化为一维脉冲时滞微分不等式不存在最终正解的问题,建立了该类方程在Robin边值条件下所有解H-振动的若干充分条件,这里H是RM中的单位向量.     

脉冲中向量中立型抛物偏微分方程的H-振动性

研究一类脉冲向量中立型抛物偏微分方程的振动性,借助Domslak引进的H-振动的概念及内积降维的方法,将多维振动问题化为一维脉冲中立型微分不等式不存在最终正解的问题,建立了该类方程在Dirichlet边值条件下所有解H-振动的若干充分判据,这里H是R~M中的单位向量.     

一类一阶非线性中立型微分方程的振动性

讨论了一类一阶非线性中立型微分方程的振动性问题,得到了其具有振动解的“sharp”条件.     

一类二阶线性微分方程的振动性及非振动性

本文研究了二阶线性方程的振动性及非振动性问题，建立了若干新的振动与非振动性结果，它们改进并推广了若干已知的定理。     

脉冲向量中立型抛物方程解的H-振动性

研究一类脉冲向量中立型抛物偏微分方程边值问题解的振动性,利用Domslak引进的H-振动的概念及内积降维的方法,将多维振动问题化为一维脉冲中立型微分不等式正解的不存在性问题,并借助于一阶脉冲中立型微分不等式,给出了该类边值问题所有解H-振动的若干充分性判据,这里H是R~M中的单位向量.     

强非线性问题的改进的L-P解法

用改进的L-P法求解了一类平方强非线性自由振动问题和一类非振动型的强非线性问题,得到了精度很好的一级近似解,方法与通用的改进的L-P法稍有不同。     

波动率服从可数状态的马氏过程的期权定价

通过对服从可数状态马尔可夫链的标的资产价格波动率进行分析,得出了在未来时刻波动的预测模型,并给出了相应的期权定价方法。     

关于可数点集的盒维数的一些探讨

本文研究了一类可数点集的盒维数的计算问题.通过构造双Lipschitz映射,把原可数点集的盒维数的求解问题转化为求解一类相对简单的可数点集的盒维数.获得了两个单调的可数点集在具有同阶间隔时具有相同的上盒维数和下盒维数的结论.该结论为计算一类可数点集的盒维数提供了方便.     

具有可数弱基空间的一个新特征

本文证明了正则空间Ｘ具有可数弱基当且仅当它是具有可数ｋ网的ｋ空间并且不含闭子空间同胚于Ｓｘ。它肯定地回答了Ｙ．Ｔａｎａｋａ在１９８３年提出的一个问题。     

Optimal control problems for wave equations

The problem on minimizing a quadratic functional on trajectories of the wave equation is considered. We assume that the density of external forces is a control function. A control problem for a partial differential equation is reduced to a control problem for a countable system of ordinary differential equations by use of the Fourier method. The controllability problem for this countable system is considered. Conditions of the noncontrollability for some wave equations were obtained.     

非时齐部分可观察Markov决策规划的最优策略问题

本文讨论了一类非时齐部分可观察Markov决策模型．在不改变状态空间可列性的条件下，把该模型转化为[5]中的一般化折扣模型，从而解决了其最优策略问题，并且得到了该模型的有限阶段逼近算法，其中该算法涉及的状态是可列的．     

Mixed problem for pseudoparabolic integro-differential equation with degenerate kernel

A mixed problem for a certain nonlinear third-order intregro-differential equation of the pseudoparabolic type with a degenerate kernel is considered. The method of degenerate kernel is essentially used and developed and the Fourier method of variable separation is employed for this equation. A system of countable systems of algebraic equations is first obtained; after it is solved, a countable system of nonlinear integral equations is derived. The method of sequential approximations is used to prove the theorem on the unique solvability of the mixed problem.     

On The Existence of a Countable Set of Positive Solutions for a Nonlocal Boundary-Value Problem with Vector-Valued Response

ABSTRACT

The existence of a countable set of positive solutions for a nonlocal boundary-value problem with vector-valued response is investigated by some variational methods based on the idea of the Fenchel conjugate. As a consequence of a duality developed here, we obtain the existence of a countable set of solutions for our problem that are minimizers to a certain integral functional. We derive (also in the superlinear case) a measure of a duality gap between primal and dual functional for approximate solutions.     

Darboux–Protter Spectral Problems for One Class of Multidimensional Hyperbolic Equations

For a multidimensional hyperbolic equation with a wave operator in the principal part, we show that the Darboux–Protter spectral problem has the countable set of eigenfunctions, and its dual problem is the Volterra problem.     

The finite-dimensional decomposition property in non-Archimedean Banach spaces

A non-Archimedean Banach space has the orthogonal finite-dimensional decomposition property（OFDDP） if it is the orthogonal direct sum of a sequence of finite-dimensional subspaces.This property has an influence in the non-Archimedean Grothendieck＇s approximation theory,where an open problem is the following： Let E be a non-Archimedean Banach space of countable type with the OFDDP and let D be a closed subspace of E.Does D have the OFDDP？ In this paper we give a negative answer to this question; we construct a Banach space of countable type with the OFDDP having a one-codimensional subspace without the OFDDP.Next we prove that,however,for certain classes of Banach spaces of countable type,the OFDDP is preserved by taking finite-codimensional subspaces.     

Homogeneous Hilbert boundary-value problem with countable set of discontinuities and logarithmic singularity of index

We consider the Hilbert boundary-value problem for the upper half-plane with a countable set of discontinuity points of coefficient of the boundary condition and with a two-side curling at infinity of a logarithmic order. We obtain formulas for the general solution to the problem.