一类具有非齐次项对称双曲系统整体弱解的存在性

研究一类具有非齐次项的对称双曲系统Cauchy问题,用补偿紧性方法和最大值原理,得到其有界弱解的整体存在性结果.这一结果推广文献[7]中对称双曲系统到非齐次对称双曲系统.这样一类问题产生于弹性理论、磁流体动力学和石油再开采领域中,具有一定理论和应用价值.     

带一类第一积分的非完整系统的Szebehely问题

研究非完整系统动力学的一类逆问题·给出非完整系统的运动方程及其显式，考虑一类仅受齐次非完整约束的力学系统的Ｓｚｅｂｅｈｅｌｙ问题，研究已知一类第一积分的一般非完整系统的情形·最后举例说明其应用·     

等变系统复眼环的极限环分支

研究一类平面等变系统的复眼环附近的极限环分支问题.首先给出了复眼环的内侧和外侧稳定性的判定量,然后研究了等变Hamilton系统的复眼环在等变小扰动下的分支问题.作为定理的应用, 文章的最后讨论了一类Z₃等变系统产生13个极限环的例子.     

一类时滞微分方程正周期解的存在性

应用锥不动点定理研究了一类时滞微分方程周期解的存在性问题,建立了该系统具有至少一个正周期解的充分条件.     

Holling Ⅳ捕食-食饵时滞系统的多个周期解

应用重合度定理研究了一类具有Holling Ⅳ类功能性反应时滞捕食-食饵系统的周期解的存在性问题,建立了该系统具有至少两个正周期解的充分条件.     

一类线性系统的有限时间量化反馈控制问题

研究了一类带有不确定参数和外部扰动的线性系统的有限时间量化反馈控制问题.应用Lyapunov函数理论,通过量化反馈,使得系统鲁棒有限时间稳定.     

广义分布参数系统的状态反馈稳定性问题(1)

关于系统的状态反馈稳定性问题的研究一直是现代控制理论研究的重要问题之一.广义分布参数系统是比分布参数系统更广的一类系统,在研究复合材料热导体中的温度分布等问题时会出现这样的系统.本文讨论了H ilbert空间中一阶广义分布参数系统的状态反馈稳定性问题.应用泛函分析及线性算子半群理论的方法给出了使闭环广义分布参数系统渐进稳定的充要条件,充分条件及状态反馈的构造性表达式.这对研究广义分布参数系统的状态反馈稳定性问题具有重要的理论价值.     

基于Kleinman迭代算法的非线性系统自适应控制器设计北大核心CSCD

应用Kleinman迭代算法,研究了一类非线性系统的在线自适应控制器设计问题.基于神经网络线性微分包含技术,对此类非线性系统进行建模描述.并在不利用系统后续参数矩阵的情况下,应用Kleinman迭代算法进行反复迭代,求解系统的Riccati方程.进而设计系统的自适应控制器,并证明了该算法的收敛性.最后通过数值仿真验证了该算法的可行性.     

自旋振荡方程的定性分析

本文应用常微分方程定性理论的方法,对白旋振荡有关的一类三维系统进行研究,给出了这一类系统的轨线分布的全局结构.     

基于Kleinman迭代算法的非线性系统自适应控制器设计

应用Kleinman迭代算法,研究了一类非线性系统的在线自适应控制器设计问题.基于神经网络线性微分包含技术,对此类非线性系统进行建模描述.并在不利用系统后续参数矩阵的情况下,应用Kleinman迭代算法进行反复迭代,求解系统的Riccati方程.进而设计系统的自适应控制器,并证明了该算法的收敛性.最后通过数值仿真验证了该算法的可行性.     

On solvability of singular integral-differential equations with convolution

In this paper, we study a class of singular integral-different equations of convolution type with Cauchy kernel. By means of the classical boundary value theory, of the theory of Fourier analysis, and of the principle of analytic continuation, we transform the equations into the Riemann-Hilbert problems with discontinuous coefficients and obtain the general solutions and conditions of solvability in class $\{0\}$. Thus, the result in this paper generalizes the classical theory of integral equations and boundary value problems.     

Optimal Control of Differential–Algebraic Equations of Higher Index,Part 2: Necessary Optimality Conditions

This paper deals with optimal control problems described by higher index DAEs. We introduce a class of problems which can be transformed to index one control problems. For these problems we show in the accompanying paper that, if the solutions to the adjoint equations are well–defined, then the first-order approximations to the functionals defining the problem can be expressed in terms of the adjoint variables. In this paper we show that the solutions to the adjoint equations are essentially bounded measurable functions. Then, based on the first order approximations, we derive the necessary optimality conditions for the considered class of control problems. These conditions do not require the transformation of the DAEs to index-one system; however, higher-index DAEs and their associated adjoint equations have to be solved.     

关于2n阶常微分方程两点边值问题解的存在性与唯一性

本文利用Leray－Schauder度理论建立了一类2n阶非线性常微分方程两点边值问题解的存在性与唯一性定理，以及利用Fredholm择一原理与Fourier展式，建立了一类2n阶线性常微分方程两点边值问题解的存在性唯一性定理．     

ON THE EXISTENCE AND UNIQUENESS THEOREMS OF SOLUTIONS FOR THE SYSTEMS OF MIXED MONOTONE OPERATOR EQUATIONS WITH APPLICATIONS

The existence, uniqueness and non-symmetric iterative approximation of solutions for a class of systems of mixed monotone operator equations are discussed. As an appplication, we utilize the results presented in this paper to study the existence and uniqueness problems of common solutions for a class of systems of functional equations arising in dynamic programming of multistage decision processes and a class of systems of nonlinear integral equations. The results obtained in this paper not only answer an open question suggested in [3] but also generalize the corresponding results of.     

Optimal Control of Differential–Algebraic Equations of Higher Index, Part 1: First-Order Approximations

This paper deals with optimal control problems described by higher index DAEs. We introduce a class of these problems which can be transformed to index one control problems. For this class of higher index DAEs, we derive first-order approximations and adjoint equations for the functionals defining the problem. These adjoint equations are then used to state, in the accompanying paper, the necessary optimality conditions in the form of a weak maximum principle. The constructive way used to prove these optimality conditions leads to globally convergent algorithms for control problems with state constraints and defined by higher index DAEs.     

A class of pseudo-monotone operators and its applications in PDE

In this paper we give a criterion of pseudo-monotone operators by which a class of operators related to elliptic partial differential equations is recognized as pseudo-monotone operators. Some applications in boundary value problems for elliptic equations and obstacle problems are given. Research supported by the Fund of IMAS     

A class of concave operators with applications

In this paper we provide some properties of a class of concave operators and apply these results in discussing three-point boundary value problems for differential equations and nonlinear Volterra integral equations.     

On abstract degenerate neutral differential equations

We introduce a new abstract model of functional differential equations, which we call abstract degenerate neutral differential equations, and we study the existence of strict solutions. The class of problems and the technical approach introduced in this paper allow us to generalize and extend recent results on abstract neutral differential equations. Some examples on nonlinear partial neutral differential equations are presented.     

一类非线性偏泛函微分方程的强迫振动性

讨论了一类时滞双曲方程边值问题,给出了该类方程在三类边界条件下解的振动条件.     

Two classes of linear equations of discrete convolution type with harmonic singular operators

In this paper, we investigate two classes of linear equations of discrete convolution type with harmonic singular operator. Using the Laurent transform theory, we turn the above linear equations into Riemann boundary value problems. Then, the solutions of the equations are obtained in the class of Hölder continuous functions.