刮板沉降箱式除尘可修复系统的适定性

研究了修复不如新情形下刮板沉降箱式除尘可修复系统的适定性问题.首先将系统方程转化为Banach空间下的抽象Cauchy问题,进一步通过线性算子半群理论证明了系统的适定性.     

具一组可修复设备的系统解的适定性和稳定性

研究具一组可修复设备的系统解的适定性和稳定性.使用泛函分析方法,特别是Banach空间上的线性算子理论和C_0半群理论,证明了系统解的适定性以及正解的存在性,证明了系统解的渐近稳定性,指数稳定性以及严格占优本征值的存在性,证实了实际问题中相关假设的合理性.     

有两种可修复方法的复杂可修复系统的最优控制

研究了具有两种可修复方法的复杂可修复系统的最优控制问题,首先将此类系统方程转化为对应的Volterra积分方程的形式,然后利用算子半群理论证明了系统解的存在唯一性,再利用范数指标函数作为衡量控制变量的标准,研究有此类系统的最优控制问题,证明了对应的最优控制问题的解的存在唯一性.     

具有临界和非临界人为故障的人-机系统解的存在唯一性及半离散化

研究了具有临界和非临界人为故障率,且修复时间任意分布的可修复的人-机系统模型.利用初等方法将系统转换为8维Banach空间下的Volterra积分方程,得到系统非负解存在且唯一.并讨论了系统解的逼近.     

带有弱奇性核的多项分数阶非线性随机微分方程解的适定性

本文主要研究一类带有多项分数阶Caputo导数的非线性随机微分方程初值问题的解的适定性.具体地,首先把多项分数阶随机微分方程等价地转化为随机Volterra积分方程;然后,给出了该随机积分方程的Euler-Maruyama (EM)格式;最后,借助于该EM格式,证明了多项分数阶随机微分方程的解的适定性.     

一类基于个体尺度的种群模型的适定性及最优不育控制策略

研究了一类具有尺度结构的线性种群模型的适定性及最优不育控制问题.首先应用Volterra积分方程和Banach不动点原理证明模型解的存在唯一性,并给出解关于控制变量连续依赖性定理;其次应用Mazur定理证明了最优策略的存在性;最后借助法锥和共轭系统导出最优性条件.     

对具有定常故障率和任意系统修复率的可修复系统的猜测分析

研究了具有定常人为故障率 (human error rates)和通常故障率 (common-cause failure rates) ,修复时间任意分布的可修复系统的数学模型 .首先将此系统转换为 Banach空间下的 Volterra积分方程 ,得到了系统非负解的存在性和唯一性结果 .     

一类可修复计算机系统的定性分析

本文讨论由软件和硬件构成的一类可修复计算机系统的动态解.运用C0-半群理论及算子理论,证明该系统的适定性和非负动态解的存在唯—性.通过研究系统相应算子的谱特征,得到系统的渐近稳定性.     

具有多重严重故障和非严重故障和修复功能的系统的可靠性分析

该文研究一个具有多重严重故障和非严重故障和修复功能的系统的可靠性问题. 在泛函分析理论的框架下,将系统方程组写成一个 Banach 空间中的抽象初值问题,利用算子半群方法,研究了该系统的适定性、稳态解的存在性以及稳定性.表明: 在系统模型的假定下,所研究的系统是适定的,存在非负动态解和稳态解, 特别在范数意义下动态解收敛到稳态解.从而由系统稳态解得到的系统指标是可靠的.     

时变时滞粘弹性板方程的整体吸引子

本文研究内部反馈中具有历史和时变时滞的粘弹性板方程.首先利用Faedo-Galerkin方法证得方程在初边值条件下解的适定性定理;其次通过构造合适的能量泛函和Lyapunov泛函证明系统的梯度性;最后利用乘子泛函建立稳定不等式,证明系统的拟稳定性及渐近光滑性,从而得到整体吸引子的存在性,并证明了该吸引子具有有限分形维数.     

两不同部件并联可修系统解的稳定性

用强连续算子半群理论证明了两不同部件并联可修系统解的存在唯一性和非负性，并通过研究相应算子的谱特征得到了该系统的稳定性。     

两不同部件并联可修系统动态解的最优控制

针对修复时间服从任意分布的两不同部件并联可修系统的模型,把系统方程的解转化为Volterra积分方程的形式,用范数指标函数作为衡量控制变量的标准,以及系统在某一时刻T的最优控制问题.     

Well-posedness and stability of the repairable system with N failure modes and one standby unit

The well-posedness and stability of the repairable system with N failure modes and one standby unit were discussed by applying the c₀ semigroups theory of function analysis. Firstly, the integro-differential equations described the system were transformed into some abstract Cauchy problem of Banach space. Secondly, the system operator generates positive contractive c₀ semigroups T(t) and so the well-posedness of the system was obtained. Finally, the spectral distribution of the system operator was analyzed. It was proven that 0 is strictly dominant eigenvalue of the system operator and the dynamic solution of the system converges to the steady-state solution. The steady-state solution was shown to be the eigenvector of the system operator corresponding to the eigenvalue 0. At the same time the dynamic solution exponentially converges to the steady-state solution.     

Analyticity and exponential stability of semigroups for the elastic systems with structural damping in Banach spaces

In this paper, we consider a second order evolution equation in a Banach space, which can model an elastic system with structural damping. New forms of the corresponding first order evolution equation are introduced, and their well-posed property is proved by means of the operator semigroup theory. We give sufficient conditions for analyticity and exponential stability of the associated semigroups.     

随机选择修理工的可修复系统指数稳定性分析

讨论了一个随机选择修理工的可修复系统解的指数稳定性,首先通过对积分微分方程组描述的可修复系统生成的系统算子的本质谱的增长性约束和扰动后本质谱半径的变化情况进行分析,进而得到了可修复系统解的指数稳定性.     

Perturbation Theory for Discrete Volterra Equations

Fixed point theory is used to investigate nonlinear discrete Volterra equations that are perturbed versions of linear equations. Sufficient conditions are established (i) to ensure that stability (in a sense that is defined) of the solutions of the linear equation implies a corresponding stability of the zero solution of the nonlinear equation and (ii) to ensure the existence of asymptotically periodic solutions.     

The problem of start control for a class of semilinear distributed systems of Sobolev type

A result on the solvability of the Cauchy problem for a semilinear equation of Sobolev type in a Banach space is obtained with the help of the theory of degenerate operator semigroups. The result is used for investigating the problem of start control in the corresponding system. Abstract results are illustrated by the example of the semilinear Dzektser equation.     

Dynamic behaviors of the periodic Lotka–Volterra competing system with impulsive perturbations

In this paper, we investigate a classical periodic Lotka–Volterra competing system with impulsive perturbations. The conditions for the linear stability of trivial periodic solution and semi-trivial periodic solutions are given by applying Floquet theory of linear periodic impulsive equation, and we also give the conditions for the global stability of these solutions as a consequence of some abstract monotone iterative schemes introduced in this paper, which will be also used to get some sufficient conditions for persistence. By using the method of coincidence degree, the conditions for the existence of at least one strictly positive (componentwise) periodic solution are derived. The theoretical results are confirmed by a specific example and numerical simulations. It shows that the dynamic behaviors of the system we consider are quite different from the corresponding system without pulses.     

Robustness of strongly and polynomially stable semigroups

In this paper we study the robustness properties of strong and polynomial stability of semigroups of operators. We show that polynomial stability of a semigroup is robust with respect to a large and easily identifiable class of perturbations to its infinitesimal generator. The presented results apply to general polynomially stable semigroups and bounded perturbations. The conditions on the perturbations generalize well-known criteria for the preservation of exponential stability of semigroups. We also show that the general results can be improved if the perturbation is of finite rank or if the semigroup is generated by a Riesz-spectral operator. The theory is applied to deriving concrete conditions for the preservation of stability of a strongly stabilized one-dimensional wave equation.