基础模糊命题演算系统BL~*的改进系统

基础模糊命题演算系统BL*是一个和基础命题演算系统BL相对独立的命题演算系统。命题演算系统L*是系统BL*的扩张,但不是系统BL的扩张。通过对系统BL*及其它模糊命题演算系统的研究,本文对BL*系统进行了修正,进一步改进了BL*系统中的公理体系。     

基础L*系统的一种扩张——Lukasiewicz系统

研究模糊命题演算的形式演绎系统 L *和 Lukasiewicz命题演算系统 Lu,提出基础系统L *—— BL *系统 ,证明 BL *系统的一种扩张与 Lukasiewicz系统之间的等价性 ,从而为 L *系统和BL *系统提供了一个应用实例。     

线性离散事件动态系统的可达性

可达性是动态系统的重要性质之一。本文讨论离散事件动态系统的可达性,给出了系统完全可达的充要条件,得到了利用系统的特征矩阵判断系统可达性的判据,证明了系统可按可达性进行分解、状态反馈不影响系统可达性等结论,还进一步讨论了一类流水线生产加工系统的可达性,本文的结果对于这类系统的分析和控制是有意义的。     

基于广义反射函数与自治系统等价的非自治系统

自治系统的研究比非自治系统要容易得多,以广义反射函数为前提,给出了等价于自治系统的非自治系统,从而将非自治系统的研究转化为自治系统的研究,并研究了该类系统的周期解及稳定性.     

不含混沌真子系统的Li-Yorke混沌

研究了一类Li-Yorke混沌系统,该系统没有真子系统是Li-Yorke混沌的,我们称之为混沌极小系统.本文证明混沌极小系统是拓扑传递的,而且该系统每个非空开集都包含一个不可数混乱集.混沌极小系统不一定是极小的,本文构造了一个这样的反例.特别地,我们考察了线段连续自映射,指出该类系统都不是混沌极小的,线段上混沌极小子系统的存在性和该系统有正熵是等价的.     

错误系统模型研究

本文研究了错误系统模型的基本组成部分,分析了错误系统模型的分类,并在此基础上对错误系统模型的层级进行了研究,最后给出了错误系统模型在消除系统错误以及优化系统中的意义。     

对称控制Hamilton系统约化理论的研究进展

一个正则控制Hamilton (regular controlled Hamiltonian, RCH)系统是一个具有外力和控制的Hamilton系统,在外力和控制作用下,一般来讲,这个RCH系统不是Hamilton系统.然而,它是一个与Hamilton系统密切相关的动力系统,我们可以在Hamilton系统的研究中,通过对外力和控制扩展的方法研究这种RCH系统.本文从具有对称的Hamilton系统的Marsden-Weinstein辛约化完备性和系统相空间几何结构变化出发,简要介绍了最近几年控制Hamilton系统约化理论及其应用研究工作的研究进展情况.     

金融系统工程研究进展与展望

金融系统本质上是一个复杂的自适应系统,基于简单系统思维建立的传统金融理论已经很难适应现代复杂金融系统的发展.金融系统工程利用系统科学与系统工程的方法论来研究复杂金融系统的动态特征与演化规律,是更接近复杂金融系统本质的新兴学科.文章基于金融系统工程领域2014-2018年的研究文献,从金融系统研究方法,金融系统参与者行为,金融系统风险传染与防治3个研究范畴总结了金融系统工程领域的研究进展,并展望了未来该领域的重点研究方向.     

中介命题演算系统$MP^{M}$的代数系统

MP~M系统是在中介逻辑系统的基础上建立起来的,用于处理数据库中不完全信息的三值逻辑命题演算系统．本文通过在MP~M系统上建立一个代数系统,对MP~M系统进行了代数抽象,讨论了MP~M系统的代数性质．本文还研究了该代数系统的次直积,以及与其它一些代数系统之间的关系．     

拓扑系统的紧性和分离性

考察拓扑系统的两种紧性——空间式紧和locale式紧,给出紧性的若干刻画,讨论了两种紧性的相互关系,证明了拓扑系统的两种紧性都是拓扑空间紧性的良好推广,说明了紧拓扑系统的闭子拓扑系统、有限和系统以及积系统仍是紧拓扑系统。最后在拓扑系统中考察了紧性加强分离性的问题,得到了紧,(强)T2拓扑系统为(强)T3,(强)T4拓扑系统等结论,并用理想收敛刻画了拓扑系统的强T2分离性。     

Robust invariant stabilization of nonlinear continuous and discrete systems

Two classes of continuous systems described by differential equations in which coefficients are functions of the state vector are considered. The systems are subject to two scalar controls and a constantly acting scalar perturbation.An analytical synthesis of a control is performed under which the system is invariant in the sense that the scalar output of the system approaches zero as time tends to infinity and does not depend on the perturbation; moreover, the limit norm of the state vector is bounded above by the least upper bound for the norm of perturbation. The case where the coefficients of the system are subject to an uncontrolled additive perturbation is considered. In this case, the limit of the output norm is bounded above by a known function of the perturbation value. The method of synthesis is based on constructing the Lyapunov function as a positive definite quadratic form with Jacobian matrix.     

模糊推理的摄动性

在模糊推理过程中,推理前件的微小变化往往会引起推理结果的较大变化。针对这种情况,本文讨论基本模糊推理,多重模糊推理以及多重多维模糊推理的摄动性问题,并根据推理过程中复合算子和蕴涵算子的不同选取对各种形式的模糊推理的最大摄动参数进行评估。     

On output feedback control of singularly perturbed systems

We treat the problem of robustness of output feedback controllers with respect to singular perturbations. Given a singularly perturbed control system whose boundary layer system is exponentially stable and whose reduced order system is exponentially stabilizable via a (possibly dynamical) output feedback controller, we present a sufficient condition which ensures that the system obtained by applying the same controller to the original full order singularly perturbed control system is exponentially stable for sufficiently small values of the perturbation parameter. This condition, which is less restrictive than those previously given in the literature, is shown to be always satisfied when the singular perturbation is due to the presence of fast actuators and/or sensors. Furthermore, we show explicitly that, in the linear time-invariant case, if this condition is not satisfied then there exists an output feedback controller which stabilizes the reduced order system but destabilizes the full order system.     

Inversion of linear dynamical systems in the presence of additive noise

We consider the problem of inversion of a stationary dynamical system (i.e., the generation of an estimate of the unknown output signal on the basis of the known output signal) in the presence of an unknown perturbation acting “not in the same channel” as the input to be estimated. We present necessary and sufficient conditions for the inversion of such systems and suggest inversion algorithms.     

输出反馈极点配置问题的扰动分析

１　引　　言 设Ａ　Ｒ　,Ｂ　　　　　　　　　　　　是关于共轭运算封闭的复数集. 输出反馈极点配置问题是指：求Ｋ　Ｒ　,使得Ａ＋ＢＫＣ以　,…,　为特征值． 输出反馈极点配置问题是线性时不变系统的基本问题之一．有关背景及应用可参阅Ｋｉｍｕｒａ的论文［２］及其参考文献．从数值分析角度看,输出反馈极点配置问题的数学研究已相当深入;已提出一些数值方法．然而扰动理论和条件数理论一直没有建立,这对分析数值计算结果是不利的．最近,孙继广［４］用隐函数理论研究了输入反馈极点配置问题．本文使用孙继广的研究方法讨论输…     

Optimal damping of perturbations in a system with unknown initial conditions

We consider the perturbation damping problem for a system in which, along with an external perturbation bounded in the L ₂-norm, there is an initial perturbation caused by unknown nonzero initial conditions. We state necessary and sufficient conditions for the existence of an optimal control law minimizing the maximum L ₂-norm of the system output for all L ₂-bounded external perturbations and bounded initial states and synthesize this control law.     

On stability radii of infinite-dimensional time-varying discrete--time systems

This note introduces a stability radius for discrete–timelinear time–varying systems on Banach spaces under structuredtime–varying perturbations of multiple–output feedbacktype. Additive perturbations are considered which can be representedas a series of infinitely many perturbation terms. We derivecounterparts to some results established for time–varyingdifferentiable systems in [5, 7] and apply the results to periodicsystems.     

On output functionals of boundary value problems on stochastic domains

We consider the computation of output functionals of random solutions to elliptic boundary value problems in domains with random boundary perturbations. We use a second‐order shape calculus to linearize the problem around a fixed nominal domain. For known mean and two‐point correlation function of the boundary perturbation, we derive, with leading order, deterministic expressions for the mean and the variance of the random output functional. These expressions include the solution of the boundary value problem on the nominal domain and a further, deterministic solution of the so‐called adjoint equation. The theoretical findings are supported and quantified by numerical experiments. Copyright © 2009 John Wiley & Sons, Ltd.     

A perturbation method for optimizing matrix stability

We present the first practical perturbation method for optimizing matrix stability using spectral abscissa minimization. Using perturbation theory for a matrix with simple eigenvalues and coupling this with linear programming, we successively reduce the spectral abscissa of a matrix until it reaches a local minimum. Optimality conditions for a local minimizer of the spectral abscissa are provided and proved for both the affine matrix problem and the output feedback control problem. Experiments show that this novel perturbation method is efficient, especially for a matrix with the majority of whose eigenvalues are already located in the left half of the complex plane. Moreover, unlike most available methods, the method does not require the introduction of Lyapunov variables. The method is illustrated for a small size matrix from an affine matrix problem and is then applied to large matrices actually arising from more sophisticated control problems used in the design of the Boeing 767 jet and a nuclear powered turbo-generator.     

Output feedback dynamic control for trajectory tracking and vibration suppression

A new output feedback dynamic tracking control scheme for multiple and variable excitation frequency vibration suppression in mechanical systems is proposed. Dynamic vibration absorbers, differential flatness, Taylor polynomials and dynamic error compensation are integrated into the control synthesis. In this fashion, significant control capabilities are added to physical or virtual dynamic vibration absorbers to simultaneously perform multiple-frequency forced vibration suppression and trajectory tracking on the primary mechanical system. Parametric uncertainty and unmodeled dynamics are also considered to be actively compensated. Real-time estimations of periodic or aperiodic dynamic perturbation forces, excitation frequencies, unavailable state variables and parametric uncertainty are not necessary. Thus, measurements of the output position variable of the controlled primary mechanical system are only required. Analytical and numerical results on three case studies prove the efficiency and robustness of the proposed control method.