Overdamped and Underdamped Linear Dynamical Systems

Conditions are given for underdamped or overdamped linear dynamical systems in terms of loop matrix parameters, (√(C)R√(C)g,g)² ? 4(√(C)L√(C)g,g) for all [boxV]g[boxV] = 1, g ∈ H. These criteria are looked upon as natural generalizations of the elementary one-loop RLC series scalar criteria (R/2L)² ? 1/LC, when written in the more suggestive form: (√(C)R√(C))² ? 4√(C)L√(C). A simplified test for determining dynamical systems with all complex natural modes or all real modes are presented with additional comments.     

非线性控制系统的一般形式及其稳定性

给出了SISO非线控制系统的点相对阶的概念,以此得出一般Brrnes Isidori标准形式。并对于具有最小相位非线性系统,给出了渐近稳定的充分条件;对于具有非最小相位系统,通过设计控制器来构建中心流形的方法,给出了其渐近稳定性的证明     

A Global Energy Theorem for Linear Systems

A fundamental theorem and inequalities were derived earlier by the author describing arithmetic-geometric means and convex behaviour of the active energy dissipated by arbitrary linear reciprocal passive systems. These results are extended to give a new global theorem concerning bounds of energy for arbitrary linear active or passive, reciprocal or non-reciprocal systems.     

On Linear Least-Squares Estimators for Continous-Time Stochastic Systems

The problem of least-squares state estimation of stochastic continuous-time linear systems is reconsidered. A concise derivation of the least-squares minimal-order estimator is presented using an innovations approach. An important result is the reinstatement of the problem in a least-squares estimation framework independent of deterministic observer theory. A second result is thus the clarification of previous approaches to the problem, particularly in relation to observer theory.     

On the Synthesis of Optimum Linear Feedback Control Systems

Standard forms are presented which define transfer functions for optimum type 1 and type 2 feedback control systems, where systems with minimum integral of time multiplied absolute value of error in the presence of a step displacement input are considered to be optimum. The ITAE criterion adopted in this paper was previously introduced by Graham and Lathrop.The optimization procedure leading to the standard forms presented here, is based upon an all digital simulation coupled to an unconstrained optimization algorithm to minimize the ITAE criterion value.It is shown with the aid of examples how actual systems can be compensated by use of appropriate standard forms to obtain optimum responses.     

Output Sensitivity Analysis of Time-invariant Linear Systems Using Polynomial Series

A new approximate method is proposed for the determination of the output sensitivity function of linear time-invariant systems using polynomial series expansions. The novelties of the proposed method are the use of the operational matrix of differentiation for the derivation of the algebraic equations approximating the differential equation, and the use of the operational matrix of polynomial series transformation, for the simplification of the computer code. The approach appears to be more direct and computationally simple than other presently known techniques.     

Two Time-Scale Feedback Stabilization of Linear Time-Varying Singularly Perturbed Systems

The stabilization of a class of singularly perturbed linear time-varying systems is considered through the separate stabilization of two lower dimensional subsystems in two different time-scales. A composite stabilizing controller is synthesized from the separate stabilizing controllers of the two subsystems, the mutually independent gains of which do not require knowledge of the small singular perturbation parameter.     

Shifted-Jacobi Series Analysis of Linear Optimal Control Systems Incorporating Observers

This paper uses the Jacobi series to analyze linear optimal control systems incorporating observers. The method simplifies the system of equations into the successive solution of a set of linear algebraic equations. An illustrative example is included to demonstrate that only a small number (m = 6) of shifted-Jacobi series are needed to obtain an accurate solution.     

基于微分包含的约束非线性系统显示预测控制

提出了一种非线性预测控制的新方法.首先基于线性微分包含理论,利用泰勒级数对系统进行线性化,通过对偏导数取最大和最小的方法构造多面体描述的线性时变系统包裹原非线性系统,然后对于多面体描述的线性不确定系统,采用多参数规划的方法建立显示模型预测控制系统.对该方法进行了仿真计算,仿真结果表明采用这种方法可以更好的描述非线性系统...     

具有时变不确定参数的线性时滞系统的鲁棒镇定

研究了具有时变不确定参数的线性时滞系统的鲁棒镇定问题．提出鲁棒稳定化控制器一种新的设计方法．现有的一些结果可以作为本文的一些特例得到．     

二阶线性单面非完整系统的Lie对称性与守恒量

研究二阶线性单面非完整系统的Ｌｉｅ对称性与守恒量。利用运动微分方程在无限小变换下的不变性,建立Ｌｉｅ对称性所满足的确定方程和限制方程,给出了结构方程和守恒量,讨论了二阶线性单非完整系统的Ｌｉｅ对称性逆问题,并举例说明结果的应用。     

组织社会化策略对高绩效工作系统的跨层次作用研究

采用问卷调查方法研究了组织社会化策略类型对高绩效工作系统的影响作用、LMX对组织社会化策略类型与高绩效工作系统关系的跨层次中介作用,以及高绩效工作系统对工作满意度和工作绩效的作用。结果表明:制度化策略和个体化策略对高绩效工作系统有显著正向影响;个体层面的LMX跨层次部分中介制度化策略对高绩效工作系统的作用;高绩效工作系统对工作满意度和工作绩效的跨层次作用效果显著;工作满意度跨层次部分中介了高绩效工作系统对工作绩效的作用。     

Reduction of Linear Two-point Boundary Value Problems with Non-separable Boundary Conditions to Cauchy Systems

It is shown that some linear two-point boundary value problems subject to non-separable boundary conditions may be reduced to initial value problems.     

诺贝尔文学奖的世界化历程

诺贝尔文学奖在其111年的颁奖历史中,已经成长为一个世界化的文学奖项。这一方面是因为奖项的设立者诺贝尔先生,从一开始即确立了不分文化形态和区域的全球性立场,另一方面在于评奖委员会在评选过程中不断探索,不断修正,努力忠于设奖者的遗愿,终于使其成为到目前为止唯一的,世界公认的,具有权威性的世界性文学奖项。诺贝尔文学奖在这个世界化的过程中,在不改变诺贝尔先生定下的评奖基本原则的前提下,探索了世界化的评奖标准,评奖范围获得了世界性拓展,实现了获奖作品的主题、题材、体裁的多样化,风格的多样化,从而成为到目前为止世界范围内历时最久、影响最广、阵营最大的国际文学奖。     

中国流动家庭类型分析

根据家庭组织形式的不同,将流动家庭区分为广义流动家庭和狭义流动家庭.如果将中国整体的人口流动看成具有完整生命周期的过程,那么流动家庭的类型变化可以反映中国人口流动所处的阶段.目前流动人口中80％以家庭形式进行流动,一起流动的又以核心家庭成员为主,因为流动人口在城镇生活仍有一些困境有待突破,且生活压力较大,因此流动家庭成员尚未大比例扩展到父一代.父一代已经进城的多出于经济目的、照顾孙子女的目的或为利用城镇便利的医疗设施,而非纯粹出于与子一代团聚的目的.     

多发性双胞胎家系的遗传分析

报道了3个多发性双胞胎家系，在这3个家系中有环境因素起主导作用的，有遗传因素起主导作用的，而这些因素都是通过母体发生效应的。     

论家庭档案的管理与作用

家庭档案既记载了家庭的历史,又折射了社会的变化,还是维护家庭及其成员权益最具权威性的法律凭证。因此,建立家庭档案不仅可以促进家庭成员的凝聚力,而且在构建和谐家庭、和谐社会等方面发挥极其重要的作用。     

家庭对儿童学前教育的影响

学前教育作为基础教育的重要组成部分,是人的一生的奠基阶段,而由于儿童在学前教育阶段自身的年龄以及心智特点,家庭在这一阶段则扮演了重要的角色,发挥着至关重要的作用,对儿童在学前教育中的社会交往能力、独立生活能力以及学习能力产生重大的影响.     

系统生物学研究进展

人类基因组计划把生物学由分子生物学时代推向系统生物学时代,生物学由分解转向整合,由叙述科学转变为定量预测科学。