二阶柯西中值定理中间点的渐近性质

对二阶柯西中值定理中间点的渐近性质进行了研究，得到的主要结果是limx→αξ-α/x-α=1/2m√2^m 2-2/(m 2)(m 1).     

Global stabilization and asymptotic tracking for a class of nonlinear systems by means of time‐varying feedback

A simple backstepping design scheme is proposed and sufficient conditions for non‐uniform in time global stabilization for parameterized systems by means of time‐varying feedback are established. Our methodology is applicable to a special class of systems that in general cannot be stabilized by static feedback and includes non‐holonomic systems in chained form. For this class of systems the main results on feedback stabilization enable us to derive sufficient conditions for the solvability of the tracking problem. Copyright © 2003 John Wiley & Sons, Ltd.     

关于最佳鉴别特征维数问题的讨论

该文对最佳鉴别特征的最佳维数问题进行了详细的讨论．文章首先对最佳维数问题进行了界定，然后指出了两种最佳特征维数为c-1维的情况即以某些基于矩的可分性判据(准则函数)为优化目标的最优特征和以某些特殊的分类器错误率为优化目标的最优特征．最后该文运用方差分析法对最佳鉴别特征进行特征选择使之代入最小距离分类器后识别率最大．     

IBM—PC微机的恒速升温差热分析测控系统

介绍电阻炉恒速升温热分析的IBM—PC微机控制系统，该系统采用C语言进行编程，控制方法采用分段PID和最小方差自校正。系统具有自适应能力，并且有操作指导和动画报警界面。     

语音信号的预滤波和倒谱参数方差的统计

对于非实验室条件下的实时语音识别系统来说，能否准确提取出所需要的语音信号特征，是决定该识别系统正识率高低的关键因素之一，对语音信号进行预滤波以抑制噪音，有利于语音信号特征的提取，本文结合一个实际系统，讨论了其降噪问题，并建议以倒谱参数方差之统计特性是否符合一定规律的为标准，来衡量预滤波的效果，文中还对数字滤波器及随机低门限时域中心削波在预滤波中的作用进行了讨论，实验结果表明，预滤波取得了较好的效果     

Stability of perturbed systems with time-varying delays

This paper gives easily verifiable sufficient conditions of robust asymptotic stability of linear time-delay systems subject to parametric unstructured or highly-structured perturbations. The criteria given in this paper are delay-independent or delay-dependent. The considered delay may be time-varying. An estimation of the transient behaviour of the studied systems is also provided (exponential rate of convergence).Scalar or vectorial inequalities involving Hurwitz matrices, matrix measures and norms constitute the mathematical foundations of the exposed results.     

已知非最小相位系统的跟踪问题研究

本文探讨了已知离散时间非最小相位系统的跟踪问题，证明了一大类针对非最小相位系统的线性控制器（其具体形式将在文中给出）不能实现对任意有界设定序列的渐近跟踪，这表明对未知离散非最小相位系统，不可能设计Ｃｌａｒｋｅ－Ｇａｗｔｈｒｏｐ型自动校正控制或自有因地制宜制品在去渐近跟踪任意有界设定序列。     

非线性组合系统基于状态观测器的分散镇定

讨论了一类非线性相似组合系统的基于估计状态反馈的分散控制问题。构造了非线性渐近状态观测器,并证明了状态误差按指数收敛到零。同时,给出了组合系统经估计状态向量的反馈控制可实现分散镇定的一个充分条件。     

Asymptotic Stabilisation of Multiple Input Nonlinear Systems via Sliding Modes

A dynamic feedback controller design method is proposed for multiple input systems. The method uses a novel choice of sliding surface to effect asymptotic linearisation of nonlinear differential input output systems and a class of state space systems. The stability of the overall system, that is a canonical state space form with a dynamic feedback, is analysed with a generalised Lyapunov approach plus an asymptotic analysis in a neighbourhood of the origin. The nonlinear system does not have to be expressed in regular form as is the case in many other sliding mode control approaches. A type of zero dynamics, which are the dynamics of the control, are involved. The resulting dynamic feedback is shown to provide chatter free control if the system is minimum phase with respect to the zero dynamics. The theoretical results are applied to Gas Jet systems with two controls.     

一种新的有限元网格优化方法

本文仔细探讨了平面网格产生畸形单元的原因,并针对性地提出了“结构优化”的概念,将其与传统的“位置优化”区别开来。本文介绍的方法通过结构优化与位置优化相结合对初始有限元网格进行调整,使最终的网格最大限度地满足有限元分析的需要,从而提出了一种能够较为彻底地提高网格质量的新的网格优化方法。