基于LINUX的嵌入式Email系统的设计与实现

嵌入式Email系统是类PC嵌入式系统,是嵌入式操作系统及其应用软件的一个重要组成部分,但是现有PC上的嵌入式Email系统都不能适应类PC嵌入式系统的硬件环境要求。文中采用了一种新的构建嵌入式Email系统的方法,设计与实现了清华嵌入式Email系统,可根据各种类PC嵌入式系统的不同要求进行定制。首先,论述了类PC嵌入式系统的硬件平台对嵌入式Email系统的苛刻要求,其次,描述了清华嵌入式Email系统的体系结构,接着,讨论了清华嵌入式Email系统的实现机制与原理,以及系统模型,最后,给出了嵌入式Email系统的特点。由于采用了现在流行的一种开放源码的组件,使得整个系统功能完善,并能够完全符合类PC嵌入式系统的要求。嵌入式Email系统已经在自主研制的掌上电脑HPC和交互式网络电视上成功地运行。     

基于彩色图像分割的机器人的目标识别

以全自主型足球机器人的视觉系统为研究对象,介绍了一种基于彩色图像分割处理的目标识别方法.根据足球机器人系统中视觉系统的实际应用环境,分析对比了不同颜色空间的优缺点,采用HSV颜色空间作为视觉系统的工作空间,减弱了光照变化对视觉系统带来的影响.针对足球机器人系统中对视觉系统实时性的具体要求,提出了一种通过量化HSV颜色空间获得直方图阈值,再通过阈值进行彩色图像分割方法.这种方法大大减少了视觉系统的工作量,提高了系统的实时性.     

基于Web Service的CAPP系统的研究

对CAPP系统的发展进行了分析,针对要提高CAPP系统的协同化和实用化水平,论述了基于Web Service的CAPP系统的设计体系结构,详细介绍了该系统的各功能模块,采用XML对CAPP中的工艺规程数据进行了详细描述.基于Web Service的CAPP系统从底层改变CAPP系统的模型,为真正实现CSCW的CAPP系统提供了新的手段.     

基于WEB的MCOD系统的研究

文章析了现行系统VOC视频点播系统的不足,自行设计了基于WEB的多媒体课件或其他媒体系统宽带网点播系统MCOD,并介绍了该系统的设计思路、组成结构、实现方案和关键技术。     

基于BAC的业务探测系统

探讨了建立业务探测系统的必要性,介绍了业务探测的相关技术,提出了系统的探测方案,根据方案设计了系统的总体架构,并运用多种技术实现了该系统.该系统为提升业务支撑系统的客户感知,提升系统的满意度从而提高电信业务支撑运营管理水平提供了有力的保障.     

基于无线通信的远程测控系统的研究

针对有线通信测控系统的不足之处 ,利用工业现场总线 ,提出了一种无线通信的远程测控系统。阐述了测控系统的硬件和软件环境 ,论述了系统结构及其工作原理 ;介绍了系统测控软件的设计 ,设计了使用LabWindows/CVI调用VC编写的DLL的接口程序 ;并以遥控小车作为无线通信远程控制系统的测控对象 ,实现了该系统     

一种基于Agent的自适应的分布式入侵检测系统

针对传统分布式入侵检测系统组件之间依赖程度大、系统不够健壮且入侵检测系统自身结构固定不能适应入侵的变化的问题,提出了一种基于Agent的自适应的分布式入侵检测系统（简称AAADIDS）．AAADIDS采用Agent概念重新构造系统的组件,改进了分布式入侵检测系统由于高层节点单一无冗余而产生的可靠性差的缺陷,从构造上克服了分布式入侵检测系统的脆弱性．同时,AAADIDS系统采用智能技术构建了自适应的入侵检测系统模型,增加了系统应对入侵行为变化的智能性．AAADIDS系统相对于传统的分布式入侵检测系统有效地提高了系统自身的可靠性和针对外界变化的适应能力．     

基于网络资源的教学评价系统的设计与实现

给出了基于网络资源的教学评价系统的系统规划,分析了系统流程和功能结构;紧密结合教学评价的现实和数字化技术,提出了可以简化系统开发步骤、完善系统功能及提高系统处理数据效率的设计方法。     

网络通信系统的信息脆性结构的研究

从研究系统脆性的角度出发,把系统的环境中所有作用于系统上的并有可能激发系统的脆性,造成系统突然崩溃的因素和事件称之为系统的脆性环境。基于系统的脆性环境建立了网络通信系统脆性结构模型,结合信息脆性嫡对网络通信系统进行信息脆性风险过程分析。分析结果表明此方法是可行的;论证了系统信息脆性结构分析方法的有效性和稳定性,最后将这套分析方法应用到一个具体网络通信系统,对其主脆性因子建立了分析模型,并取得了比较满意的结果。     

基于AVR单片机的开关磁阻电机调速系统的研究

开关磁阻电动机调速系统是一种新型调速系统,本文介绍了开关磁阻电机调速系统的基本原理以及一种以ATmega128为控制核心的调速系统,该系统充分利用了ATmega128接口丰富,功能强,速度快的特点,简化了系统硬件,实现了电压PWM控制、变角度控制相结合的控制策略,达到了很好的运行效果.     

具多时滞的不确定多变量反馈系统的鲁棒稳定化

用矩阵测度研究了具有时滞的不确定系统,给出了在多变量反馈控制律作用下,系统指数渐近稳定的判别准则,推广和改进了文[1～3]的工作.     

Global Robust Exponential Stability for Interval Delayed Neural Networks with Possibly Unbounded Activation Functions

In this paper, we mainly study the global robust exponential stability of the neural networks with possibly unbounded activation functions. Based on the topological degree theory and Lyapunov functional method, we provide some new sufficient conditions for the global robust exponential stability. Under these conditions, we prove existence, uniqueness and global robust exponential stability of equilibrium point. In the end, some examples are provided to demonstrate the validity of the theoretical results.     

Global exponential robust stability of reaction–diffusion interval neural networks with continuously distributed delays

This paper considers the existence of the equilibrium point and its global exponential robust stability for reaction-diffusion interval neural networks with variable coefficients and distributed delays by means of the topological degree theory and Lyapunov-functional method. The sufficient conditions on global exponential robust stability established in this paper are easily verifiable. An example is presented to demonstrate the effectiveness and efficiency of our results.     

Exponential stability of switched stochastic delay systems with non-linear uncertainties

This article considers the robust exponential stability of uncertain switched stochastic systems with time-delay. Both almost sure (sample) stability and stability in mean square are investigated. Based on Lyapunov functional methods and linear matrix inequality techniques, new criteria for exponential robust stability of switched stochastic delay systems with non-linear uncertainties are derived in terms of linear matrix inequalities and average dwell-time conditions. Numerical examples are also given to illustrate the results.     

Robust reliable control design for networked control system with sampling communication

In this article, the problem of robust exponential stability and reliable stabilisation for a class of continuous-time networked control systems (NCSs) with a sample-data controller and unknown time-varying sampling rate is considered. The analysis is based on average dwell-time, Lyapunov–Krasovskii functional and linear matrix inequality (LMI) technique. The delay-dependent criteria are developed for ensuring the robust exponential stability of the considered NCSs. The obtained conditions are formulated in terms of LMIs that can easily be solved by using standard software packages. Furthermore, the result is extended to study the robust stabilisation for NCS with parameter uncertainties. A state feedback controller is constructed in terms of the solution to a set of LMIs, which guarantee the robust exponential stabilisation of NCS and the controller. Finally, numerical examples are presented to illustrate the effectiveness of the obtained results.     

具有非线性扰动多时滞系统鲁棒稳定性分析与分散鲁棒控制

研究一类非线性参数扰动满足范数有界条件时多重时滞系统的鲁棒稳定性及其分散鲁棒控制。首先利用Lyapunov函数方法分析系统的鲁棒稳定性,获得一种新的稳定性条件,然后利用标量Lyapunov方程方法讨论系统指数稳定的条件,通过对系统采取分散反馈控制,进一步得到系统可鲁棒镇定和可指数镇定的条件。     

Improved exponential estimates for neutral systems

Improved exponential estimates and a new sufficient condition for the exponential stability of neutral type time‐delay systems are established in terms of linear matrix inequalities (LMIs). A new Lyapunov‐Krasovskii functional candidate with appropriately constructed exponential terms is introduced to prove the exponential stability and to reduce the conservatism. For the uncertain case, a corresponding condition for the robust exponential stability is also given. It is shown by numerical examples that the proposed conditions are less conservative than existing results. Copyright © 2009 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society     

Exponential stability of nonlinear impulsive switched systems with stable and unstable subsystems

Exponential stability and robust exponential stability relating to switched systems consisting of stable and unstable nonlinear subsystems are considered in this study. At each switching time instant, the impulsive increments which are nonlinear functions of the states are extended from switched linear systems to switched nonlinear systems. Using the average dwell time method and piecewise Lyapunov function approach, when the total active time of unstable subsystems compared to the total active time of stable subsystems is less than a certain proportion, the exponential stability of the switched system is guaranteed. The switching law is designed which includes the average dwell time of the switched system. Switched systems with uncertainties are also studied. Sufficient conditions of the exponential stability and robust exponential stability are provided for switched nonlinear systems. Finally, simulations show the effectiveness of the result.     

Research on robust control and exponential stabilization for large scale impulsive hybrid network systems with time-delay

This paper investigates the stability of network control systems, regarded as a class of large-scale hybrid systems, for ubiquitous computing environment. The problem of robust exponential stabilization for the hybrid systems is addressed, which are composed of impulsive subsystems with time-delay and parameter uncertainties. Using the Lyapunov–Krasovskii functional approach and linear matrix inequality method, an adaptive robust controller is designed to stabilize the uncertain continuous subsystems. Then the delay-dependent exponential stability conditions for the whole hybrid system are derived by analyzing the stability of the subsystems. An example is given to show the effectiveness of the proposed design method.     

New stability criteria for neutral-type Cohen–Grossberg neural networks with discrete and distributed delays

This paper studies the existence, uniqueness and globally robust exponential stability for a class of uncertain neutral-type Cohen–Grossberg neural networks with time-varying and unbounded distributed delays. Based on Lyapunov–Krasovskii functional, by involving a free-weighting matrix, using the homeomorphism mapping principle, Cauchy–Schwarz inequality, Jensen integral inequality, linear matrix inequality techniques and matrix decomposition method, several delay-dependent and delay-independent sufficient conditions are obtained for the robust exponential stability of considered neural networks. Two numerical examples are given to show the effectiveness of our results.