Non‐fragile H ∞ control for switched stochastic delay systems with application to water quality process

In this paper, the problem of non‐fragile observer‐based H _∞ control for discrete‐time switched delay systems is investigated. Both data missing and time delays are taken into account in the links from sensors to observers and from controllers to actuators. Because data missing satisfies the Bernoulli distribution, such problem is transformed into an H _∞ control problem for stochastic switched delay systems. Average dwell time approach is used to obtain sufficient conditions on the solvability of such problems. A numerical example and a real example for water quality control are provided to illustrate the effectiveness and potential applications of the proposed techniques. Copyright © 2013 John Wiley & Sons, Ltd.     

Fault detection for continuous‐time switched systems under asynchronous switching

In this paper, the problem of fault detection for continuous‐time switched systems under asynchronous switching is investigated. The designed fault detection filter is assumed to be asynchronous with the original systems. Attention is focused on designing a fault detection filter such that the estimation error between the residual and the fault is minimized in the sense of H _∞ norm. By employing piecewise Lyapunov function and average dwell time techniques, a sufficient condition for the existence of such a filter is exploited in terms of certain linear matrix inequalities. Finally, an example of a switched electrical circuit is provided to illustrate the effectiveness of the proposed approach. Copyright © 2013 John Wiley & Sons, Ltd.     

基于受限领域自动问答系统设计

自动问答系统的设计一直是自然语言处理领域的研究热点。尤其是在受限领域,基于问题库的问答系统具有准确、快捷和高效等优点。该文设计了一种融合社交网络技术的基于《计算机网络》课程的自动问答系统,其问答库的构建采用了VSM模型。实验证明,该系统具有较高的准确率,有一定的推广意义。     

基于Android平台的盲人手机系统设计与开发

人们生活中的绝大部分信息都是通过视觉获得的,所以盲人能够从外界获取的信息量很少,但这并不能阻止他们努力提高生活质量的渴望。智能手机的快速发展给盲人提供了前所未有的机遇。开发盲人手机具有极大的应用价值。该文主要介绍了在Android平台上设计和实现的一款盲人手机系统,该系统使用了语音识别、语音合成及Web Service等相关技术,实现了语音拨打电话、语音接听电话、语音发送短信、语音播报来电短信、语音报时、语音播报日期和语音播报天气等功能,并能在Android手机中稳定运行,方便盲人使用手机,具有较高的实用价值。     

一种简单便携的存储介质信息检测及备份装置研究

随着信息时代的飞速发展,数据信息在生活中的作用越来越显重要,数据恢复在社会生活中的应用越来越广,这便需要对存储介质的信息进行必要的检测和备份。虽然一些常见的软件可以通过PC端实现检测和备份功能,但也就是针对常见USB设备和一些专业性比较强的硬盘,不方便备份且不易携带,因此能提供一种兼容各种存储介质,并且方便使用、易于携带且不依赖于电脑就能实现检测和备份的设备非常重要。本文阐述了一种简单便携的存储介质信息检测及备份装置的研究设计．．     

基于QNX的SAT监控系统的研究与实现

首先介绍系统分析工具包(SAT)的工作过程,其次描述利用SAT功能所设计和开发的监控系统,再介绍SAT所提供的几种数据过滤器,最后对软件开发中所遇到的问题进行分析并提出相应的解决方法.该系统的建立有助于优化系统,提高系统的整体性能.     

相分离对SiO2薄膜粗糙度的影响

用氨水做催化剂配制碱溶胶,用盐酸做催化剂配制酸溶胶,在酸、碱混合溶胶中添加聚丙稀酸(PAA)引发相分离,通过添加不同含量的PAA,制备出具有不同粗糙度的透明薄膜,随后经过三甲基氯硅烷(TMCS)修饰,具有疏水性能和不同的疏水效果。     

Preparation of heat‐resistant gradient‐index polymer optical fiber rods based on poly(N‐isopropylmaleimide‐co‐methyl methacrylate)

Using the interfacial gel polymerization method, a heat‐resistant gradient‐index polymer optical fiber (GI POF) was developed based on the copolymer of methyl methacrylate (MMA) and N‐isopropylmaleimide (IPMI) as the matrix material and bromobenzene (BB) as dopant. The gradient distribution of IPMI in the GI POF rod was determined by element analysis. IPMI had great advantage in improving glass transition temperature (T_g) and forming a gradient‐index profile. There was a significant enhancement in the heat‐resistant property in comparison with a conventional GI POF rod. The combination of high thermal stability and easy fabrication makes the novel BB–IPMI–MMA system very suitable for heat‐resistant GI POF. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 87: 280–283, 2003     

聚氨酯/聚丙烯酸酯复合乳液的研制进展

综述了近年来聚氨酯－丙烯酸酯（PUA）复合乳液研究的新进展，总结介绍了各类聚氨酯－聚丙烯酸酯复合乳液（PUA共混复合乳液、PUA复合核／壳乳液、互穿网络PUA复合乳液）的制备方法和性能特点。并对该领域进一步的发展作了展望。     

Microcellular foaming of PE/PP blends

Three different polyethylene/polypropylene (PE/PP) blends were microcellular foamed and their crystallinities and melt strengths were investigated. The relationship between crystallinity, melt strength, and cellular structure was studied. Experimental results showed that the three blends had similar variation patterns in respect of crystallinity, melt strength, and cellular structure, and these variation patterns were correlative for each blend. For all blends, the melt strength and PP melting point initially heightened and then lowered, the PP crystallinity first decreased, and then increased as the PE content increased. At PE content of 30%, the melt strength and PP melting point were highest and the PP crystallinity was least. The blend with lower PP crystallinity and higher melt strength had better cellular structure and broader microcellular foaming temperature range. So, three blends had best cellular structure at PE content of 30%. Furthermore, when compared with PE/homopolymer (hPP) blend, the PE/copolymer PP (cPP) blend had higher melt strength, better cellular structure, and wider microcellular foaming temperature range, so it was more suited to be microcellular foamed. Whereas LDPE/cPP blend had the broadest microcellular foaming temperature range because of its highest melt strength within three blends. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 4149–4159, 2007