On delay-dependent robust stability of a class of uncertain mixed neutral and Lur’e dynamical systems with interval time-varying delays     

Chun Yin  Shou-ming Zhong  Wu-fan Chen 《Journal of The Franklin Institute》2010,347(9):1623-1642

This paper deals with the problem of a new delay-dependent robust stability criteria for a class of mixed neutral and Lur’e systems. The system has time-varying uncertainties, interval time-varying delays and sector-bounded nonlinearity. The proposed method is based on Lyapunov method, a delay-dependent criterion for asymptotic stability is established in terms of linear matrix inequality (LMI). Numerical examples show the effectiveness of the proposed method.  相似文献   

清代云南临沧地区的学校教育     

罗春梅 《临沧师范高等专科学校学报》2007,(4):29-33

清代,临沧地区的教育获得了前所未有的发展,统治阶级在这一地区大力兴办书院、义学,培养了很多人才,推动了本地教育和文化的发展,为本地教育的近现代化奠定了基础。  相似文献   

普通高校群体活动改革理论与实践   总被引：3，自引：0，他引：3       下载免费PDF全文

陆淳 《武汉体育学院学报》2009,43(7):97

运用文献资料、调查访问、问卷调查、数理统计等方法,对大学生余暇时间活动现状、群体活动理念、群体活动的组织管理、体育竞赛的组织与运作和构建群体活动工作网络等方面进行研究.结果表明,大学生余暇时间活动内容呈多元化,体育锻炼被排在次要位置;高校群体活动在组织运作上应围绕四个层面展开,使群体竞赛贯穿全年,实现大学校园里人人崇尚体育,人人追求身心健康,人人关注、人人参与、人人体验、人人享受体育的目标.  相似文献   

基于培养学生应用和创新能力的“数字电子技术”课程的教学改革与实践     

晋春  李峰  张尤赛  张佳 《环球赛鸽科技》2015,(17)

“数字电子技术”已渗透到现代信息技术的各个领域,成为电子信息类学科一门重要的专业基础课。本文围绕培养电子设计与应用类人才这一目标,探讨了“数电”课程改革的基本思路,对课程教学内容、教学方式和方法等方面做了几点优化改革与创新,取得了较好的成效,具有一定的参考价值。  相似文献   

基于角度分析法的城市空间可达性研究     

高鑫  陈春 《科技广场》2015,(1):30-34

本文首先介绍了量化分析空间系统的角度分析法,并利用最小角度路径和角度偏离值等度量概念,去衡量开放空间中两点间的可达性。其次,本文仿照空间句法中的"轴线法",提出了"中心轴线法",用中心轴线的角度变化去代表空间的角度转动情况。最后,本文给出了轴线和空间的角度偏离值,用于对独立空间进行可达性分析,并且给出角度偏离矩阵等概念,用于表示整个研究空间的可达性情况。  相似文献   

生态技术创新视角下工业产业的种群效应实证研究     

万春 《软科学》2015,(3):43-46

以2001~2011年江西省的工业产业为样本,采用生态技术创新种群行为模型对种群效应进行实证分析,发现多数种群的个体数量已经逼近或超过区域创新资源决定的生态阈值,种群内部、种群之间由协同效应转向竞争效应,发出了环境过载的警示。  相似文献   

基于多频互控分析的记发器信令生成器的工程设计实现     

曾春 《重庆电子工程职业学院学报》2015,(1):147-151

1号信令是电话接续的重要信令,作为1号信令重要组成部分的记发器信令的生成与检测一般都是由专用芯片实现。由于硬件接口和功能固定,在实际使用中往往受到很大限制,因此用通用芯片来实现这一功能可以大大增加灵活性,兼容性。但在软硬件设计之前,准确分析记发器信令的信号波形特性十分重要,往往会决定最终的设计性能指标。首先分析记发器信令的具体物理特性,其具体实验数据取自于满足1号信令协议标准的相关设备,然后分析记发器信号的多频互控流程,包括编码序号和频率成分的对应关系、信号的具体分类、信号的发送流程等,这对于建立从协议层到物理层的相关机制都是十分有意义的。最后给出工程设计的基本思路,包括从ARM+DSP的架构设计、逻辑层次设计、相互之间的接口关系、配合机制等。  相似文献   

Electroosmotic flow hysteresis for dissimilar ionic solutions     

An Eng Lim  Chun Yee Lim  Yee Cheong Lam 《Biomicrofluidics》2015,9(2)

Electroosmotic flow (EOF) with two or more fluids is commonly encountered in various microfluidics applications. However, no investigation has hitherto been conducted to investigate the hysteretic or flow direction-dependent behavior during the displacement flow of solutions with dissimilar ionic species. In this investigation, electroosmotic displacement flow involving dissimilar ionic solutions was studied experimentally through a current monitoring method and numerically through finite element simulations. The flow hysteresis can be characterized by the turning and displacement times; turning time refers to the abrupt gradient change of current-time curve while displacement time is the time for one solution to completely displace the other solution. Both experimental and simulation results illustrate that the turning and displacement times for a particular solution pair can be directional-dependent, indicating that the flow conditions in the microchannel are not the same in the two different flow directions. The mechanics of EOF hysteresis was elucidated through the theoretical model which includes the ionic mobility of each species, a major governing parameter. Two distinct mechanics have been identified as the causes for the EOF hysteresis involving dissimilar ionic solutions: the widening/sharpening effect of interfacial region between the two solutions and the difference in ion concentration distributions (and thus average zeta potentials) in different flow directions. The outcome of this investigation contributes to the fundamental understanding of flow behavior in microfluidic systems involving solution pair with dissimilar ionic species.  相似文献   

Numerical simulation on the opto-electro-kinetic patterning for rapid concentration of particles in a microchannel     

Dong Kim  Jaesool Shim  Han-Sheng Chuang  Kyung Chun Kim 《Biomicrofluidics》2015,9(3)

This paper presents a mathematical model for laser-induced rapid electro-kinetic patterning (REP) to elucidate the mechanism for concentrating particles in a microchannel non-destructively and non-invasively. COMSOL^®(v4.2a) multiphysics software was used to examine the effect of a variety of parameters on the focusing performance of the REP. A mathematical model of the REP was developed based on the AC electrothermal flow (ACET) equations, the dielectrophoresis (DEP) equation, the energy balance equation, the Navier-Stokes equation, and the concentration-distribution equation. The medium was assumed to be a diluted solute, and different electric potentials and laser illumination were applied to the desired place. Gold (Au) electrodes were used at the top and bottom of a microchannel. For model validation, the simulation results were compared with the experimental data. The results revealed the formation of a toroidal microvortex via the ACET effect, which was generated due to laser illumination and joule-heating in the area of interest. In addition, under some conditions, such as the frequency of AC, the DEP velocity, and the particle size, the ACET force enhances and compresses resulting in the concentration of particles. The conditions of the DEP velocity and the ACET velocity are presented in detail with a comparison of the experimental results.  相似文献   

健美操训练对女性有氧适能、身体形态与心理健康的影响研究     

李银银  魏纯 《湖北体育科技》2015,(2):137-139

采用实验测试法、文献资料法和数理统计法,对湖南理工学院非体育专业30名女大学生12周健美操训练后进行有氧适能、身体形态等指标的测试,说明健美操对女性改善有氧适能、身体形态与心理健康中的作用。  相似文献