具有变时滞过程的微机控制系统

具有变时滞过程的微机控制系统张兴福ＴｈｅＭｉｃｒｏｃｏｍｐｕｔｅｒＣｏｎｔｒｏｌＳｙｓｔｅｍｗｉｔｈＶａｒｉａｂｌｅＴｉｍｅＤｅｌａｙＰｒｏｃｅｓｓ￥ＺｈａｎｇＸｉｎｇｆｕ引言过程工业中存在的时滞问题，特别是变时滞问题，是影响控制系统稳定性和控制品质...     

不确定时滞系统鲁棒H∞完整性设计

研究一类不确定时滞系统的鲁棒Ｈ＾∞完整性综合设计问题。首先将故障执行器输出信息假设为能量有界信号,最终将问题归结为通过求解－Ｒｉｃｃａｔｉ方程得到时滞无关的状态反馈控制律。     

带有时滞及不确定性的循环大系统分散镇定状态反馈H∞设计

研究了较对称组合系统及循环对称组合系统更为一般的系统──循环系统，利用Ｈ∞理论及Ｒｉｃｃａｔｉ方程方法分别就确定性时滞系统和不确定性时滞系统得出使闭环系统稳定的分散状态反馈控制器的设计方法。所得结论均可平行推广到对称组合及循环对称组合系统。     

基于Riccati-ItXô方程设计线性时滞系统鲁棒控制器的方法*

利用Ｒｉｃｃａｔｉ－Ｉｔｏ型矩阵代数方程研究线性时不变系统的状态反馈镇定问题，对时滞系统给出了一种状态反馈镇定方法，这种镇定方法适应于许多时滞系统，其设计方案具有滞后无关性及对于许多系统滞后项系数任意性的完全适应性，本文第二部分研究对不变线性不确定系统的鲁棒镇定，利用Ｒｉｃｃａｔｉ－Ｉｔｏ型矩阵代数方程给出了这类系统鲁棒镇定控制器的设计方法。     

时滞系统的状态反馈和基于观测器的输出反馈设计

考虑了同时具有状态和输入时滞线性定常系统的Ｈ＾∞镇定问题。基于动态耗散理论和微分对策原理,通过采用了带积分项的储存函数,对系统的器和基于观测器的输出反馈设计问题进行了处理,它们的可解充分条件可以化为与时滞相关的矩阵相关的矩阵不等式和Ｒｉｃｃａｔｉ方程的形式,得到的与时滞相关的状态反馈控制律和基于观测器的输出反馈控制律都能使闭环系统内稳且具有Ｈ＾∞干扰衰减。     

脉冲时滞微分不等式及鲁棒控制设计中的应用

本文首先建立脉冲微分不等式的稳定性结果。利用此结果并结合Ｒｉｃｃａｔｉ方程方法,对含变时滞测度微分系统给出了其鲁棒控制设计,最后给出一设计实例。     

具有状态滞后的线性不确定时滞系统鲁棒输出反馈控制

针对具有状态滞后和时变未知且有界不确定性的线性时变不确定时滞系统，研究了当状态不完全可测时的鲁棒镇定问题。利用Ｒｉｃｃａｔｉ方程方法，提出了一种基于观测器的动态输出反馈镇定控制器设计方法，并得到了不确定时滞系统可输出反馈镇定的充分条件。最后通过一数值例子来说明了所得结果的可行性。     

具有参数扰动时滞系统的鲁棒镇定性

利用标量的Ｌｙａｐｕｎｏｖ函数，结合代数Ｒｉｃｃａｔｉ方程和Ｒａｙｌｅｉｇｈ’ｓ原理，讨论了具有参数扰动时滞系统的鲁棒镇定性，获得了一个充分条件。     

非线性时滞摄动系统的H∞鲁棒控制

研究具有时滞的非线性不确定性系统的Ｈ∞鲁棒控制问题。基于代数Ｒｉｃｃａｔｉ方程的正定解设计出状态反馈控制器使得闭环系统满足相应的Ｈ∞鲁棒性能准则。     

具有时滞的线性奇异系统镇定的Riccati方程方法

本文考虑了具时滞的线性奇异系统的镇定问题，利用Ｒｉｃｃａｔｉ方程方法给出了系统无记忆反馈控制器的设计，并得到了系统可经状态反馈镇定的条件。     

煤矿井下安全监控分站的设计及其仿真实现

为了设计一种具有低成本、低功耗、易操作、功能强且可靠性高的煤矿井下安全分站,针对煤矿安全生产实际,文章提出了采用MCS-51系列单片机为核心、具有CAN总线通信接口的煤矿井下安全监控分站的设计方案;首先给出煤矿井下安全监控分站的整体构架设计,然后着重阐述模拟量输入信号处理系统的设计过程,最后说明单片机最小系统及其键盘、显示、报警、通信等各个组成部分的设计;为验证设计方案的可行性与有效性,使用Proteus软件对设计内容进行仿真验证,设计的煤矿井下安全监控分站具有瓦斯、温度等模拟量参数超标报警功能和电机开停、风门开闭等开关量指示功能;仿真结果表明:设计的煤矿井下安全监控分站具有一定的实际应用价值.     

View-based model-driven architecture for enhancing maintainability of data access services

In modern service-oriented architectures, database access is done by a special type of services, the so-called data access services (DAS). Though, particularly in data-intensive applications, using and developing DAS are very common today, the link between the DAS and their implementation, e.g. a layer of data access objects (DAOs) encapsulating the database queries, still is not sufficiently elaborated, yet. As a result, as the number of DAS grows, finding the desired DAS for reuse and/or associated documentation can become an impossible task. In this paper we focus on bridging this gap between the DAS and their implementation by presenting a view-based, model-driven data access architecture (VMDA) managing models of the DAS, DAOs and database queries in a queryable manner. Our models support tailored views of different stakeholders and are scalable with all types of DAS implementations. In this paper we show that our view-based and model driven architecture approach can enhance software development productivity and maintainability by improving DAS documentation. Moreover, our VMDA opens a wide range of applications such as evaluating DAS usage for DAS performance optimization. Furthermore, we provide tool support and illustrate the applicability of our VMDA in a large-scale case study. Finally, we quantitatively prove that our approach performs with acceptable response times.     

A pragmatic multi-method investigation of discrepant technological events: Coping,attributions, and ‘accidental’ learning

Discrepant technological events or situations that entail a problem, a misunderstanding or a difficulty with the Information Technology (IT) being employed, are common in the workplace, and can lead to frustration and avoidance behaviors. Little is known, however, about how individuals cope with these events. This paper examines these events by using a multi-method pragmatic approach informed by coping theory. The results of two studies – a critical incident study and an experiment – serve to build and test, respectively, a theoretical model that posits that individuals use a variety of strategies when dealing with these events: they experience negative emotions, make external attributions, and adopt engagement coping strategies directed at solving the event, eventually switching to a disengagement coping strategy when they feel they have no control over the situation. Furthermore, users’ efforts may result in ‘accidental’ learning as they try to overcome the discrepant IT events through engagement coping. The paper ends with a discussion of the results in light of existing literature, future opportunities for research, and implications for practice.     

The Distributed Time-Triggered Simulation Scheme: Core Principles and Supporting Execution Engine

Distributed real-time simulation is a young technology field but its practice is under increasing demands. In recent years the author and his collaborators have been establishing a new approach called the distributed time-triggered simulation (DTS) scheme which is conceptually simple and easy to use but widely applicable. The concept was initiated in the course of developing a new-generation object-oriented real-time programming scheme called the time-triggered message-triggered object (TMO) programming scheme. Some fundamental issues inherent in distributed real-time simulation that were learned during recent experimental studies are discussed along with some approaches for resolving the issues. An execution engine developed to support both the TMOs engaged in control computation and the TMOs engaged in DTS is also discussed along with its possible extensions that will enable significantly larger-scale DTSs.     

Software-Konfigurationsmanagement in großen Softwareprojekten

Zusammenfassung Mit zunehmender Größe der Softwaresysteme verschärfen sich die für die Software-Herstellung typischen Probleme: Beherrschen großer Objektmengen, Erhalten der Systemkonsistenz, Kontrolle der ständigen Änderungseinflüsse und Gewährleisten einer langen Lebensdauer. Die Disziplin Konfigurationsmanagement bildet den methodischen Ansatz, diese Probleme besser zu beherrschen. Software-Konfigurationsmanagement faßt die Herstellung von Softwaresystemen als eine Abfolge von kontrollierten Änderungen an gesicherten Zwischen- und Endergebnissen auf. Dargestellt werden die Objekte und Funktionen des Software-Konfigurationsmanagements sowie die hierfür in großen Software-Projekten benötigten Methoden, Instanzen und Hilfsmittel.     

Information for Authors

正http://www.zju.edu.cn/jzus http://www.springerlink.com Aim The Journals of Zhejiang University-SCIENCE(A/B/C)are edited by the international board of distinguished Chinese and foreign scientists,and are aimed to present the latest developments and achievements in scientific research in China and     

Editorial:Brain-machine interface(BMI) and cyborg intelligence

正Brain-machine interfaces(BMIs)aim at building a direct communication pathway between the brain and an external device,and represent an area of research where significant progress has been made during the past decade.Based on BMIs,mind information can be read out by neural signals to control     

Information for Authors

正http://www.zju.edu.cn/jzus http://www.springerlink.com Aim The Journals of Zhejiang University-SCIENCE(A/B/C)are edited by the international board of distinguished Chinese and foreign scientists,and are aimed to present the latest developments and achievements in scientific research in China and overseas to the world’s scientific circles,especially to stimulate     

SCIENCE CHINA Information Sciences SUBJECT INDEX TO VOLUME 57(2014)

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Information for Authors

正http://www.zju.edu.cn/jzus http://www.springerlink.com Aim The Journals of Zhejiang University-SCIENCE(A/B/C)are edited by the international board of distinguished Chinese and foreign scientists,and are aimed to present the latest developments and achievements in scientific research in China and overseas to the world’s scientific circles,especially to stimulate