广义循环系统的特性分析

本文将正常循环系统推广为广义循环大系统，并利用矩阵理论，集中分析了这类大系统的一些重要性质及其分散固定模的特征。结果表明，Nn阶的广义循环大系统的性质如稳定性、能控性、能观性、固定模的存在性等，均可由一些低阶系统的相应性质来描述。并且广义循环大系统的有穷固定模可通过低阶系统的不可控不可观模态求得，从而避免了因系统的高雏性带来的计算困难。本文的结论为进一步研究这类系统提供了理论基础。     

线性相似组合系统的特性分析

本文讨论线性相似组合系统的一些性质，结果表明这类大系统的特性可由两个低阶修正子系统的相应性质确定。     

循环组合系统的结构性质

研究了循环组合系统的结构性质.结果表明,由于其结构的特殊性,循环组合系统的 结构能控性和结构固定模的存在性,可以通过其修正子系统的结构能控性和结构固定模的存 在性来得到.     

一类具有相似结构的组合系统的结构可控性与渐近合作性

研究一类由若干个具有相似结构的子系统和一个外部系统所组成的组合系统,并证明在 适当的内联条件下,这类系统的结构可控性和渐近合作性等定性性质可由其修正的低阶子系 统和解耦系统的相应性质所决定.     

一类具有相似结构的组合系统的结构可控性与渐近合作性

研究一类由若干个具有相似结构的子系统和一个外部系统所组成的组合系统，并证明在适当的内联条件下，这类系统的结构可控性和渐近合作性等定性性质可由其修正的低阶子系统和解耦系统的相应性质所决定。     

广义代数Riccati方程正解的研究

研究一类广义代数Riccati方程,该方程在随机控制领域有重要的应用,因而被许多 学者所研究.通过引进能稳性的概念,给出了该方程有唯一正解的一个充分必要条件,所得结 果不仅改进了以往的结论,也推广了确定性代数Riccati方程的相应性质.     

广义代数Riccati方程和最优调节器的研究

利用能稳性和精确能观性, 对广义代数Riccati方程和相关的随机最优调节器问题进行了深入的研究. 对广义代数Riccati方程得到了下列结果: 如果随机系统既是能稳定的又是精确能观的, 则广义代数Riccati方程有一个最大解, 同时也是一个反馈镇定解. 在精确能观性的假设下, 广义代数Riccati方程的所有非负定解(如果存在的话)必是正的反馈镇定解. 作为应用, 最优调节器问题, 广义代数Riccati方程的最大解, 反馈镇定解三者之间的关系获得了澄清. 所有这些结果在随机控制和随机稳定性理论中是有     

广义系统的能控、能观性判别条件

该文讨论广义系统能控、能观性问题,给出了广义系统能控和能观性一种新的判别条件.     

一类不确定相似广义互联系统的广义状态重构

研究了一类具有相似结构的广义互联系统 ,根据系统的相似结构构造了一个动态组合系统 ,并以组合系统的可测输出为基础来实现广义互联系统中各个子系统的广义状态重构 ,从而提出了相似性研究的新方向 .这类系统的各个孤立子系统都包含非线性项 ,而且子系统之间的互联项都是非线性非匹配不确定的 ,研究表明 ,广义互联系统的相似结构可以简化其子系统的广义状态重构     

一类具有对称内联子系统的不确定大系统的二次稳定性

本文研究了一类由若干个相似子系统和一个外部系统通过对称地内联组成的不确定大系统的二次稳定性问题用二个低阶子系统以及相应的Ｈ∞范数的术语给出了这样一个系统是二次稳定的充分条件，并且证明了这个条件对于这个系统的过界系统的二次稳定性也是必要的。     

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.     

Call for Papers The 6^th International Conference on Grid and Cooperative Computing

Recent years have seen rapid advances in various grid-related technologies, middleware, and applications. The GCC conference has become one of the largest scientific events worldwide in grid and cooperative computing. The 6th international conference on grid and cooperative computing (GCC2007) Sponsored by China Computer Federation (CCF),Institute of Computing Technology, Chinese Academy of Sciences (ICT) and Xinjiang University ,and in Cooperation with IEEE Computer Soceity ,is to be held from August 16 to 18, 2007 in Urumchi, Xinjiang, China.     

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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