空间信息合作与并行处理

面向海量空问信息的网络地理信息系统是当前空间信息领域的发展方向，合作和并行是多Agent系统的特点．介绍一个基于Agent的分布式地理信息系统系统Geo-Agents，该系统主要由GuServer，Facilitator，接口Agent，GIS功能Agent等组成．对Geo-Agents系统中的合作和并行模式进行了分析和探讨．合作主要体现在两个方面：接口Agent间的合作以及在接口Agent控制下的合作；并行则主要依靠GIS功能Agent来完成，可以分为三种类型：同构合作并行、异构合作并行以及互斥并行．最后，以空问数据导航和叠加分析作为实例，验证了Geo-Agents系统对空间信息的合作和并行处理。     

Geo—Agents系统中的合作与并行分析

1 前言 Geo-Agents是一个基于Agent的分布式GIS原型系统(如图1所示)。系统由Facilitator、接口Agent、GIS功能A-gent和GuServer等四种GIS Agent组成。其中,Facilitator是系统管理Agent,主要承担全局管理和协调功能;GIS功能A-gent对分布式GIS系统中的空间分析或查询功能进行封装,具有响应外界请求,完成不同数据要求的同一类空间分析或查询功能,并可以利用Agent间的统一通信机制返回查询结果;接口Agent是用来与用户交互、完成用户指定任务的,是     

基于移动Agent的WebGIS体系结构

针对分布式地理信息系统应用服务的分布性、动态性、异构性和遗留性等特点,在分析已有的WebGIS体系结构特点和移动Agent技术在分布式计算中的优点,将移动Agent应用到WebGIS中.给出基于移动Agent的WebGIS多层结构服务请求模型,并采用进程代数的方法刻画了该体系结构的动态模型.经过演算推理,证明该系统模型的有效性、可用性、可靠性和合理性.实现了WebGIS的功能集成,构成一个跨平台的、动态的、多种空间信息的GIS系统,提高分布式GIS应用系统的效率,扩大其应用范围.     

Agent及基于空间信息的辅助决策

讨论了地理信息系统和空间决策支持系统的发展趋势以及所面临的问题,并指出将Agent技术引入其中将会为解决它们发展所面临的问题提供一种新的有效的方法。重点介绍了一个基于Agent的分布地理信息系统模型Geo-Agents和一个基于Agent的空间决策支持模型,讨论了它们的体系结构、组成、工作模式以及发展方向等。     

Geo-Agents系统中的负载控制策略

Geo-Agents是一个基于Agent的分布式GIS系统．首先分析Geo-Agents系统中的负载问题：主机负载和网络负载．主机负载指的是运行在该主机上的Agent数目；而网络负载则由Agent之间的通信和地理空间数据的传输组成．主机负载和网络负载是相互关联的．在Geo-Agents系统中，由于地理空间数据的数据量非常巨大，因此减少网络负载是首位的问题，只有在网络负载一致时才考虑均衡主机负载．针对Geo-Agents系统中负载情况，给出了两个负载控制策略：Agent调度策略和对等主机策略，并对Geo-Agents系统的主机负载和网络负载进行控制．     

分布式GIS的多Agent系统建模与实现

将Agent技术引入到分布式GIS领域，提出了一个面向分布式GIS的多Agent系统模型，为分布式GIS的研究和开发提供了一种新的方法．首先设计了系统的体系结构，将分布式GIS系统中的Agent分成三类：Facilitator，GIS功能Agent和接口Agent，并给出了GIS Agent的结构和特征以及Agent之间的通信机制；然后采用DCOM技术和多线程技术，实现了一个空间多Agent系统的原型，并对其中的关键技术(同步技术、Agent的调度、Agent的强制终止等)进行了分析和探讨．     

基于智能体架构的网络行为监控集成系统

设计了一个采用分布式多Agent架构的网络行为监控集成系统NBMIS(Network Behavior Monitoring Integrated System).阐述了该系统的集成框架,Agent的交互模型与Agent的结构.详细讨论了系统中各个Agent的功能及实现的关键技术.NBMIS具有分布式多Agent协同、系统可扩展性好的特点,在网络结点数庞大和网络高负荷运行情况下能获得良好的监控性能.应用实践表明NBMIS能有效地对网页浏览、附件下载、邮件收发、FTP文件传输、IM聊天等网络行为进行监视和控制,且能有效发现潜在的网络安全问题并及时报警.     

基于计算机审计的多Agent系统体系架构

提出了一种基于计算机审计的多Agent系统体系架构,分析了该结构中各子系统的组成 及各Agent功能特点。介绍了系统中移动审计Agent和移动Agent服务器设计实现。原型系统能够 实现实时分布在线计算机审计,表明该体系架构是切实可行的。     

基于Agent的分布仿真平台原型系统设计与实现

基于Agent的分布仿真是基于Agent的建模与仿真ABMS(Agent-Based Modeling and Simulation)研究的重要组成部分。在提出的基于Agent的分布仿真软件框架和通信系统设计与实现的基础上,利用Java语言和面向对象的方法设计实现了一个基于Agent的分布仿真平台原型系统ADSimE。介绍了该分布式仿真平台的主要实现细节,给出了全系统的主要Agent类的UML设计,重点阐述了保守策略仿真Agent类和乐观策略仿真Agent类的设计、处理流程以及KQML消息解析的实现细节。最后以闭合排队网络为例,说明了怎样在该环境下进行基于Agent的分布仿真应用的开发。     

分布式多Agent专家系统设计与实现

为实现测试与诊断的相对分离，设计了基于多Agent的专家系统——SMAS。采用COM／CORBA分布式组件技术，实现通用建模子系统、知识获取子系统、诊断运行子系统等。故障诊断功能由分级分布的智能Agent并行或分级完成。Agent的组织和分布模式由系统提供的建模子系统完成建模，对不同的UUT系统具有通用性。分布式的结点Agent既可自主驱动运行，也可由其它Agent触发驱动，因而系统既可用于综合测试数据的分析诊断，也可用于与ATE的在线、交互式测试、诊断和分析。     

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