基于网络的并行计算系统模型

随着Internet迅速发展,利用网上资源构筑分布式并行计算环境进行中、大粒度任务的分布式并行计算已呈现出重要研究价值。另外,Agent理论的日益成熟及多Agent系统MAS(Multi-Agent System)的出现,为开放式分布系统的开发和应用提供了新的模式。结合移动Agent在并行计算中的任务特性,对网络并行计算进行了抽象的分析和描述,然后给出了一个基于移动Agent计算的任务流模型实例。     

基于移动代理的分布式并行计算中间件设计与实现

文中提出了一个基于移动代理(Mobile Agent)的分布式并行计算中间件，用于将Internet用户闲置的计算资源与其他成员共享。针对分布式并行计算中存在的问题，利用移动代理技术的特点，将中间件的体系结构分为两层，为分布式并行计算提供各种基础服务，尤其是任务迁移和容错机制。着重介绍了分布式并行计算中间件的主要实现技术，实现了一个分布式并行计算原型系统并给出实验结果。     

一种基于移动Agent的分布式并行计算模型

针对传统的分布式并行计算方案所存在的缺点,提出了一种基于移动Agent技术的分布式并行计算模型。在简单介绍移动Agent技术后,给出了基于移动Agent的分布式并行计算模型,并详细叙述了该模型的具体工作过程和实现方案。模型设计完成后,用此模型来解决计算量很大的数值计算问题。首先利用数学工具分析设计出该问题的适合于分布式并行计算的方案,然后依照模型实现实验程序。实验测试表明根据该模型实现的分布式并行计算程序具有较高的加速比和并行效率,并有效地提高了分布式并行计算的稳定性、灵活性、可扩展性和移动性。     

一种基于移动Agent的分布式并行计算模型

针对传统的分布式并行计算方案所存在的缺点,提出了一种基于移动Agent技术的分布式并行计算模型.在简单介绍移动Agent技术后,给出了基于移动Agent的分布式并行计算模型,并详细叙述了该模型的具体工作过程和实现方案.模型没计完成后,用此模型来解决计算量很大的数值计算问题.首先利用数学工具分析设计出该问题的适合于分布式并行计算的方案,然后依照模型实现实验程序.实验测试表明根据该模型实现的分布式并行计算程序具有较高的加速比和并行效率,并有效地提高了分布式并行计算的稳定性、灵活性、可扩展性和移动性.     

基于移动Agent的分布式测控系统任务调度研究

动态任务调度是分布式测控系统中的一项关键技术。基于移动Agent提出了一种新的分布式测控系统动态任务调度算法。算法采用IBM Aglets系统设计和执行移动Agent,利用移动Agent-Aglet在系统运行过程中动态迁移任务,从而有效地提高了系统效率,实现了负载均衡的目标。详细介绍了任务迁移的实现及Aglet通信机制。     

一种移动Agent数据保护机制的研究

1.研究背景移动Agent系统是一个分布式的计算平台,在移动A-gent系统中移动Agent是由代码、数据和控制信息(如线程状态)组成的一段可以自动迁移程序,该程序能自动执行计算任务,同时也可以与其它移动Agent通信进行协同计算。在移动Agent系统中,移动Agent可以在当前主机(Host)上暂停现有的计算,迁移到系统中其他的主机上并继续执行计算任务,实现计算的移动。     

分布式DWMS中移动Agent间的协同工作

分布式工作流管理系统中工作流引擎的分布特性使管理者难以从整体上协调各节点间的工作。对此,文章将移动Agent技术应用于分布式工作流管理系统中。移动Agent作为一种移动工作流引擎存储整个工作流过程模型并在各节点间自主移动,通过与系统管理者的动态交互可使管理者实时监控整个流程的运行状态。为解决系统中单一移动Agent任务过于繁重的问题,将移动Agent分为协同移动Agent和任务移动Agent两类,通过他们之间的协同工作提升工作流过程的运行效率。     

Multi Agent在分布式测控系统动态任务调度中的实现

Multi Agent实现是基于Multi Agent的分布式测控系统动态任务调度算法实现的关键技术。采用Java作为开发工具,根据Multi Agent的功能,详细论述了Multi Agent在分布式测控系统动态任务调度中的实现。基于Multi Agent的动态任务调度算法根据各主机的负载状态,在系统运行过程中利用移动Agent动态迁移任务。文中详细论述了利用Aglets系统开发和执行移动Agent,从而有效地提高了系统效率,实现了动态任务调度的目标。     

基于移动Agent的新型分布式入侵检测系统

通过阐述入侵检测系统的基本概念和移动Agent的优点,并将移动Agent技术与分布式技术相结合,提出了一种基于移动Agent的新型分布式入侵检测系统DIDSBMA,它具有传统入侵检测技术无法比拟的优势,极大地提高了系统的稳定性、可测量性和容错性,真正实现了分布式入侵检测。     

基于移动Agent的分布式数据库的研究

本文对移动Agent技术进行了系统地概述和探讨,提出把移动Agent技术应用于分布式数据库系统中,并给出了在分布式数据库系统中利用移动Agent技术实现并发控制和分布式查询的方法。     

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