多层结构可视化系统应用服务器的设计与实现

本文设计了一种基于多层结构的可视化系统核心的三层结构,并重点讨论了其应用服务器的设计与实现。应用服务器在系统中专门负责通信的控制,它利用Java的Socket和JNI技术进行前端Web浏览器和后端绘制服务器的通信连接和传输,并实现了多线程机制。实验表明,此系统结构更合理、更利于后期维护和扩展,能最大限度的降低对客户端的软硬件要求。     

基于多层结构的可视化系统的设计与实现

设计实现了一种基于多层结构的可视化系统.系统采用三层结构,由Web客户端、Web服务器/应用服务器、绘制服务器构成.系统以应用服务器为核心,由应用服务器负责系统的通信控制.实验结果表明,此系统结构更合理、更利于后期维护和扩展,能最大限度的降低对客户端的软硬件要求.     

分布式多层结构的设计与实现

就分布式数据库的多层结构平台进行了研究，给出了一种基于Sybase的PowerBuilder和应用服务器EAServer的多层结构数据库的设计方法，对车辆管理系统应用到多层结构进行了分析和说明。     

基于Weblogic的农村养老保险管理系统的设计和实现

随着社会保险制度改革的不断深入，建立一个统一管理、标准规范的管理信息系统势在必行。本文从系统设计、数据库结构和系统实现的关键技术等几个方面论述了采用BEA Weblogic作为应用服务器，基于三层B／S结构而设计的农村养老保险管理系统的实现原理和设计技术。     

基于Web Services的GIS多层体系结构研究

通过分析通用的Web Services架构和OWS技术体系结构，提出了一个基于Web Services的多层GIS组件体系结构，介绍了该结构的特点及各服务组件的功能。最后给出了该体系结构的一个实现技术方案，并详细分析和讨论了其中Web应用服务器、应用服务器及数据服务器三部分在设计与实现中关键技术的处理策略。     

动态定位多层结构中的应用服务器

本文分析讨论了多层结构在Delphi中的实现,在此基础上分析如何动态定位应用服务器,并举例说明。     

C/S结构业务系统平移到多层体系结构技术的研究

比较多层体系结构与传统C/S结构的特点,以商标注册与管理系统为例,探讨从Client/Server结构平移到多层体系结构中所涉及的技术.并具体说明客户端、应用服务器和数据服务器的设计、实现和优化.     

基于三层结构交易中间件系统设计

介绍了三层结构交易中间件体系结构的系统实现模型，论述了在该模型下通信层和交易调度层的设计思路和实现方法，给出了交易调度层动态优先级算法的实现思路。     

基于J2EE的LBS服务器平台设计

本文在详细分析J2EE多层分布式结构之优点的基础上，结合分析移动位置服务系统的特殊要求，提出基于J2EE EJB技术构建移动位置服务服务器的设计思路，并针对应用服务器设计和数据服务器设计的关键技术做了详细分析，给出解决办法。文章最后给出了一种服务器具体实现方案。     

基于体系仿真的异构数据库集成环境的实现

该文提出了一种基于组件技术的三层C／S结构的分布式联邦数据库模式，用来管理和实现分布式异构数据库信息集成和数据访问，将系统功能模块封装到组件中并放在中间层的应用服务器上，使得此异构系统具有良好的可重构性。并以PowerBuilder9．0为开发工具、EAServer的Jaguar CTS为应用服务器实现了一个基于仿真系统的异构数据库通用集成环境。     

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