基于AJAX和Servlet的Web GIS的研究与实现

基于Internet的地理信息系统(Web GIS)是Web技术和GIS技术相结合的产物,是实现GIS互操作的一条最佳解决途径.在分析Web GIS体系结构以及各种实现技术的基础上,通过对AJAX技术和Servlet技术特点及优势的介绍和分析,提出了基于AJAX和Sevlet的Web GIS的设计方案,并在CNGI移动奥运项目的智能交通系统(ITS)Web发布平台中进行了初步实现.     

基于Web数据库的图形报表技术研究

分析了基于Web平台数据库图形报表系统的实现技术并提出了基于Web平台图形报表系统的架构，阐述了Java Servlet技术、Formula One组件技术，基于前面所述架构和Servlet、Formula One等技术给出了制作图形报表的方法和实现技术。研究了对Web应用极具前途的XML数据库的模式及查询，得出了初步的结果。     

网络地理信息系统

网络地理信息系统（Web GIS)是当前GIS的技术热点。从分析计算模式的进化过程出发，指出了基于Web的分布式计算环境，使传统GIS有望实现开放目标，以满足数据共享与互操作需求，进而综述了Web GIS概念，包括网络协议的GIS拓展、Web GIS新型数据模型、相关算法、多源数据集成以及网络优化模式（分布式并行处理），最后通过自行开发的Web GIS浏览器（Java Applet)具体予以实现。     

Web GIS的新技术

随着网络技术的发展，Web GIS将成为今后GIS应用的发展方向，该文在回顾Web GIS技术的基础上，对目前新出现的两种WebGIS技术：Java Servlet和GML进行了介绍，这两种新技术的出现为Web GIS的应用开辟了新的方向。     

Servlet技术在提高Web应用客户响应速度中的实现

以J2EE平台下运用Servlet技术提高Web应用客户响应速度为事例，论述了Servlet的技术优势，介绍了主要的Servlet方法，给出了Web应用中如何规划构架EJB-Servlet-JSP组合模型的技术思路和Servlet技术在Web应用中的具体实现。     

基于Web/Java技术的SNMP网络性能管理的研究

本文研究了简单网络管理协议和网络性能管理的有关内容。通过对简单网络管理协议(SNMP)、MIB-Ⅱ管理信息结构(SMI)的分析和使用，设计了基于Web的客户层 服务层 资源层的三层网络管理模型。采用Java Servlet实现Web服务器，C语言实现应用服务器，Java Applet作为客户端。Socket作为信息转发通道。系统采用Java Applet Servlet技术，实现了基于Web的管理方式。     

基于Java技术的分布式异构数据库Web访问技术

文章简要介绍了Servlet和JDBC的技术原理,分析了Applet实现的二层Client／Server结构的Web环境下数据库访问技术的局限性,并由此讨论引入三层Client／Server结构加以解决,最后给出了基于Servlet和JDBC技术的分布式异构数据库Web访问技术的实现模型.     

基于SVG的实时Web GIS技术研究

web GIS是传统GIS发展的必然，目前有很多实现方法同样存在许多困难。本文讨论了当前Web GIS的发展态势以及面临的主要技术问题，详细分析了一种基于XML的矢量图形描述语言（SVG）的概念、它应用于Web GIS上的优点以及用于构建实时的web GIS的关键技术，并给出了一个应用实例。     

基于XML的Web数据交换

结合XML技术，提出了一个基于XML的Web数据交换的3层模型以及应用服务器的模型，并采用纯Java技术（Servlet,JSP,JavaBean)实现了应用服务器，最后给出一个实例。     

基于CORBA和Java Servlet的多层分布式应用系统的实现

Servlet是Java技术在Web上的扩展,支持Web服务器的应用开发。本文介绍了Java Servlet的工作原理,并将CORBA分布式对象技术运用于异构平台中网络数据库应用的设计,提出了基于CORBA和Java Servlet的5层Web数据库应用体系结构,并给出了基于该体系结构的一个具体项目实例。     

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)

正~~     

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