ASP.NET客户端状态管理技术的分析与比较

由于HTTP协议的无状态性,在开发基于HTTP的B/S结构的Web应用程序时,就需要解决状态管理的问题。在ASP.NET中有客户端状态管理和服务器端状态管理两种状态管理技术。本文中通过对ASP.NET的客户端状态管理技术的特点进行分析与比较,指出了各种技术的优缺点,并给出了一些实用的使用建议。     

Language-Based Caching of Dynamically Generated HTML

Increasingly, HTML documents are dynamically generated by interactive Web services. To ensure that the client is presented with the newest versions of such documents it is customary to disable client caching causing a seemingly inevitable performance penalty. In the system, dynamic HTML documents are composed of higher-order templates that are plugged together to construct complete documents. We show how to exploit this feature to provide an automatic fine-grained caching of document templates, based on the service source code. A service transmits not the full HTML document but instead a compact JavaScript recipe for a client-side construction of the document based on a static collection of fragments that can be cached by the browser in the usual manner. We compare our approach with related techniques and demonstrate on a number of realistic benchmarks that the size of the transmitted data and the latency may be reduced significantly.     

VoiceXML dialog system of the multimodal IP-Telephony—The application for voice ordering service

The development of IP-Telephony in recent years has been substantial. The improvement in voice quality, the integration between voice and data, especially the interaction with multimedia has made the 3G communication more promising. The value added services of Telephony techniques alleviate the dependence on the phone and provide a universal platform for the multimodal telephony applications. For example, the web-based application with VoiceXML has been developed to simplify the human–machine interaction because it takes the advantage of the speech-enabled services and makes the telephone-web access a reality. However, it is not cost-efficient to build voice only stand-alone web application and is more reasonable that voice interfaces should be retrofitted to be compatible or collaborate with the existing HTML or XML-based web applications. Therefore, this paper considers that the functionality of the web service should enable multiple access modalities so that users can perceive and interact with the site in either visual or speech response simultaneously. Under this principle, our research develops a prototype system of multimodal VoIP with the integrated web-based Mandarin dialog system which adopts automatic speech recognition (ASR), text-to-speech (TTS), VoiceXML browser, and VoIP technologies to create user friendly graphic user interface (GUI) and voice user interface (VUI). The users can use traditional telephone, cellular phone, or even VoIP connection via personal computer to interact with the VoiceXML server. In the mean time, the users browse the web and access the same content with common HTML or XML-based browser. The proposed system shows excellent performance and can be easily incorporated into voice ordering service for a wider accessibility.     

基于标记图的Web数据模型

本文详细探讨了一种新的Ｗｅｂ数据模型－标记图,给类格的形式化描述。     

Towards a web-based progressive handwriting recognition environment for mathematical problem solving

The emergence of pen-based mobile devices such as PDAs and tablet PCs provides a new way to input mathematical expressions to computer by using handwriting which is much more natural and efficient for entering mathematics. This paper proposes a web-based handwriting mathematics system, called WebMath, for supporting mathematical problem solving. The proposed WebMath system is based on client–server architecture. It comprises four major components: a standard web server, handwriting mathematical expression editor, computation engine and web browser with Ajax-based communicator. The handwriting mathematical expression editor adopts a progressive recognition approach for dynamic recognition of handwritten mathematical expressions. The computation engine supports mathematical functions such as algebraic simplification and factorization, and integration and differentiation. The web browser provides a user-friendly interface for accessing the system using advanced Ajax-based communication. In this paper, we describe the different components of the WebMath system and its performance analysis.     

分布式异构空间数据共享研究

在构建防震减灾WebGIS体系的过程中,引入GML来描述空间数据,设计了空间数据库系统,以实现多源异构数据的共享。系统基于客户层、服务器层和数据库服务器三层体系结构来建造。客户层实现图形用户界面并完成数据的表示。服务器包括Web服务器和GIS应用服务器,前者主要用以客户端通信、后者则要实现对数据库服务器的访问,多源空间数据的获取、转换和输出标准的GML文件等。数据库服务器用来存放本地数据和链接分布式异构数据库。系统采用Java Servlet来完成Web服务器和GIS应用服务器的功能开发,通过Java applet实现客户端、并利用SVG来实现GML数据的可视化。     

个性化网页编辑器的可视化设计与实现

通用的网页编辑工具忽视了不同用户在数据需求方面的个性差异，降低了网页编辑工具的使用效率，本文提出了一种基于可视化文档和数据库技术的个性化网页编辑器的新思路，通过对网页编辑器个性化特征的分析，介绍了这一编辑器的结构和功能。并给出利用Borland C Builder的VCL组件实现文档可视化设计的方法。     

利用ASP技术实现对数据库的操作

利用ASP,可以很容易地把HTML(超文本标记语言)文本、脚本命令及ActiveX组件混合在一起构成ASP页,以此来生成动态网页,创建交互式的Web站点,实现对Web数据库的访问。当用户使用浏览器请求ASP主页时,Web服务器响应,调用ASP引擎来执行ASP文件,并解释其中的脚本语言(JScript或VBScript),通过ODBC连接数据库,由数据库访问组件ADO(ActiveX Data Ob-jects)完成数据库操作,最后ASP生成包含有数据查询结果的HTML主页返回用户端显示。用ASP中数据库连接的多种方法,可以有效利用ASP技术访问WEB数据库。     

VoiceXML dialog system of the multimodal IP-Telephony—The application for voice ordering service

The development of IP-Telephony in recent years has been substantial. The improvement in voice quality, the integration between voice and data, especially the interaction with multimedia has made the 3G communication more promising. The value added services of Telephony techniques alleviate the dependence on the phone and provide a universal platform for the multimodal telephony applications. For example, the web-based application with VoiceXML has been developed to simplify the human–machine interaction because it takes the advantage of the speech-enabled services and makes the telephone-web access a reality. However, it is not cost-efficient to build voice only stand-alone web application and is more reasonable that voice interfaces should be retrofitted to be compatible or collaborate with the existing HTML or XML-based web applications. Therefore, this paper considers that the functionality of the web service should enable multiple access modalities so that users can perceive and interact with the site in either visual or speech response simultaneously. Under this principle, our research develops a prototype system of multimodal VoIP with the integrated web-based Mandarin dialog system which adopts automatic speech recognition (ASR), text-to-speech (TTS), VoiceXML browser, and VoIP technologies to create user friendly graphic user interface (GUI) and voice user interface (VUI). The users can use traditional telephone, cellular phone, or even VoIP connection via personal computer to interact with the VoiceXML server. In the mean time, the users browse the web and access the same content with common HTML or XML-based browser. The proposed system shows excellent performance and can be easily incorporated into voice ordering service for a wider accessibility.     

利用HTML5实现网页图表的研究

越来越多的网络应用程序开始使用B/S模式,从网站统计到企业报表,从普通的饼图到复杂的数据表格,越来越多的图表需要在浏览器中进行展示。通过对下一代网页标准HTML5中的一些新特性的研究,展示了通过这些新特性在web图表展示上的应用。     

A multi-tier semantics for Hop

Hop is a multi-tier programming language where the behavior of interacting servers and clients are expressed by a single program. Hop adheres to the standard web programming style where servers elaborate HTML pages containing JavaScript code. This JavaScript code responds locally to user’s interactions but also (following the so-called Ajax style) requests services from remote servers. These services bring back new HTML fragments containing additional JavaScript code replacing or modifying the state of the client. This paper presents a continuation-based denotational semantics for a sequential subset of Hop. Though restricted to a single server and a single client, this semantics takes into account the key feature of Hop namely that the server elaborates client code to be run in the client’s browser. This new client-code dynamically requests services from the server which, again, elaborate new client code to be run in the client’s browser. This semantics details the programming model advocated by Hop and provides a sound basis for future studies such as security of web applications and web continuations.     

基于Web浏览器的SSL VPN网关系统的设计和实现

在分析IPSec VPN与SSLVPN各自优劣势的基础上,提出了一种基于Web浏览器的SSL VPN网关系统的体系结构并给出了具体的实现方法.系统主要由HTTP协议代理Applet、VPN网关上的Web服务器和VPN反向代理服务器组成.系统提供了两种安全访问内网的模式,即隧道模式和替换模式.用户直接通过浏览器从VPN网关上下载Applet或点击用户界面中提供的资源列表就可以安全地访问内部网络中的资源.     

Visual preview for link traversal on the World Wide Web

This paper demonstrates a technique for augmenting current World Wide Web browser implementations with features found in classical hypertext applications but unknown to the World Wide Web community until now. An example implementation is shown using Netscape Navigator 4.x using JavaScript, dynamic HTML and Java. The implementation follows an architecture based on a proxy server which acts as a gateway between the Internet and the browsing client. Based on the detailed example, support for further features is discussed.     

Java Web应用的安全性分析及对策

本文分析了JavaWeb应用中可能存在的安全隐患,给出了JavaWeb应用中系统资源的保护措施,并提出在浏览器与服务器交互的过程中,根据客户端向服务器请求的方法、表单控件所提交数据的表示形式,利用J2SE中java.util.regex类库,通过正则表达式对提交的数据过滤、分析。根据对用户请求方法和提交数据的表示形式的预计进行安全评估,依据评估的结果再进行相应的处理,从而提高JavaWeb应用的安全性。     

基于B/S架构的NBI实验数据发布系统

东方超环中性束注入（EAST-Neutral Beam Injection,EAST-NBI）系统的实验数据发布方式众多,因开发语言不同难以集成,且多使用客户端/服务器（Client/Server,C/S）模式进行设计,服务器只对单一局域网内客户端提供服务,外网客户不能获得数据服务.针对这一现状,设计了基于浏览器/服务器（Browser/Server,B/S）架构的实验数据发布系统,满足多用户通过外网获取实验数据的需求.浏览器端使用HTML+CSS+JavaScript进行开发,服务器端使用Java语言开发.系统包含最新数据自动显示和历史数据查询两种模式,最大程度上集成现有发布项目.数据基于WebSocket协议进行传输,处于全双工状态下进行交互,这样既实现了新数据的自动推送,又为历史数据的请求和回应提供通道.同时,系统还提供评论功能.该系统已投入到EAST-NBI实验中,获得很好的实验效果.     

CRM系统中基于ASP.NET的OLAP的设计与实现

介绍了客户关系管理（customer relationship management,CRM）、数据仓库和联机分析处理（on-line analytical processing,OLAP）服务,分析了基于数据仓库的CRM系统中OLAP设计的系统架构.基于ASP.NET和SQL Server2000,并综合运用OWC（office web components）、可扩展标记语言（extensible markup language,XML）等相关技术,提出了拓宽OLAP服务域,实现OLAP报表在Web上显示的一个解决方案.说明了系统的部署配置方法和应用程序的构建过程,给出了实现通过内嵌OWC的Web客户端页面,调用XML Web Service,与OLAP服务器建立连接并进行访问的具体方法.     

Web服务器性能评测

Web服务器性能评测是一种理解Web服务器对不同负载反应能力的方法，它对Web服务器的容量规划和性能增强有很大的帮助。讨论了Web服务器性能评测的原理、方法、难点及解决方案，介绍了基于Web负载的特点、ON／OFF源模型及浏览器／服务器体系结构，开发了一个Web服务器性能评测工具－WSBench。WSBench产生渐近自相似的HTTP请求序列，从静态文档、动态文档（没有数据库存取）、动态文档（有数据库存取）及前三者根据Zipf法则的组合4个层次来评测Web服务器的性能。性能测试结果表现为每秒请求数、每秒字节数和往返时间3个指标。最后讨论了Web服务器性能问题及使用WSBench测得的指标来建议Web服务器性能增强可以采用的方法。     

用定制控件实现对远程数据和图像的查询浏览

作为针对Internet／Intranet应用开发的技术，ActiveX被广泛应用于Web服务器以及客户端的各个方面。介绍了通过构造一个ActiveX控件，然后在Web页面中嵌入ActiveX控件，实现在客户端对远端服务器上数据和图像的查询浏览。用户端不必下载数据文件到本地，也不必再安装工具软件，使得查询浏览数据和图像更加方便快捷。     

一种基于位置信息的Web页面分割方法

提出并实现了一种针对HTML文档的页面分割方法,其目的是为了能有效提取新闻网页的正文以进行数据挖掘.基本思想是通过模拟网页浏览器的部分渲染工作,来还原HTML文档中每个标签在浏览器窗口上的显示位置,并以此对页面分割,用于提取一些重要区域的信息.在实验中,对10多个知名新闻站点如新浪、网易、TOM新闻等,利用这一方法提取其网页中的新闻正文,准确率在88.5%左右,表明了这一方法的有效性和可行性.