基于面向服务架构体系的WEB组合技术应用研究

Web服务是基于XML和HTTPS的一种服务,其通信协议主要基于简单对象访问协议(SOAP),服务的描述通过WSDL、UD-DI来发现和获得服务的元数据。Web服务建好以后,SOAP提供了标准的RPC方法来调用Web service,并意味着下面的Webservice是以对象的方式表示的。SOAP规范定义了SOAP消息的格式,以及怎样通过HTTP协议来使用SOAP。该文基于此,对面向服务架构体系的WEB组合技术应用进行了初步研究。     

Distributing decision support systems on the WWW: the verification of a DSS metadata model

The explosion of information on the World Wide Web (WWW) and on corporate Intranets has made it increasingly important to have methods of organizing and understanding the available content. One method being used to facilitate both the location of specific Web content and the assessment of its quality is metadata. This paper focuses on verifying a metadata model designed for distributing decision support systems (DSS) on the Web. The verification utilizes an experiment to assess end-users' understanding of specific DSS.     

Phone‐Web: Accessing WWW using a telephone set

In order to provide a ubiquitous, comprehensive and versatile service on the WWW the development of a WWW telephone browsing system named Phone‐Web is proposed. This Phone‐Web browser system would act as an intermediary between the telephone user and Web sites, thereby facilitating access to the WWW from any phone. The Phone‐Web system would filter Web page information and then convert it into speech format. Users of the Phone‐Web system could retrieve and hear information stored on WWW servers by using telephone handsets. For this system to work it requires a new hypertext language “Hyper Phone Markup Language” (HPML) and a dedicated Phone‐Web browser. By using the proposed HPML language, Web page designers can easily specify service information in a set of HPML pages, which would be included in the site they are designing. The Phone‐Web browser would be capable of retrieving and then converting the HPML pages into speech patterns. By connecting to the Phone‐Web browser, telephone users can access any information on any site using the HPML language from any telephone anywhere in the world. However, HPML‐specified pages can also be accessed using existing browsers (e.g., Netscape Navigator, Microsoft Internet Explorer, etc.) This means that both telephone and computer users can now access the same set of Web pages to retrieve the same information. Therefore, instead of maintaining the existing two systems (access via the telephone or computer) service providers can now maintain one system, which would provide a versatile, and comprehensive service for users at all levels of Web‐literacy. This revised version was published online in August 2006 with corrections to the Cover Date.     

Web站点的超链结构挖掘

ＷＷＷ是一个由成千上万个分布在世界各地的Ｗｅｂ站点组成的全球信息系统,每个Ｗｅｂ站点又是一个由许多Ｗｅｂ页构成的信息（子）系统。由于一个文档作者可以通过超链把自己的文档与任意一个已知的Ｗｅｂ页链接起来,而一个 Ｗｅｂ站点上的信息资源又通常是由许多人共同提供的, 因此 Ｗｅｂ站点内的超链链接通常是五花八门、各种各样的,它们可以有各种含义和用途。文章分析了ＷＷＷ系统中超链的使用特征和规律,提出了一个划分超链类型、挖掘站点结构的方法,初步探讨了它在信息收集和查询等方面的应用。     

面向Web服务的空间元数据管理研究

空间元数据系统是网络环境下解决空间信息共享的主要途径之一,本文探讨了空间元数据管理过程中所涉及的一些标准和技术,同时针对分布式Web环境下的空间数据信息,提出基于全局空间元数据库中心,分层多级的元数据管理方法.目前的元数据标准描述缺少服务信息的描述,本文对元数据描述信息进行了扩展,在管理系统中增加元数据服务,使之能在UDDI中发布服务,实现空间数据服务的发现.并在此基础上对分布式Web环境下的空间元数据管理系统的实现进行了初步探索.     

一种高效的RDF图模式匹配算法

随着越来越多的信息被表示为RDF格式,如何高效地对RDF信息进行分发和过滤成为一个重要的问题·在语义Web环境下的信息分发系统中,输入的RDF信息需要和大量的用户订阅条件进行匹配,而用户的订阅条件可以被表示为RDF图模式·根据RDF图的特点,并对其增加了一些约束,设计了一种新的RDF图模式匹配算法·实验结果表明,该算法的匹配效率远远高于传统的图模式匹配算法·     

Query processing with quality control in the World Wide Web

Recent research on integrating database and World Wide Web (WWW) technologies has changed the navigation approach to searching information in the Web. People now can issue queries via a simple query interface or a databaselike query language to retrieve information from semistructured WWW data sources. However, the quality of query processing in the WWW is still low due to many factors such as unpredictable response time, irrelevant results, and outofdate data. Such lowquality query processing is intolerable to either users or service providers. In this paper, we present a qualitycontrolled query processing method in the WWW. Quality parameters that users can specify with their queries are introduced. Distance functions that are used to evaluate the goodness of query quality parameters are defined. A query processing model with quality control is introduced. A quality control protocol in query processing is presented. Qualitycontrolled query scheduling algorithms including admission scheduling, promotion/demotion scheduling and execution scheduling are proposed. Other relevant issues such as query classification, system parameter estimation, and query queue management are also discussed. Query processing with quality control is a promising way to solve the uncertain and lowquality query processing problems in the WWW.     

基于CWM的元数据的形式化推理框架研究

在基于公共仓库元模型(CWM)建立元数据的过程中,参与建立元数据的团体的不同经验以及描述数据的不同视角不可避免地带来元数据的冲突和冗余等问题,然而CWM的图形化特点使之缺乏精确的语义,所以如何在其上进行推理以自动发现这些问题至今没有得到很好的解决.研究了利用描述逻辑--一个一阶谓词逻辑的可判定子集形式化CWM元模型和元数据并进行推理的方法,将一致性检测分为水平一致性和演化一致性分别处理,在处理演化一致性的过程中对CWM元模型进行了扩展,使之支持元数据的版本能力从而能够推理由于演化引起的不一致问题,然后利用推理引擎LOOM对两种情形进行推理检测以发现不一致信息,取得了令人满意的结果,表明提出的方法是可行的.     

Web资源质量元数据度量方法研究

该文针对Web信息资源描述现状,将Web资源/信息质量评测模型WebQM理解为Web资源质量元数据模型。按照都柏林核心元数据集DC规范,使用DC元数据对网络资源进行描述,将质量元模型中质量评价准则映射为相对应的质量元数据,并讨论了如何使用质量元数据对质量准则进行度量。     

Web资源质量元数据度量方法研究

该文针对web信息资源描述现状,将web资源／4-8息质量评测模型WebQM理解为web资源质量元数据模型。按照都柏林核心元数据集DC规范,使用DC元数据对网络资源进行描述,将质量元模型中质量评价准则映射为相对应的质量元数据。并讨论了如何使用质量元数据对质量准则进行度量。     

Integrating Concepts and Knowledge in Large Content Networks

Large content networks like the World Wide Web contain huge amounts of information that have the potential of being integrated because their components fit within common concepts and/or are connected through hidden, implicit relationships. One attempt at such an integration is the program called the “Web of Data,” which is an evolution of the Semantic Web. It targets semi-structured information sources such as Wikipedia and turns them into fully structured ones in the form of Web-based databases like DBpedia and then integrates them with other public databases such as Geonames. On the other hand, the vast majority of the information residing on the Web is still totally unstructured, which is the starting point for our approach that aims to integrate unstructured information sources. For this purpose, we exploit techniques from Probabilistic Topic Modeling, in order to cluster Web pages into concepts (topics), which are then related through higher-level concept networks; we also make implicit semantic relationships emerge between single Web pages. The approach has been tested through a number of case studies that are here described. While the applicative focus of the research reported here is on knowledge integration on the specific and relevant case of the WWW, the wider aim is to provide a framework for integration generally applicable to all complex content networks where information propagates from multiple sources.     

一种以RIF元模型为中心的语义Web规则互换方法

作为W3C(WWW Consortium)的推荐标准,RIF(Rule Interchange Format)致力于语义Web中不同规则语言之间以及不同规则系统之间的规则互换.以RIF为中心互换规则是规则互换发展的必然趋势.本文首先定义RIF的元模型,给出RIF规则的UML Profile;然后构建以RIF为中心的规则互换结构RIA(Rule Interchange Architecture),它支持RIF与主要规则语言SWRL(Semantic Web Rule Language),RuleML(Rule Markup Language)和R2ML(REWERSE Rule Markup Language)之间的互换以及这四种语言的抽象语法和具体语法之间的互换;此外分析互换过程中出现的信息缺失问题并提出相应的对策;最后基于ATL(Atlas Transformation Language)转换语言,设计实现规则互换原型系统RIA 1.0.     

THESUS: Organizing Web document collections based on link semantics

The requirements for effective search and management of the WWW are stronger than ever. Currently Web documents are classified based on their content not taking into account the fact that these documents are connected to each other by links. We claim that a pages classification is enriched by the detection of its incoming links semantics. This would enable effective browsing and enhance the validity of search results in the WWW context. Another aspect that is underaddressed and strictly related to the tasks of browsing and searching is the similarity of documents at the semantic level. The above observations lead us to the adoption of a hierarchy of concepts (ontology) and a thesaurus to exploit links and provide a better characterization of Web documents. The enhancement of document characterization makes operations such as clustering and labeling very interesting. To this end, we devised a system called THESUS. The system deals with an initial sets of Web documents, extracts keywords from all pages incoming links, and converts them to semantics by mapping them to a domains ontology. Then a clustering algorithm is applied to discover groups of Web documents. The effectiveness of the clustering process is based on the use of a novel similarity measure between documents characterized by sets of terms. Web documents are organized into thematic subsets based on their semantics. The subsets are then labeled, thereby enabling easier management (browsing, searching, querying) of the Web. In this article, we detail the process of this system and give an experimental analysis of its results.Received: 16 December 2002, Accepted: 16 April 2003, Published online: 17 September 2003     

Information retrieval in the World-Wide Web: Making client-based searching feasible

Finding specific information in the World-Wide Web (WWW, or Web for short) is becoming increasingly difficult, because of the rapid growth of the Web and because of the diversity of the information offered through the Web. Hypertext in general is ill-suited for information retrieval as it is designed for stepwise exploration. To help readers find specific information quickly, specific overview documents are often included into the hypertext.Hypertext systems often provide simple searching tools such as full text search or title search, that mostly ignore the “hyper-structure” formed by the links.In the WWW, finding information is further complicated by its distributed nature. Navigation, often via overview documents, still is the predominant method of finding one's way around the Web.Several searching tools have been developed, basically in two types:

• •A gateway, offering (limited) search operations on small or large parts of the WWW, using a pre-compiled database. The database is often built by an automated Web scanner (a “robot”).
• •A client-based search tool that does automated navigation, thereby working more or less like a browsing user, but much faster and following an optimized strategy.

This paper highlights the properties and implementation of a client-based search tool called the “fish-search” algorithm, and compares it to other approaches. The fish-search, implemented on top of Mosaic for X, offers an open-ended selection of search criteria.Client-based searching has some definite drawbacks: slow speed and high network resource consumption. The paper shows how combining the fish search with a cache greatly reduces these problems. The “Lagoon” cache program is presented. Caches can call each other, currently only to further reduce network traffic. By moving the algorithm into the cache program, the calculation of the answer to a search request can be distributed among the caching servers.     

WWW浏览导航与结构优化技术

In this paper,we introduce some typical WWW navigation systems and Web site optimizationsystems,analyse the properties of navigation and optimization techniques, present some key problemsand techniques that are valuable to pay special attention and discuss the future works.     

语义元数据的描述及生成技术研究

语义元数据是有关Web内容语义信息的数据描述,它的有效表示及生成是构建语义Web的关键性技术。本文在讨论各种语义元数据的表示方法后,研究语义元数据的生成技术,在分析现有技术的特点和不足后,评述语义元数据生成技术的发展趋势。     

SemreX中基于语义的文档参考文献元数据信息提取

为了实现科研工作者之间的文献知识的共享,结合语义网技术,提出了一种从文档中提取参考文献元数据信息的方法．该方法采用模式匹配方式,可以从文档中提取作者、标题、出版时间、期刊名等信息,并使用OWL本体描述语言进行形式化,为进一步的语义搜索奠定基础．实验数据证明了该方法的有效性．     

基于元数据的军械保障信息资源共享服务研究

针对军械保障领域内不同信息系统之间的异构问题和元数据的特点,提出了基于元数据的WebService资源共享解决方案．设计了一种SXML统一中间信息格式,作为信息交换调用的桥梁,将JDBC和JDOM应用于信息包装器和信息解析器的设计,实现了异构信息的交换．     

XML与信息共享

本文论述了信息共享的关键问题，即如何建立一致的元数据资源描述。作者指出，XML在信息共享方面扮演了重要角色，但在元数据的语义、结构和语法三个方面，XML仅在语法层次上保证了元数据描述语言的一致性，并不能解决信息共享的根本问题。信息共享需要在元数据的交换格式、标记格式、元素内容结构、元素语义和数据元等方面能够互操作，需要建立一套完整的标准体系。作者在文章中提出了目前信息共享面临的问题及其解决途径，对信息共享的标准体系作了概要的描述。