J2EE平台上基于Web Services的数据集成研究

数据集成是共享分布的异构数据资源的核心问题.在分析常用数据集成技术的基础上,结合Web Services技术和组件技术,提出了基于Web Services和组件技术实现Mediated系统的数据集成方案.最后,以J2EE为平台给出了一种面向服务的低偶合的数据集成框架,中介器和包装器由EJB组件实现,由组件部署的Web服务为用户提供一个透明的统一的接口,实现异地异构数据资源的共享和整合.     

基于SOA的分布式构件库管理模型

针对现有分布式构件库管理的不足,提出一种基于SOA的分布式构件库管理模型,将分散独立的构件或构件库包装成为Web Services,彻底屏蔽了分散独立的构件或构件库的异构性。提出了统一XML构件信息描述模型,利用XQuery映射统一Web Services返回的XML格式。在UDDI中注册后,将对构件的查询转化为对UDDI的查询。提高了检索构件{服务}的查全性和查准性。     

Web Services在数字图书馆中的应用

分析传统数字图书馆存在的问题,研究利用Web Services在互操作性和资源共享等方面的优势,将Web服务运用到数字图书馆系统的分析设计中,介绍基于Web Services体系架构的系统集成技术在数字图书馆实现过程中的应用。     

基于SOA的分布式构件库管理模型

针对现有分布式构件库管理的不足,提出一种基于SOA的分布式构件库管理模型,将分散独立的构件或构件库包装成为Web Services,彻底屏蔽了分散独立的构件或构件库的异构性.提出了统一XML构件信息描述模型,利用XQuery映射统一web Services返回的XML格式.在UDDI中注册后,将对构件的查询转化为对UDDI的查询.提高了检索构件{服务}的查全性和查准性.     

异构组件互操作研究

目前工业级的分布式组件模型有:DCOM,CORBA以及EJB.不同组件模型间缺乏统一的互操作标准,形成了企业内部应用集成和跨企业应用互操作的瓶颈,总结了目前实现异构组件互操作的主要方法并分析了其不足.Web Services的出现为实现异构组件互操作提供了新的契机,提出了基于Web Services的异构组件互操作方案,并以CORBA为例,说明了分布式组件与Web Services的集成.     

Web资源统一检索主要技术研究

统一检索门户旨在针对各种异构数字资源为用户提供一种整合检索服务，以提高资源的利用率。对Web数据源统一检索关键技术进行了阐述，包括：元数据框架、检索适配器接口、Web资源配置描述、Web检索适配器、检索调度系统、网页分析提取技术等。     

分布异构环境下数据库访问技术的研究

详细分析了当前分布异构数据库访问技术的研究现状和发展趋势,结合Web Services的优势构造了一个基于Web Services的分布异构数据库访问系统,并阐述了系统的实现过程。该系统能够有效地支持分布式数据查询,数据源透明并且支持跨平台检索。     

基于UDDI的语义元数据定义及映射

使用Web Services技术可使多个信息源共同向客户提供信息,形成较理想的分布式应用。但源于多数据源的数据在格式上并不统一,如何处理这些异构数据成为需要解决的问题。UDDI是用于发现有用Web服务的技术,如果能将对异构数据源的描述信息加入其中,则有助于异构数据的处理。本文给出了一种可行的方法来实现这一目的,实验证明在基于Web的分布式系统中应用有较好效果。     

语义Web Services描述框架的比较研究

由于Web Services可处于分布式环境中、在异构平台上进行交互以及高度的集成性等优点,Web Services技术引起了越来越多的人的关注,而语义Web Services一直是该领域的研究热点。文章首先通过一个例子说明语义Web Services产生的必要性,然后主要介绍了目前Web Services领域的OWL—S、WSMO、SAWSDL和FLOWS四种服务描述框架,并对其进行比较分析。     

数字图书馆中分布式异构数据库信息检索模型的研究与实现

本文根据当前我国数字图书馆分布式异构特点带来的检索问题,提出了基于CORBA中间件的分布式异构信息检索模型,并对解决方案中的四大部分-IDL映射、数据字段统一映射、服务器端服务对象和客户端调用服务过程作了详细的分析与实现。     

Toward Web mining of cross-language query translations in digital libraries

This paper proposes an effective query-translation approach that enables a cross-language information retrieval (CLIR) service to be more easily supported in digital library systems that only contain monolingual content. A query-translation engine called LiveTrans is used to process the translation requests of cross-lingual queries from connected digital library systems. To automatically extract translations not covered by standard dictionaries, the engine is developed based on a novel integration of dictionary resources and Web mining approaches, including anchor-text and search-result methods. The engine exploits a broad range of multilingual Web resources used as live bilingual corpora to alleviate translation difficulties. It is shown to be particularly effective for extracting multilingual translation equivalents of query terms containing proper names or new terminology. The obtained results show the feasibility of and great potential for creating English-Chinese CLIR services in existing digital libraries and new applications in cross-language Web searching, although difficulties still remain that need to be investigated further.     

Using distributed objects to build the Stanford digital libraryInfobus

For digital libraries to thrive, the providers of information processing services must be able to evolve their systems autonomously. However, as the complexity of their offerings increases, software tools more sophisticated than existing Web facilities are needed. Distributed object technology may be the answer. The availability of high-volume, increasingly sophisticated information is making the need for metadata facilities more urgent. Traditional, library-based approaches break down when used in an advanced digital library. More modular mechanisms are needed, and the CORBA system is one approach. Digital libraries are affected at a deep technical level by the widely differing user traditions of Web users and library patrons. The challenge and opportunity of digital libraries will be the synthesis of these traditions. The authors set out to create a technical infrastructure to support the construction of digital libraries. In their view, a digital library comprises widely distributed resources that can be maintained autonomously by different organizations and will not require adherence to uniform interfaces     

基于语义Web服务的数字化应急预案检索系统框架

为了解决目前应急预案信息不全面、缺乏共享性等问题,结合语义Web服务技术,建立基于语义Web服务的数字化应急预案检索系统。在分布式异构网络环境中,从预案发布到预案检索、预测推理等一系列全方位的服务。使用OWL-S/UDDI注册机制,结合本体概念、SWRL推理等技术来实现系统功能,具有良好的适用性。     

XML-based specification for Web services document security

The Internet and related technologies have seen tremendous growth in distributed applications such as medicine, education, e-commerce, and digital libraries. As demand increases for online content and integrated, automated services, various applications employ Web services technology for document exchange among data repositories. Web services provide a mechanism to expose data and functionality using standard protocols, and hence to integrate many features that enhance Web applications. XML, a well-established text format, is playing an increasingly important role in supporting Web services. XML separates data from style and format definition and allows uniform representation, interchange, sharing, and dissemination of information content over the Internet. XML and Web services provide a simplified application integration framework that drives demand for models that support secure information interchange. Providing document security in XML-based Web services requires access control models that offer specific capabilities. Our XML-based access control specification language addresses a new set of challenges that traditional security models do not address.     

SemWebDL: A privacy-preserving Semantic Web infrastructure for digital libraries

Recent advances in digital libraries have been closely intertwined with advances in Internet technologies. With the advent of the Web, digital libraries have been able to reach constituencies previously unanticipated. Because of the wide deployability of Web-accessible digital libraries, the potential for privacy violations has also grown tremendously. The much touted Semantic Web, with its agent, service, and ontology technologies, is slated to take the Web to another qualitative level in advances. Unfortunately, these advances may also open doors for privacy violations in ways never seen before. We propose a Semantic Web infrastructure, called SemWebDL, that enables the dynamic composition of disparate and autonomous digital libraries while preserving user privacy. In the proposed infrastructure, users will be able to pose more qualitative queries that may require the ad hoc collaboration of multiple digital libraries. In addition to the Semantic Web-based infrastructure, the quality of the response would rest on extraneous information in the form of a profile. We introduce the concept of communities to enable subject-based cooperation and search speedup. Further, digital libraries heterogeneity and autonomy are transcended by a layered Web-service-based infrastructure. Semantic Web-based digital library providers would advertise to Web services, which in turn are organized in communities accessed by users. For the purpose of privacy preservation, we devise a three-tier privacy model consisting of user privacy, Web service privacy, and digital library privacy that offers autonomy of perspectives for privacy definition and violation. We propose an approach that seamlessly interoperates with potentially conflicting privacy definitions and policies at the different levels of the Semantic Web-based infrastructure. A key aspect in the approach is the use of reputations for outsourcing Web services. A Web service reputation is associated with its behavior with regard to privacy preservation. We developed a technique that uses attribute ontologies and information flow difference to collect, evaluate, and disseminate the reputation of Web services.     

基于网格的联邦数字图书馆

介绍了一种联邦数字图书馆结构,它通过对网络中数字图书馆资源进行一定的服务封装形成数字图书馆资源仓储节点,在此基础上运用网格思想对仓储节点进行整合,形成数字图书馆资源联邦,使用户能够通过联邦门户透明地访问联邦中所有数据仓储节点中的图书馆数据资源。为了满足专业化、个性化数字图书馆建立的需求,联邦提供了以检索为基础的个性化数字图书馆实例的动态定制服务。     

基于云计算的数字图书馆公共服务平台架构

数字图书馆公共服务平台为数字化全民阅读提供了一个有效的途径,为广大用户提供大量数字版资源的在线阅读、下载和分享等. 随着数字化信息资源的爆炸式增长,如何有效的解决海量数字图书馆信息资源的存储和处理,并能将不同区域和类型的数字图书馆资源集成起来成为研究的热点. 依据安徽教育出版社的数字图书馆公共服务的全民阅读平台,研究云计算下数字图书馆的平台架构,利用云计算的分布式存储和并行计算的特点,为出版社的数字图书馆建设提供可行性研究方案.     

用于教育资源管理的网格文件系统

基于Internet的远程教育是当今及未来教育的一种重要途径，它需要管理大量的教育资源及用户。在这样一个网格环境下，需要有一个具有高可扩展性、具有动态复制的分布式文件共享途径。该文在回顾了文件共享方面的相关工作之后，提出了一种基于Web的分布式文件管理架构——网格文件系统(GridFS)。描述了它的拓扑结构及文件访问服务和元信息服务。GridFS对许多网格应用、数字图书馆的互联和多级Web Cache系统是有益的。     

基于Web Services的构件分类与检索研究

目前有很多构件分类和检索方法,其中大部分都不能很好地支持构件库的跨平台操作。文中介绍了这种基于WebServices的构件分类检索的模型,在以刻面分类检索的基础上采用Web Services技术对其封装,只要访问方能遵照相应WebServices接口的定义来发送和接收消息即可,实现了构件库跨平台、跨语言的互操作功能,大大提高了构件库的普适性、可互操作性和可扩展性。