一种异构数据集成模型研究及实现

分析比较了几种常用的异构数据集成方法,提出一种基于Web服务的异构数据集成模型。该模型以XML技术为支撑,以web服务作为数据访问接口,并在．NET框架下实现数据转换,有效地解决了异构数据源的共享问题。     

集成Web 数据的系统框架与实现方法

基于我们正在研究和开发的项目Panorama，本文提出了一个基于XML和CORBA的Web数据集成系统框架，该框架可以集成来自Web上多个异构的数据源，包括关系数据库、面向对象数据库,HTML和XML文档及结构化文本文件。在系统实现中，把Web看作是一个巨大的虚拟数据库，以CORBA作为分布式对象模型，以XML作为公共誓据模型，并且以XML-QL作为全局查询语言来完成Web上的数据查询和集成。文中还详细分析和描述了系统框架中的一些主要模块的实现方法，具有很好的可操作性。     

一种基于XML的Web数据集成方案

介绍了Web环境下异构数据集成技术产生的背景和研究目的以及相关的概念、技术和方法，针对XML作为合适的数据交换格式的特点介绍了基于XML的信息集成的关键因素，提出了一种基于XML的Web数据集成操作模型，并讨论了该模型在Web数据集成时数据交换和共享过程，给出了集成构架的结构及组成。     

基于XML的信息工程监理异构数据集成研究

针对信息工程监理数据管理的特点,采用XML技术与Web Services技术开发出了一个三层架构的信息工程监理异构数据集成系统.该系统结合了XML技术与全局数据模式,以XML技术进行数据的交互,转换来自不同数据源的数据,对各异构数据源中的数据进行集成,为各异构数据源建立可共享的集成查询平台.应用结果表明,该异构数据集成系统具有良好的透明性、各平台独立性以及可共享性,较好地解决了信息工程监理中异构数据的管理.     

基于Web服务的异构数据交换方案设计与实现

基于Web服务的异构数据交换方案能够解决互联网环境下跨编程语言、跨操作系统的异构数据交换问题。基于Web服务架构，设计了一个层次式的异构数据交换方案，并利用XML技术以及SUN公司的JWSDP完成了一个异构数据交换原型系统，它实现了关系数据库异构数据的自描述和分布式环境下的交换与共享。同时，详细介绍了其核心模块——XML模式与关系模式的转换。     

Web信息集成的研究

在信息和服务迅猛增长的Web上构建信息集成系统是当前的一个研究热点，本文针对web信息集成的目标，结合XML和RDF等主要的Web技术及本体的概念，构建了一个基于本体的查询-应答框架，它通过有效地集成Web上的各种异构数据源来为终端用户提供更为方便的服务和应用。     

基于XML／web服务的分布式电子商务体系研究

传统分布式计算技术不适合于在松散耦合、异构的、有防火墙的Internet环境下进行电子商务系统的设计与开发。Web服务标准（WSDL,SOAP和UDDI）的产生以及XML技术的广泛应用带来了分布式网络应用的革命,实现了真正意义上的平台独立性和语言独立性。基于XML／Web服务的分布式电子商务体系能满足远程的数据交互、异构平台间相互通讯以及穿越防火墙等一系列复杂的功能需求。提出了一种新的基于xML／Web服务的电子商务应用体系结构,并针对电子商务系统结构、异构数据集成、公共数据格式等几个关键性问题进行了深入的研究。     

基于XML的Web数据集成技术的研究

本文首先介绍了Web环境下异构数据集成技术产生的背景和研究目的以及相关的概念、技术和方法,然后针对XML作为合适的数据交换格式的特点介绍了基于XML的信息集成的关键因素,基于此,提出了一种基于XML的Web数据集成操作模型,并讨论了该模型在Web数据集成时数据交换和共享过程。最后,给出了集成构架的结构及组成。     

基于Web Services的异构数据源集成

提出使用Web Services和XML技术解决异构数据源集成问题，设计了异构数据源集成系统。该系统分为应用层、全局数据操作层、局部数据操作层和数据源系统层。通过Web对异构数据源进行互连查询，并使用数据类型映射技术．来统一各种数据源数据类型之间的异构性。     

XML数据集成平台的研究与应用

为了提供访问异构数据源的统一接口,使开发人员不必考虑数据模型的异构性、数据抽取,数据合成等问题,设计了一个基于XML技术的数据集成平台,采用XML作为数据模型以统一的方式查询异构数据源,并将其应用到了防讯决策支持系统的开发中.实验结果表明,用XML作为数据集成模型和XQuery处理技术相结合可有效的解决数据源的差异性问题,提高集成平台的可扩展性.     

On the improvement of active XML (AXML) representation and query evaluation

Active XML (AXML) as intensional data aims to exploit potential computing powers of XML, Web services and P2P architecture. It is considered a powerful extension of XML to deal with dynamic XML data from autonomous and heterogeneous data sources on a very large scale via Web services. However, AXML is still at an immature stage and various issues need to be investigated before it can be accepted widely. This paper will focus on two issues facing the current AXML system, namely the representation and the query process. We propose superior representation and improved query evaluation for AXML. For justification purposes, we compare our proposed algorithms with the existing algorithms.     

基于移动Agent和XML的异构数据库集成模型研究

为了解决异构数据库的数据集成和共享问题,提出了一个基于移动Agent和XML的异构数据库集成模型:采用虚拟法和XML技术,建立了全局数据集成框架;同时,采用移动Agent技术,解决了局部数据库数据智能集成的问题,优化了查询处理模块,有效地提高了数据库的查询效率.     

基于本体的XML语义集成和查询的研究

XML因其结构上的灵活性和易扩展性已经成为Web上异构数据转换和传输的标准,但是含有不同模式的XML数据源之间却很难进行相互操作,这给XML数据检索带来了更大的不便.先提出一种从XML模式到OWL本体的映射算法,然后借助共享全局本体和同义词典实现多个映射后的本体在语义上的集成从而解决XML结构异构的问题,最后提出一种利用语义集成进行XML语义查询的框架并初步实现.     

XML schema mappings for heterogeneous database access

The unprecedented increase in the availability of information, due to the success of the World Wide Web, has generated an urgent need for new and robust methods that simplify the querying and integration of data. In this research, we investigate a practical framework for data access to heterogeneous data sources. The framework utilizes the extensible markup language (XML) Schema as the canonical data model for the querying and integration of data from heterogeneous data sources. We present algorithms for mapping relational and network schemas into XML schemas using the relational mapping algorithm. We also present library system of databases (libSyD), a prototype of a system for heterogeneous database access.     

Building semantic trees from XML documents

The distributed nature of the Web, as a decentralized system exchanging information between heterogeneous sources, has underlined the need to manage interoperability, i.e., the ability to automatically interpret information in Web documents exchanged between different sources, necessary for efficient information management and search applications. In this context, XML was introduced as a data representation standard that simplifies the tasks of interoperation and integration among heterogeneous data sources, allowing to represent data in (semi-) structured documents consisting of hierarchically nested elements and atomic attributes. However, while XML was shown most effective in exchanging data, i.e., in syntactic interoperability, it has been proven limited when it comes to handling semantics, i.e.,  semantic interoperability, since it only specifies the syntactic and structural properties of the data without any further semantic meaning. As a result, XML semantic-aware processing has become a motivating challenge in Web data management, requiring dedicated semantic analysis and disambiguation methods to assign well-defined meaning to XML elements and attributes. In this context, most existing approaches: (i) ignore the problem of identifying ambiguous XML elements/nodes, (ii) only partially consider their structural relationships/context, (iii) use syntactic information in processing XML data regardless of the semantics involved, and (iv) are static in adopting fixed disambiguation constraints thus limiting user involvement. In this paper, we provide a new XML Semantic Disambiguation Framework titled XSDFdesigned to address each of the above limitations, taking as input: an XML document, and then producing as output a semantically augmented XML tree made of unambiguous semantic concepts extracted from a reference machine-readable semantic network. XSDF consists of four main modules for: (i) linguistic pre-processing of simple/compound XML node labels and values, (ii) selecting ambiguous XML nodes as targets for disambiguation, (iii) representing target nodes as special sphere neighborhood vectors including all XML structural relationships within a (user-chosen) range, and (iv) running context vectors through a hybrid disambiguation process, combining two approaches: concept-basedand context-based disambiguation, allowing the user to tune disambiguation parameters following her needs. Conducted experiments demonstrate the effectiveness and efficiency of our approach in comparison with alternative methods. We also discuss some practical applications of our method, ranging over semantic-aware query rewriting, semantic document clustering and classification, Mobile and Web services search and discovery, as well as blog analysis and event detection in social networks and tweets.     

网格环境下基于XML的异构数据集成系统

分析地震、地质行业的数据资源特点,在数据网格中间件OGSA-DAI基础上提出一种基于XML的分布异构数据访问与集成框架,实现数据的透明访问和联合查询。系统以XML作为公共数据模型,使用三层模式集成机制,以XQuery同时作为XML模式之间的映射语言及全局查询语言,简化全局视图的构造和系统的查询处理。     

Growing triples on trees: an XML-RDF hybrid model for annotated documents

Since the beginning of the Semantic Web initiative, significant efforts have been invested in finding efficient ways to publish, store, and query metadata on the Web. RDF and SPARQL have become the standard data model and query language, respectively, to describe resources on the Web. Large amounts of RDF data are now available either as stand-alone datasets or as metadata over semi-structured (typically XML) documents. The ability to apply RDF annotations over XML data emphasizes the need to represent and query data and metadata simultaneously. We propose XR, a novel hybrid data model capturing the structural aspects of XML data and the semantics of RDF, also enabling us to reason about XML data. Our model is general enough to describe pure XML or RDF datasets, as well as RDF-annotated XML data, where any XML node can act as a resource. This data model comes with the XRQ query language that combines features of both XQuery and SPARQL. To demonstrate the feasibility of this hybrid XML-RDF data management setting, and to validate its interest, we have developed an XR platform on top of well-known data management systems for XML and RDF. In particular, the platform features several XRQ query processing algorithms, whose performance is experimentally compared.