Towards semantically enhanced Web service repositories

The success of the Web services technology has brought topics as software reuse and discovery once again on the agenda of software engineers. While there are several efforts towards automating Web service discovery and composition, many developers still search for services via online Web service repositories and then combine them manually. However, from our analysis of these online repositories, it yields that, unlike traditional software libraries, they rely on little metadata to support service discovery. We believe that the major cause is the difficulty of automatically deriving metadata that would describe rapidly changing Web service collections. In this paper, we discuss the major shortcomings of state of the art Web service repositories and as a solution, we report on ongoing work and ideas on how to use techniques developed in the context of the Semantic Web (ontology learning, matching, metadata based presentation) to improve the current situation.     

五矿集团进出口数据仓库的构建研究

数据仓库是实现企业分析决策的有效技术。文章从数据仓库设计原则出发，首先使用Power Designer构建了业务模型；然后设计了一套通用性、可扩展性较强的ETL（Extract、Transform、Load）具，对数据进行全面的抽取、转换、清洗和装载处理；最后通过设计Business Objects的语义层对数据进行分析和展现，从而实现了对五矿进出口数据仓库构建。     

Computer aided teaching in civil engineering materials science at the University of Stuttgart

During the past five years the Institute of Construction Materials at the University of Stuttgart (IWB) has participated in different projects concerning e-teaching. Amongst other efforts co-workers of IWB have created a set of virtual content concerning concrete technology within a German e-teaching network in civil engineering materials science called “WiBA-Net” (). The content of this network consists of teaching material that is organized at four different levels of granularity. At the most basic level single items (“assets”) are collected. At the second level such assets are arranged into single pages filling one screen. Several pages dealing with aspects of a single topic are ordered into a teaching path at the third level and finally a set of teaching paths forms an entire course at level four. Virtual searching methods are offered on all four levels depending on the state of the user. Besides the mentioned teaching material also virtual communication facilities are offered within the network. During the work on WiBA-Net, which consists of six German Universities, questions concerning the reusability of virtual content, metadata enhancement techniques and the concept of Blended Learning were focused. Educational and didactic aspects have been closely taken into account and quality assuring evaluation methods have been applied. Meanwhile first experiences have been made in real life teaching and learning situations, which give us an idea of future needs and development in the field.     

数字正射影像数据的存储管理

数字正射影像是地理信息的重要组成部分。影像数据库的建立重点在于海量影像数据的存储和影像元数据库的建立。该文着重介绍“数字正射影像管理系统”中的存储设计方案和元数据建设方案。     

OO4O对Oracle 9i Spatial的空间数据访问及管理

简述了Oracle 9i Spatial中空间数据的对象关系模型,无数据表和数据表共同管理空间数据的存储方式。讨论了在Visual C 环境下,采用OO4O(Oracle Object for OLE,Oracle对象链接和嵌入)访问、查询和编辑Oracle 9i Spatial的空间数据的方法,并对关键技术进行了分析。     

An Approach for Deriving a Global Representation of Data Sources Having Different Formats and Structures

In this paper we propose an approach for deriving a global representation of data sources having different formats and structures. The proposed approach is based on the exploitation of a particular conceptual model for both uniformly representing such data sources and reconstructing both their intra-source and their inter-source semantics. Along with the global representation, our approach returns two support structures which improve the access transparency to stored information, namely, a set of mappings, encoding the transformations carried out during the construction of the global representation, and a set of views, allowing to obtain instances of the concepts of the global representation from instances of the concepts of the input data sources. The paper also describes a prototype which implements the proposed approach.A preliminary and partial version of this paper appears under the title A semi-automatic technique for constructing a global representation of information sources having different formats and structure in the Proceedings of the Conference Database and Expert System Applications (DEXA 2001), Munich, September 2001.     

基于CWM的元数据集成中形式化推理技术的研究

在使用公共仓库元模型（CWM）进行元数据集成的过程中，参与集成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。本文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元模型和模型并进行推理的方法，将一致性检测分为水平一致性和演化一致性进行分别处理，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，表明本文提出的方法是可行的。     

多级集群文件系统的全局命名空间的设计与实现

随着存储数据的爆炸性增长和集群技术的快速发展，集群文件系统的研究越来越成为一个焦点，该文设计并实现了一个多级集群文件系统（MCFS）的全局命名空间，MCFS系统采用元数据分层管理思想，建立一个统一的元数据树，从而使整个系统运行在一个松耦合、异构的环境下实现全局命名空间，提高了系统的并行性和可扩展性。在介绍了MCFS命名空间管理的同时，进行了相应的试验测试和性能分析。     

科学数据共享平台Web服务中间层的设计与实现

本文介绍了基于Web服务中间层实现的科学数据共享平台的设计,该平台通过Web服务中间层的注册中心实现异构数据库系统的数据汇交,通过Web服务中间层的查询中心实现数据的分级、有偿的、有控制的共享。     

基于对象技术的内容管理数据模型研究与实现

内容管理是一项新兴技术，具有重要的实用价值。首先分析了内容管理技术的发展现状和存在的问题，在此基础上提出了一种基于对象技术的内容管理平台数据模型，最后采用Java语言实现了一个基于此模型的内容管理平台，证明了该模型设计的合理性和先进性。