基于主题的智能Web信息采集系统的研究与实现

研究并实现了一个基于主题的智能信息采集系统IFWC,该系统以全信息理论为支撑,吸收传统向量空间模型的思想,采用基于概念的向量空间模型,从词的语义层次对文本进行主题相关性分析;使用扩展元数据的语义相关性判定算法,对页面内的URL进行主题相关性预测。实验证明,该系统采集速度快,采集下来的页面精度高。     

基于主动信息服务的信息共享传播技术

信息共享传播方法的结构在本质上可分为两种：信息交换结构与信息广播结构，而主动信息服务作为一种强有力的信息传播方式得到了广泛关注。文中简要探讨了信息分发的基本方法和主动信息服务的关键技术，包括信息的个性化特征与用户肖像模型、元数据信息标引与XML、信息发布与信息过滤技术、以及信息的分布式存储与个性化信息仓储及其意义。     

RSS元数据的信息抽取集成技术

介绍了RSS的发展及应用,描述了其元数据的定义;在此基础上,讨论了RSS元数据的语义标注抽取及集成技术,给出了具体的实现流程。包括XML解析器和关系数据库的应用,并采用特定格式的配置文件来检验元数据的规范性,满足用户对不同元数据的抽取。     

一种基于XML和元数据的工具框架的研究

在数据仓库及OLAP系统中,元数据占据着重要地位。鉴于元数据的重要性,本文将其思想加以扩展,应用到开发中。本文将其抽象为一个框架模型,与工具相关的任何数据都以元数据的形式保存在元数据库,以元数据驱动任务操作。使得开发人员只专心于设计相关工具所需的元数据及其样式,简化了设计过程,同时增强了系统的灵活性和可扩展性。     

Metadata-driven optimal transcoding in a multimedia proxy

An adaptive multimedia proxy is presented which provides (1) caching, (2) filtering, and (3) media gateway functionalities. The proxy can perform media adaptation on its own, either relying on layered coding or using transcoding mainly in the decompressed domain. A cost model is presented which incorporates user requirements, terminal capabilities, and video variations in one formula. Based on this model, the proxy acts as a general broker of different user requirements and of different video variations. This is a first step towards What You Need is What You Get (WYNIWYG) video services, which deliver videos to users in exactly the quality they need and are willing to pay for. The MPEG-7 and MPEG-21 standards enable this in an interoperable way. A detailed evaluation based on a series of simulation runs is provided.     

A historical and contemporary study on annotations to derive key features for systems design

This paper provides a comprehensive study on annotations by defining their contours and complexity. This work adds a new complementary approach to the usual case and user studies, and also investigates history in order to benefit from previous knowledge and our cultural heritage. This study emphasizes an aspect which has never previously been taken into account: the temporal dimension involved in annotations. Moreover, it discusses both the notion of hypertext between documents and annotations and the idea of annotations as context for documents. The study gives the necessary historical and cultural background to derive a set of key features of annotations that must be taken into account when designing systems that have to support the management of digital annotations on digital contents.     

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。