Document replication strategies for geographically distributed web search engines

Large-scale web search engines are composed of multiple data centers that are geographically distant to each other. Typically, a user query is processed in a data center that is geographically close to the origin of the query, over a replica of the entire web index. Compared to a centralized, single-center search engine, this architecture offers lower query response times as the network latencies between the users and data centers are reduced. However, it does not scale well with increasing index sizes and query traffic volumes because queries are evaluated on the entire web index, which has to be replicated and maintained in all data centers. As a remedy to this scalability problem, we propose a document replication framework in which documents are selectively replicated on data centers based on regional user interests. Within this framework, we propose three different document replication strategies, each optimizing a different objective: reducing the potential search quality loss, the average query response time, or the total query workload of the search system. For all three strategies, we consider two alternative types of capacity constraints on index sizes of data centers. Moreover, we investigate the performance impact of query forwarding and result caching. We evaluate our strategies via detailed simulations, using a large query log and a document collection obtained from the Yahoo! web search engine.     

浅谈如何利用Web of Science分析科技期刊发展策略

Web of Science数据库可以按照研究领域、刊载源、论文作者、机构以及国家区域等方面,将引文和被引论文分类统计.除了作为期刊质量的评估手段外,这些统计结果对分析期刊发展中的成绩和不足,量化、细化未来发展计划提供了有利的参考信息.     

Mathematical models for academic webs: Linear relationship or non-linear power law?

Previous studies of academic web interlinking have tended to hypothesise that the relationship between the research of a university and links to or from its web site should follow a linear trend, yet the typical distribution of web data, in general, seems to be a non-linear power law. This paper assesses whether a linear trend or a power law is the most appropriate method with which to model the relationship between research and web site size or outlinks. Following linear regression, analysis of the confidence intervals for the logarithmic graphs, and analysis of the outliers, the results suggest that a linear trend is more appropriate than a non-linear power law.     

Web数据挖掘在搜索引擎中的应用

分析了搜索引擎的结构组成,从Web的结构挖掘、内容挖掘、使用挖掘3方面对Web挖掘在搜索引擎中的应用进行阐述。     

web使用挖掘在智能化教学系统中的应用

网络教学已经成为当前计算机辅助教学的重要手段,网络教学系统的智能化是当前研究的热点。人工智能、数据挖掘技术等均已应用到网络教学系统中,目的就是为了更好地体现个性化、差异化教学。本文从web使用挖掘技术的角度,研究了web使用挖掘在智能化教学系统中的应用。     

基于Web的B／S模式网络管理信息系统的设计与实现

随着Internet/Intranet技术的发展,基于Web的企业计算和信息管理将逐步取代传统的PC计算机和信息管理系统。本文基于Web技术,在Internet/Intranet上为襄樊某设计院(以下简称设计院)设计与实现了管理信息系统,该系统以B／S模式实现数据信息的管理,具有简洁、高效、使用方便等特点,具有良好的可扩充性、可维护性。     

从文献计量学角度对Web2.0环境下信息服务研究的分析(2005-2010年)

以CNKI数字出版平台为依据,从文献计量学角度对Web2.0环境下信息服务研究进行分析。从文献分布、作者构成概况和研究方向,进行深入研究。     

Web数据挖掘在急性高原病易感人群预测中的应用

将Web数据挖掘技术应用于急性高原病易感人群的预测中,通过Web技术与数据挖掘技术相结合,将分散于Web中的数据经过检索、清洗、处理后存储在专门的数据仓库中。在现有研究成果的基础上,提出一个简便、高效的急性高原病易感人群预测模型。     

社会性书签在高校信息检索课的应用

Web2．0时代的信息检索有了新的内容,高校信息检索课必须随之更新教学内容、改革教学方式。文章以具体的教学案例探讨社会性书签在信息检索课中的创新应用。     

Web Service相关概念实例解析

为了解决大型系统中跨平台交互问题,特别是解决企业应用系统集成和跨平台交互问题,使企业能够更加经济、有效地整合系统资源,微软开发的.NET中引入了WebService技术。本文讨论了WebService的概念、原理,介绍了WebService的架构和特点,并通过实例演示了其在网络上的具体应用。