领域知识文档的语义检索方法研究

语义检索是解决信息检索中准确度、人性化要求的一个非常有潜力的方法。通过对知识文档进行主题词标注,然后建立从词元→主题词→知识文档的二级索引结构;对用户的检索,进行查询词到主题词的转化,计算语义相似度,按照语义相似度算法进行排序文档。目前基于知识文档的语义检索系统已经在某集团公司进行部署和应用,取得了前5项结果命中用户总查询90%的效果,说明这种方法是语义检索的一种有效途径。     

PageRank算法的分析及其改进

在分析PageRank算法存在偏重旧网页、主题漂移、网页权值均分、忽视用户浏览兴趣现象的基础上,对其进行改进,考虑网页修改日期、网页文本信息、网站权威度、用户兴趣度等重要因素,重新计算网页PR值。实验结果表明,改进算法可提高搜索引擎对网页排序的准确度,以及用户对检索结果的满意度。     

一种基于社会化标注的网页检索方法

利用社会化标注对网页检索进行改进,提出一种加权的社会化SimRank算法。从社会化标注系统中提取网页以及标签词之间的相似度信息。分别用这2类相似度信息来计算网页本身的质量同网页与查询之间的相关性。依据网页的质量和相关性信息对网页进行重排序。在del.icio.us网站抽取真实标注数据集进行实验,结果表明,该方法挖掘到的信息能够较好地改善网页检索效果。     

一种基于加权领域本体的语义检索方法

提出了新方法WOSR,以对已经被本体概念标注的领域信息资源进行语义检索.WOSR方法首先建立领域本体,再采用均等概率分布方法为概念赋权,然后通过概念的权重求出概念相似度,最后计算用户检索请求和信息资源之间的语义相似度,并根据相似度的大小排序输出检索结果.实验结果表明,WOSR方法比其他经典方法的检索效果更好.     

基于学习自动机和用户兴趣的PageRank算法研究

针对传统PageRank算法存在的平分链接权重和忽略用户兴趣等问题,提出一种基于学习自动机和用户兴趣的页面排序算法LUPR。在所提方法中,给每个网页分配学习自动机,其功能是确定网页之间超链接的权重。通过对用户行为进一步分析,以用户的浏览行为衡量用户对网页的兴趣度,从而获得兴趣度因子。该算法根据网页间的超链接和用户对网页的兴趣度衡量网页权重计算每个网页的排名。最后的仿真实验表明,较传统的PageRank算法和WPR算法,改进后的LUPR算法在一定程度上提高了信息检索的准确度和用户满意度。     

基于用户浏览行为分析的用户兴趣度计算

从用户的浏览行为可以反映用户的兴趣出发,分析了用户的浏览行为与兴趣之间的关系,通过分析把能反映用户兴趣的典型浏览行为归纳为保存页面、打印页面、将页面加入收藏夹、复制页面内容、访问同一页面的次数和在页面上浏览时间这些浏览行为.针对这些浏览行为下的用户兴趣度计算做出阐述,并且在分析基于网页驻留时间和浏览次数计算网页兴趣度的算法的基础上,考虑网页大小的影响因素,使用基于浏览速度计算网页兴趣度,同时利用BP神经网络进行用户兴趣度融合.     

云计算下支持语义的可搜索加密方法研究

传统的云计算下的可搜索加密算法没有对查询关键词进行语义扩展,导致了用户查询意图与返回结果存在语义偏差,并且对检索结果的相关度排序不够合理,无法满足用户对智能搜索的需求。对此,提出了一种支持语义的可搜索加密方法。该方法利用本体知识库实现了用户查询的语义拓展,并通过语义相似度来控制扩展词的个数,防止因拓展词过多影响检索的精确度。同时,该方法利用文档向量、查询向量分块技术构造出对应的标记向量,以过滤无关文档,并在查询-文档的相似度得分中引入了语义相似度、关键词位置加权评分及关键词-文档相关度等影响因子,实现了检索结果的有效排序。实验结果表明,该方法在提高检索效率的基础上显著改善了检索结果的排序效果,提高了用户满意度。     

搜索引擎结果中Web文档的排序研究

信息检索结果中，如何对检索结果进行排序在很大程度上影响了用户所得到的检索结果。对现存典型的词频统计排序技术和超链分析排序技术进行了分析，并借助向量空间模型，提出了一种基于概念语义的查询词-文档相似度排序方法。     

基于潜在语义索引的Web信息预测采集过滤方法

Web信息急速膨胀使有效定向采集特定领域信息成为网上信息检索中一个日益重要的研究方向．提出一种基于潜在语义索引的Web信息预测采集过滤方法．在样本文档集潜在语义索引对文档相似计算的基础上，构造出用户兴趣模型，判断页面相关性进行文本过滤．通过对Web站点结构分析、对未知网页的相关性预测来控制信息采集过程．在保持定向采集精度的同时，缩短采集时间、减少存储、加快检索，节约了网络资源。     

基于语义相似度的个性化信息检索方法

随着网络资源的爆炸式增长以及语义网的出现,个性化检索成为当前信息检索研究的热点.提出一种基于语义相似度的个性化信息检索方法.通过分析三种传统的语义相似度计算方法,针对三种方法的优缺点,提出一种改进的基于领域本体的语义相似度计算方法,该方法将有向边权重、概念层次差以及概念属性,引用到语义相似度的计算中.并在已有的领域本体的基础上构建用户个性化模型,使用本体来存储用户兴趣,最终应用到个性化检索中.实验结果表明,该方法有效地对用户的查询请求进行概念扩充,提高了搜索的查全率与查准率.     

Call for Papers The 6^th International Conference on Grid and Cooperative Computing

Recent years have seen rapid advances in various grid-related technologies, middleware, and applications. The GCC conference has become one of the largest scientific events worldwide in grid and cooperative computing. The 6th international conference on grid and cooperative computing (GCC2007) Sponsored by China Computer Federation (CCF),Institute of Computing Technology, Chinese Academy of Sciences (ICT) and Xinjiang University ,and in Cooperation with IEEE Computer Soceity ,is to be held from August 16 to 18, 2007 in Urumchi, Xinjiang, China.     

煤矿井下安全监控分站的设计及其仿真实现

为了设计一种具有低成本、低功耗、易操作、功能强且可靠性高的煤矿井下安全分站,针对煤矿安全生产实际,文章提出了采用MCS-51系列单片机为核心、具有CAN总线通信接口的煤矿井下安全监控分站的设计方案;首先给出煤矿井下安全监控分站的整体构架设计,然后着重阐述模拟量输入信号处理系统的设计过程,最后说明单片机最小系统及其键盘、显示、报警、通信等各个组成部分的设计;为验证设计方案的可行性与有效性,使用Proteus软件对设计内容进行仿真验证,设计的煤矿井下安全监控分站具有瓦斯、温度等模拟量参数超标报警功能和电机开停、风门开闭等开关量指示功能;仿真结果表明:设计的煤矿井下安全监控分站具有一定的实际应用价值.     

法律信息库系统

本文分析了法律数据库的结构和特点，介绍了采用面向对象设计方法和超文本数据库技术开发和实现法律信息库系统将作为重要网络资源之一为不同用户进行法律咨询服务。     

View-based model-driven architecture for enhancing maintainability of data access services

In modern service-oriented architectures, database access is done by a special type of services, the so-called data access services (DAS). Though, particularly in data-intensive applications, using and developing DAS are very common today, the link between the DAS and their implementation, e.g. a layer of data access objects (DAOs) encapsulating the database queries, still is not sufficiently elaborated, yet. As a result, as the number of DAS grows, finding the desired DAS for reuse and/or associated documentation can become an impossible task. In this paper we focus on bridging this gap between the DAS and their implementation by presenting a view-based, model-driven data access architecture (VMDA) managing models of the DAS, DAOs and database queries in a queryable manner. Our models support tailored views of different stakeholders and are scalable with all types of DAS implementations. In this paper we show that our view-based and model driven architecture approach can enhance software development productivity and maintainability by improving DAS documentation. Moreover, our VMDA opens a wide range of applications such as evaluating DAS usage for DAS performance optimization. Furthermore, we provide tool support and illustrate the applicability of our VMDA in a large-scale case study. Finally, we quantitatively prove that our approach performs with acceptable response times.     

International Journal of Automation and Computing Table of Contents

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Information for authors

正SCIENCE CHINA Information Sciences(Sci China Inf Sci),cosponsored by the Chinese Academy of Sciences and the National Natural Science Foundation of China,and published by Science China Press,is committed to publishing highquality,original results of both basic and applied research in all areas of information sciences,including computer science and technology;systems science,control science and engineering(published in Issues with odd numbers);information and communication engineering;electronic science and technology(published in Issues with even numbers).Sci China Inf Sci is published monthly in both print and electronic forms.It is indexed by Academic OneFile,Astrophysics Data System(ADS),CSA,Cabells,Current Contents/Engineering,Computing and Technology,DBLP,Digital Mathematics Registry,Earthquake Engineering Abstracts,Engineering Index,Engineered Materials Abstracts,Gale,Google,INSPEC,Journal Citation Reports/Science Edition,Mathematical Reviews,OCLC,ProQuest,SCOPUS,Science Citation Index Expanded,Summon by Serial Solutions,VINITI,Zentralblatt MATH.     

Erratum to: Fast global kernel fuzzy c-means clustering algorithm for consonant/vowel segmentation of speech signal

正Erratum to:J Zhejiang Univ-Sci C(ComputElectron)2014 15(7):551-563doi:10.1631/jzus.C1300320The original version of this article unfortunately contained mistakes.Algorithm 6 should be as follows:Algorithm 6 FGKFCM-F clustering Input:(1)X={x_1,x_2,…,x_N},,x_iR~d,i=1,2,…,N,the dataset;(2)C,1C≤N,the number of clusters;(3)ε0,the stopping criterion;     

Journal of Zhejiang University-SCIENCE C (Computers & Electronics) Total contents

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A pragmatic multi-method investigation of discrepant technological events: Coping,attributions, and ‘accidental’ learning

Discrepant technological events or situations that entail a problem, a misunderstanding or a difficulty with the Information Technology (IT) being employed, are common in the workplace, and can lead to frustration and avoidance behaviors. Little is known, however, about how individuals cope with these events. This paper examines these events by using a multi-method pragmatic approach informed by coping theory. The results of two studies – a critical incident study and an experiment – serve to build and test, respectively, a theoretical model that posits that individuals use a variety of strategies when dealing with these events: they experience negative emotions, make external attributions, and adopt engagement coping strategies directed at solving the event, eventually switching to a disengagement coping strategy when they feel they have no control over the situation. Furthermore, users’ efforts may result in ‘accidental’ learning as they try to overcome the discrepant IT events through engagement coping. The paper ends with a discussion of the results in light of existing literature, future opportunities for research, and implications for practice.