共查询到20条相似文献，搜索用时 968 毫秒
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针对传统的基于关键字Web图像检索中的语义缺失问题,结合Web图像的视觉特征和描述文本,利用本体描述Web图像的语义特征,构建了基于本体的Web图像语义检索模型。该模型以领域本体描述Web图像的语义特征,通过自动图像标注技术构建Web图像本体库,用户可以通过输入关键词或者提交示例图像进行图像检索。实验表明,该模型具有较高的图像检索准确率。 相似文献
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语义关联检索模型作为一个嵌入式组件存在,它通过对用户提交的检索表达式进行语义分析,形成扩展的检索条件子句,实现基于语义关联的检索范围的合理扩大;同时,它根据扩展的检索条件子句中的元素在语义上的关联程度确定各元素的权值,从而实现相应检索结果根据权值大小的排序输出。 相似文献
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王青 《内蒙古科技与经济》2011,(22):53-54,57
目前,基于本体的查询扩展技术仍然面临来自可扩展性、可雏护性和快速响应等多方面的困难和挑战。有鉴于此,文章提出一种新颖的基于云计算技术的查询扩展实现机制,以更好的支持基于本体的查询扩展应用,并与相关工作进行对比分析。从2002年开始,机构库（InstitutionalReposito—ry）的相关问题引起了信息管理、编辑出版等领域学者的关注。 相似文献
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本文针对关键词检索无法反映出文章的语义信息及无法满足用户的个性化检索的问题，结合本体和智能Agent技术。提出了一种基于本体的信息检索智能Agent模型，研究并分析了在这种模型框架下检索信息的流程。 相似文献
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XBRL作为财务信息电子交换标准,能提高数据交换效率和精度。XBRL数据交换存在语义冲突问题,即语义转换困难和单一关键词匹配功能缺陷。分析XBRL语义异构性,提出一种基于本体的集成方法,研究XBRL本体转换模型,通过RDF数据查询解析技术实现对XBRL报告的单一关键词匹配,并利用Jena API实现RDF到SQL的查询转换。 相似文献
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Internet已成为全球最丰富的数据源,数据类型繁杂且动态变化,如何从中快速准确地检索出用户所需要的信息是一个亟待解决的问题.传统的搜索引擎基于语法的方式进行搜索,缺乏语义信息,难以准确地表达用户的查询需求和被检索对象的文档语义,致使查准率和查全率较低且搜索范围有限.本文对现有的语义检索方法进行了研究,分析了其中存在的问题,在此基础上提出了一种基于领域的语义搜索引擎模型,结合语义Web技术,使用领域本体元数据模型对用户的查询进行语义化规范,依据领域本体模式抽取文档中的知识并RDF化,准确地表达了用户的查询语义和作为被查询对象的文档语义,可以大大提高检索的准确性和检索效率,详细地给出了模型的体系结构、基本功能和工作原理. 相似文献
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Both general and domain-specific search engines have adopted query suggestion techniques to help users formulate effective queries. In the specific domain of literature search (e.g., finding academic papers), the initial queries are usually based on a draft paper or abstract, rather than short lists of keywords. In this paper, we investigate phrasal-concept query suggestions for literature search. These suggestions explicitly specify important phrasal concepts related to an initial detailed query. The merits of phrasal-concept query suggestions for this domain are their readability and retrieval effectiveness: (1) phrasal concepts are natural for academic authors because of their frequent use of terminology and subject-specific phrases and (2) academic papers describe their key ideas via these subject-specific phrases, and thus phrasal concepts can be used effectively to find those papers. We propose a novel phrasal-concept query suggestion technique that generates queries by identifying key phrasal-concepts from pseudo-labeled documents and combines them with related phrases. Our proposed technique is evaluated in terms of both user preference and retrieval effectiveness. We conduct user experiments to verify a preference for our approach, in comparison to baseline query suggestion methods, and demonstrate the effectiveness of the technique with retrieval experiments. 相似文献
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This article presents conceptual navigation and NavCon, an architecture that implements this navigation in World Wide Web pages. NavCon architecture makes use of ontology as metadata to contextualize user search for information. Based on ontologies, NavCon automatically inserts conceptual links in Web pages. By using these links, the user may navigate in a graph representing ontology concepts and their relationships. By browsing this graph, it is possible to reach documents associated with the user desired ontology concept. This Web navigation supported by ontology concepts we call conceptual navigation. Conceptual navigation is a technique to browse Web sites within a context. The context filters relevant retrieved information. The context also drives user navigation through paths that meet his needs. A company may implement conceptual navigation to improve user search for information in a knowledge management environment. We suggest that the use of an ontology to conduct navigation in an Intranet may help the user to have a better understanding about the knowledge structure of the company. 相似文献
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用户模型是数字图书馆个性化系统中的关键技术,传统的用户模型没有考虑词与词之间的内在联系,本文提出了一种基于本体的用户模型,该模型基于建立的兴趣分类本体,借鉴了检索领域常使用的激活模型来完成用户模型的更新,并在用户模型的基础上,设计了个性化服务推荐流程。 相似文献
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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. 相似文献
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本文分析了正方法,查询修正中的用户信息行为,吸收网页抓取、检索与浏览并重的思想,综合考虑用户Web搜索过程中的行为特点、查询修正所用词汇的可用来源,给出一个新的面向Web搜索的查询修正解决方案. 相似文献
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[目的/意义] 移动视觉搜索是智慧图书馆知识服务创新的重要内容。移动环境下,根据动态变化的情境推断用户意图,为用户提供合适的资源是智慧型知识服务的必然要求。[方法/过程] 在分析融合情境的智慧图书馆移动视觉搜索服务模型构建动因的基础上,归纳模型的内在特征,对模型体系框架和关键问题进行了设计和论述,并提出相应的技术要点。[结果/结论] 将情境计算应用于移动视觉搜索服务中,是弥补语义鸿沟、提高查询相关度和用户满意度的有效途径。该研究可为智慧图书馆个性化知识服务的优化提供参考。 相似文献
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Jamal Abdul Nasir Iraklis Varlamis Samreen Ishfaq 《Information processing & management》2019,56(5):1605-1617
Searching for relevant material that satisfies the information need of a user, within a large document collection is a critical activity for web search engines. Query Expansion techniques are widely used by search engines for the disambiguation of user’s information need and for improving the information retrieval (IR) performance. Knowledge-based, corpus-based and relevance feedback, are the main QE techniques, that employ different approaches for expanding the user query with synonyms of the search terms (word synonymy) in order to bring more relevant documents and for filtering documents that contain search terms but with a different meaning (also known as word polysemy problem) than the user intended. This work, surveys existing query expansion techniques, highlights their strengths and limitations and introduces a new method that combines the power of knowledge-based or corpus-based techniques with that of relevance feedback. Experimental evaluation on three information retrieval benchmark datasets shows that the application of knowledge or corpus-based query expansion techniques on the results of the relevance feedback step improves the information retrieval performance, with knowledge-based techniques providing significantly better results than their simple relevance feedback alternatives in all sets. 相似文献
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数字图书馆是传统图书馆在信息时代的发展与完善,目前已成为用户获取信息的重要渠道,但由于采用基于关键词的信息检索,缺乏对用户查询语言的深层次理解和分析,难以满足实际的需要.笔者在分析数字图书馆中存在的一系列问题的基础上,融合本体技术构建了基于本体的数字图书馆语义检索模型,并详细阐述了模型中各个模块的主要功能及其实现策略.实验结果表明,该模型取得了很好的预期效果,显著提高了信息检索的效率、准确度和知识获取的深度与广度. 相似文献