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P2P是近年来网络研究领域的热点。当前P2P网络的研究多集中在文件共享的应用,其检索机制只支持基于关键词的查询,缺乏对语义检索的支持。本文将语义网技术和P2P的优点结合起来,建立P2P网络的语义检索机制。通过建立基于本体概念的分布式倒排索引,使检索过程不再是关键词的精确匹配,而是通过不同节点本体中的概念之间的语义关系的逻辑推理实现检索请求与文档在语义上的匹配。实验表明,本文提出的结构化P2P网络语义检索方法,比基于关键词精确匹配的检索方法有较高的查全率和查准率。 相似文献
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针对基于关键字的搜索引擎缺乏语义的问题,提出了一种面向专业领域的语义搜索引擎模型.以领域本体形式化描述为基础,构建本体语义框架,进而给出语义搜索模型.在模型中,以概念、概念-实例以及关键字等3种扩展特征项作为基础,对查询扩展算法和文档语义标注算法进行了研究,并且构建了语义索引,通过引入向量空间模型判定扩展检索词与语义文档的相似度.实验结果表明,该模型较传统模型较大提高了检索的查准率和查全率. 相似文献
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传统文档特征权重模型仅考虑关键词本身,文档内其他相关词汇并没有参与计算,信息检索时无法返回全面和准确的结果。为解决该问题提出了一种基于本体的林业领域文档特征权重模型。该模型计算TF-IDF特征权重;结合林业领域本体,分别获取关键词和林业领域内其他词汇的语义距离、语义重合度和概念的层次差,并计算语义相关度;结合TF-IDF和语义相似度的结果计算特征权重。实验证明该模型可以提高文本检索的查准率和查全率,使检索结果更加满足用户的需求。 相似文献
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以地理信息领域为应用背景,面向地理空间语义检索,基于地球信息科学中的空间拓扑理论,以空间本体为语义检索的概念空间,提出了一种语义相关度的算法。其特点是考虑了传统字面匹配相关度与语义关系相关度两部分的融合,同时引入了本体关系权值的机制控制在不同语义检索应用中本体的关联程度,并体现了其与语义距离的反比关系。通过所作的相关实验,验证了该语义相关度算法在地理空间语义检索应用中可以达到良好的效果,并且也为其他领域应用提供了较好的参考和借鉴价值。 相似文献
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Semantic search attempts to go beyond the current state of the art in information access by addressing information needs on the semantic level, i.e. considering the meaning of users’ queries and the available resources. In recent years, there have been significant advances in developing and applying semantic technologies to the problem of semantic search. To collate these various approaches and to better understand what the concept of semantic search entails, we study semantic search under a general model. Extending this model, we introduce the notion of process-based semantic search, where semantics is exploited not only for query processing, but might be involved in all steps of the search process. We propose a particular approach that instantiates this process-based model. The usefulness of using semantics throughout the search process is finally assessed via a task-based evaluation performed in a real world scenario. 相似文献
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提出一个分布式的、基于语义服务的开放式信息检索模型(D-IRSW).该模型采用统一接口规范的不同的语义检索服务作用于不同的本体库,实现针对不同本体库的个性化检索;然后由语义检索服务引擎(SRSE)对不同语义检索服务返回的结果进行去重和排序. 相似文献
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Semantic annotation, indexing, and retrieval 总被引:3,自引:0,他引:3
Atanas Kiryakov Borislav Popov Ivan Terziev Dimitar Manov Damyan Ognyanoff 《Journal of Web Semantics》2004,2(1):49-79
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《Expert systems with applications》2014,41(18):8225-8233
The current web IR system retrieves relevant information only based on the keywords which is inadequate for that vast amount of data. It provides limited capabilities to capture the concepts of the user needs and the relation between the keywords. These limitations lead to the idea of the user conceptual search which includes concepts and meanings. This study deals with the Semantic Based Information Retrieval System for a semantic web search and presented with an improved algorithm to retrieve the information in a more efficient way.This architecture takes as input a list of plain keywords provided by the user and the query is converted into semantic query. This conversion is carried out with the help of the domain concepts of the pre-existing domain ontologies and a third party thesaurus and discover semantic relationship between them in runtime. The relevant information for the semantic query is retrieved and ranked according to the relevancy with the help of an improved algorithm. The performance analysis shows that the proposed system can improve the accuracy and effectiveness for retrieving relevant web documents compared to the existing systems. 相似文献
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As the information on the Internet dramatically increases, more and more limitations in information searching are revealed, because web pages are designed for human use by mixing content with presentation. In order to overcome these limitations, the Semantic Web, based on ontology, was introduced by W3C to bring about significant advancement in web searching. To accomplish this, the Semantic Web must provide search methods based on the different relationships between resources.In this paper, we propose a semantic association search methodology that consists of the evaluation of resources and relationships between resources, as well as the identification of relevant information based on ontology, a semantic network of resources and properties. The proposed semantic search method is based on an extended spreading activation technique. In order to evaluate the importance of a query result, we propose weighting methods for measuring properties and resources based on their specificity and generality. From this work, users can search semantically associated resources for their query, confident that the information is valuable and important. The experimental results show that our method is valid and efficient for searching and ranking semantic search results. 相似文献
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In this paper, we describe the first hybrid Semantic Web service matchmaker for OWL-S services, called OWLS-MX. It complements crisp logic-based semantic matching of OWL-S services with token-based syntactic similarity measurements in case the former fails. The results of the experimental evaluation of OWLS-MX provide strong evidence for the claim that logic-based semantic matching of OWL-S services can be significantly improved by incorporating non-logic-based information retrieval techniques. An additional analysis of false positives and false negatives of the hybrid matching filters of OWLS-MX led to an even further improved matchmaker version called OWLS-MX2. 相似文献
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随着互联网的不断发展,用户因不能准确输入查询关键字而无法准确获取未知领域信息的问题日益严重。作为一种根据已知领域知识获取未知领域知识的全新检索方式,类比检索逐渐成为研究热点。类比检索通过分析词对之间的潜在关系而准确地返回目标信息。例如,给定类比查询请求Q={A:B,C:?},A与B之间具有某种潜在关系,类比检索的目标是得到?所代表的目标词(集)D,其中A与B的关系和C与D的潜在关系相似。类比检索的两个难点是潜在关系挖掘和目标词抽取,这两个问题对于中文而言,更具挑战性。提出了基于SVM的中文类比检索方法 (SVM based Chinese Analogy Retrieval,SVMbCAR)。该方法的两个主要成分包括基于SVM的关系代表词抽取和目标词确定。基于真实测试数据集(包含源自人立方的600个人物实体对)的实验表明,SVMbCAR方法抽取关系代表词的准确率为82.3%,抽取目标词的准确率为90.5%。 相似文献