共查询到20条相似文献，搜索用时 31 毫秒
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一种改进的余弦向量度量法文本检索模型 总被引：2，自引：1，他引：1
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社会标注在网络中的应用越来越广泛,它为信息资源的标引、组织、检索提供了一种全新的模式。国外学者对社会标注的信息标引功能和标引方式、社会标注系统在信息检索中的功用及基于社会标注的信息检索技术等方面进行了研究,取得了一系列成果,但还存在不足之处。该领域的研究趋势在于规范化社会标注的表达,去除标签噪声及垃圾,使标签序化、层级化等。 相似文献
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Multimodal biomedical image indexing and retrieval using descriptive text and global feature mapping
Matthew S. Simpson Dina Demner-Fushman Sameer K. Antani George R. Thoma 《Information Retrieval》2014,17(3):229-264
The images found within biomedical articles are sources of essential information useful for a variety of tasks. Due to the rapid growth of biomedical knowledge, image retrieval systems are increasingly becoming necessary tools for quickly accessing the most relevant images from the literature for a given information need. Unfortunately, article text can be a poor substitute for image content, limiting the effectiveness of existing text-based retrieval methods. Additionally, the use of visual similarity by content-based retrieval methods as the sole indicator of image relevance is problematic since the importance of an image can depend on its context rather than its appearance. For biomedical image retrieval, multimodal approaches are often desirable. We describe in this work a practical multimodal solution for indexing and retrieving the images contained in biomedical articles. Recognizing the importance of text in determining image relevance, our method combines a predominately text-based image representation with a limited amount of visual information, in the form of quantized content-based visual features, through a process called global feature mapping. The resulting multimodal image surrogates are easily indexed and searched using existing text-based retrieval systems. Our experimental results demonstrate that our multimodal strategy significantly improves upon the retrieval accuracy of existing approaches. In addition, unlike many retrieval methods that utilize content-based visual features, the response time of our approach is negligible, making it suitable for use with large collections. 相似文献
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中文期刊文献通用词标引分析 总被引：1，自引：0，他引：1
通用因素是文献主题的构成因素之一，对主体因素起细分作用。通用词是指那些在专业领域没有独立检索意义的泛指词。在中文期刊文献标引的过程中，通用词的使用对其标引结果产生着重要的影响。文章讨论了通用词标引的一般规则，并以《中国期刊网》中的文献为例，进行抽样统计和实例分析，归纳了通用词标引的错误现象及其原因，并对期刊文献的通用词标引提出了几点改进意见。 相似文献
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基于混合索引的中文全文检索系统研究 总被引：1，自引：0，他引：1
在中文全文检索系统中引入了混合索引,建立了混合索引之Hash索引,给出了Hash索引在内存中的存储结构,并给出了这种索引下的检索算法。这种索引既能保证索引的全面性,又能提高系统检索效率。通过实际构建系统,探讨了基于混合索引的中文全文检索系统的实现。 相似文献
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Jee-Hyub Kim Byung-Kwan Kwak Seungwoo Lee Geunbae Lee Jong-Hyeok Lee 《Information Retrieval》2001,4(2):115-132
In Korean information retrieval, compound nouns play an important role in improving precision in search experiments. There are two major approaches to compound noun indexing in Korean: statistical and linguistic. Each method, however, has its own shortcomings, such as limitations when indexing diverse types of compound nouns, over-generation of compound nouns, and data sparseness in training. In this paper, we propose a corpus-based learning method, which can index diverse types of compound nouns using rules automatically extracted from a large corpus. The automatic learning method is more portable and requires less human effort, although it exhibits a performance level similar to the manual-linguistic approach. We also present a new filtering method to solve the problems of compound noun over-generation and data sparseness. 相似文献
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Summarizing Similarities and Differences Among Related Documents 总被引：10，自引：0，他引：10
In many modern information retrieval applications, a common problem which arises is the existence of multiple documents covering similar information, as in the case of multiple news stories about an event or a sequence of events. A particular challenge for text summarization is to be able to summarize the similarities and differences in information content among these documents. The approach described here exploits the results of recent progress in information extraction to represent salient units of text and their relationships. By exploiting meaningful relations between units based on an analysis of text cohesion and the context in which the comparison is desired, the summarizer can pinpoint similarities and differences, and align text segments. In evaluation experiments, these techniques for exploiting cohesion relations result in summaries which (i) help users more quickly complete a retrieval task (ii) result in improved alignment accuracy over baselines, and (iii) improve identification of topic-relevant similarities and differences. 相似文献
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基于潜语义标引的自然语言检索 总被引：3，自引：0，他引：3
在信息检索中, 向量空间模型是最有效的数学工具之一。由于自然语言检索的特殊性, 以及传统信息检索模型受到同义词、多义词的影响, 检索的查准率不高。为了提高自然语言检索的查准率, 我们对基于概念的信息检索模型——
潜语义标引(LS I) 模型进行了探讨, 并分析了基于LS I 的两个实例。 相似文献
潜语义标引(LS I) 模型进行了探讨, 并分析了基于LS I 的两个实例。 相似文献
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从文献检索到信息检索——网络环境下检索课教学内容与方法的调整 总被引：21，自引：0，他引：21
从文献检索到信息检索最大的变化 :一是由文献单元向信息单元为基础的组织方式的改变 ;二是由手工分类、主题标引、著者标引经过机器的主题词、自由词抽取、标引发展到全文标引乃至超文本检索。网络技术、超媒体技术和智能技术等是促其变化的关键。作为一门学科的教学必须创建以CAI课件为主导的实践教学方法和建立信息检索课程的基本框架体系。参考文献 4。 相似文献
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Athena Salaba 《Cataloging & classification quarterly》2013,51(1):23-51
This study examines end-user interactions with indexing language information during subject searching in a library catalog and their understanding of this information and its function in term selection. Participants were asked to interact with the indexing language (Library of Congress Subject Headings) and were asked to express their general understanding of the information provided and each specific type of information included in the indexing language. In addition, participants were asked to express their understanding of the function of indexing language information in term selection, its usefulness and desirability as an integrated tool into the information retrieval system during subject searching. Study findings and their implications are discussed and future research is considered. 相似文献
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Ontology在自然语言检索中的应用研究 总被引：13，自引：0，他引：13
在分析自然语言检索的基础上，提出将Ontology引入检索系统。对于自然语言检索而言，Ontology的应用不仅可以提高信息源标引质量和改善用户界面，还有助于解决自然语言检索系统中存在的问题。论文最后还提出了在检索系统中引入Ontology有待解决的问题。 相似文献
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2006-2007年国外对信息检索基础理论的研究主要集中于决策理论、隐含语义索引理论研究以及信息检索评价理论研究。关于信息检索基本原理的研究主要集中在信息检索中的分类、信息检索模型、信息检索类型和检索方式等方面。信息检索中的分类的研究重点包括有关分类器的研究;有关特征选择的研究;有关领域相关词的研究。信息检索类型的研究主要包括焦点检索、图像检索、视频检索、合作过滤、机器音译、无线网中网。检索方式的研究主要包括上下文检索、集成检索、问答系统检索以及用户查询处理等问题。 相似文献
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在网络环境下,主题法将成为学位论文主要的标引与检索工具,其标引质量影响数据质量。结合工作实践,就学位论文主题标引的特点与基本规则以及工作中遇到的问题进行分析,目的在于提高网络环境下学位论文主题标引质量以及学位论文的检准率。 相似文献