共查询到16条相似文献，搜索用时 406 毫秒
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本文提出了一种新的基于相关反馈的跨语言信息检索查询翻译优化技术,就实现该技术的关键步骤"估计检索词在相关文献集合中的翻译概率"设计了4种不同的算法,并通过伪相关反馈实验比较了这4种算法,验证了查询翻译优化技术的有效性.实验结果显示,4种翻译优化算法都能够提高检索结果的精度,其中基于词对齐的翻译算法相对更优越.此外,查询式的长度和检索主题的特征对不同查询翻译优化算法产生着不同程度的影响. 相似文献
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英汉交互式跨语言检索系统设计与实现 总被引：1，自引：0，他引：1
吴丹 《现代图书情报技术》2009,3(2):89-95
针对跨语言信息检索的查询翻译歧义性问题,采用交互式系统开发设计方法,对基于相关反馈的跨语言信息检索技术进行研究和分析,提出一个英汉交互式跨语言信息检索系统,实现用户辅助查询翻译、多级用户相关性判断,以及翻译优化与查询扩展等相关反馈功能,结果明显提高了检索效果。 相似文献
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查询扩展技术通过向初始查询请求加入相似或相关的词,组成更为准确的扩展查询表达式,来减少查询请求与相关文献在表达上的不匹配现象,改善检索性能.与传统的查询扩展不同,XML查询扩展不仅要对文档内容进行有效扩展,而且还要考虑结构扩展.本文提出了一种基于伪反馈的XML查询扩展方法,将初始检索结果聚类,获得与查询请求最为相关的文档簇,然后在文档簇中抽取词组,找到符合用户查询意图的扩展查询词组,并在扩展查询词组的基础上进行结构扩展,最终形成完整的"内容+结构"的查询扩展表达式.相关实验结果表明,相对没有扩展的查询,所提方法具有更好的精度. 相似文献
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基于用户相关反馈的带结构语义的XML查询词扩展 总被引：1，自引：0，他引：1
在XML文档的信息检索中,检索质量不高的一个主要原因是用户难以提出准确描述其查询意图的查询表达式,而查询扩展技术被认为是可以帮助用户构建符合其查询意图的查询表达式.本文在XML信息检索中提出了基于用户相关反馈的查询扩展技术,在查询扩展中除了考虑词频因素外还充分考虑了XML文档的结构特点对于扩展查询词选取的影响,包括文档中元素的语义权重、元素所在层次和词项与初始查询词间的距离因素对于扩展查询词选取的影响.实验证明本方法是可行的,且能较好地提高检索结果的准确率. 相似文献
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要实现网络信息或数字图书馆信息的有效多语言获取,需充分考虑用户交互.通过用户实验,检验用户相关反馈机制在多语言信息获取中的作用,并分析用户行为特点.实验结果证明,查询扩展、翻译优化以及两者的结合均是有效的用户相关反馈方法. 相似文献
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相关反馈是近年来信息检索领域的研究热点，是自动查询扩展中的一种重要形式，相关反馈主要包括检索词加权和检索词选择。本文介绍了在相关反馈技术中经典的检索词排序算法，对它们带来的性能改进做了比较，并提出了相关反馈的实际应用中需要解决的一些问题。 相似文献
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特征词抽取和相关性融合的伪相关反馈查询扩展 总被引：2，自引：0，他引：2
针对现有信息检索系统中存在的词不匹配问题,提出一种基于特征词抽取和相关性融合的伪相关反馈查询扩展算法以及新的扩展词权重计算方法。该算法从前列n篇初检局部文档中抽取与原查询相关的特征词,根据特征词在初检文档集中出现的频度以及与原查询的相关度,将特征词确定为最终的扩展词实现查询扩展。实验结果表明,该方法有效,并能提高和改善信息检索性能。 相似文献
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交互式跨语言信息检索是信息检索的一个重要分支。在分析交互式跨语言信息检索过程、评价指标、用户行为进展等理论研究基础上,设计一个让用户参与跨语言信息检索全过程的用户检索实验。实验结果表明:用户检索词主要来自检索主题的标题;用户判断文档相关性的准确率较高;目标语言文档全文、译文摘要、译文全文都是用户认可的判断依据;翻译优化方法以及翻译优化与查询扩展的结合方法在用户交互环境下非常有效;用户对于反馈后的翻译仍然愿意做进一步选择;用户对于与跨语言信息检索系统进行交互是有需求并认可的。用户行为分析有助于指导交互式跨语言信息检索系统的设计与实践。 相似文献
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Research on cross-language information retrieval (CLIR) has typically been restricted to settings using binary relevance assessments.
In this paper, we present evaluation results for dictionary-based CLIR using graded relevance assessments in a best match
retrieval environment. A text database containing newspaper articles and a related set of 35 search topics were used in the
tests. First, monolingual baseline queries were automatically formed from the topics. Secondly, source language topics (in
English, German, and Swedish) were automatically translated into the target language (Finnish), using structured target queries.
The effectiveness of the translated queries was compared to that of the monolingual queries. Thirdly, pseudo-relevance feedback
was used to expand the original target queries. CLIR performance was evaluated using three relevance thresholds: stringent,
regular, and liberal. When regular or liberal threshold was used, a reasonable performance was achieved. Using stringent threshold,
equally high performance could not be achieved. On all the relevance thresholds the performance of the translated queries
was successfully raised by pseudo-relevance feedback based query expansion. However, the performance of the stringent threshold
in relation to the other thresholds could not be raised by this method. 相似文献
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采用提问式融合与相关反馈方法的结合,对现有的TopN文献选取策略研究和分析,提出利用相关度系数选取数量可变的TopN文献进行扩展查询的提问融合算法,即基于可变N反馈的提问融合算法。通过实验对固定N和可变N算法进行对比分析,结果显示可变N反馈在一定程度上可以改进检索性能。 相似文献
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信息检索系统中的用户相关反馈机制 总被引：3，自引：0，他引：3
陈定权 《现代图书情报技术》2002,18(4):33-35
从理论上论述了向量空间模型和概率模型是如何通过相关反馈机制来提高检索性能，还讨论了在不同模型中，相关反馈是如何实现查询式扩展和检索词权值调整的。 相似文献
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Rocchio's similarity-based Relevance feedback algorithm, one of the most important query reformation methods in information retrieval, is essentially an adaptive supervised learning algorithm from examples. In spite of its popularity in various applications there is little rigorous analysis of its learning complexity in literature. In this paper we show that in the binary vector space model, if the initial query vector is 0, then for any of the four typical similarities (inner product, dice coefficient, cosine coefficient, and Jaccard coefficient), Rocchio's similarity-based relevance feedback algorithm makes at least n mistakes when used to search for a collection of documents represented by a monotone disjunction of at most k relevant features (or terms) over the n-dimensional binary vector space {0, 1}
n
. When an arbitrary initial query vector in {0, 1}
n
is used, it makes at least (n + k – 3)/2 mistakes to search for the same collection of documents. The linear lower bounds are independent of the choices of the threshold and coefficients that the algorithm may use in updating its query vector and making its classification. 相似文献
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The application of relevance feedback techniques has been shown to improve retrieval performance for a number of information retrieval tasks. This paper explores incremental relevance feedback for ad hoc Japanese text retrieval; examining, separately and in combination, the utility of term reweighting and query expansion using a probabilistic retrieval model. Retrieval performance is evaluated in terms of standard precision-recall measures, and also using number-to-view graphs. Experimental results, on the standard BMIR-J2 Japanese language retrieval collection, show that both term reweighting and query expansion improve retrieval performance. This is reflected in improvements in both precision and recall, but also a reduction in the average number of documents which must be viewed to find a selected number of relevant items. In particular, using a simple simulation of user searching, incremental application of relevance information is shown to lead to progressively improved retrieval performance and an overall reduction in the number of documents that a user must view to find relevant ones. 相似文献