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1.
As text documents are explosively increasing in the Internet, the process of hierarchical document clustering has been proven to be useful for grouping similar documents for versatile applications. However, most document clustering methods still suffer from challenges in dealing with the problems of high dimensionality, scalability, accuracy, and meaningful cluster labels. In this paper, we will present an effective Fuzzy Frequent Itemset-Based Hierarchical Clustering (F2IHC) approach, which uses fuzzy association rule mining algorithm to improve the clustering accuracy of Frequent Itemset-Based Hierarchical Clustering (FIHC) method. In our approach, the key terms will be extracted from the document set, and each document is pre-processed into the designated representation for the following mining process. Then, a fuzzy association rule mining algorithm for text is employed to discover a set of highly-related fuzzy frequent itemsets, which contain key terms to be regarded as the labels of the candidate clusters. Finally, these documents will be clustered into a hierarchical cluster tree by referring to these candidate clusters. We have conducted experiments to evaluate the performance based on Classic4, Hitech, Re0, Reuters, and Wap datasets. The experimental results show that our approach not only absolutely retains the merits of FIHC, but also improves the accuracy quality of FIHC.  相似文献   

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In this paper we present a new algorithm for relevance feedback (RF) in information retrieval. Unlike conventional RF algorithms which use the top ranked documents for feedback, our proposed algorithm is a kind of active feedback algorithm which actively chooses documents for the user to judge. The objectives are (a) to increase the number of judged relevant documents and (b) to increase the diversity of judged documents during the RF process. The algorithm uses document-contexts by splitting the retrieval list into sub-lists according to the query term patterns that exist in the top ranked documents. Query term patterns include a single query term, a pair of query terms that occur in a phrase and query terms that occur in proximity. The algorithm is an iterative algorithm which takes one document for feedback in each of the iterations. We experiment with the algorithm using the TREC-6, -7, -8, -2005 and GOV2 data collections and we simulate user feedback using the TREC relevance judgements. From the experimental results, we show that our proposed split-list algorithm is better than the conventional RF algorithm and that our algorithm is more reliable than a similar algorithm using maximal marginal relevance.  相似文献   

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A new dictionary-based text categorization approach is proposed to classify the chemical web pages efficiently. Using a chemistry dictionary, the approach can extract chemistry-related information more exactly from web pages. After automatic segmentation on the documents to find dictionary terms for document expansion, the approach adopts latent semantic indexing (LSI) to produce the final document vectors, and the relevant categories are finally assigned to the test document by using the k-NN text categorization algorithm. The effects of the characteristics of chemistry dictionary and test collection on the categorization efficiency are discussed in this paper, and a new voting method is also introduced to improve the categorization performance further based on the collection characteristics. The experimental results show that the proposed approach has the superior performance to the traditional categorization method and is applicable to the classification of chemical web pages.  相似文献   

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An algorithm based upon reference and citation links is shown to improve effectiveness in compiling a bibliography on a cross-disciplinary medical subject area. Sets of documents are generated and compared to a set of documents identified by researchers as being relevant to their informational needs. The result is a rank ordered list of documents as they relate to the chosen entry document. The algorithm is described as a generalized technique applicable to any cross-disciplinary informational query which has as its objective the compilation of a bibliography of pertinent documents.  相似文献   

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In this paper, a document summarization framework for storytelling is proposed to extract essential sentences from a document by exploiting the mutual effects between terms, sentences and clusters. There are three phrases in the framework: document modeling, sentence clustering and sentence ranking. The story document is modeled by a weighted graph with vertexes that represent sentences of the document. The sentences are clustered into different groups to find the latent topics in the story. To alleviate the influence of unrelated sentences in clustering, an embedding process is employed to optimize the document model. The sentences are then ranked according to the mutual effect between terms, sentence as well as clusters, and high-ranked sentences are selected to comprise the summarization of the document. The experimental results on the Document Understanding Conference (DUC) data sets demonstrate the effectiveness of the proposed method in document summarization. The results also show that the embedding process for sentence clustering render the system more robust with respect to different cluster numbers.  相似文献   

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Searching hierarchically clustered document collections can be effective[6], but creating the cluster hierarchies is expensive, since there are both many documents and many terms. However, the information in the document-term matrix is sparse: Documents are usually indexed by relatively few terms. This paper describes the implementations of three agglomerative hierarchic clustering algorithms that exploit this sparsity so that collections much larger than the algorithms' worst case running times would suggest can be clustered. The implementations described in the paper have been used to cluster a collection of 12,000 documents.  相似文献   

10.
雷晓  常春  刘伟 《情报科学》2021,39(1):135-141
【目的/意义】为保证叙词表术语收录的完整性,需要及时将领域出现但未收录的新术语补充收录到叙词表 中,结合候选词的时间及文档词频特征,从时间序列角度探索新术语的分布情况以指导新术语遴选是值得研究的 问题。【方法/过程】文章主要对词汇文档词频对应的时间序列进行研究,将时间序列进行词频归一化及时间等长预 处理,引入k-means聚类算法,对候选词汇进行基于时间序列趋势变化的聚类,探索术语以及非术语趋势变化的规 律,进而总结新术语应该满足的趋势变化特征。【结果/结论】通过聚类研究,总结得出新术语普遍处于增长趋势。 实证将处于增长状态的候选词汇遴选出来,经过专家判断,该方法可以有效从候选词汇中遴选出其中能补充到叙 词表中的新术语,该方法有比较高的准确率。【创新/局限】创新之处表现为叙词表新术语的遴选中同时考虑了时间 变化和文档词频因素,局限于数据处理规模,实证中只统计了论文关键词的词频数据。  相似文献   

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Most document clustering algorithms operate in a high dimensional bag-of-words space. The inherent presence of noise in such representation obviously degrades the performance of most of these approaches. In this paper we investigate an unsupervised dimensionality reduction technique for document clustering. This technique is based upon the assumption that terms co-occurring in the same context with the same frequencies are semantically related. On the basis of this assumption we first find term clusters using a classification version of the EM algorithm. Documents are then represented in the space of these term clusters and a multinomial mixture model (MM) is used to build document clusters. We empirically show on four document collections, Reuters-21578, Reuters RCV2-French, 20Newsgroups and WebKB, that this new text representation noticeably increases the performance of the MM model. By relating the proposed approach to the Probabilistic Latent Semantic Analysis (PLSA) model we further propose an extension of the latter in which an extra latent variable allows the model to co-cluster documents and terms simultaneously. We show on these four datasets that the proposed extended version of the PLSA model produces statistically significant improvements with respect to two clustering measures over all variants of the original PLSA and the MM models.  相似文献   

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Considerable evidence exists to show that the use of term relevance weights is beneficial in interactive information retrieval. Various term weighting systems are reviewed. An experiment is then described in which information retrieval users are asked to rank query terms in decreasing order of presumed importance prior to actual search and retrieval. The experimental design is examined, and various relevance ranking systems are evaluated, including fully automatic systems based on inverse document frequency parameters, human rankings performed by the user population, and combinations of the two.  相似文献   

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We demonstrate effective new methods of document ranking based on lexical cohesive relationships between query terms. The proposed methods rely solely on the lexical relationships between original query terms, and do not involve query expansion or relevance feedback. Two types of lexical cohesive relationship information between query terms are used in document ranking: short-distance collocation relationship between query terms, and long-distance relationship, determined by the collocation of query terms with other words. The methods are evaluated on TREC corpora, and show improvements over baseline systems.  相似文献   

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This research has investigated the feasibility of using a distance measure, called the Bayesian distance, for automatic sequential document classification. It has been shown that by observing the variation of this distance measure as keywords are extracted sequentially from a document, the occurrence of noisy keywords may be detected. This property of the distance measure has been utilized to design a sequential classification algorithm which works in two phases. In the first phase keywords extracted from a document are partitioned into two groups—the good keyword group and the noisy keyword group. In the second phase these two groups of keywords are analyzed separately to assign primary and secondary classes to a document. The algorithm has been applied to several data bases of documents and very encouraging results have been obtained.  相似文献   

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Term discrimination values have been suggested as an effective means for the selection and weighting of index terms in automatic document retrieval systems. This paper reports an algorithm for the calculation of term discrimination values that is sufficiently fast in operation to permit the use of exact values, rather than the approximate values studied in previous work. Evidence is presented to show that the relationship between term discrimination and term frequency is crucially dependent upon the type of inter-document similarity measure that is used for the calculation of the discrimination values.  相似文献   

17.
"参考文献"与"引文"的差异   总被引:2,自引:1,他引:2  
林晓军  王昕 《情报科学》2000,18(2):180-181,184
"参考文献"、"引文"是文献计量学中引文分析法常用的两个学术用语,针对目前某些文献中对这两个术语使用比较混乱的现象,本文从信息的角度论述了这两个术语的基本概念和相互关系.  相似文献   

18.
In this paper, we describe a model of information retrieval system that is based on a document re-ranking method using document clusters. In the first step, we retrieve documents based on the inverted-file method. Next, we analyze the retrieved documents using document clusters, and re-rank them. In this step, we use static clusters and dynamic cluster view. Consequently, we can produce clusters that are tailored to characteristics of the query. We focus on the merits of the inverted-file method and cluster analysis. In other words, we retrieve documents based on the inverted-file method and analyze all terms in document based on the cluster analysis. By these two steps, we can get the retrieved results which are made by the consideration of the context of all terms in a document as well as query terms. We will show that our method achieves significant improvements over the method based on similarity search ranking alone.  相似文献   

19.
We present an efficient document clustering algorithm that uses a term frequency vector for each document instead of using a huge proximity matrix. The algorithm has the following features: (1) it requires a relatively small amount of memory and runs fast, (2) it produces a hierarchy in the form of a document classification tree and (3) the hierarchy obtained by the algorithm explicitly reveals a collection structure. We confirm these features and thus show the algorithm's feasibility through clustering experiments in which we use two collections of Japanese documents, the sizes of which are 83,099 and 14,701 documents. We also introduce an application of this algorithm to a document browser. This browser is used in our Japanese-to-English translation aid system. The browsing module of the system consists of a huge database of Japanese news articles and their English translations. The Japanese article collection is clustered into a hierarchy by our method. Since each node in the hierarchy corresponds to a topic in the collection, we can use the hierarchy to directly access articles by topic. A user can learn general translation knowledge of each topic by browsing the Japanese articles and their English translations. We also discuss techniques of presenting a large tree-formed hierarchy on a computer screen.  相似文献   

20.
廖开际  杨彬彬 《情报杂志》2012,31(7):182-186
基于词频统计思想的传统文本相似度算法,往往只考虑特征项在文本中的权重,而忽视了特征项之间的语义关系.综合考虑了特征项在文本中的重要程度以及特征项之间的语义关系,提出构建文本特征项的加权语义网模型来计算文本之间的相似度,并在模型构建的过程中,对特征项的选取、权值计算做了适当的改进.最后用实验验证了基于加权语义网的文本相似度算法相较于传统的算法,相似度计算的精确度有了进一步的提高.  相似文献   

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