共查询到18条相似文献，搜索用时 173 毫秒
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本文分析了如何利用领域本体来改善实例与文档的相关度,提出了语法相关度、语义相关度计算方法,还提出了将基于关键字与语义的排序算法相结合的观点. 相似文献
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[目的/意义] 随着人们对检索文档之间关联关系的理解越来越多样化和细粒度化,检索文档内信息单元间关联关系的构建显得越来越重要。本研究旨在以学术文档内信息单元间关联关系为基础,构建文档的细粒度聚合与关联机制。[方法/过程] 本研究从跨体裁聚合单元知识体系所蕴涵的各类关联关系出发,从信息组在的角度阐述支持情景和语义关联的细粒度聚合理论框架、知识组织系统构建和聚合单元元数据标注等关键问题,并提出聚合机制。[结果/结论] 研究认为构建蕴含聚合单元语义关系、学科领域语义关系、任务和文本关系的本体,采用可反应聚合单元层级与关联关系的聚合单元元数据,是细粒度聚合机制发挥效用的关键。 相似文献
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现有的相似度计算方法大都依赖于作者间的直接关联,忽略了间接关联.文章提出一种新的基于SimRank的作者相似度计算方法,充分考虑作者关键词二分图网络的整体结构特性,利用图结构相似度算法挖掘出作者间以及词汇间的潜在关联关系.初步实验表明该方法能够有效地识别作者之间的相似度,相比于传统的关键词耦合,该方法可以明显提高作者相似度计算的准确性. 相似文献
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利用本体和主题词表的集成查询元数据 总被引：5，自引：0，他引：5
提出了通过集成现存的本体和主题词表构造元数据模式的一种新方法。这个集成基于主题词术语和本体概念之间的蕴含关系规范，并产生具体应用的元数据模式。同时给出了如何利用结果元数据模式进行元数据查询。在元数据查询中，利用术语关系的蕴含语义。提出了一种面向数据库的解决方法。 相似文献
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基于本体基础提出相似度和相关度分析,以充分挖掘领域本体所提供的背景知识,通过语义推理将描述的隐含语义显式化,提供计算机被描述资源的可理解语义.设计了实现该方法的Web信息检索模型,实验表明该方法能提高查准率和查全率. 相似文献
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《Information processing & management》2001,37(1):1-14
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
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Zenun Kastrati Ali Shariq Imran Sule Yildirim Yayilgan 《Information processing & management》2019,56(5):1618-1632
This paper presents a semantically rich document representation model for automatically classifying financial documents into predefined categories utilizing deep learning. The model architecture consists of two main modules including document representation and document classification. In the first module, a document is enriched with semantics using background knowledge provided by an ontology and through the acquisition of its relevant terminology. Acquisition of terminology integrated to the ontology extends the capabilities of semantically rich document representations with an in depth-coverage of concepts, thereby capturing the whole conceptualization involved in documents. Semantically rich representations obtained from the first module will serve as input to the document classification module which aims at finding the most appropriate category for that document through deep learning. Three different deep learning networks each belonging to a different category of machine learning techniques for ontological document classification using a real-life ontology are used.Multiple simulations are carried out with various deep neural networks configurations, and our findings reveal that a three hidden layer feedforward network with 1024 neurons obtain the highest document classification performance on the INFUSE dataset. The performance in terms of F1 score is further increased by almost five percentage points to 78.10% for the same network configuration when the relevant terminology integrated to the ontology is applied to enrich document representation. Furthermore, we conducted a comparative performance evaluation using various state-of-the-art document representation approaches and classification techniques including shallow and conventional machine learning classifiers. 相似文献
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Lexical cohesion is a property of text, achieved through lexical-semantic relations between words in text. Most information retrieval systems make use of lexical relations in text only to a limited extent. In this paper we empirically investigate whether the degree of lexical cohesion between the contexts of query terms’ occurrences in a document is related to its relevance to the query. Lexical cohesion between distinct query terms in a document is estimated on the basis of the lexical-semantic relations (repetition, synonymy, hyponymy and sibling) that exist between there collocates – words that co-occur with them in the same windows of text. Experiments suggest significant differences between the lexical cohesion in relevant and non-relevant document sets exist. A document ranking method based on lexical cohesion shows some performance improvements. 相似文献
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本文首先提出一种改进的X^2统计量，以此衡量词条对文本分类的贡献。然后根据模式聚合理论，将对各文本类分类贡献比例相近似的词条聚合为一个特征，建立出文本集的特征向量空间模型。此方法有效地降低了文本特征向量空间的维数。最后使用决策树进行分类，从而既保证了分类精度又获得了决策树易于抽取可理解的分类规则的优势。 相似文献
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【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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[研究目的]针对主流话题发现模型存在数据稀疏、维度高等问题,提出了一种基于突发词对主题模型(BBTM)改进的微博热点话题发现方法(BiLSTM-HBBTM),以期在微博热点话题挖掘中获得更好的效果。[研究方法]首先,通过引入微博传播值、词项H指数和词对突发概率,从文档层面和词语层面进行特征选择,解决数据稀疏和高维度的问题。其次,通过双向长短期记忆(BiLSTM)训练词语之间的关系,结合词语的逆文档频率作为词对的先验知识,考虑了词之间的关系,解决忽略词之间关系的问题。再次,利用基于密度的方法自适应选择BBTM的最优话题数目,解决了传统的主题模型需要人工指定话题数目的问题。最后,利用真实微博数据集在热点话题发现准确度、话题质量、一致性三个方面进行验证。[研究结论]实验表明,BiLSTM-HBBTM在多种评价指标上都优于对比模型,实验结果验证了所提模型的有效性及可行性。 相似文献