共查询到20条相似文献，搜索用时 0 毫秒
1.
查准率和查全率之间的关系 总被引：3，自引：0，他引：3
澄清了学术界对查准率和查全率关系争论中的一些不正确的观点。通过对查准率和查全率的概念分析,得到了定性的结论:查全率依赖于查准率,查准率的提高有利于查全率的提高。通过对两者间关系的数学推导,得到了查准率和查全率之间一般性的定量关系。 相似文献
2.
模糊关系方程与情报检索的查全率和查准率 总被引：3，自引：0，他引：3
情报检索的查全率与查准单一直为情报检索的人员研究课题，笔者利用模糊关系方程论述了查全率与查准率之间的关系，井用实例验证了模糊关系方程在该方面的应用。 相似文献
3.
关于查全率与查准率相互关系问题的新认识 总被引：5，自引：0，他引：5
用集合方法描述查全率与查准率的分布情况 ,分析检索效率 ,认为某次检索与下一次检索的查准率与查全率是独立事件 ,应用离散方法讨论它们之间的关系。建立平面与空间坐标方法观察查全率与查准率点集在空间的分布情况 ,讨论得出查全率的变化与查准率的变化不存在关系。 相似文献
4.
通过对检索效果评价中的数学模式进行分析,从检索效率的评价方面概述了信息检索系统评价的发展过程、类型。论述了一些指标和模型,主要有查全率、查准率以及各种基于查全率与查准率的数学模型。探讨了E数学模型意义和E模型与查全率、查准率关系之间的重大联系。以美国学者G.Salton的三组实验数据为例进行计算,并与张保明的集合重合度模型进行了比较。 相似文献
5.
6.
检索策略的质量评价方法 总被引：2，自引：0，他引：2
有多篇文章讨论了查准率和查全率之间的种种关系.用两个相关的检索课题对二者的关系做了比较研究,表明这二者之间不存在任何关系.从而得出衡量检索策略质量评价方法：衡量一个检索策略质量应该同时根据两种不同的文献分类方法的指标来衡量. 相似文献
7.
基于语义网的网络信息检索相关性研究 总被引：3，自引：0，他引：3
针对传统网络信息检索中出现的查全率和查准率低下的问题，对Mizzaro相关性理论以及语义网理论进行介绍，指出查全率和查准率不高的主要原因在于检索算法采用词型匹配而非词义匹配以及对来源信息的标引缺乏语义描述信息，提出一种语义信息标引方法和语义查询扩展方法来改善查全率和查准率，然后通过一个计算机科学领域本体实侧详细阐述实现过程。 相似文献
8.
新版CBMdisc(以下称CBM)提供检索途径更为多样，信息更为详细，同时其词语之使用范畴也有了新的变化。文章主要从实例出发，对新版CBM自由词和主题词两种途径进行比较、分析。探讨如何调整查全率和查准率之间的关系。旨在提高医学信息的有效利用率。 相似文献
9.
10.
检索刊物的质量好坏将直接影响读者对文献的查全率和查准率,如:存贮文献是否齐全,索引系统是否完善以及文献标引的深度等都对查全率有直接影响;索引词的专指性以及是否精确反映文献主题,组配规则是否严密,词间关系是否正确等都会影响查准率。 相似文献
11.
基于目标宽度特征的脉间跳频雷达距离精确成像 总被引：2，自引：0，他引：2
根据雷达目标的宽度特征 ,提出了目标检测窗口内雷达信号的逆Chirp z变换局部成像处理方法 .利用有限的输入数据长度 ,有效提高目标局部距离像的采样分辨率 ,获得更精确的距离像 .与传统的数据长度补零逆傅里叶变换方法相比 ,在相同的采样分辨率条件下 ,该方法能有效减小计算量 .仿真实验结果与理论分析相符合 ,证明了该方法的有效性 . 相似文献
12.
介绍命名实体识别在文本信息处理领域的重要地位,分析了中文命名实体识别存在的困难,介绍中文命名实体识别的一般过程、评价标准及方法。提出了一种在构造内部规则和外部规则的同时采用概率统计的中文命名实体的识别方法,并利用这种基于规则和统计相结合的方法。实验证明该方法获得了较高的准确率和召回率,具有可行性和合理性,同时也指出了它的局限性。 相似文献
13.
A comparative evaluation has been carried out on the Philips “DIRECT” and the British “INSPEC” retrieval system. DIRECT is based on automatic indexing whereas INSPEC uses manual subject indexing.Two queries were submitted to both systems, using the same data base. The results are expressed in terms of recall and precision. Both recall and precision of INSPEC were found to be higher than those of DIRECT by 20%. It is concluded that this is mainly a result of the query formulation. The effectiveness obtained with automatic indexing of documents is equivalent to that of the manual procedure. 相似文献
14.
基于词嵌入语义的精准检索式构建方法 总被引：1，自引：0，他引：1
[目的/意义]使用科技文献数据库进行文献检索时,检索式中的关键词如果不够全面,将导致检索结果查全率较低;检索式中的关键词如果一词多义,则可能向检索结果中引入无关文献,导致查准率较低。[方法/过程]针对这两类问题,本文提出使用词嵌入这一新颖的文本数据化表现形式,一方面通过语义分析对检索关键词进行扩充从而提高查全率;另一方面通过发现语义异常点来提高查准率。[结果/结论]本文将该方法应用于人工智能领域中深度学习方向上的文献检索式构建,实验结果表明该方法能在一定程度上提高检索的查全率和查准率。 相似文献
15.
大量图像信息的产生使得基于内容的图像检索技术成为研究热点.由于颜色特征具有稳定性和计算简单的特点,本文首先介绍了利用全局颜色直方图进行图像检索的基本思想,然后分析了它的局限性,并给出了改进的方法:特征提取采用结合空间信息的颜色一致向量方法.在特征度量时,依据所设计的评价实验,对这两种方法进行了比较,并给出了实验结果和图像检索性能的评价.实验表明,所述的图像检索方法具有较好的查全率和查准率. 相似文献
16.
In this paper, for the first time, we present global curves for the measures precision, recall, fallout and miss in function of the number of retrieved documents. Different curves apply for different retrieved systems, for which we give exact definitions in terms of a retrieval density function: perverse retrieval, perfect retrieval, random retrieval, normal retrieval, hereby extending results of Buckland and Gey and of Egghe in the following sense: mathematically more advanced methods yield a better insight into these curves, more types of retrieval are considered and, very importantly, the theory is developed for the “complete” set of measures: precision, recall, fallout and miss. 相似文献
17.
《Information processing & management》2001,37(3):507-520
The results from a series of three experiments that used Text Retrieval Conference (TREC) data and TREC search topics are compared. These experiments each involved three novel user interfaces (one per experiment). User interfaces that made it easier for users to view text were found to improve recall in all three experiments. A distinction was found between a cluster of subjects (a majority of whom were search experts) who tended to read fewer documents more carefully (readers, or exclusives) and subjects who skimmed through more documents without reading them as carefully (skimmers, or inclusives). Skimmers were found to have significantly better recall overall. A major outcome from our experiments at TREC and with the TREC data, is that hypertext interfaces to information retrieval (IR) tasks tend to increase recall. Our interpretation of this pattern of results across the three experiments is that increased interaction with the text (more pages viewed) generally improves recall. Findings from one of the experiments indicated that viewing a greater diversity of text on a single screen (i.e., not just more text per se, but more articles available at once) may also improve recall. In an experiment where a traditional (type-in) query interface was contrasted with a condition where queries were marked up on the text, the improvement in recall due to viewing more text was more pronounced with search novices. Our results demonstrate that markup and hypertext interfaces to text retrieval systems can benefit recall and can also benefit novices. The challenge now will be to find modified versions of hypertext interfaces that can improve precision, as well as recall and that can work with users who prefer to use different types of search strategy or have different types of training and experience. 相似文献
18.
《Information processing & management》2020,57(3):102183
Semantic representation reflects the meaning of the text as it may be understood by humans. Thus, it contributes to facilitating various automated language processing applications. Although semantic representation is very useful for several applications, a few models were proposed for the Arabic language. In that context, this paper proposes a graph-based semantic representation model for Arabic text. The proposed model aims to extract the semantic relations between Arabic words. Several tools and concepts have been employed such as dependency relations, part-of-speech tags, name entities, patterns, and Arabic language predefined linguistic rules. The core idea of the proposed model is to represent the meaning of Arabic sentences as a rooted acyclic graph. Textual entailment recognition challenge is considered in order to evaluate the ability of the proposed model to enhance other Arabic NLP applications. The experiments have been conducted using a benchmark Arabic textual entailment dataset, namely, ArbTED. The results proved that the proposed graph-based model is able to enhance the performance of the textual entailment recognition task in comparison to other baseline models. On average, the proposed model achieved 8.6%, 30.2%, 5.3% and 16.2% improvement in terms of accuracy, recall, precision, and F-score results, respectively. 相似文献
19.
Arabic is a morphologically rich language that presents significant challenges to many natural language processing applications because a word often conveys complex meanings decomposable into several morphemes (i.e. prefix, stem, suffix). By segmenting words into morphemes, we could improve the performance of English/Arabic translation pair’s extraction from parallel texts. This paper describes two algorithms and their combination to automatically extract an English/Arabic bilingual dictionary from parallel texts that exist in the Internet archive after using an Arabic light stemmer as a preprocessing step. Before using the Arabic light stemmer, the total system precision and recall were 88.6% and 81.5% respectively, then the system precision an recall increased to 91.6% and 82.6% respectively after applying the Arabic light stemmer on the Arabic documents. 相似文献
20.
最小二乘支持向量机（least squares support vector machine,LS—SVM）具有很好的非线形逼近能力和泛化能力,通过研究逆模型存在的条件,提出了基于LS—SVM的逆模型辨识方法。仿真结果表明基于LS—SVM的逆模型辨识方法在处理非线性对象时,辨识精度、辨识速度、泛化能力都要强于BP算法。 相似文献