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1.
E V Muench 《Bulletin of the Medical Library Association》1971,59(3):404-419
A computerized English/Spanish correlation index to five biomedical library classification schemes and a computerized English/Spanish, Spanish/English listings of MeSH are described. The index was accomplished by supplying appropriate classification numbers of five classification schemes (National Library of Medicine; Library of Congress; Dewey Decimal; Cunningham; Boston Medical) to MeSH and a Spanish translation of MeSH The data were keypunched, merged on magnetic tape, and sorted in a computer alphabetically by English and Spanish subject headings and sequentially by classification number.SOME BENEFITS AND USES OF THE INDEX ARE: a complete index to classification schemes based on MeSH terms; a tool for conversion of classification numbers when reclassifying collections; a Spanish index and a crude Spanish translation of five classification schemes; a data base for future applications, e.g., automatic classification. Other classification schemes, such as the UDC, and translations of MeSH into other languages can be added. 相似文献
2.
电子文件分类方案是指导电子文件分类的重要工具。本文通过对国际上典型的文件分类方案、指南、标准等进行深入分析,并结合相关实践经验,明确了电子文件分类的定位,提出了建立基于业务活动分析的电子文件分类方案应当遵循的原则,并对其建立方法进行了详细说明,以期对我国电子文件分类工作有所指导。 相似文献
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[目的/意义] 探究不同学科分类方案对于学科标准化方法效果的影响,并比较不同学科标准化方法的效果。[方法/过程] 在Web of Science学科分类方案下就比均值法、比中位数法、Z-score法这三种常用的标准化方法的效果进行比较研究;变更不同粒度的学科分类方案,对这三种标准化方法在Essential Science Indicators （ESI）、经济合作与发展组织（OECD）学科分类方案下的敏感性进行实证检验。[结果/结论] 结果显示,使用不同学科分类方案并未对各标准化方法的效果产生较大影响,各标准化方法的效果基本保持不变。从CCDF引文分布曲线的图形上来看,使用三种标准化方法处理后的CCDF曲线形状较原始引文的CCDF曲线形状明显更加聚拢,并且三种标准化方法在更换不同粒度的学科分类方案后引文分布情况仍大致相同。结合top z%法从定量数值的角度再次进行检验,可以发现,三种标准化方法的效果在变更不同粒度的学科分类方案后基本保持不变,并呈现出如下规律：在截取全局top30%以下论文时,比均值法、Z-score法的标准化效果虽然略有不同,但是都优于比中位数法;截取top30%-40%阶段论文时,Z-score法的优势较为突出;截取top40%以上论文时,比中位数法则呈现出明显优于其他两者的效果。 相似文献
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《Journal of Informetrics》2020,14(4):101076
The effective representation of the relationship between the documents and their contents is crucial to increase classification performance of text documents in the text classification. Term weighting is a preprocess aiming to represent text documents better in Vector Space by assigning proper weights to terms. Since the calculation of the appropriate weight values directly affects performance of the text classification, in the literature, term weighting is still one of the important sub-research areas of text classification. In this study, we propose a novel term weighting (MONO) strategy which can use the non-occurrence information of terms more effectively than existing term weighting approaches in the literature. The proposed weighting strategy also performs intra-class document scaling to supply better representations of distinguishing capabilities of terms occurring in the different quantity of documents in the same quantity of class. Based on the MONO weighting strategy, two novel supervised term weighting schemes called TF-MONO and SRTF-MONO were proposed for text classification. The proposed schemes were tested with two different classifiers such as SVM and KNN on 3 different datasets named Reuters-21578, 20-Newsgroups, and WebKB. The classification performances of the proposed schemes were compared with 5 different existing term weighting schemes in the literature named TF-IDF, TF-IDF-ICF, TF-RF, TF-IDF-ICSDF, and TF-IGM. The results obtained from 7 different schemes show that SRTF-MONO generally outperformed other schemes for all three datasets. Moreover, TF-MONO has promised both Micro-F1 and Macro-F1 results compared to other five benchmark term weighting methods especially on the Reuters-21578 and 20-Newsgroups datasets. 相似文献
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[目的/意义] 探讨不同学科分类体系在机构科研影响力评价中的差异及对评价结果的影响。[方法/过程] 以Incites数据库为数据来源,选择5种分类体系、8种分类方案。首先对14 955个机构不同分类方案下的学科标准化引文影响力(Category Normalized Citation Impact,CNCI)进行相关性分析,考察不同分类体系下评价结果的整体相似性。然后以国内双一流建设中的36所高校为例,比较和分析不同分类方案下机构CNCI值的变化情况及差异产生的具体原因,研究分类体系对个体机构评价的影响。[结果/结论] 不同学科分类方案下得到的CNCI值相关性显著(最低相关性达到0.85),即不同分类体系得到的整体评价结果具有较高的相似度。但是不同分类体系下的评价结果也存在聚类特征,OECD、ESI、SCADC、CT1相互之间相关系数高、结果更相近,WoS、CT2和CT3评价结果更接近,分类体系的粒度是决定评价结果的重要因素。36所高校在不同的分类体系下评价结果的整体相关性较高,但个别高校CNCI值变化较大,特别是在热点主题上有突出发文的机构。评价结果的巨大差异其根本原因是论文划分到不同类目中,不同类目下的引用基准值不同。在评价过程中更加推荐粒度较细的分类体系,减少热点主题等对引用基准值的影响。 相似文献
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本文旨在为国内外分类法拥有者快速实现现有分类法的Web版、Web Service术语服务、Linked Data化和自动分类等网络共享服务提供参考和支持。以《中国图书馆分类法》第四版为例,采用CNKOS对分类法进行语义化描述,使用Lucene全文检索引擎、Ext Js插件、Axis SOAP引擎和URL Rewrite等关键技术实现了分类法共享服务(CLSS)原型系统。经验证明所有功能模块运行和调用都符合预期效果。实践证明该套解决方案可投入使用,而且其他分类法类型的中文知识组织系统均可依此方法快速完成相应的部署。但是,对于部分复杂的自动分类需求,如要获得更为准确的分类号还需更深入的研究或人工辅助。图5。表4。参考文献21。 相似文献
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<军事信息资源分类法>和<中文新闻信息分类与代码>是两部作为国家标准颁布的新分类法.本文介绍其特点,说明我国情报检索语言在进步中. 相似文献
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用传统分类表与叙词表编制TAXONOMY 的理论可行性研究 总被引：2，自引：0，他引：2
Taxonomy概念可以理解为一个用于支持浏览功能的、基于某一特定环境或领域的概念等级体系。它由等级结构和主题词两个基本元素组成,在形式上结合了分类法和叙词表的特点,为用传统分类法和叙词表编制Taxonomy提供了理论可能性。但由于分类法、叙词表和Taxonomy在性质与功能上均有不同之处,在利用传统分类法和叙词表编制Taxonomy过程中会遇到一些问题,首先,分类法和叙词表在主题范覆盖范围方面可能满足不了Taxonomy的要求;其次,分类法和叙词表的两个基本元素,等级结构和主题词在多大程度上可被利用,有待进一步实证。另外,如何将环境因素结合到Taxonomy类表中,是个有待补充的问题。 相似文献
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《Cataloging & classification quarterly》2013,51(1):163-182
ABSTRACT SALIS is a repository of open source software along with metadata information. It is a pilot project covering the areas of computer networks and information systems. The objective is to demonstrate the usefulness of such repositories to the Indian academic and developer community in making informed decisions while using open source software. To enable organization and retrieval of the information stored in the repository, a modified CCS (Computing Classification Scheme) by ACM (Association of Computing Machinery) was used. Since a sizeable section of the end-user community was familiar with the USPTO classification scheme, a need was felt to classify the software by the USPTO scheme also. Instead of classifying by two schemes, it was decided to have a mapping or a concordance between the two schemes so that the classification process can be simplified. The approach used to derive a concordance between two diverse classification schemes is described. 相似文献
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This article explores the topic of fiction classification. The first section attempts to define the field, discussing fiction classification, its schemes, objectivity, aboutness, and shelf classification. The second section suggests three new ideas building upon the foundation of the first: a faceted multi-warrant classification, controlled term affective dimension searching, and the design of a user-oriented recommendation-based system. 相似文献
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Taxonomy:定义、辨析和应用 总被引：1，自引：0，他引：1
文章旨阐释Taxonomy概念,包括三部分内容:Taxonomy概念的定义、Taxonomy与文献分类法、叙词表、本体和主题指南的区别与联系以及Taxonomy的具体应用。 相似文献
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陈国琛先生作为民国时期重要的文书档案专家,提出了诸多行之有效的文书档案改革方案。在文书档案改革中,陈国琛先生十分重视档案的分类问题,他提出了档案分类的标准、程序、分类人员的选拔、分工的标准与分类权限的确定等档案分类思想,并明确提出档案分类与图书分类的不同,不可张冠李戴的观点。此外,他还富有建设性地构建了全国省、区、县、市政府通用档案分类表,即“陈国琛档案分类表”。陈国琛先生的档案分类思想在一定程度上推动了我国档案学分类理论和实践的发展,其档案分类思想不仅对当时行政机关档案管理工作有重大影响,同时对现行档案分类体系的构建也有重要的参考价值和启示意义。 相似文献
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跨网关整合检索和整合浏览机制 总被引：19，自引：1，他引：18
介绍跨网关门户的3个层次,着重分析跨网关整合检索的检索协议、元数据格式和著录标引问题,提出可能的解决机制,并进-步探讨跨网关整合浏览的技术线路和基于分类映射的实现机制. 相似文献
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介绍分类表在数据共享格式描述中的研究进展,重点分析其在数据描述格式转换中面临的难点以及可能的解决措施,在此基础上展望未来的研究方向,以期为国内分类表用于数据交换服务提供参考。 相似文献
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《Cataloging & classification quarterly》2013,51(2):69-83
The Bahi'i World Centre Library developed a classification for Bahi'i materials by expanding the Library of Congress BP300-395 section. With the development of a computerized cataloguing system (called MAGE) at the Bahi'i World Centre Library, and particularly with the review of authorities for Bahi'i subject headings, this classification has been further modified. The experience provides an interesting example of how the process of computerization can affect classification schemes. 相似文献
18.
刘丽娟 《中华医学图书馆杂志》2008,17(2):47-49
近年来,有关阿尔茨海默病的文献大量涌现,但《中图法》第4版中并无相关类目。通过对《中图法》R749．16老年及早老性精神障碍和中国精神疾病分类的分析,参照国际疾病分类（ICD-10）和《美国精神疾病诊断与统计手册》第4版修订本（DSM-IV-R）和《中国精神障碍分类与诊断标准》第3版（CCMD-3）相关类目的现行标准和原则,提出3种分类方案。 相似文献
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Hierarchical Text Categorization (HTC) is the task of generating (usually by means of supervised learning algorithms) text classifiers that operate on hierarchically
structured classification schemes. Notwithstanding the fact that most large-sized classification schemes for text have a hierarchical
structure, so far the attention of text classification researchers has mostly focused on algorithms for “flat” classification,
i.e. algorithms that operate on non-hierarchical classification schemes. These algorithms, once applied to a hierarchical
classification problem, are not capable of taking advantage of the information inherent in the class hierarchy, and may thus
be suboptimal, in terms of efficiency and/or effectiveness. In this paper we propose TreeBoost.MH, a multi-label HTC algorithm consisting of a hierarchical variant of AdaBoost.MH, a very well-known member of the family of “boosting” learning algorithms. TreeBoost.MH embodies several intuitions that had arisen before within HTC: e.g. the intuitions that both feature selection and the selection
of negative training examples should be performed “locally”, i.e. by paying attention to the topology of the classification
scheme. It also embodies the novel intuition that the weight distribution that boosting algorithms update at every boosting
round should likewise be updated “locally”. All these intuitions are embodied within TreeBoost.MH in an elegant and simple way, i.e. by defining TreeBoost.MH as a recursive algorithm that uses AdaBoost.MH as its base step, and that recurs over the tree structure. We present the results of experimenting TreeBoost.MH on three HTC benchmarks, and discuss analytically its computational cost.
相似文献
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