倒排文档压缩技巧d-gaps的改进——文档标识号重置法

倒排文档是信息检索系统中最普遍使用的索引机制,而索引文件的压缩能大大提高检索速度和节约磁盘空间。倒排文件压缩的传统做法是文档(标识号)间距法（d-gaps）。然而，剧烈变化的间距值并不能被著名的前缀自由代码有效编码压缩。为了使间距值得到有效的压缩，本文设计了一个文档标识号重置法。模拟试验表明能更有效压缩d-gaps倒排文档。     

医学期刊论文主题标引存在的问题及对策

分析医学期刊论文主题标引现状.发现主题标引存在的主要问题是选词不当,字面组配、副主题词组配不准确,揭示论文主题不全面等.建议医学期刊编辑在做主题标引工作时,应了解并掌握主题标引的基本知识、标引的基本原则及标引技巧,使标引工作进一步规范化,以提高医学期刊论文的标引质量,从而扩大医学期刊的影响力.     

Reference books and computerized information services: partners in librarianship

As a basis for thoughts on the roles of reference books and computerized information services in general, a comparison is made of the value to medical libraries of a comprehensive reference tool (the new dual media publication Biomedical Research in Progress) and a comprehensive information center file (the Smithsonian Science Information Exchange, the national resource for information on research in progress). It is concluded that a detailed reference tool which is physically present for library users has several advantages, in particular the provision of both detailed and comprehensive retrieval of all biomedical research information at substantially less annual cost and with faster access time than is possible with comparable questions put to an information center. On the other hand, the information center is able to provide more up-to-date material in more flexible combinations. The recommendation is made that medical libraries avoid treating the comprehensive reference tool and the computerized information file as alternatives and instead view both as necessary and complementary to each other.     

医学文献主题标引中副主题词使用问题分析

对医学文献标引中关于副主题词使用的常见错误进行了分析,通过实例说明副主题词的修饰限制作用,并对副主题词的使用规则进行了探讨,对提高副主题词标引质量提出了建议。     

基于OKAPI的XML信息检索实现研究

OKAPI能实现强大的自由文本检索与评价功能,但要实现基于XML的信息检索,却要做适当改造。改造时,一方面尽量不破坏原有系统的体系结构,又要能实现对XML文档的索引、查询和表示。为此,必须完成面向XML的文档预处理和索引、面向XML的文档检索及检索模型的选择。图3。公式3。参考文献10。     

Searching the TELEGEN and BIOTECHNOLOGY Files

TELEGEN and BIOTECHNOLOGY, two new databases on thc SDC ORBIT system, index the whole range of genetic engineering literaturc. TELEGEN covers business aspects of the industry, as well as technical literature: BIOTECHNOLOGY covers patents and technical literature only. Both files are PROXIMITY-searchable. File design and content, as well as search techniques specific to each file, are discusscd in detail. The readcr should. after completing this introduction, try one or more of the sample questions included to "learn by experience" the capabilities of each file.     

Currency of full-text medical journals: CCML and MEDIS vs. MEDLINE

The authors ask whether full-text versions of medical journals are available for searching sooner than their biblographic counterparts. The journals in question are those found in the Comprehensive Core Medical Library (CCML) from BRS Information Technologies and in Mead Data Central's MEDIS Current Journal Files. All journals in these two files are full-text, and neither file contains any indexing features. Update schedules for the full-text version of the MEDLINE journals in each of these files were compared with the most recent issue available in the National Library of Medicine's (NLM) MEDLINE on five different dates. The data revealed substantial fluctuation in comparative currency for MEDIS/MEDLINE over the period of the test. On the date of the last snapshot, June 8, 1990, MEDLINE and MEDIS were offering the same currency for 43% of the journals, and MEDIS was providing first access to 29% of the titles. The CCML/MEDLINE comparison showed less variation. In the last snapshot MEDLINE and CCML were providing access to the same issue for 36% of the journals, and CCML was offering first access to 14%. Prior to publication, this paper was submitted to all three vendors for comment. Significant portions of their responses are quoted.     

高校图书馆建立地方文献数据库的探讨——以沂蒙地方文献数据库为例

本文以建立沂蒙地方文献数据库的工作实践为例,从附注项、分类号和主题标引等方面探讨了将地方文献资源整合到高校图书馆收藏范围的著录问题,提出了对地方文献应当采用主题标引进行重点著录的观点。     

基于多层次概念语义网络结构的中文医学信息语义标引体系和语义检索模型研究

为了提高中文医学信息检索效率,本文应用语义学研究成果,深入剖析统一医学语言系统(UMLS),从理论上对多层次概念语义网络结构进行了探讨,以此设计了适用于中文医学信息特点的三层概念语义网络结构,并分别确定了各个概念语义网络层次的语义类型和语义关系,进一步完善了医学信息语义网络.以信息检索的认知理论为依据,建立了基于三层概念语义网络结构的中文医学信息语义标引体系和语义检索模型.对扩展检索和语义检索进行统计学Kappa检验,认为两种检索方法的一致性非常显著(p<0.01);与扩展检索中的任何一种方法相比,语义检索方法具有更高的检索效率.     

Online searching for human nutrition: an evaluation of databases.

This study compares six databases which contain information on applied and clinical human nutrition: AGRICOLA, BIOSIS, CAB ABSTRACTS, EMBASE, MEDLINE, and SCI-SEARCH. Five research questions were searched, and the results were compared to identify the database of first choice and to determine the degree of overlap among the databases. Results indicate that for most of the human nutrition questions searched, MEDLINE was the most productive database. However, MEDLINE alone only uncovered 24% to 69% of the citations available. A combination of MEDLINE and at least one other database is recommended. The results of this study suggest that for most human nutrition questions, AGRICOLA is the best file to complement MEDLINE.     

Semantic indexing: a case study

Semantic indexing is a way of coding digital texts and images to represent their associated abstract meanings in database form. Databases encoded in this way enable users to answer complex questions and provide multiple, organized, summary views of their contents. In this article, the author discusses the techniques used in creating a semantically indexed database and provides examples of the utility thereby gained. The author examines the differences between traditional indexing and semantic indexing, and provides insight into the methodology of semantic indexing, using examples.     

自由标引问题研究

自由标引是现代情报检索工作中使用的一项重要技术，本文详细分析了自由标引的选词、后控制、计算机化管理、数据库检索等方面的问题。     

合理利用医学图书CIP数据，提高书目数据标准化

概述了在版编目的发展,从医学类图书CIP数据的分类标引、主题标引和著录数据三方面分析了医学图书在版编目数据存在的问题,并对提高CIP数据质量和图书馆书目数据标准化规范化程度提出一些建议。     

Medical rare book provenance

Provenance is defined as the record of a book's ownership history. Its value and uses are explored. A survey of provenance practices in medical school rare book libraries found that only 21% of the reporting libraries maintain this important file. Examples of the uses and value of a provenance file in a medical rare book collection are presented. Decisions necessary to institute and maintain such a file are outlined and discussed.     

Evolution of a State Periodical Index: Converting an In-House Index to a MARC-Based Database on the Web

This article describes the process of transforming the Arkansas Periodical Index, which began as a card file index in the University of Arkansas (U. of A.) Libraries, to an online database. As in many other states, in-house indexes were compiled to cover local history journals and subject-related magazines. A variety of software now exists to mount locally created databases, one option being the choice to use the same turnkey software that runs the library's online catalog. We began by converting our card files to a local Inmagic DB/Textworks database. The U. of A. received the 1991 Gale Research Award for Excellence in Reference and Adult Library Services for that design. We later mapped the database structure to MARC fields and mounted it as a Web-accessible database through our library OPAC vendor, Innovative Interfaces, Inc. (III). The authors begin with a brief history of periodical indexing, the reasons for choosing MARC formatting, and the field mapping required. The article explains the development of the database to include other publication formats, such as material from biographical compendiums, newspaper indexing, and university publications. The mapping incorporates indexing several publication formats in the same database. It also provides fields for linking citations back to the OPAC records, where users may find call numbers for journals or books, be connected to the full text of articles when available, or to an association's own website when applicable. We address some of the concerns for libraries in developing indexing projects. The article offers a mapping table of migrated fields that can be used by others wanting to encourage the rediscovery of local print periodicals and to expand access to the various materials otherwise buried in the library's special collections. The Arkansas Publications Index was released in April 2005 and is available free at http://arkindex.uark.edu/.     

中文书目数据常见问题分析

本文在多年编目工作实践与研究的基础上，总结了目前各编目机构制作的中文机读书目数据中经常出现的著录、主题标引、分类标引方面的质量问题，并对此作了一定的分析。     

National Library of Medicine Classification compared with Bliss class H

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Survey of medical literature borrowed from the national lending library for science and technology

This paper reports the results of a four-week questionnaire survey carried out at the National Lending Library (N.L.L.), Great Britian, to discover which types of organizations were the principal users of medical literature, what types of literature were used, and which were the main sources of references to medical publications. Industrial organizations and universities accounted for the majority (62 percent) of the loans, most of which were English-language periodicals published since 1960. For the whole sample, citation lists in periodical articles were the principal sources of references, although for literature published in the last fifteen months, abstracting and indexing journals were the main sources. Of the latter, Index Medicus proved to be the most fruitful source of references. By asking whether the item requested was really useful to their work, a measure of the reliability of the different sources of references was obtained.Appendixes include the questionnaire, a list of the most frequently borrowed journals, and a list of abstracting and indexing journals used as sources of references.     

文书类档案的分类标引研究

本文介绍了一种档案文献的计算机分类标引算法。该算法以主题词作为分类的依据,对不能直接映射归类的档案,统计文献主题词隶属于各个类的隶属度,利用模糊关系对档案进行分类标引,为了提高分类效率,使分类系统具有实用性,提出了几种措施。     

Retrieving information from scientific periodicals

Considers the indexing of scientific and medical periodicals, covering the need for indexes, the effect on information retrieval of the electronic revolution, types of journals and entries, the process of indexing, cumulation, and publisherAndexer relations