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SRW是一种基于Web Service的网络联机检索协议,它为我们通过Web提供信息检索服务,提供了类似于Z39.50的检索能力,从而提供了基于Web的书目资源整合方法.实现一个SRW服务虽然比实现一个Z39.50服务要相对简单,但其中会涉及一些新的概念、标准和技术问题,例如,SOAP通信架构,CQL检索语法,Dublin Core元数据标准等.本文描述了一个SRW服务系统的设计思想及具体实现.对涉及的关键技术,如SRW的三个主要操作的执行、SOAP消息的内容及封装、CQL语法的解析、MARC数据与Dublin Core元数据的转换等进行了详细的介绍. 相似文献
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Z39.50/Web网关系统的设计与实现原则 总被引：7，自引：2，他引：5
Z39.50 协议在异构系统之间的信息检索方面具有独特的优势, 而Z39.50/Web 网关的目的在于利用Web 的简单易用性和易接近性, 使Z39.50 应用得到更广泛的利用。本文首先介绍了Z39.50 协议的主要内容, 然后讨论了基于Web 的Z39.50 应用的机制, 最后着重阐述了在书目信息的检索应用方面, 设计和实现一个实用的Z39.50/Web 网关系统应该遵循的原则。 相似文献
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分布式检索系统及其体系结构 总被引：5，自引：0，他引：5
分布式检索是目前网络环境下信息检索的重要技术和方式。分布式检索具有有效性、高性能、高可靠性和低成本等方面的优势 ,因而是数字图书馆、网络检索系统的核心技术。本文介绍了分布式检索中使用的几种查询协议 ,并提出一些分布式信息检索系统的模块结构及实现技术框架。图 1。参考文献 8。 相似文献
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传统的关键词检索技术在文本检索和HTML文档检索上得到了广泛的应用,但它运用于检索XML文档时却不尽如意.为此,本文引入一种改进的遗传算法,对XML文档上的关键词检索进行了研究,提出了XML文档标记的自适应遗传训练算法与XML文档上关键词语义检索及结果排序算法. 相似文献
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张英 《浙江传媒学院学报》2002,9(2):95-96
随着Imemet的高速发展,网上信息呈指数级增长,同时各行业对信息的使用也更加广泛,这对信息的管理和检索提出了很高的要求.本文所研究的就是面向Web基于内容的视频检索,以及支持检索的搜索引擎技术的研究. 相似文献
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从因特网上检索我国法律法规是一项很实用的技术.本文介绍了因特网上检索中国法律法规的几条途径,并给出了一些主要信息源的地址、特点及检索方式. 相似文献
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浅谈信息检索与信息检索技术 总被引：6，自引：0，他引：6
通过对传统检索技术与网上检索技术的比较,论述了信息检索和信息检索技术的发展状况、趋势(主要简述网络检索与网络检索技术、多媒体信息检索与多媒体信息检索关键技术等). 相似文献
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互联网的信息检索技术 总被引：11，自引：0，他引：11
本文从Internet信息检索的问题和困难出发,介绍了目前的研究现状和水平.然后对Internet上传统的信息检索工具Archic、WAIS、Gopher、Veronica进行了介绍.WWW的出现使得人们检索和获取信息的方式发生了本质改变,因此本文重点论述了WWW上的信息检索技术.从WWW的工作原理到WWW的浏览程序Netscape,最后详细地介绍WWW的各种检索工具并对它们进行了评价. 相似文献
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Matt Cook 《The Journal of Academic Librarianship》2018,44(1):145-149
As academic library collections are moved off site to make room for learning commons-type collaboration spaces, exploratory research processes (e.g. stacks browsing activities) are threatened. Given the range of benefits associated with chance information encounters in the physical book stacks, the disappearance of accessible collections is problematic. Fortunately, by focusing on embodied aspects of the physical browsing experience we can leverage emerging technologies to preserve instances of serendipitous information retrieval. Virtual reality, in this case, provides a browsing platform that allows for the type of search activity typically associated with research in the physical books stacks and preserves the benefits thereof. 相似文献
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We present a system for multilingual information retrieval that allows users to formulate queries in their preferred language and retrieve relevant information from a collection containing documents in multiple languages. The system is based on a process of document level alignments, where documents of different languages are paired according to their similarity. The resulting mapping allows us to produce a multilingual comparable corpus. Such a corpus has multiple interesting applications. It allows us to build a data structure for query translation in cross-language information retrieval (CLIR). Moreover, we also perform pseudo relevance feedback on the alignments to improve our retrieval results. And finally, multiple retrieval runs can be merged into one unified result list. The resulting system is inexpensive, adaptable to domain-specific collections and new languages and has performed very well at the TREC-7 conference CLIR system comparison. 相似文献
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Sarah A. Buchanan 《Cataloging & classification quarterly》2013,51(5):349-360
The recording of provenance is of particular importance in special collections cataloging, as knowledge of provenance lends authenticity and reliability to the materials held. A method of cataloging collection-level provenance in bibliographic records through a short mnemonic code, a Special Collections and Archives Code (SPAC), is described which enhances visibility of collections and retrieval in a catalog. A collection code not only collocates unique individual items that share a common characteristic, but can also constitute part of a linked data approach to visualizing integrated collections in the form of a “virtual bookplate.” 相似文献
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Finding useful information from large multimodal document collections such as the WWW without encountering numerous false positives poses a challenge to multimedia information retrieval systems (MMIR). This research addresses the problem of finding pictures. The fact that images do not appear in isolation, but rather with accompanying, collateral text is exploited. Taken independently, existing techniques for picture retrieval using (i) text-based and (ii) image-based methods have several limitations. This research presents a general model for multimodal information retrieval that addresses the following issues: (i) users' information need, (ii) expressing information need through composite, multimodal queries, and (iii) determining the most appropriate weighted combination of indexing techniques in order to best satisfy information need. A machine learning approach is proposed for the latter. The focus is on improving precision and recall in a MMIR system by optimally combining text and image similarity. Experiments are presented which demonstrate the utility of individual indexing systems in improving overall average precision. 相似文献
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Query languages for XML such as XPath or XQuery support Boolean retrieval: a query result is a (possibly restructured) subset of XML elements or entire documents that satisfy the search conditions of the query. This search paradigm works for highly schematic XML data collections such as electronic catalogs. However, for searching information in open environments such as the Web or intranets of large corporations, ranked retrieval is more appropriate: a query result is a ranked list of XML elements in descending order of (estimated) relevance. Web search engines, which are based on the ranked retrieval paradigm, do, however, not consider the additional information and rich annotations provided by the structure of XML documents and their element names.This article presents the XXL search engine that supports relevance ranking on XML data. XXL is particularly geared for path queries with wildcards that can span multiple XML collections and contain both exact-match as well as semantic-similarity search conditions. In addition, ontological information and suitable index structures are used to improve the search efficiency and effectiveness. XXL is fully implemented as a suite of Java classes and servlets. Experiments in the context of the INEX benchmark demonstrate the efficiency of the XXL search engine and underline its effectiveness for ranked retrieval. 相似文献
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基于检索相关性转移的本体论检索系统 总被引：1，自引：1，他引：0
在讨论当前情报检索系统的相关性判断基础上,指出在相关性判断的多维度多层次的复杂概念中用户关心的是语用相关,但多数检索系统仅能提供形式相关.建议运用本体论的基本原理,建立本体论的情报检索系统,从而实现检索的语用相关判断. 相似文献
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Compound noun segmentation is a key first step in language processing for Korean. Thus far, most approaches require some form of human supervision, such as pre-existing dictionaries, segmented compound nouns, or heuristic rules. As a result, they suffer from the unknown word problem, which can be overcome by unsupervised approaches. However, previous unsupervised methods normally do not consider all possible segmentation candidates, and/or rely on character-based segmentation clues such as bi-grams or all-length n-grams. So, they are prone to falling into a local solution. To overcome the problem, this paper proposes an unsupervised segmentation algorithm that searches the most likely segmentation result from all possible segmentation candidates using a word-based segmentation context. As word-based segmentation clues, a dictionary is automatically generated from a corpus. Experiments using three test collections show that our segmentation algorithm is successfully applied to Korean information retrieval, improving a dictionary-based longest-matching algorithm.
相似文献
| Jong-Hyeok LeeEmail: |
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Due to the heavy use of gene synonyms in biomedical text, people have tried many query expansion techniques using synonyms
in order to improve performance in biomedical information retrieval. However, mixed results have been reported. The main challenge
is that it is not trivial to assign appropriate weights to the added gene synonyms in the expanded query; under-weighting
of synonyms would not bring much benefit, while overweighting some unreliable synonyms can hurt performance significantly.
So far, there has been no systematic evaluation of various synonym query expansion strategies for biomedical text. In this
work, we propose two different strategies to extend a standard language modeling approach for gene synonym query expansion
and conduct a systematic evaluation of these methods on all the available TREC biomedical text collections for ad hoc document
retrieval. Our experiment results show that synonym expansion can significantly improve the retrieval accuracy. However, different
query types require different synonym expansion methods, and appropriate weighting of gene names and synonym terms is critical
for improving performance.
相似文献
| Chengxiang ZhaiEmail: |
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Scaling Up the TREC Collection 总被引：3，自引：3，他引：0
Due to the popularity of Web search engines, a large proportion of real text retrieval queries are now processed over collections measured in tens or hundreds of gigabytes. A new Very Large test Collection (VLC) has been created to support qualification, measurement and comparison of systems operating at this level and to permit the study of the properties of very large collections. The VLC is an extension of the well-known TREC collection and has been distributed under the same conditions. A simple set of efficiency and effectiveness measures have been defined to encourage comparability of reporting. The 20 gigabyte first-edition of the VLC and a representative 10% sample have been used in a special interest track of the 1997 Text Retrieval Conference (TREC-6). The unaffordable cost of obtaining complete relevance assessments over collections of this scale is avoided by concentrating on early precision and relying on the core TREC collection to support detailed effectiveness studies. Results obtained by TREC-6 VLC track participants are presented here. All groups observed a significant increase in early precision as collection size increased. Explanatory hypotheses are advanced for future empirical testing. A 100 gigabyte second edition VLC (VLC2) has recently been compiled and distributed for use in TREC-7 in 1998. 相似文献