共查询到19条相似文献，搜索用时 339 毫秒
1.
基于概念空间方法的信息检索技术研究 总被引：14，自引：0，他引：14
为了解决词汇差异问题,词表构造在信息检索系统中有着重要意义。概念空间方法是利用计算机自动构造概念语义网络(词表)并以此为基础进行概念检索的一种方法。由词语作为语义网络的节点,词语之间的关联权重以一个给定文档集合中词语的共现率来计算,其大小代表它们之间的相似性。检索时系统采用人工智能方法激活与检索入口词相关的术语或概念,为用户提供交互式的检索用语建议。方法的具体步骤包括文档和对象列表收集、对象过滤和自动标引、共现分析和联想检索四个阶段。这种方法多用于英文检索系统,但对我国的信息检索系统也有重要的借鉴意义。 相似文献
2.
隐含语义检索及其应用 总被引：5，自引：1，他引：4
隐含语义检索(Latent Semantic Indexing, LSI) 是一种基于概念的文献检索方式。它区别于传统的基于用户查询条件与文档的单词匹配的文献检索方法, 根据文档与查询条件在语义上的关联而向用户提交查询结果。本文介绍了隐含语义检索在文献检索中的一种实现方法, 为文献检索提供了一种新的途径。 相似文献
3.
国外搜索引擎检索效能研究述评 总被引：2，自引：0，他引：2
在网络搜索引擎的使用中,搜索引擎的检索效能成为影响用户信息获取效果和搜索引擎服务质量的重要因素.目前,国外的相关研究主要采取实验的方法,从用户体验角度出发评价搜索引擎的检索效能,主要步骤包括确定信息需求、选择搜索引擎、评价结果文档相关度以及确定测度指标.最常用的测度指标是查全率和查准率.此外,影响用户检索效能的指标还有搜索引擎返回结果文档的排序质量、重复度,而索引的数量、用户满意度等指标都会影响用户使用的效果.无论是从搜索引擎的用户使用角度,还是用户评价角度,"用户参与"的模式是最贴近检索现实的. 相似文献
4.
搜索引擎的智能检索机制 总被引：6，自引：0，他引：6
探讨搜索引擎的一些智能检索机制,包括基于概念匹配的检索,对网络信息进行深层次挖掘,分析并预测用户的信息需求和提供个性化、专业化的检索服务。 相似文献
5.
针对当前书目检索过程中缺少检索建议与提示而影响检索性能的现状,进行检索建议与提示策略的研究。通过阐述检索行为的概念与属性、分析用户的检索心理,挖掘用户行为数据,并在此基础上实施访问OPAC网站、输入检索词、获得检索结果及选择检索结果等检索过程与行为的引导服务与查询帮助,从而较为准确地判断用户的查询意图,对用户的检索行为给出实时的、丰富的检索建议与提示,以期增强书目检索功能,提高系统的互动性,提升用户的查询体验。 相似文献
6.
本文通过加权检索与逻辑检索的比较分析和引入负值权数的概念, 论述了在计算机情报检索中加权法提问式与提问逻辑式在表达意义上的可等价性, 并提出了合理确定权数的一种简便方法。文中还侧重论述了加权检索在采用顺排文档与倒排文档检索中的实现方法。 相似文献
7.
试析影响网络数据库检索效率的因素 总被引：4，自引：0，他引：4
从用户使用的角度对网络数据库的数据质量、检索功能、输出功能、网络环境、用户素质与检索水平等影响网络数据库检索效率的因素进行分析,并提出相应的对策。 相似文献
8.
影响网络信息检索效率的因素及检索策略与技巧的选择 总被引：1，自引：0，他引：1
分析了影响用户网络信息检索效率的因素,指出在网上进行信息检索时,要想提高检索效率,准确、快速、全面地获得检索结果,必须采取一定的检索策略和技巧。 相似文献
9.
刘俊熙 《现代图书情报技术》2003,(Z1)
信息需求的核心就是及时有效地满足。在网络环境下 ,用户依赖检索工具得到的信息需求满足是粗线条 ,缺乏准确率的 ,往往需要花费更多的时间对信息过滤 ,相对应网络信息集合级数的增长 ,对特定信息的检索效率反而更差了。为此作者指出用户的检索行为应着眼于网络信息资源的整合模式 ,检索功能的智能运用间的互动效应 相似文献
10.
VISION:集成分类法、主题词表和语义元数据的概念网络 总被引：19，自引：2，他引：17
本文提出了一种在分类法和主题词表的基础上集成语义元数据、构建概念网络、实现概念检索的方法.和其他的概念检索系统相比,它的最大特色是在检索之前先将信息资源根据其内容和主题组织到概念网络中.这样的概念网络,既是一个资源组织的框架,又是一个知识浏览和概念检索的信息空间.同时,还能支持用户学习.文章介绍了国内外概念检索的研究现状,讨论了集成分类法、主题词表和语义元数据构建概念网络的方法和好处.介绍了一个原型系统VISION,它是在<中国分类主题词表>的基础上,利用北京大学图书馆计算机类的书目数据实现的.文章最后进行深入讨论并介绍下一步的研究工作. 相似文献
11.
针对自然语言提问的特点,提出基于短语索引的用户提问的处理方法,给出了短语结构索引的生成方法,设计了提问处理流程。在此方法中,系统接收完整的句子作为提问,采用自然语言处理技术对提问逐步处理,从提问中抽取短语作为检索对象。与关键词相比,短语可以表达更为具体的概念,有助于提高系统的查准率。图1。表1。参考文献13。 相似文献
12.
Genetic Approach to Query Space Exploration 总被引：2，自引：0，他引：2
This paper describes a genetic algorithm approach for intelligent information retrieval. The goal is to find an optimal set of documents which best matches the user's needs by exploring and exploiting the document space. More precisely, we define a specific genetic algorithm for information retrieval based on knowledge based operators and guided by a heuristic for relevance multi-modality problem solving. Experiments with TREC-6 French data and queries show the effectiveness of our approach. 相似文献
13.
G. S. Osipov I. V. Smirnov I. A. Tikhomirov 《Scientific and Technical Information Processing》2010,37(6):432-437
A relational-situational method for analysis of natural language texts is outlined based on the theory of communicative grammar
of the Russian language and the theory of heterogeneous semantic networks. It is shown that the relational-situational method
can be used for precise search of documents in local and globalnets and electronic libraries 相似文献
14.
A Hierarchical Document Retrieval Language 总被引：1，自引：0，他引：1
Ronald R. Yager 《Information Retrieval》2000,3(4):357-377
The focus of this work is on the development of a document retrieval language which attempts to enable users to better represent their requirements with respect to retrieved documents. We describe a framework for evaluating documents which allows, in the spirit of computing with words, a linguistic specification of the interrelationship between the desired attributes. This framework, which makes considerable use of the Ordered Weighted Averaging (OWA) operator, also supports a hierarchical structure which allows for an increased expressiveness of queries. 相似文献
15.
Fernando Martínez-Santiago L. Alfonso Ureña-López Maite Martín-Valdivia 《Information Retrieval》2006,9(1):71-93
A usual strategy to implement CLIR (Cross-Language Information Retrieval) systems is the so-called query translation approach.
The user query is translated for each language present in the multilingual collection in order to compute an independent monolingual
information retrieval process per language. Thus, this approach divides documents according to language. In this way, we obtain
as many different collections as languages. After searching in these corpora and obtaining a result list per language, we
must merge them in order to provide a single list of retrieved articles.
In this paper, we propose an approach to obtain a single list of relevant documents for CLIR systems driven by query translation.
This approach, which we call 2-step RSV (RSV: Retrieval Status Value), is based on the re-indexing of the retrieval documents
according to the query vocabulary, and it performs noticeably better than traditional methods.
The proposed method requires query vocabulary alignment: given a word for a given query, we must know the translation or translations
to the other languages. Because this is not always possible, we have researched on a mixed model. This mixed model is applied
in order to deal with queries with partial word-level alignment. The results prove that even in this scenario, 2-step RSV
performs better than traditional merging methods. 相似文献
16.
语义矢量空间模式（SVSM）及其试验评价——自然语言处理与文献自动标引 总被引：4，自引：0，他引：4
Ｇｅｏｆｒｅｙ Ｚ．Ｌｉｕ 《情报学报》1996,(6)
本文介绍一种基于句法分析和格式语义结构，被称为“语义矢量空间模式”的文献自动标引／检索技术。在此模式中，自然语言文献和检索提问均表示为语义矩阵。通过计算语义矩阵的相似值，检索系统可以预测文献与给定提问之间的相关度，从而达到检索相关文献的目的。初步试验结果表明，若文献及检索提问较长，特别是以原文献作为提问样本时，此检索技术与康奈尔大学的ＳＭＡＲＴ系统相比，在检全率、检准率和相关排序有效性方面均有所改进 相似文献
17.
基于句模分析的自然语言处理能识别面向搜索引擎应用的自然语言检索句中的核心检索项.在此基础上,本文通过定义产生式规则和使用归约算法,对常见自然语言提问中蕴含的核心检索项间的逻辑关系进行识别与处理,对自然语言提问中可能蕴含的概念间的逻辑关系进行识别,把概念间可能存在的逻辑关系转化为必要的逻辑运算并确定逻辑优先级.通过在开发的教育资讯搜索引擎与新闻搜索引擎系统上的使用与性能对比分析,该算法能提升自然语言提问的理解能力,提高搜索引擎的智能性.文中亦对其不足进行了说明,并指出在此基础上进一步的研究内容. 相似文献
18.
Users are often faced with complex information needs that are not easily represented as a single query. With current technology,
the burden of issuing these individual queries, analysing retrieved documents for relevance, as well as aggregating results
falls upon the time-poor and informationally overloaded user. Aggregated search techniques represent the new generation of
search applications that endeavour to help users perform these complex tasks. However, the way in which different data types
are combined in current aggregated search applications is often performed using static hard-coded structures. We suggest that
a useful alternative is to marry techniques from natural language generation, such as text planning and summarisation, in
order to dynamically determine the best organisation of retrieved information. These organisations can be motivated by linguistic
theories that consider issues such as the role that the information plays to facilitate a task, and the relationships between
different pieces of information. With reference to a discourse strategy, it is possible to draw on several data sources automatically
to generate a useful, focused, and coherent answer. We focus on exploring the parallels between aggregated search and natural
language generation in the hope that the fields can be mutually informed, leading to further advances in the way search technologies
can better serve the user. These issues are discussed and presented with examples of existing systems across different domains. 相似文献
19.
Improving English and Chinese Ad-Hoc Retrieval: A Tipster Text Phase 3 Project Report 总被引：1，自引：1，他引：0
K.L. Kwok 《Information Retrieval》2000,3(4):313-338
Both English and Chinese ad-hoc information retrieval were investigated in this Tipster 3 project. Part of our objectives is to study the use of various term level and phrasal level evidence to improve retrieval accuracy. For short queries, we studied five term level techniques that together can lead to good improvements over standard ad-hoc 2-stage retrieval for TREC5-8 experiments. For long queries, we studied the use of linguistic phrases to re-rank retrieval lists. Its effect is small but consistently positive.For Chinese IR, we investigated three simple representations for documents and queries: short-words, bigrams and characters. Both approximate short-word segmentation or bigrams, augmented with characters, give highly effective results. Accurate word segmentation appears not crucial for overall result of a query set. Character indexing by itself is not competitive. Additional improvements may be obtained using collection enrichment and combination of retrieval lists.Our PIRCS document-focused retrieval is also shown to have similarity with a simple language model approach to IR. 相似文献