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1.
化学家利用Internet通用资源搜索引擎如Yahoo、Google获取Internet资源时,检索结果常包含大量相关性较小的内容。Internet化学资源导航系统如ChemDex用人工方法收集和组织资源使资源内容质量和相关性比通用搜索引擎有所提高,但进行细致的分类仍比较困难。由中国科学院过程工程研究所建立、Internet化学化工资源导航系统ChIN的维护工具ChIN-Manag-er采用把两个内容相关的资源简介页互链来表示资源之间的密切相关关系,目前维护人员主要通用测览分类目录来确定相关资源,但这种方式在被索引的资源数量日益增大时其可用性降低。本论文开发了一种新的基于ChIN数据库检索的链接两个关系密切的相关简介页的方法。该方法针对ChIN数据库中简介页的组织特点设计了面向不同资源类型数据表的多种检索策略,这些策略侧重于被检索字段的确定;并为20余种不同类型的资源描述表建立了实现相应检索策略的检索界面。这些检索界面无缝集成到了ChIN-Manager相应的资源编辑界面中,为ChIN提供了一种快速确定被索引资源的密切相关资源的方法。  相似文献   

2.
ChIN化学化工资源导航系统的新进展   总被引:8,自引:3,他引:5  
Internet化学化工资源导航系统ChIN已经被公认为国内最有影响的Internet化学化工资源导航站点,也受到国际同行的肯定和关注。本文从ChIN的最新版本及其专门管理工具ChIN-Manager、基于概念的自然语言检索方法-隐含语义检索LSI应用于ChIN的研究、将ChIN无缝集成到化学化工虚拟社区平台的尝试3个方面来介绍ChIN在最近两年内的新进展。  相似文献   

3.
Internet化学化工资源导航系统ChIN已经被公认为国内最有影响的Internet化学化工资源导航站点,也受到国际同行的肯定和关注。本文从ChIN的最新版本及其专门管理工具ChIN-Manager,基于概念的自然语言检索方法一隐含语义检索ISI应用于ChIN的研究、将ChIN无缝集成到化学化工虚拟社区平台的尝试3个方面来介绍ChIN在最近两年内的新进展。  相似文献   

4.
Internet化学信息的系统挖掘工具   总被引:1,自引:0,他引:1  
本文简要介绍中国科学院过程工程所(原化工冶金所)在Internet化学化工信息资源系统挖掘方面正在形成的一个较完整的化学专业信息获取平台,包括:(1)国家科学数字图书馆化学学科信息门户ChIN;(2)网络化学化工专业搜索引擎ChemEngine;(3)化学深层网挖掘工具ChemDB Portal.其中ChIN已经成熟,是国内权威、中国唯一被国际承认的网络化学资源导航系统;ChemEngine是通用搜索引擎技术与化学相关的领域知识相结合形成的化学化工专业搜索引擎,初步测试优于国际具有类似功能的系统:德国的ChemGuide和美国的Chemlndustry.ChemDB Portal则是正在进行的、基于XML对化学深层网数据进行提取和索引方法的研究,这一方法尚未见报道.这些工具可为检索网络化学相关信息提供更方便、更好的专业化解决方案.  相似文献   

5.
化学信息门户ChIN十年回顾   总被引:1,自引:0,他引:1  
中国科学院过程工程所(原化工冶金所)自1997年开始建立和维护的Internet化学化工资源导航系统ChIN,目前作为国家科学数字图书馆:化学学科信息门户运行,它是一个集Internet化学资源的发现、收集、分类、描述,门户网站导航系统的生成和向Web发布、用户集成交流环境等功能较为完善的化学化工门户系统。ChIN已经在Internet上连续不间断地运行了约10年时间。目前与国际上知名的同类系统如ChemDex、Links for Chemists等相比,无论从索引的资源总量、内容质量、还是系统的整体性能上。ChIN都毫不逊色。本文回顾了ChIN在这10年中工具与版本的发展、运行的概况、及被访问的情况等。  相似文献   

6.
卢秉亮  朱健  张磊  郎勇 《微处理机》2007,28(1):75-77,81
Internet网络环境搜索引擎主要由三部分组成:搜索器、索引数据库和用户界面。检索器是搜索引擎中的核心和关键。通常的网络搜索引擎采用的是集合或模糊检索算法,其检索结果冗余大。主要介绍了搜索引擎索引数据库的结构;基于Spider的通用搜索器的实现;索引表的生成过程;精确检索原理、算法及实现。采用精确检索算法的搜索引擎,所搜索的信息冗余度小并且效率高。  相似文献   

7.
化学主题网络爬虫的设计和实现   总被引:1,自引:0,他引:1  
由于通用搜索引擎检索返回的结果过多、主题相关性不强以及随着人们对提供的各项信息服务的要求越来越高,基于整个Web的信息采集越来越力不从心。同时它无法及时地采集到足够的最新的Web信息,也不能满足人们日益增长的个性化需求。本文通过把Internet化学资源导航系统所积累的化学知识与搜索引擎的自动采集技术相结合展开了对化学主题网络爬虫开发的研究。结果表明,基于Widrow-Hoff分类器的化学主题网络爬虫能有效的采集化学相关的网页。  相似文献   

8.
随着互联网应用的深入,越来越多的用户希望通过搜索引擎获得特定行业的相关信息,通用搜索引擎无法有效地满足相应需求。文中主要介绍医药行业垂直搜索引擎的设计与实现。设计基于智能搜索引擎的架构,采用了任务驱动的聚焦搜索、隐藏搜索技术;字词混合倒排索引及优化的字倒排索引、检索技术。提供了资源收集阶段的可控策略爬行,和高效的索引、检索功能。实现了针对医药行业的高专业度、高准确率、高效率的信息垂直搜索。  相似文献   

9.
基于内容的WEB图像检索引擎   总被引:1,自引:0,他引:1       下载免费PDF全文
现在的图像搜索引擎大多是基于关键字的检索,怎样从Internet的海量数据中检索到自己想要的图像信息,是一个亟待解决的问题。本文提出了基于内容Web图像检索引擎及其体系结构,研究其数据库结构设计,基于内容检索中索引和相关反馈的问题。  相似文献   

10.
介绍了Intirnet的发展,Internet所提供的各种服务,以及通过Intemet获取各种化学信息和资源的新趋势,着重介绍了运用通用搜索引擎和各种化学主题检索各类化学信息与资源,并对部分重要的化学信息和资源的网址提供了详细列表。  相似文献   

11.
Water resources     
Abstract

Water, which was taken for granted and assumed to exist in abundance, has become one of our most precious natural resources. Hence hydrological and water management problems represent key areas of applied science in the current worldwide economic and ecological situations. Satellite remote sensing technologies have been used more and more to satisfy urgent requirements for information relating to water resources. Many efforts have been undertaken in Europe to develop appropriate methods and to advance these systems to an operational level. Main emphasis is given to processes in which land surfaces and inland waters are involved, dealing with the estimation of precipitation, the assessment of soil moisture, surface runoff and the forecasting of runoff, be it from rainfall or from snowmelt. Remote sensing methods are of fundamental importance for soil moisture monitoring on a global and on a regional scale. Experimental research has demonstrated that if, in principle, observations in the visible and thermal infrared regions of the electromagnetic spectrum are able to detect the surface moisture of bare soils, microwave sensors are the most promising tools for quantitative estimates of this parameter. A valuable amount of research on this subject has been performed in Europe and is reviewed within the framework of the most advanced international research. Within Europe regional or local aspects and problems dominate. Therefore the efforts and achievements concerned with these areas and applications, and the progress towards operational use, will be focused on primarily. The most advanced and most promising operational applications exist in the field of snow hydrology to improve power production.  相似文献   

12.
Decision-making episodes are knowledge intensive processes, operating on and adding to organizational knowledge resources. Decision support systems (DSS) perform some of the knowledge management (KM) that is integral to these episodes. Interest in the field of KM, among both practitioners and researchers has mushroomed in the late 1990s. Initiatives that aim to deliberately, explicitly manage organizations' knowledge resources have become commonplace. A basic prerequisite for fully understanding how an organization can, could, or should conduct KM is an appreciation of the kinds of knowledge resources it has. In this paper, a framework of knowledge resources is introduced, focusing on identifying and organizing basic classes of knowledge resources, and supplemented by the identification of attribute dimensions for characterizing knowledge across these classes. Developed via a Delphi methodology involving an international panel of practitioners and researchers, this framework is assessed as being relatively successful in terms of completeness, accuracy, clarity, and conciseness criteria. The result is a basis for investigating effects of alternative knowledge resource portfolios, and for studying how an organization does, could, or should conduct its KM — including its decision-making episodes.  相似文献   

13.
《Computers & Education》2005,44(3):301-325
Within the university the introduction of computers is creating a new criterion of differentiation between those who as a matter of course become integrated in the technocratic trend deriving from the daily use of these machines and those who become isolated by not using them. This difference increases when computer science and communications merge to introduce virtual educational areas, where the conjunction of teacher and pupil in the space–time dimension is no longer an essential requirement, and where the written text is replaced (or rather complemented) by the digital text.In this article, a historical defence is made of the presence of this new standard in the creation of digital educational resources such as the hyperdocument, as well as the barriers and technological problems deriving from its use. Furthermore, HyCo, an authoring tool, is introduced which facilitates the composition of hypertexts, which are stored as semantic learning objects, looking for that through of a simple and extremely intuitive interface and interaction model, any teacher with a minimum knowledge of computer science has the possibility of transforming his or her experience and knowledge into useful and quality hypermedia educational resources.  相似文献   

14.
 This article lists currently available sources of information on classifier systems and classifier systems research, both on-line and in print. The need for new resources, and improvements to certain existing ones, are suggested.  相似文献   

15.
We describe a suite of standards, resources and tools for computational encoding and processing of Modern Hebrew texts. These include an array of XML schemas for representing linguistic resources; a variety of text corpora, raw, automatically processed and manually annotated; lexical databases, including a broad-coverage monolingual lexicon, a bilingual dictionary and a WordNet; and morphological processors which can analyze, generate and disambiguate Hebrew word forms. The resources are developed under centralized supervision, so that they are compatible with each other. They are freely available and many of them have already been used for several applications, both academic and industrial.
Shuly WintnerEmail:
  相似文献   

16.
The widespread availability of digital learning resources in a variety of media formats offers the possibility to make a profound difference in education. This potential has not been fully realised for range of interrelated reasons. In this paper we study the key characteristics of learning resources that have proved effective in changing learning and teaching, and relate them to existing frameworks for understanding resources. We outline the relationships between resources, their users, and the way they are used, and explore issues that influence practitioners in choosing a particular resource. Our study is based on a review of resources for e-learning and chemistry in post-compulsory education, undertaken for the UK Joint Information Systems Committees (JISC), as part of a wider study examining ‘The Effectiveness of Resources, Tools and Support Services used by Tutors in Designing and Delivering E-Learning Activities’.  相似文献   

17.
The reachability of a strongly connected network may be destroyed after link damage.Since many networks are directed or equivalent directed,connected by directed links with the potential for reversal.Therefore the reachability can be restored by reversing the direction of links.[1] has studied this matter under unlimited resources (transmitter and receiver) condition.In this paper the reconnectability of a network with limited number of receivers and transmitters is discussed.Also a linear time algorithm is given to find a reconnected reversal for limited receivers and transmitters.  相似文献   

18.
19.
《Computers & Education》2013,60(4):1257-1272
Technology Enhanced Learning is a research field that has matured considerably over the last decade. Many technical solutions to support design, authoring and use of learning activities and resources have been developed. The first datasets that reflect the tracking of actual use of these tools in real-life settings are beginning to become available. In this article, we present an exploratory study that relies on these datasets to support semi-automatic assembly of learning activities and resources for specific contexts. Starting from learning designs and other online sources that describe well designed learning experiences as they were used in practice, we derive sequencing patterns that capture re-occurring patterns of activities. A semi-automatic assembly framework uses these patterns to support teachers in the design and authoring of course activities. We present a case study that integrates recommendation support for sequencing activities as well as associated resources in the LAMS learning activity environment. Results indicate that the perceived usefulness is high: both teachers with expertise in the use of learning design tools as well as teachers with no background knowledge in the area indicate that the recommendations helped them in the authoring process. In addition, they feel more confident using learning design tools when support is provided that is driven by best practice knowledge.  相似文献   

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