Database Search Agent for Network Information Resources

自20世纪60年代以来的数据库搜索服务提供主机-终端计算。但是，当前开放系统计算、网络、客户/服务器计算和信息管理标准的发展正在改变当今的系统。书目数据库是最有用的数据库，由联机数据库服务、光盘、OPAC和Internet提供。万维网将影响未来数据库搜索的设计，用户对更广泛访问的需求也将如此。由于这些数据库的许多用户在复杂的环境中面临着难以访问的问题，因此需要数据库代理来访问不同的网络信息资源。但是这种数据库代理设备存在一些问题。对数据库代理的要求是自动识别各个系统的接口(命令)和数据库。这些问题将通过对现有搜索系统的分析来找到解决方案。另一个问题是自动相关性判断。需要重新认识相关性判断的概念，将用户判断和系统判断的相关性要素进行划分，基于Z39.50标准的客户/服务器架构实现了不同数据库搜索系统之间的检索兼容。Z39.50标准会对一些图书馆的OPAC产生影响，但该标准并不被认为是对多文字数据库的检索

the database searching service since the 1960s is providing host-terminal computing. But, current developments in open systems computing, networking, client/server computing and standards for information management are changing today's systems. Bibliographic databases are most useful databases and they are provided by online database service, CD-ROM,OPAC and Internet. The World Wide Web will influence the design of database searching of the future as will users' damands for wider access. Because many users of these database are faced to difficult to access in the complexed circumstance, database agent is needs to access different network information resources. But this database agent device has some problems. Requirements for database agents are to identify automatically interfaces (commands) and databases of individual systems. These problems will be found the solution by the analysis of existing searching systems. Another problem is the automatic relevance judgment. It is necessary to recognize the concept of relevance judgment and divide the element of the relevance between users judgment and system judgment.Client/server architecture based on Z39.50 standards achieves compatibility for retrieval between diverse database searching systems. Z39.50 standards will influence some library OPAC,but this standard is not considered the multi-literal database searching