Research And Implement Of OAI-based Integrated Information Retrieve System

With the development of computer technology, network technology and information retrieval technology, the information demand of the customer features as networking, integration, intelligence and personality. In the field of library science and information science, especially in the framework of digital library, the integrated query and integrated explore based on distributed computer technology and all kinds of interoperable mechanism become our important research content. With making use of metadata open harvesting and query integrated, OAI-PMH provides an independent interoperable framework for Web site. Under this background, this paper presents the possibility of providing distributed integration information retrieve on the basis of the integration metadata repository, which is constituted by the open harvesting of the OAI-PMH (Open Archives Initiative - Protocol of Metadata Harvester) metadata.Firstly, it summarizes the distributed computing technology, distributed architecture, interoperability and the development trend of the integration information retrieve. Distributed computer and distributed architecture is the base of interoperability. The main distributed computer technology includes DCOM, RMI, CORBA and Remoting. Distributed operating platform includes CORBA, JINI, Web Services and Enterprise JavaBean. Interoperability of computer environment builds up on the network, data, application and services. The interoperable patterns in the region of digital library all originate from the interoperability of computer environment. We try our best to realize the service integrated in the level of systembecause the integration in the level of data is very difficult.And then, it illustrates the brief condition of OAI development, the specification of OAI-PMH protocol and the research progress on this topic both at home and abroad. OAI-PMH, as low entry metadata interoperable protocol based on XML, the POST or GET method of HTTP, is able to realize the metadata open harvesting on the Internet and provide the customers with metadata repository query service. The hot technology in the integrated information retrieve represents as web mining, knowledge retrieve, distributed heterogeneous information resources retrieve and personality retrieve.The major goal for this paper is to design an integrated information query system based on the OAI open metadata harvesting. Therefore, it mainly focuses on the establishment of the lab environment and the implement of each system module of OAI open harvesting system. The finished modules include the OAI interface module of data provider, the query module and query schedule management module of service provider, as well as the query service module based on the harvested metadata. With a good logic design, all functions of the above modules are implemented through programming, and all the programs can be run well after the integration tests for each module, thereby realizing the metadata open harvesting between the local and the internet, and providing customers with metadata repository query service. The lab environment doesn't equal to the practical environment, so this paper lists some problems need to be resolved and researched in the future.Based on the standardization of encode pattern and content semantic, Z39.50 can realize the interoperability between different information retrieve systems. This paper makes a brief comparison on interoperable mechanism and function between OAI and Z39.50. In order to improve the quality of OAI system, the following topics still need to be discussed: the decrease match default in metadata transform, the choice and optimization of query algorithm and the syndication of metadata in data provider's repository, etc.