Study And Application Of Key Technologies For Distributed Agricultural Science And Technology Information Sharing

With the quick development and widespread application of computer and network technology in agricultural domain, the amount of information which is collected, saved, processed and transmitted has grown rapidly. A lot of sharing and serving systems of agricultural science and technology information are constructed by different departments throughout our country. But these systems lack a unified plan and management in the important implementation techniques and storage technologies. The system heterogeneity and dynamic distribution become basic features of the systems at present. Particularly the heterogeneity in semantics results in information sharing's difficulty. And most agricultural information serving systems don't support the semantic association of retrieval information. Therefore, the efficiency and correction of information serving are unsatisfactory. Most of these systems cannot also provide the personalized information service according to a user's preference.Based on these conditions, this paper presents an architecture of the distributed agricultural science and technology information sharing based on middleware and metadata. Also the key technologies of the distributed agricultural science and technology information sharing are studied. To implement the integration of distributed agricultural science and technology information, this paper builds the metadata standards for agricultural science and technology information. Moreover, the metadata extracting method of automatic extraction based on middleware and artificial description is implemented. The metadata replica consistency controller technology is studied in detail in order to implement the metadata copy fault-tolerance and load-balanced. To implement the concept extending retrieving based on agricultural ontology, this paper studies the Chinese segmentation algorithm based on agriculture domain dictionary and semantics extending method based on agricultural ontology. To provide the personalization information services for users, this paper studies the methods of automatic modeling and artificial modeling to build a user interest model by which users'intent can be inferred. The retrieving results which satisfy users are obtained by users'personalization ontology. The information is pushed by the technology of polymerizing user groups'interest ontology and a person's interest ontology.According to the above key technologies and methods, the Tibet intelligent retrieval and sharing platform of distributional agricultural science and technology information is developed based on ASP.NET and SQL Server 2005. The platform can provide a public and unified data access interface of different distributed data sources for users to make full use of different distributed heterogeneous data resources. In the last experiment, the intelligent retrieval and sharing platform provided proves that the architecture and methods are effective.This paper incorporates several innovations. The architecture of the distributed agricultural science and technology information sharing based on the middleware technology is presented to support the integration service of agricultural science and technology information. Based on this, the automatic extracting and matching method of heterogeneous database model based on agriculture ontology is designed to improve the efficiency and correction of agriculture information intelligent retrieving in integration environment:. The automatic user interest modelling based on agricultural ontology is proposed to implement the personalization information services. The Tibet intelligent retrieval and sharing platform of distributed agricultural science and technology information is developed to verify the efficiency of the methods proposed by this paper.