Study Of Science And Technology Information Portal Technology

A scientific and technological information portal is a domain-oriented and integrated vertical portal. Its implementation involves applications of some key technologies associated with topic-specific Web information discovery, distributed heterogeneous information integrated retrieval and personalized information dissemination. This thesis focuses on the technologies of topic-specific Web information discovery. After a comprehensive examination of general Web information discovery (search engine) technologies, several fundamental problems of topic-specific Web information discovery are analyzed. Then some algorithmic models and theories of topic-specific Web crawling are studied. Underlain by these models and theories, a crawling algorithm based on "tunneling" and Bayes classification is explored and a mathematical function model of tunneling distance for this algorithm is established, and moreover the practical procedure of this crawling algorithm is discussed. Finally, aiming at the technological implementation of the Web information resource organization capability of the scientific and technological information portal of General Equipment Department of China, a scheme of a topic-specific Web information discovery system which named i-Scape is proposed, and some coding experiments of its core modules are conducted.