A Metadata-based Search Engine Design And Realization

The development of Internet makes it a huge base of information, but the quality of information obtainment does not get ahead. The most of traditional search engines are based on matching of key words, so they don't have capacity of understanding documents on Internet, which result in the low accuracy of searching. This paper provides a new searching model based on Metadata and RDF. Metadata is data about data, while RDF is a good tool that describes and carries metadata. Because computer can understand the meaning of metadata carried by RDF, our searching engine can provide information retrieval based on concept or content. This system includes four modules: design of vocabularies, a tool for generating RDF description, a run-at-server procedure to collecting and parsing RDF description and a B/S procedure for user to retrieve. The vocabulary defines a set of metadata that is used to describe resources. The RDF generating tool help user to describe resource on Internet. There are two ways of description, one is embedding RDF information into web pages in the form of XML Island, the other is directly sending RDF description information to RDF document buffer at the searching engine server; RDF collecting and parsing module's responsibility is searching web pages which is described by RDF, then storing them to RDF documents buffer in the form of text file, RDF Parser will parse RDF doc in these text files to triples which is stored at index database; finally, retrieve module provides interface for user to retrieve, and display the retrieve result in the form of metadata.In addition, we have researched the controlled vocabulary and the automatic generation of metadata, which is used to perfect the mechanism we provide. Vcabulary can make description and query more convenient, and the latter can make the system more automatic.