Research On Knowledge Representation And Knowledge Reasoning Of Semantic Web

Knowledge representation, in brief, is the modeling for real world. At present, knowledge on the web has the following characteristics: (1) dynamic characteristics, information on the web is increasing or decreasing everyday; (2) A huge mount of information on the web is with contradictions;(3) contents on the web is open and distributed. Mostly files on the web are stored and transmitted in form of HTML (Hypertext Markup Language) . With the deep application of Web, the disadvantages of HTML become more and more obviously, one of them that web pages marked with HTML lacked of semantic and are not understood by computers. Nowdays, how to fastly extracts useful information and how to conveniently transmit, communication, acquire information from a huge of data on the web became hotspots noticed by high technology domain. This results in the appearance of semantic Web.In 2001, Tim burners-Lee, founder of WWW, mentioned the notion of semantic web, which was interested by people. In 2001, two special topic conferences were convened.Semantic Web was initated by Tim Berners-Lee, the founder of WWW, in 2001, and there is no doubt that the concepts attracted peoples' interests so greatly that two corresponding seminars were held then in that year. The main purpose of the Semantic Web was to enlarge current WWW, and in that way to make the information on Web semantic which can be understood by computers and easy for the communication and the cooperation between human and computer. Thus, the study emphasized particularly on the formats understood and handled by computer. Semantic Web and the logical reasoning regulations are constructed mainly based on XML and RDF for purposes of completing its knowledge representtation and the speculation understood by computers. The important contents in the study of Semantic Web include the Info-Indication, the Ontology, and Brainpower Ontology, and so forth, these are all interrelated. There are two levels of research in this Semantic Web and its logical speculation regulations, one is the logical formalized research task based on theories, actually the logical systems; the other one the ontological research based on the logical theories which can be regarded as the practical research.OWL (Web Ontology Language) developed on the basis on DAML+OIL, it can clearly express meanings of term on the glossary and relation between terms. Terms and relation between terms call Ontology. OWL holds more mechanism to express semantic than XML, RDF and RDF Schema. So OWL exceeds XML, RDF and RDF Schema only express the readable document on the Web by machine. But OWL will be helpness for representation of rule and range constraint of value property takes.Semantic Network, as the tool of knowledge representation in artificial intelligence domain, represents knowledge by directed graph, adapt to the logical reasoning. The SNetL ( Semantic Network Language) , which designed and developed by professor Xia Youming, is the formalized language of Semantic Network. The core is describing knowledge in the form of triple, realizing the separating idea by tab expression. The relations are handled as nodes to establish the relationships between the relations and to describe the meanings expressed by natural langeuage. This can provide better question putting and answering ability.As the tools of knowledge representation, OWL is similar to SNetL. They all can describe knowledge in the form of triple. This dissertation expound knowledge representation of OWLand SnetL in detail, and put forward the transformed methods of knowledge representation from OWL to SNetL, construct knowledgebase of common-software domain, reasoning for knowledge in common-software domain.