Reasoning In Semantic Query Execution In A Distributed Environment

Semantic Web is an extension of the WWW (World Wide Web), which aims to elevate simpledata in WWW to semantic layer, so that we can share knowledge in an easier way and use machineto process data more efficiently. Ontology theory is one of the key techniques to achieve SemanticWeb. It focuses on object classification, object attributes and object relations of knowledge in acertain domain. Semantic reasoning is an important link in developing Semantic Web. To ontologycreators, semantic reasoning checks conflicts in ontology definition and optimizes the model; whileto ontology users, semantic reasoning unveils knowledge beneath the data.This research mainly studies semantic query reasoning in a distributed environment, in otherwords, querying semantic data using reasoning. There are two approaches at present:materialization and query rewriting. We conducted a comparison between these two approacheswith the help of Amazon cloud computing service and LUBM. The result shows that queryrewriting is more feasible than materialization when data grows to a large scale. Based on thisconclusion, we developed an application which can be used to query and manage semantic data inan distributed environment. The application can also be used as a prototype of similar practicalsystems and a tool for other Semantic Web researches.