Design And Implementation Of3D Object Query In Virtual High-Speed Railway Scene Based On Geo-Ontology

Constructing of the virtual high-speed railway environment has significant meanings for high-speed railway stimulation and management. However, there are several issues that limit the development of the construction work, for example, large amount of kinds and complex relationship of models are included in the virtual high-speed railway scene, and the integration of related disciplines are difficult. Thus, how to better define and manage the concepts and relationship of those models is a key point in virtual high-speed railway scene modeling. Geo-Ontology is a conceptual model in the information field of specified geographic space, which provides solutions to many puzzles in geographic information science, such as the conceptual models of geographic information system, geographic information’s expression and semantic interoperability, spatial data’s sharing and reusing, as well as spatial information services and their integration. The Geo-Ontology theory may help us to clearly define spatial and attribute relationship of the models in the virtual high-speed railway scene, which are used to accomplish automatic jointing and efficiently manage of those models. So this paper will focus on how to use the Geo-Ontology to implement3D objects queries in the virtual high-speed railway scene.This thesis firstly did a systematic analysis on Geo-Ontology’s definition, characteristics, classifications, as well as construction tools and methods, and deeply discussed the advantages of using Geo-Ontology in the virtual high-speed railway scene. Secondly, after the domain knowledge of the high speed system was analyzed, a Geo-Ontology construction method based on the conceptual relationship of the hierarchical organization was proposed to design the relationship structure of high-speed railway ontology, the object properties and numeric attribute of the high-speed railway ontology. Meantime, the strategy of the maintenance of ontology database was also discussed in detail. Thirdly, two kinds of query tools based on key words and mouse clicking were designed, and corresponding query methods and structures were also provided. Moreover, the procedure of query expansion based on the Geo-Ontology was further designed, and calculation methods of the similarity and correlation of those concepts in query expansion were explained. Finally, using the Protege and OWL language, a prototype system was developed to offer the query function in the virtual high-speed railway system. Experimental results show that the high-speed railway ontology has good usability in query of the virtual high-speed railway scene system. The methods addressed in this thesis are feasible.