Study On The Model And Key Technologies For Geographic Modeling Knowledge Service

With the rapid development of computer technology, geospatial information services and interoperability technology, there has been an exponential growth in the number of different geographic information and related services. Users can easily get a lot of relevant information and services which to their attentions. The popularity, knowledge and intelligence of geospatial information has become the focus of modern geospatial information services. However, as the volume of information and services grows, the accuracy, relevance and timeliness of the information and services is difficult to meet people's needs. It has appeared difficult for users to find the most relevant geospatial knowledge which they concern in the sea of geographic information and services. In addition, the real-time decision support provided by existing GIS spatial analysis cannot meet the needs of government or other users for the deficiency in technology of geographic information systems. To solve these problems, we can provide intelligent spatial decision analysis through sharing and reuse geospatial information and services based on provision of geospatial knowledge services. GIS have been developed from information services to the knowledge services. At present, there have appeared better technology for knowledge acquisition and expression. However, there is limited studies about modeling, inference, related management, and geospatial theoretical models and rules of inference. To make it easy for different users when using geospatial information and services, this paper proposed the concept of geospatial knowledge, information and services, geospatial knowledge service implementation model and re-extend the definition of the inference rules of geospatial knowledge and services to achieve geospatial knowledge services. The paper presents the research work through the following 5 aspects:(1) It deeply studied geospatial knowledge services from background, significance and target of applications. By sorting out the existing methods of geographic information service sharing, service chain combinations and related studies, it proposed the importance of the geospatial application and knowledge services. It achieved the application of geospatial knowledge and services by using formalized representation and applications of visualization to show existing knowledge and knowledge services.(2) There was deep studies of the basic concepts of geospatial knowledge which pointed out the relationship among data, information and services. It further defined the concept of geospatial knowledge according to definition of the concept and inherent relationship. The paper focuses on the basic characteristics of geospatial knowledge to meet its geospatial characteristics. At the same time, it further studied the geospatial knowledge acquisition, expression, modelling and inference, including research objects, theoretical basis and technical support, based on existing related methods about knowledge. Around the semantics, the paper focused more on the methods of visualization and formalization expression about the geospatial knowledge based on SWEET ontology and knowledge base technology.(3) The paper proposed the necessity of geospatial knowledge services and its development based on the definition of existing geospatial knowledge. It first proposed the theory of geospatial knowledge service concept model based on existing database. At the same time, the main details about building geospatial knowledge database were proposed to achieve intelligent management of geospatial knowledge and services which considering the ontology, geospatial knowledge management theory and geospatial information service chain theory. Besides, it proposed the use of semantic enhancement services, service-oriented knowledge processing methods, service chain regularization rules and knowledge inference methods to achieve the reuse of geospatial knowledge and services and intelligent choice.(4) It conducted much studies about the inference methods through bringing the spatial-temporal characteristic of geospatial knowledge. As a result, the geospatial knowledge services semantic spatial-temporal inference rules were created by extending the Jena's inference method with time and space constraints feature which can assist in improving the accuracy of the service selecting. The paper applied the existing methods of services composition to the composition inference of geospatial knowledge services. The method abstracted the domain knowledge as abstract service chain and achieved a composition inference of geospatial knowledge services using the current knowledge about specific services chains' inference. The semi-automated inference is a tremendous progress in the knowledge of geospatial services.(5) It designed related experiments about geospatial knowledge services to verify the theory and method, including the management portals of geospatial knowledge service and geospatial knowledge services inference.