Study On Semantic Service Discovery And Service Chain Of Land Resource Information

With the further development of land resource informationization, the sharing of land resource and the intergration of various processing functionality have been widely adopted based on the Web Service technology. However the complexity of business processing tasks necessitates the combination of basic atom Web Services to user-oriented and application-specific service compositions. Recently the maturity of Web Services, proposal of semantic Web and the service composition serves as an effective way to share geospatial information service and to integrate the service chain.This dissertation, on the basis of OGC Web Service Framework, aims to propose a service composition oriented service chain model for land resource by combining the theories and methods of semantic Web Service discovery to composition, geospatial information service and land information management. Therefore, semantic descriptions of land information service and association rules between services can be established. A solution to composite land resource information service based on intelligent planning can be designed. Finally, a prototype platform for discovery, composition and execution of land resource information semantic services can be realized. The main research work are as follows:1. Semantic annotation and semantic web service model for land information service are discussed; and association rules of land management business are described based on logic description language. A service composition oriented service chain model, which is geared to integrated association rules and semantic web service, is proposed.2. Based on the analysis of vertical management mechanism of land resources in China, a distributed service metadata repository involving three levels, that is, province-city-county is established. Registration and retrieval of shared land resource data and service are implemented according to the ebXML Registry Information Model (ebRIM) and Catalogue Service Specification (CSW).3. Spatiotemporal evolution of land resource is analyzed. From the perspective of land resource change among the spatio-temporal process database, the present database and the past database, the service composition problems corresponding to business process of land resource management is translated to intelligent plan problem of service composition. Plan domain and problem for land service composition are defined. A solution to composite land resource information service based on intelligent plan is designed.4. On the basis of these theories and methods, a prototype platform for service catalogue and service chain integration of land resource information services is established.The result shows that the service chain integration model of land resource information based on intelligent plan can take full advantage of geospatial information service and service composition method, and can achieve semantic integration and heterogeneous data and services share. Service publication, periodic harvest of remote metadata and distributed search are implemented by the multi-level catalogue service, which can realize fully share and discovery of data and service of land resource owned by different level administrative department. A prototype platform of land resource service catalogue and service composition is established. Automatic service composition and dynamic execution was achieved to some extent. Service composition method proposed in this paper enriches the means of GIS service chain integration and provides a new approach to the realization of GIS service chain.