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Kaitao He, China Geological Survey (China)
Yu Tang, National University of Defense Technology (China)
Keyan Xiao, Institute of Mineral Deposit (China)
Kaitao He, China Geological Survey (China)
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1. Introduction: Supported by national geological Program and the national high technology research and development (863) program of China, China Geological Survey begins to study and conducted a project on National Mineral Resource Assessment (NMRA). The enormous geological surveying data is collected and stored respectively, but these data distributed in more than thirty provinces of China will be centralized and integrated finally to implement all-around applications. We use web services, together with Open GIS Consortium specifications, to establish Geomatics Web Service (GWS) to implement NMRA. GWS is a collection of geological operations which is accessible through an interface and provides spatial application functions. GWS can make distributed NMRA process be completed on web. All work, such as data acquiring, sharing, collaborate processing, and etc, can be done by different data services and processing services.
2. Key issues of NMRA based on GWS: (1) Digital Mineral Deposit Model. Traditional mineral deposit model usually provides qualitative description of geological properties, tonnage, scale and genesis of a group of similar type of mineral deposits. These types of qualitative models provide guidelines for establishment of digital mineral deposit model which has been considered as a new research area. We established Digital Mineral Deposit Model including reasoning network and knowledgebase. The model and system were validated using a case study of porphyry copper deposits in China.
(2) GWS can make distributed NMRA process be completed on web. All work, such as data acquiring, data sharing, collaborate processing, and etc, can be done by different data services and processing services.We build the system architecture of NMRA based on GWS to describe system components, logic layers, and their relations.
(3) Flow model and selection method of GWS composition. Most of applications of NMRA need composition of multiple GWS to implement complicated work. The ability to efficiently and effectively integrate many GWS is referred as GWS composition. We studied and built the Flow model of GWS composition. A well-known problem with execution of service composition is the difficulty of selecting the appropriate services for the flow. Then we propose a GWS Dynamic Selection Model by defining a set of generic selection criteria (including service grade, reliability, invocation frequency etc) to implement optimum service instance selection.
3. Conclusions: Based on GWS composition, we implement a test-bed to demonstrate the validity of our concepts and methodology. We selects three-river area in southwest of China to implement mineral resource assessment. The experiment data are distributed in five nodes of three provinces, i.e., Yunnan, Sichuan and Tibet. This work will hopefully provide some theoretical and technical bases for subsequent research and practical applications of nationwide mineral resource assessment.
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