Quick Search Of Spatial Information Services In Hybrid Network

With gradually expanding into kinds of applications, Geographic Information Systems is becoming more socialization and popularity. It has developed into the Spatial Information Science from the traditional sense of information system. A notable feature of the network and popular Spatial Information Science is the development of spatial information sharing technology, which is especially performed in widely used applications of spatial information services.Currently, the spatial information services research is mainly concerning the service itself, including the construction and content of services, the content and processing way of supported data, the service functions, etc. However, with the continues increasing demand and development of related techniques, the following issues have been emerged:1. Along with the widespread application of Web Service technology, the quantity of spatial information service has sharply increased. How to quickly identify, locate and access the target spatial information services has become a new subject;2. Because the spatial information has some characters such as massive, heterogeneous, having different sources, the spatial information service is different from other ordinary Web Service. Hence, what kind of supported network could provide the spatial information services on time more efficiently?3. To search services rapidly and use services accurately, what kind of search algorithm is more efficient?This paper takes the above problems as a start, with "Quick search of spatial information services in hybrid network" as the key point, carries out an in-depth study from supporting the network environment and quick search algorithm. The expected results include quick locating, identifying and accessing to spatial information services in network, improving the efficiency of using spatial information services, and promoting the sharing of spatial information services.This paper’s main findings are as follows:1. Spatial Information Service System Architecture StudyBecause the system architecture is the basis of spatial information services research, this paper studies a variety of the architectures which appear in the developing process of information services. Their respective advantages and disadvantages are analyzed and integrated with OGSA system, also, a system architecture based on hybrid network spatial information service is proposed. The system can effectively guide the definition of spatial information services, deployment and access, etc.2. Spatial Information Services ResearchIn this paper, classifications and characteristics of the space information service are firstly studied, followed by in-depth study of the spatial information service model, and combined with registered and unregistered service, a Spatial Information Service Model based on the Regional Registration Center is proposed. The model well solves the current problem of spatial information services--"where to register" and "how to register". Then combination of spatial information services is studied, in which could provide a more effective delivery of spatial information services capacity. Finally, with the study of the service package, this paper conducted a spatial information service SOAP package.3.Research on Hybrid NetworkAfter an in-depth study of both Grid and a P2P single network, considering the advantages of each network, this paper proposes a hybrid network model, strictly defines the network topology, and studies the establishment and maintenance of hybrid networks. The presenting and defining of Hybrid network provides a good support to service network, it overcomes the grid system scalability shortcomings and besides, abandons scattered contents in P2P systems, effectively improves the spatial information services to quickly identify the network environment.4. Quick Search AlgorithmSearch algorithm is the key point of the quick search of spatial information services, this paper studies the quick Kad routing algorithm, and makes effective improvements in a hybrid network environment. Based on the searching for space information service, this paper presents an active search (not registered) and passive search (based on registration), and a detailed definition of the content of these two approaches. In improved Kad algorithm, this paper makes an in-depth study of the network nodes query and location, and effectively improves the search node routing. In addiition, this paper establishes a rapid index for those spatial information service information which has been registered or has been searched, including Chinese word segmentation and the inverted index, so that spatial information services could be more quickly and efficient.5. Experiment SimulationThis paper carried out a large number of simulation experiments, including defining the experimental scenarios, making coverage of statistics and effective analysis to experimental data.The results verify the effectiveness and possibility of the algorithm.