Luo Xiangang

Research of Service Oriented Spatial Information Grid Technology

With the spatial information’s continuous expansion and increased popularity, the amount of the spatial information grow explosively, and the current services have not meet the needs of accessing to and processing spatial information. This thesis starts with the grid technology, doing researches to services oriented spatial information grid technology, focusing on the basic model and security of grid, and researching on the spatial information grid which has the capacity of on-demand services, as well as can integrated organize and coordination process massive of distributed spatial information resources. At last, this thesis proposes a spatial information service architecture design model based on the environment of grid, and has carried on the preliminary discussion to the grid spatial information service, as well as has implemented a simple grid services model.

The Application and Realization of Map Search Engine in WEBGIS

With the development of internet, especially the widespread of network electronic map, the spatial information on internet is increasing amazingly. Then how to search the wanted information from the massive spatial information fast and accurately is needed to resolve. At this background, spatial search engine based on internet grows up quickly. At the same time, how to display map data in client by the map search engine is important in the research. In this paper, I will mainly introduce the current condition and key techniques of map search engine and design the system structure based on it. In addition, I will realize the work flow and give the prototype of map search engine in WEBGIS application.

A Webgis Load-Balancing Algorithm Based on Collaborative Task Clustering

This paper analyzes deficiencies of load-balancing technologies in the current webgis and discusses the necessity and feasibility to solve load-balancing in webgis through server farms. A new distributed dynamic scheduling model based on server farms is given. A webgis load-balancing algorithm based on collaborative task clustering is proposed. The new algorithm divides the collaborative computing task into n subtasks; then generates collaborative task clustering; at last, dynamically allocate them to every gis server which is in the above model. It maximizes the execution time of collaborative spatial computing; effectively improve the utilization and the parallel processing capacity of webgis; provides faster and better webgis service for users. A test-bed is established. A series of test results prove that the algorithm has good global load balancing performance.