Design And Research On Query Subsystem Of Railway Over-gauge And Overload Goods Transportation Based On MapXtreme Java

Railway is the main artery of national economy. There is a lot of information about facilities and business in railway. To establish special railway information system which manage these information meet the needs of China Railway Information Plan, and it is the sign of railway modernization. The transportation of railway over-gauge and overload goods mainly meet the demand of national large-scale projects and the construction of national defense. So the safe, rapid transportation of these goods has deep influence on the whole national economy and national defense modernization. The transportation of railway over-gauge and overload goods has strict technical requirement and complex organization work, and a lot of work, such as measure, compute, are still on the manual stage. Thus how to assure the effective and safe transportation of railway over-gauge and overload goods by modern information methods is becoming an important problem.This thesis is based on the Administration of Railways' project named Railway Over-gauge and Overload Transportation Information System. We develop the Query Subsystem of Railway Over-gauge and Overload Goods Transportation by GIS technologies because of the trait and basic work flow of railway over-gauge and overload goods transportation which has to manage a lot of geographic and spatial data. And we use the MapXtreme Java platform which is a product of MapInfo Company to develop this subsystem.This thesis analyses the function needs of the subsystem and deeply research relative technologies about the system, such as the obtaining and storage methods of geographic and spatial data, the hierarchy of API, Web deployment and so on. We design the system frame, software architecture and implementing methods of some key functions through the medium client develop mode of MapXtreme Java. The subsystem visualizes much information of railway over-gauge and overload goods transportation which is invisible in the past, and it make the management and business analysis of railway over-gauge and overload goods transportation more convenience.There are some special conditions, such as cannot pass line and necessary nodes, in the path search of railway over-gauge and overload goods transportation. The innovative point of this thesis is putting forward a best path search algorithm for railway over-gauge and overload goods transportation based on deep analysis and research of relative shortest path search algorithm in GIS domain. According to the relative measure data of over-gauge and overload goods, this algorithm can automatically initialize the railway network. Then the algorithm computes the shortest path of each section which is divided by the sorted necessary nodes and gets a feasible best path at last. The algorithm has good performance in practical application.