Study Of Network Analysis In GIS Route Program Of Policeman Tour And Its Application

Going into action rapidly for policemen is one of the bases of preventing and striking criminal cases to seriously harm the national and the public security. Besides timely response to the report of an incident to the police that can provide correct route for policemen to set out, the shortest route is a general factor to ensure policemen arrive at the scene in time. Generally, it is impossible to arrange the police force in all of streets and crossings, and there is a main path that the sentinel patrolmen waited post and the patrol in their jurisdictional area form a state including both movement and motionless, to satisfy the requirement of timely going in to action for policemen. By applying network analysis method, this work studies three problems: how to find out a good path that policemen arrive at the accident site as soon as possible, how to design the sentinel patrolman post so that the policemen can arrive at the areas that cases appear frequently within the specified time from the post, and the shortest ergodic path when a petrol path traversing all of the streets in the jurisdictional area is given.At first, the GIS system characteristics are analyzed, the mathematical models for the GIS system are presented and the shortest base path algorithm in network analysis is also discussed. An example from the actual geographical information of urban district of Nanning City is taken by using quad-fork heap sort and subgraph division method, which demonstrates the efficiency of the presented modified algorithm. Secondly, based on the modified Dijkstra algorithm, the distribution of the sentinel patrolman waited post is calculated by using linear programming method, to provide the basis for arrangement analysis of sentinel patrolman waited post through linear programming method. Based on the Chinese postman problem solving ideas, the solving step of the patrol routes is given by application of Hungary method. At the same time, Hungary method is improved to avoid the cycle of death problem because of its arbitrary selection zero. Then the solving method of regional patrol optimal path planning in the jurisdictional area is established. The results showed that the related algorithm even for the whole urban district of Nanning City is convergence very well and is an efficient method.The application examples of police GWP system show that the method established in this paper has good value.