On Study Of The Emergency Transportation Routing Selection Problems Optimization

In recent years, with the global warming, the melting glaciers and the degradation of theenvironment, the natural disasters happened become more and more frequently. Successivedeterioration of the ecological environment and the natural environment resulted in thedecline of the human living conditions and quality of life. China has broad terrain. The naturaldisasters, which threatened the people life and property safety seriously, even causedenormous economic losses and casualties, brought negative influence to people’s normal life,such as floods, typhoons, landslides and earthquakes still occur. Therefore, it is veryimportant for the government to establish a reasonable and efficient plan for disastersreduction, ensure the operational efficient for the rescue system, decrease the damage fromnatural disasters as possible. The selection of emergency transportation vehicle routing is thekey to provide the relief supplies timely and accurately. However, the path optimization ofemergency background is relatively complex, for example, the main factors including thearrival time for all disaster points, the connectivity of the path, the scheduling of vehiclesneed to consider, which belongs to multi-objective optimization problem.In view of the above-mentioned facts, This paper reviewed the research status atdomestic and abroad for the vehicle routing problems, and then introduced the basic theoryknowledge, which mainly included the classification of the vehicle routing problems and thevehicle routing problems’ model, the analysis of the emergency vehicle routing’s factors, thebasic methods of genetic algorithm and multi-objective optimization. And built upon thisbasic, on the background of natural disasters, according to the characteristics of emergencylogistics, aimed at the network topology structure under different environment, applying therelevant knowledge of operational research, we proposed two different models. The firstmodel which mainly considered the dynamic change of post-earthquake on road, and on thebasis of the network structure that one rescue center transports materials to the other disasterpoints, and the vehicle speed is set as a continuous function followed by time, established theoptimization model in order to minimize time and maximization the road connectivity. Giventhere are many distastes region asked one rescue center for help, we designed the secondmodel with hard time windows, and the objective functions is to optimize the distance andused vehicles’ numbers.Combined with the features of each model, this article solved them from different pointof view respectively. Two network diagrams with21nodes and31nodes was designed as theexample of the first model respectively, this multi-objective problem was converted intosingle objective problem, we traversed all valid path and compared with differentexperimental parameters, and found the corresponding path when the value of weighted decision utility could attain its maximum. Whereas genetic algorithm has the potentialeffectiveness in dealing with complex problem, the second model utilized push forwardinsertion heuristic for generating initial solution, chose the arena’s principle for constructingPareto optimal solution, designed multi-objective genetic algorithm, and the numericalexample was inspired by Solomon data set and changed some data, and then we obtained thesatisfied solution, verified the feasibility and effectiveness of this idea. This paper can providea reference for emergency management personnel who make rescue activities when thenatural disasters happened, and it can also help them formulate the corresponding rescue plan.