Optimization On Emergency Facility Location And Patrol Routing Problem Against Pirate Attacks

China adheres to the basic state policy of opening up and actively promotes high-level opening up.Customs statistics show that in 2022,the total value of China’s imports and exports in goods exceeded 42 trillion yuan,keeping China as the world’s largest trading nation in goods for six consecutive years.Maritime transport plays an important role in international trade transportation with its significant advantages of large volume and low cost,while frequent pirate attacks seriously threaten the safety of maritime transportation and international trade.In order to effectively prevent and combat piracy crimes,this thesis studies the emergency facility location and patrol route problems.On the one hand,establishing emergency facilities with reasonable layout can realize emergency rescue when pirate attacks occur;on the other hand,scientifically arranging patrol routes of patrol boats can prevent potential pirate attacks and reduce the probability of pirate attacks.The main work of this thesis are as follows:(1)Establish a projection pursuit model to evaluate the risk of pirate attacks incidents.The pirate attack incident points are divided into general risk level points and high risk level points,which will lay the foundation for the subsequent research on emergency facility location and patrol route optimization.(2)Establish a two-stage optimization model of emergency facility location and patrol route against pirate attacks.In the first stage,factors such as fairness,timeliness,and the different in the demand for emergency response services among pirate attack accidents with different risk levels are considered.Based on this,the first stage model was constructed to realize the minimum of distance risk from emergency facilities to the pirate attack point and the minimum construction cost of emergency facilities,and realize the full coverage of emergency facilities for general risk level piracy attack points and the key coverage of high risk level points.In the second stage,optimize patrol route with the goal of minimizing the total patrol cost of the patrol boat.Among them,all pirate attack incident points of past are patrolled,and highrisk points are patrolled with focus and frequency.Then,according to the two-stage characteristics of the model,a two-stage heuristic algorithm is designed to solve the problem.(3)Taking part of the Strait of Malacca as the research area for example application analysis.A real-coded accelerating genetic algorithm is introduced to solve the projection pursuit model to realize the risk assessment and division.Then,the two-stage model is solved by a two-stage heuristic algorithm.The calculation results show that the final emergency facility location scheme can achieve full coverage of general risk level points and key coverage of high risk level points,and the patrol path can realize the overlapping patrol of high risk level points by patrol boats.The results verified the scientificity and effectiveness of the model and algorithm built in this thesis.This thesis further enriches the relevant theory of the pirate attack problem.The established emergency facility location and patrol routing model provides a reference for systematically dealing with piracy attacks and provides a basis for relevant departments to make decisions about piracy prevention and control.It has practical significance to ensure the smooth advancement of China’s opening to the outside world and the safety of maritime transportation.