Modeling And Simulation Analysis Of Crowd Evacuation Behavior Under Terrorist Attack

In recent years,terrorist attacks have attracted the extensive attention of the international community and gradually evolved into a global problem.Terrorist attacks will not only cause damage to public facilities but seriously lead to casualties.Therefore,how to quickly evacuate people from terrorist attacks to safe places is an urgent problem to be solved.At present,emergency evacuation is an effective means to solve terrorist attacks and reduce casualties.Existing models are not suitable for evacuation simulation in 3D space terrorist attack scenes,since they largely ignore the influence of obstacles.In this paper,the terrorist attack scene is modeled in three-dimensional space and the impact of obstacles on the evacuation of obstacles.The ability to understand the movement of pedestrians and attackers,as well as the impact of the environment on casualties,which is conducive to the treatment of terrorist attacks to reduce casualties,also provides assistance to the prediction of attackers.In response to the above problems,firstly,this paper proposes a dual role crowd simulation model in 3D space.The model consists of four components: the map,pedestrian,attacker,and interaction models.The main contribution is as follows:(1)The model is 3D,the people and obstacles occupying the ground area have height.(2)Expand the foundation model,design a new shortest path function to calculate static situations and dynamic situations.(3)We model the attacker’s field of view and consider in detail whether the obstacles block the attacker’s line of sight.In addition,the motion movement of the attacker moves the mechanics method,calculating the attraction of each pedestrian in the field of view,to determine the direction of movement.The entire model has strong adaptability and flexibility,can meet the variable emergency response needs,and can accurately study the evacuation movement of the crowd in terrorist attacks.Secondly,this paper also proposes an information acquisition and distribution capability model of terrorist attacks from the perspective of managers.The information acquisition capability means that the manager can only get the position of an attacker at a specified area,which indicates the high and low of the information acquisition capability.This article adds a monitoring area in space,increasing the record of memory,and changing the probability density function of pedestrian movement.Make the model easily adjust the monitoring area.In addition,the information distribution capability means that the manager issues the time interval of the attacker location information,the length of the time interval represents the high and low of the administrator information publishing capability.Add a timer in the model while updating the person’s memory field based on the timer,thereby changing the probability density function.This model starts from the perspective of public places managers,simulating the evacuation of crowds under terrorist attacks,and effectively helps public places to develop management programs.Finally,the impact of studying obstacles and information integrity in terrorist attacks on crowd evacuation.The obstacles in terrorist attacks will hinder the mobile routes and directions of pedestrians,and the evacuation is negative.However,tall obstacles not only block attackers and hinder the attacker’s mobile route,protect pedestrians,play a positive effect on evacuation.Therefore,the obstacle is in terrorist attacks to put "double-edged sword".The model in this paper was used to conduct 300 experiments.We get data from each experiment,the death toll,and evacuation time to evaluate the efficiency of crowd evacuation.The following conclusions are drawn:(1)A single obstacle in front of the exit is more conducive to evacuation than no obstacle.(2)higher-density obstacles can better protect pedestrians from being chased by attackers,and(3)the direction of the aisle formed between obstacles should be consistent with the direction of the exit so that pedestrians can be evacuated more efficiently to reduce the death toll.In particular,we also discovered two interesting phenomena,namely,circle and dispersion which also explain why fewer deaths occur in the presence of high-density obstacles.In addition,the information acquisition capacity has been experimentally,and the monitoring area of the appropriate size is conducive to the evacuation of the population.