Simulation Study On Key Problems In Large-scale Emergencies Response

In recent years,with the social development and transformation,deepening human practices and increasing complex of economic interests among people,emergencies including natural and man-made disasters occurred frequently,especially the large-scale ones which on one hand are prone to raise the public concern and lead to proliferation of rumors,and on the other hand,can cause large amount of wounded persons that need to be treated.In order to control the public opinion to prevent proliferation of rumors and improve the efficiency of treatment to decrease the casualties,this paper mainly focuses on the study of two key problems,i.e.spread and evolution of Internet rumors and allocation of medical resources,in emergency response with modeling and simulation approach,which provides theory basis for Internet rumors control and medical emergency management.The research contents are listed as follows:One is research on spread and evolution of Internet rumors and the coping strategies under large-scale emergencies.In this part,a system dynamics model is established in order to explore the rules of spread and evolution of Internet rumors when an emergency occurs.Firstly,the main forces which act on spread and evolution off Internet rumors,and their respective behavioral characteristics and motivations are figured out based on expert interviews and literature research.Then,in accordance with analysis of mutual causal impact between different factors influencing the spread of Internet rumors,system causal diagram and the main feedback loops are built centering on those acting forces.On the basis of system causal diagram,SD model including dynamics flow diagram and structural equations are constructed,in which SIR model is introduced to simulate the rumor dissemination among Netizens.Finally,the change trends of key variables in the system over time are obtained via simulation experiments,and their rationality is analyzed.In addition,the affect of the main control variables on rumor popularity is studied by changing their values,based on which government's coping strategies regarding rumors are analyzed.The other is the study on medical resources allocation in emergency.A simulation model based on patient-processed procedure is proposed while we are trying to allocate medical resources efficiently between regular patients and accident patients when a large scale emergent accident happens.In this model,time dependent health condition,diagnostic decision and confidence,and Bayesian prediction distribution based assessment duration and patient arrival interval are considered.Medical resources allocation scenarios are evaluated by an indicator based on death rate and average system stay.In simulation experiment part,(1)LXPM GA(genetic algorithm)is used to obtain the optimal resource allocation scenario.Besides,selection operator in LXPM GA is redesigned by comparing the optimizing time and quality of optimal solution of GA based on different selection operator;(2)Three resources allocation rules are compared,and the one based on patient scale is proved to be better than the other two rules,which provides efficient reference for hospitals to make emergency medical resources allocation decision and contingency plan.