| The New Coronary Pneumonia(COVID-19)epidemic is the world’s fastest spreading,most widely infected,and most difficult to prevent and control public health emergencies in the past100 years,and it poses a huge challenge to the emergency management capabilities of governments around the world in dealing with unconventional emergencies.It is well known that viruses can spread rapidly due to population movement,especially in public places like ticket halls,restaurants and supermarkets,where there are complex internal structures and frequent population movements,which can easily induce virus transmission and increase the risk of epidemics.Therefore,the research on crowd behavior modeling,crowd behavior patterns and prevention and control strategies in the context of epidemic prevention and control is of great practical significance to accurately study and judge the transmission pathways of the epidemic and contain its spread.At present,existing studies on COVID-19 epidemics mainly explore the spatial diffusion characteristics of disease transmission at large scales(e.g.,country-to-country,provincial and municipal scales,etc.)at the macro level,but not enough attention is paid to the spatio-temporal aggregation characteristics of crowds at small scales at the micro level,for example,little is known about the influence of daily interactions between people and individual behaviors on disease transmission in buildings.Therefore,in this paper,based on the microscopic scale of the internal space of buildings,based on the social force model,for different evacuation scenarios such as indoor positioning service points and sudden hazard sources in pedestrian passages,considering the behavioral characteristics of daily activities of the crowd and the psychology of epidemic prevention,establishing the local interaction rules of individual movements,establishing the disease transmission model of coupled pedestrian movements,the two-way pedestrian traffic dynamics model and the emergency evacuation of the crowd respectively.Through corresponding numerical simulations,we focus on the psychological and behavioral characteristics of the crowd in the context of epidemic prevention and control,explore the main factors affecting disease spread and evacuation time,and reveal the generation and evolution laws of disease spread speed and crowd congestion for evacuation.At the same time,the process and path of disease transmission and the optimization strategy of traffic organization for emergency crowd evacuation are studied for the outbreak of epidemic,and the research results can provide useful theoretical basis and decision-making reference for relevant departments in the precise prevention and control of epidemic and the optimization of emergency crowd evacuation path.The main work of this paper is as follows:(1)Considering the transmission of strong infectious diseases under unconventional health emergencies,we propose a disease transmission model with coupled pedestrian movement based on the social force model and introduce the "disease transmission factor" to establish the rule of change of pedestrian transmission level,and classify pedestrians into two infection levels:susceptible pedestrians and infected pedestrians.At the same time,a "dynamic disease transmission distance" is introduced to determine the local interaction rules between the two types of pedestrians.Through data simulation,we focus on the effects of different infection rates,infection radius,number of service points and window service hours on disease transmission,and discuss and analyze the formation mechanism of macroscopic phenomena induced by different factors.The results of the study show that the new model demonstrates the typical population macroscopic phenomena in disease transmission(e.g.congestion,arching and "fast is slow" effect);the fast and slow disease transmission is positively correlated with the infection rate and dynamic infection distance,and negatively correlated with the number of service points and window service time.This work reproduces the mechanism of human-to-human transmission of diseases at the microscopic scale,and provides useful references for scientific and precise prevention and control of outbreaks.(2)Considering that pedestrians have anti-epidemic psychology towards people wearing masks,the "psychological avoidance force coefficient" is introduced to describe pedestrians’ avoidance behavior,and its magnitude indirectly reflects the degree of pedestrians’ psychological avoidance,so as to establish the interaction between pedestrians and avoidance rules,and construct a two-way pedestrian traffic flow model with psychological anti-epidemic effect.The focus is on the effect of the psychological size of prevention on the overall movement efficiency of two-way pedestrian flow,and the mechanism of the formation of the intra-system chaos induced by pedestrian avoidance of pedestrians wearing masks.It is shown that the new model can show the complex nonlinear phenomena of "formation","free phase","coexistence phase" and "congestion phase" of two-way pedestrian flow.The new model can show the complex nonlinear phenomena such as "formation","free phase","coexistence phase" and "congestion phase" of two-way pedestrian flow.In addition,by introducing the velocity entropy,the transformation and evolution law of pedestrian orderly and disorderly movement states in two-way pedestrian flow is explored.The above research helps to precisely implement prevention and control measures to prevent the spread of the epidemic,and provides a useful theoretical basis for epidemic prevention and control.(3)An improved social force group evacuation model and two new crowd emergency evacuation strategies are proposed by considering the psychological and behavioral differences between patients and non-patients,establishing the form of local interaction forces between patients and non-patients.The advantages and disadvantages between different evacuation strategies used by pedestrians and their effects on disease transmission rates are focused on,and the formation mechanisms of macroscopic phenomena induced by different kinds of evacuation strategies(such as the generation and evolution of clusters)are analyzed and discussed.The results of the study show that the evacuation strategy of isolating patients in place is more effective in inhibiting the spread of disease and reducing the risk of disease transmission than the strategy of evacuating patients through special channels.The above study can provide useful reference for dynamic prevention and emergency control of public health emergencies in public places. |
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