Modeling And Analysis Of Novel Coronavirus Epidemic Situation

Novel coronavirus pneumonia is a respiratory infectious disease caused by coronavirus.The outbreak of the novel coronavirus in 2020 has caused huge damage to society and economy of China.In the development of this epidemic,mathematical models are used to fit the epidemic data,assess the trend,and evaluate effectiveness of preventive measures to help us eliminate the epidemic as soon as posssible.This thesis firstly introduces some classic infectious disease compartment model,including SIR model,SEIR model,and SEIR-HDP model,and gives the calculation method of basic regeneration number of each model.Then,a basic regeneration number model derived from Lotka-Euler was used to calculate the basic regeneration number of the novel coronavirus epidemic which is between 2.6 and 4.The same method was used to calculate the basic regeneration number of SARS.By comparison,conclusion that pneumonia can be prevented and controlled can be obtained.In the view of the large error in the effective regeneration number calculated by above model,this paper establishes a time-varying parameter SEIR-DH model based on the classic infectious disease compartment model,and divides population into susceptible population,incubation period patient population,and onset patient population;uses the index function to control the change in the contact rate between incubation and confirmed patients to reflect the impact of measures such as isolation on the contact rate;changes the setting of the traditional model constant removal rate and uses removal rate over time.Finally,the solution method of the model parameters and the calculation method of the basic regeneration number and the effective regeneration number are given.This thesis modeled the national(except Hubei)outbreak data for 20 days since January 24,and obtained a mean absolute percentage error of 1.8%for fitted datas and 0.9%for the next 23 days.The fitting and prediction effects are very suitable for the data modeling of this epidemic.The model was used to predict the trend of epidemic situation,and it was concluded that the epidemic situation would last about 50 days and the number of infected people would eventually be around 14,000.The effects of epidemic prevention measures were compared by adjusting parameters,and it was concluded that current epidemic prevention measures have reduced the number of infected people and the duration of the epidemic situation.At the same time,it is pointed out that we should focus on the control of patients in incubation period.