[Retracted] A Multiobjective Optimization Model for Prevention and Control of Coronavirus Disease 2019 in China

Table 1

Symbols of key variates.

Symbol	Unit	Description
N	Person	Total population
s(t)	%	Percentage of the infected at time t in the total population
i(t)	%	Percentage of patients at time t in the total population
e(t)	%	Percentage of the susceptible at time t in the total population
r(t)	%	Percentage of the recovered at time t in the total population
	%	Percentage of the susceptible diagnosed as normally infected per day
	%	Percentage of the susceptible diagnosed as infected per day
h	%	Remove ratio (the sum of death rate and recover rate per day)
λ	Person	Daily contracting ratio (the mean number of people infected by a patient through contact)
	$	Fixed cost of setting up i storages
	$	Subsidy of medical staff
	$	Transport cost of each dose per unit of distance
	day	Travel time from i to j
	day	Time threshold of vaccine delivery (violating the threshold will bring a penalty cost)
	Dose	Quantity of vaccines delivered from i to j
	km	Distance between i and j
	Dose	Vaccine demand of j
	Group	Number of medical groups delivered from i to j
β	—	Ratio of the infected to medical staff
I	Person	Number of the infected
	km/h	Vaccine delivery speed from storages to the epidemic prefecture
	Dose/day	Vaccine production speed
	Person	Number of medical staff delivered from i to j
	Dose	The drug storage capacity of the i-th inventory point