Abstract:A comprehensive study about the spread of COVID-19 cases in Turkey and South Africa has been presented in this paper . An exhaustive statistical analysis encompassing arithmetic, geometric, harmonic means, standard deviation, skewness, variance, Pearson and Spearman correlation was derived from the data collected from Turkey and South Africa within the period of 11 . It was observed that in the case of Turkey, a negative Spearman correlation for the number of infected class and a positive Spearman correlation … Show more
“…It is very necessary to ensure that, the proposed optimal solution exists. For this reason, we employ Filippove-Cesari theorem as used in [37] . In this case, we show that, the existence of the optimal control solution is guaranteed if the following conditions are satisfied; The admissible control set is compact and bounded.…”
Section: Optimal Control On the Modelmentioning
confidence: 99%
“… A linear function in the state and control variables bound the state systems of differential equations. The convexity of the integrand of cost functional with respect to u on the set A [37] . …”
Section: Optimal Control On the Modelmentioning
confidence: 99%
“…We now have the Hessian matrix of the given cost functional as; Since the computed Hessian matrix above is everywhere positive definite, it follows that, the objective functional, Q ( u 1 , u 2 , u 3 , u 4 , u 5 ) is strictly convex [37] . We also have that, given that the integrand of the objective functional, holds under the condition Applying Pontryagin’s maximum principle where we have the state variables as and gives the Hamiltonian function; We now take into accounts the existence of the adjoint function λ i , such that they satisfy the equations; with the transversality condition given that ∀ u i where we have The optimal control strategies with respect to the befitting variation argument is given as; We progress with the numerical simulations on the optimal control by using the estimated parameters in Table 2 .…”
Highlights
COVID-19 spread dynamics with environmental compartment is proposed.
Global stability of the disease-free and endemic equilibria was obtain using Lyapunov’s function.
Global sensitivity analysis was studied.
A cost-effectiveness analysis presented.
“…It is very necessary to ensure that, the proposed optimal solution exists. For this reason, we employ Filippove-Cesari theorem as used in [37] . In this case, we show that, the existence of the optimal control solution is guaranteed if the following conditions are satisfied; The admissible control set is compact and bounded.…”
Section: Optimal Control On the Modelmentioning
confidence: 99%
“… A linear function in the state and control variables bound the state systems of differential equations. The convexity of the integrand of cost functional with respect to u on the set A [37] . …”
Section: Optimal Control On the Modelmentioning
confidence: 99%
“…We now have the Hessian matrix of the given cost functional as; Since the computed Hessian matrix above is everywhere positive definite, it follows that, the objective functional, Q ( u 1 , u 2 , u 3 , u 4 , u 5 ) is strictly convex [37] . We also have that, given that the integrand of the objective functional, holds under the condition Applying Pontryagin’s maximum principle where we have the state variables as and gives the Hamiltonian function; We now take into accounts the existence of the adjoint function λ i , such that they satisfy the equations; with the transversality condition given that ∀ u i where we have The optimal control strategies with respect to the befitting variation argument is given as; We progress with the numerical simulations on the optimal control by using the estimated parameters in Table 2 .…”
Highlights
COVID-19 spread dynamics with environmental compartment is proposed.
Global stability of the disease-free and endemic equilibria was obtain using Lyapunov’s function.
Global sensitivity analysis was studied.
A cost-effectiveness analysis presented.
“…The work of [8] has characterized the epidemic of COVID-19 in Heilongjiang province. For more works, interested readers are referred to [9] , [10] , [11] , [12] , [13] , [14] , [15] .…”
Highlights
A predictive COVID-19 model is considered.
The second wave of COVID-19 in Iran is studied.
Some predictive results of the peak epidemic outbreak are given.
Estimated times of the end of the epidemic in Iran in several scenarios are approximated in the plots.
The second wave of COVID-19 is predicated to happen between August and December 2020.
“…Some parameters were used to calibrate the parameters of the SIRD model on the reported COVID-19 cases in Hubei region, China, the selected model was used to forecast the evolution of the outbreak at the epicenter for three weeks ahead [16]. A comprehensive comparison was carried out on COVID-19 cases using some mathematical model between Turkey and South Africa [17]. It is against this background that this study attempts to model the daily cumulative active, critical and confirmed COVID-19 cases as it influences the number of reported deaths in Nigeria between 28 th of February to 6 th of July 2020, using count regression models like; Poisson Regression (PR), Negative Binomial Regression (NBR) and Generalized Poisson Regression (GPR) models.…”
COVID-19 is currently threatening countries in the world. Presently in Nigeria, there are about 29,286 confirmed cases, 11,828 discharged and 654 deaths as of 6th July 2020. It is against this background that this study was targeted at modeling daily cases of COVID-19’s deaths in Nigeria using count regression models like; Poisson Regression (PR), Negative Binomial Regression (NBR) and Generalized Poisson Regression (GPR) model. The study aim at fitting an appropriate count Regression model to the confirmed, active and critical cases of COVID-19 in Nigeria after 118 days. The data for the study was extracted from the daily COVID-19 cases update released by the Nigeria Centre for Disease Control (NCDC) online database from February 28th, 2020 – 6th, July 2020. The extracted data were used in the simulation of Poisson, Negative Binomial, and Generalized Poisson Regression model with a program written in STATA version 14 and fitted to the data at a 5% significance level. The best model was selected based on the values of -2logL, AIC, and BIC selection test/criteria. The results obtained from the analysis revealed that the Poisson regression could not capture over-dispersion, so other forms of Poisson Regression models such as the Negative Binomial Regression and Generalized Poisson Regression were used in the estimation. Of the three count Regression models, Generalized Poisson Regression was the best model for fitting daily cumulative confirmed, active and critical COVID-19 cases in Nigeria when overdispersion is present in the predictors because it had the least -2log-Likelihood, AIC, and BIC. It was also discovered that active and critical cases have a positive and significant effect on the number of COVID-19 related deaths in Nigeria.
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