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1.
Chaos Solitons Fractals ; 140: 110107, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33519107

RESUMO

We present a mathematical model for the transmission of COVID-19 by the Caputo fractional-order derivative. We calculate the equilibrium points and the reproduction number for the model and obtain the region of the feasibility of system. By fixed point theory, we prove the existence of a unique solution. Using the generalized Adams-Bashforth-Moulton method, we solve the system and obtain the approximate solutions. We present a numerical simulation for the transmission of COVID-19 in the world, and in this simulation, the reproduction number is obtained as R 0 = 1 : 610007996 , which shows that the epidemic continues.

2.
PLoS One ; 19(7): e0300590, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38950034

RESUMO

This research manuscript aims to study a novel implicit differential equation in the non-singular fractional derivatives sense, namely Atangana-Baleanu-Caputo ([Formula: see text]) of arbitrary orders belonging to the interval (2, 3] with respect to another positive and increasing function. The major results of the existence and uniqueness are investigated by utilizing the Banach and topology degree theorems. The stability of the Ulam-Hyers ([Formula: see text]) type is analyzed by employing the topics of nonlinear analysis. Finally, two examples are constructed and enhanced with some special cases as well as illustrative graphics for checking the influence of major outcomes.


Assuntos
Algoritmos , Modelos Teóricos , Dinâmica não Linear
3.
ISA Trans ; 124: 103-114, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-33867134

RESUMO

In this paper, a fractional-order SIRD mathematical model is presented with Caputo derivative for the transmission of COVID-19 between humans. We calculate the steady-states of the system and discuss their stability. We also discuss the existence and uniqueness of a non-negative solution for the system under study. Additionally, we obtain an approximate response by implementing the fractional Euler method. Next, we investigate the first and the second waves of the disease in Iran and Japan; then we give a prediction concerning the second wave of the disease. We display the numerical simulations for different derivative orders in order to evaluate the efficacy of the fractional concept on the system behaviors. We also calculate the optimal control of the system and display its numerical simulations.


Assuntos
COVID-19 , Número Básico de Reprodução , COVID-19/epidemiologia , Humanos , Irã (Geográfico)/epidemiologia , Japão , Modelos Teóricos
4.
Adv Differ Equ ; 2020(1): 490, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32952538

RESUMO

We provide a SEIR epidemic model for the spread of COVID-19 using the Caputo fractional derivative. The feasibility region of the system and equilibrium points are calculated and the stability of the equilibrium points is investigated. We prove the existence of a unique solution for the model by using fixed point theory. Using the fractional Euler method, we get an approximate solution to the model. To predict the transmission of COVID-19 in Iran and in the world, we provide a numerical simulation based on real data.

5.
Adv Differ Equ ; 2020(1): 299, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32572336

RESUMO

We present a fractional-order model for the COVID-19 transmission with Caputo-Fabrizio derivative. Using the homotopy analysis transform method (HATM), which combines the method of homotopy analysis and Laplace transform, we solve the problem and give approximate solution in convergent series. We prove the existence of a unique solution and the stability of the iteration approach by using fixed point theory. We also present numerical results to simulate virus transmission and compare the results with those of the Caputo derivative.

6.
Springerplus ; 5(1): 882, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27386330

RESUMO

We investigate in this manuscript the existence of solution for two fractional differential inclusions. At first we discuss the existence of solution of a class of fractional hybrid differential inclusions. To illustrate our results we present an illustrative example. We study the existence and dimension of the solution set for some fractional differential inclusions.

7.
Philos Trans A Math Phys Eng Sci ; 371(1990): 20120144, 2013 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-23547222

RESUMO

In this paper, by using fixed-point methods, we study the existence and uniqueness of a solution for the nonlinear fractional differential equation boundary-value problem D(α)u(t)=f(t,u(t)) with a Riemann-Liouville fractional derivative via the different boundary-value problems u(0)=u(T), and the three-point boundary condition u(0)=ß(1)u(η) and u(T)=ß(2)u(η), where T>0, t∈I=[0,T], 0<α<1, 0<η

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