Recent Advances in Fractional Differential Equations, Delay Differential Equations and Their Applications

A special issue of Fractal and Fractional (ISSN 2504-3110). This special issue belongs to the section "General Mathematics, Analysis".

Deadline for manuscript submissions: closed (9 May 2022) | Viewed by 32543

Special Issue Editor


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Guest Editor
1. Section of Mathematics, International Telematic University Uninettuno, Corso Vittorio Emanuele II, 39, 00186 Roma, Italy
2. Department of Mathematics, Faculty of Science, Hadhramout University, Hadhramout 50512, Yemen
Interests: qualitative theory; ordinary differential equations; functional differential equations; dynamical systems; mathematical modeling
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

Differential equations both partial (PDE) and ordinary (ODE) give key tools in understanding the mechanisms of physical systems, and solving various problems of nonlinear phenomena. In particular, we mention diffusive processes as problems in elasticity theory and in the study of porous media.

Differential equations enable mathematics to be associated with other disciplines such as science, medicine, and engineering, since real-life problems in these fields give rise to differential equations which can only be solved using mathematics. Topics related to the theoretical and numerical aspects of differential equations have been undergoing tremendous development for decades. Numerical investigations in particular have played a decisive role in dynamical systems, control theory, and optimization, to name but a few areas. Indeed, the qualitative study of differential equations provide the appropriate framework setting to develop new inequalities and to consider different types of equations. On the other hand, these inequalities and equations are used to obtain useful estimates and bounds of terms in specific differential equations, but also in characterizing the solutions' set.

There is a large and very active community of scientists working on these topics, and focusing on their applications to dynamical programming, biology, information theory, statistics, physics, and engineering processes.

This Special Issue will collect ideas and significant contributions to the theories and applications of analytic inequalities, functional equations and differential equations. We welcome both original research articles and articles discussing the current state-of-the-art.

Dr. Omar Bazighifan
Guest Editor

Manuscript Submission Information

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Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Fractal and Fractional is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2700 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • fractional calculus
  • fractional differential equations
  • functional and difference equations
  • ODE
  • PDE
  • calculus of variations
  • dynamical systems
  • asymptotic analysis
  • potential theory
  • comparison methods
  • differential models in engineering and physical sciences

Published Papers (18 papers)

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Editorial

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3 pages, 193 KiB  
Editorial
Editorial for Special Issue “Recent Advances in Fractional Differential Equations, Delay Differential Equations and Their Applications”
by Omar Bazighifan
Fractal Fract. 2022, 6(9), 503; https://doi.org/10.3390/fractalfract6090503 - 8 Sep 2022
Viewed by 1048
Abstract
Differential equations, both fractional and ordinary, give key tools in understanding the mechanisms of physical systems and solving various problems of nonlinear phenomena [...] Full article

Research

Jump to: Editorial

15 pages, 366 KiB  
Article
Multivalent Functions and Differential Operator Extended by the Quantum Calculus
by Samir B. Hadid, Rabha W. Ibrahim and Shaher Momani
Fractal Fract. 2022, 6(7), 354; https://doi.org/10.3390/fractalfract6070354 - 24 Jun 2022
Cited by 9 | Viewed by 1424
Abstract
We used the concept of quantum calculus (Jackson’s calculus) in a recent note to develop an extended class of multivalent functions on the open unit disk. Convexity and star-likeness properties are obtained by establishing conditions for this class. The most common inequalities of [...] Read more.
We used the concept of quantum calculus (Jackson’s calculus) in a recent note to develop an extended class of multivalent functions on the open unit disk. Convexity and star-likeness properties are obtained by establishing conditions for this class. The most common inequalities of the proposed functions are geometrically investigated. Our approach was influenced by the theory of differential subordination. As a result, we called attention to a few well-known corollaries of our main conclusions. Full article
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11 pages, 367 KiB  
Article
Stationary Response of a Kind of Nonlinear Stochastic Systems with Variable Mass and Fractional Derivative Damping
by Shuo Zhang, Lu Liu and Chunhua Wang
Fractal Fract. 2022, 6(6), 342; https://doi.org/10.3390/fractalfract6060342 - 20 Jun 2022
Cited by 2 | Viewed by 1290
Abstract
Viscoelasticity and variable mass are common phenomena in Micro-Electro-Mechanical Systems (MEMS), and could be described by a fractional derivative damping and a stochastic process, respectively. To study the dynamic influence cased by the viscoelasticity and variable mass, stationary response of a kind of [...] Read more.
Viscoelasticity and variable mass are common phenomena in Micro-Electro-Mechanical Systems (MEMS), and could be described by a fractional derivative damping and a stochastic process, respectively. To study the dynamic influence cased by the viscoelasticity and variable mass, stationary response of a kind of nonlinear stochastic systems with stochastic variable-mass and fractional derivative, damping is investigated in this paper. Firstly, an approximately equivalent system of the studied nonlinear stochastic system is presented according to the Taylor expansion technique. Then, based on stochastic averaging of energy envelope, the corresponding Fokker–Plank–Kolmogorov (FPK) equation is deduced, which gives an approximated analytical solution of stationary response. Finally, a nonlinear oscillator with variable mass and fractional derivative damping is proposed in numerical simulations. The approximated analytical solution is compared with Monte Carlo numerical solution, which could verify the effectiveness of the obtained results. Full article
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11 pages, 402 KiB  
Article
A New Approach to Compare the Strong Convergence of the Milstein Scheme with the Approximate Coupling Method
by Yousef Alnafisah
Fractal Fract. 2022, 6(6), 339; https://doi.org/10.3390/fractalfract6060339 - 17 Jun 2022
Cited by 4 | Viewed by 1460
Abstract
Milstein and approximate coupling approaches are compared for the pathwise numerical solutions to stochastic differential equations (SDE) driven by Brownian motion. These methods attain an order one convergence under the nondegeneracy assumption of the diffusion term for the approximate coupling method. We use [...] Read more.
Milstein and approximate coupling approaches are compared for the pathwise numerical solutions to stochastic differential equations (SDE) driven by Brownian motion. These methods attain an order one convergence under the nondegeneracy assumption of the diffusion term for the approximate coupling method. We use MATLAB to simulate these methods by applying them to a particular two-dimensional SDE. Then, we analyze the performance of both methods and the amount of time required to obtain the result. This comparison is essential in several areas, such as stochastic analysis, financial mathematics, and some biological applications. Full article
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14 pages, 332 KiB  
Article
Contribution of Using Hadamard Fractional Integral Operator via Mellin Integral Transform for Solving Certain Fractional Kinetic Matrix Equations
by Mohamed Abdalla and Mohamed Akel
Fractal Fract. 2022, 6(6), 305; https://doi.org/10.3390/fractalfract6060305 - 31 May 2022
Cited by 14 | Viewed by 1441
Abstract
Recently, the importance of fractional differential equations in the field of applied science has gained more attention not only in mathematics but also in electrodynamics, control systems, economic, physics, geophysics and hydrodynamics. Among the many fractional differential equations are kinetic equations. Fractional-order kinetic [...] Read more.
Recently, the importance of fractional differential equations in the field of applied science has gained more attention not only in mathematics but also in electrodynamics, control systems, economic, physics, geophysics and hydrodynamics. Among the many fractional differential equations are kinetic equations. Fractional-order kinetic Equations (FOKEs) are a unifying tool for the description of load vector behavior in disorderly media. In this article, we employ the Hadamard fractional integral operator via Mellin integral transform to establish the generalization of some fractional-order kinetic equations including extended (k,τ)-Gauss hypergeometric matrix functions. Solutions to certain fractional-order kinetic matrix Equations (FOKMEs) involving extended (k,τ)-Gauss hypergeometric matrix functions are also introduced. Moreover, several special cases of our main results are archived. Full article
28 pages, 2516 KiB  
Article
Numerical Solutions of Variable-Coefficient Fractional-in-Space KdV Equation with the Caputo Fractional Derivative
by Che Han and Yu-Lan Wang
Fractal Fract. 2022, 6(4), 207; https://doi.org/10.3390/fractalfract6040207 - 7 Apr 2022
Cited by 13 | Viewed by 1907
Abstract
In this paper, numerical solutions of the variable-coefficient Korteweg-De Vries (vcKdV) equation with space described by the Caputo fractional derivative operator is developed. The propagation and interaction of vcKdV equation in different cases, such as breather soliton and periodic suppression soliton, are numerically [...] Read more.
In this paper, numerical solutions of the variable-coefficient Korteweg-De Vries (vcKdV) equation with space described by the Caputo fractional derivative operator is developed. The propagation and interaction of vcKdV equation in different cases, such as breather soliton and periodic suppression soliton, are numerically simulated. Especially, the Fourier spectral method is used to solve the fractional-in-space vcKdV equation with breather soliton. From numerical simulations and compared with other methods, it can be easily seen that our method has low computational complexity and higher precision. Full article
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17 pages, 376 KiB  
Article
Inequalities for Fractional Integrals of a Generalized Class of Strongly Convex Functions
by Tao Yan, Ghulam Farid, Hafsa Yasmeen, Soo Hak Shim and Chahn Yong Jung
Fractal Fract. 2022, 6(3), 168; https://doi.org/10.3390/fractalfract6030168 - 18 Mar 2022
Cited by 1 | Viewed by 1579
Abstract
Fractional integral operators are useful tools for generalizing classical integral inequalities. Convex functions play very important role in the theory of mathematical inequalities. This paper aims to investigate the Hadamard type inequalities for a generalized class of functions namely strongly [...] Read more.
Fractional integral operators are useful tools for generalizing classical integral inequalities. Convex functions play very important role in the theory of mathematical inequalities. This paper aims to investigate the Hadamard type inequalities for a generalized class of functions namely strongly (α,hm)-p-convex functions by using Riemann–Liouville fractional integrals. The results established in this paper give refinements of various well-known inequalities which have been published in the recent past. Full article
16 pages, 346 KiB  
Article
Fractional p(·)-Kirchhoff Type Problems Involving Variable Exponent Logarithmic Nonlinearity
by Jiabin Zuo, Amita Soni and Debajyoti Choudhuri
Fractal Fract. 2022, 6(2), 106; https://doi.org/10.3390/fractalfract6020106 - 12 Feb 2022
Cited by 2 | Viewed by 1438
Abstract
In this paper, we investigate a fractional p(·)-Kirchhoff type problem involving variable exponent logarithmic nonlinearity. With the help of the Nehari manifold approach, the existence and multiplicity of nontrivial weak solutions for the above problem are obtained. The main [...] Read more.
In this paper, we investigate a fractional p(·)-Kirchhoff type problem involving variable exponent logarithmic nonlinearity. With the help of the Nehari manifold approach, the existence and multiplicity of nontrivial weak solutions for the above problem are obtained. The main aspect and challenges of this paper are the presence of double non-local terms and logarithmic nonlinearity. Full article
11 pages, 303 KiB  
Article
Asymptotic Behavior of Solutions of Even-Order Differential Equations with Several Delays
by Osama Moaaz and Wedad Albalawi
Fractal Fract. 2022, 6(2), 87; https://doi.org/10.3390/fractalfract6020087 - 3 Feb 2022
Cited by 3 | Viewed by 1139
Abstract
The higher-order delay differential equations are used in the describing of many natural phenomena. This work investigates the asymptotic properties of the class of even-order differential equations with several delays. Our main concern revolves around how to simplify and improve the oscillation parameters [...] Read more.
The higher-order delay differential equations are used in the describing of many natural phenomena. This work investigates the asymptotic properties of the class of even-order differential equations with several delays. Our main concern revolves around how to simplify and improve the oscillation parameters of the studied equation. For this, we use an improved approach to obtain new properties of the positive solutions of these equations. Full article
22 pages, 366 KiB  
Article
Some Novel Fractional Integral Inequalities over a New Class of Generalized Convex Function
by Soubhagya Kumar Sahoo, Muhammad Tariq, Hijaz Ahmad, Bibhakar Kodamasingh, Asif Ali Shaikh, Thongchai Botmart and Mohammed A. El-Shorbagy
Fractal Fract. 2022, 6(1), 42; https://doi.org/10.3390/fractalfract6010042 - 13 Jan 2022
Cited by 22 | Viewed by 2253
Abstract
The comprehension of inequalities in convexity is very important for fractional calculus and its effectiveness in many applied sciences. In this article, we handle a novel investigation that depends on the Hermite–Hadamard-type inequalities concerning a monotonic increasing function. The proposed methodology deals with [...] Read more.
The comprehension of inequalities in convexity is very important for fractional calculus and its effectiveness in many applied sciences. In this article, we handle a novel investigation that depends on the Hermite–Hadamard-type inequalities concerning a monotonic increasing function. The proposed methodology deals with a new class of convexity and related integral and fractional inequalities. There exists a solid connection between fractional operators and convexity because of its fascinating nature in the numerical sciences. Some special cases have also been discussed, and several already-known inequalities have been recaptured to behave well. Some applications related to special means, q-digamma, modified Bessel functions, and matrices are discussed as well. The aftereffects of the plan show that the methodology can be applied directly and is computationally easy to understand and exact. We believe our findings generalise some well-known results in the literature on s-convexity. Full article
14 pages, 1358 KiB  
Article
An Implicit Numerical Approach for 2D Rayleigh Stokes Problem for a Heated Generalized Second Grade Fluid with Fractional Derivative
by Anam Naz, Umair Ali, Ashraf Elfasakhany, Khadiga Ahmed Ismail, Abdullah G. Al-Sehemi and Ahmed A. Al-Ghamdi
Fractal Fract. 2021, 5(4), 283; https://doi.org/10.3390/fractalfract5040283 - 20 Dec 2021
Cited by 5 | Viewed by 2120
Abstract
In this research work, our aim is to use the fast algorithm to solve the Rayleigh–Stokes problem for heated generalized second-grade fluid (RSP-HGSGF) involving Riemann–Liouville time fractional derivative. We suggest the modified implicit scheme formulated in the Riemann–Liouville integral sense and the scheme [...] Read more.
In this research work, our aim is to use the fast algorithm to solve the Rayleigh–Stokes problem for heated generalized second-grade fluid (RSP-HGSGF) involving Riemann–Liouville time fractional derivative. We suggest the modified implicit scheme formulated in the Riemann–Liouville integral sense and the scheme can be applied to the fractional RSP-HGSGF. Numerical experiments will be conducted, to show that the scheme is stress-free to implement, and the outcomes reveal the ideal execution of the suggested technique. The Fourier series will be used to examine the proposed scheme stability and convergence. The technique is stable, and the approximation solution converges to the exact result. To demonstrate the applicability and viability of the suggested strategy, a numerical demonstration will be provided. Full article
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19 pages, 330 KiB  
Article
A Study on Controllability of a Class of Impulsive Fractional Nonlinear Evolution Equations with Delay in Banach Spaces
by Daliang Zhao
Fractal Fract. 2021, 5(4), 279; https://doi.org/10.3390/fractalfract5040279 - 17 Dec 2021
Cited by 7 | Viewed by 1792
Abstract
Under a new generalized definition of exact controllability we introduced and with a appropriately constructed time delay term in a special complete space to overcome the delay-induced-difficulty, we establish the sufficient conditions of the exact controllability for a class of impulsive fractional nonlinear [...] Read more.
Under a new generalized definition of exact controllability we introduced and with a appropriately constructed time delay term in a special complete space to overcome the delay-induced-difficulty, we establish the sufficient conditions of the exact controllability for a class of impulsive fractional nonlinear evolution equations with delay by using the resolvent operator theory and the theory of nonlinear functional analysis. Nonlinearity in the system is only supposed to be continuous rather than Lipschitz continuous by contrast. The results obtained in the present work are generalizations and continuations of the recent results on this issue. Further, an example is presented to show the effectiveness of the new results. Full article
15 pages, 423 KiB  
Article
Solvability of a New q-Differential Equation Related to q-Differential Inequality of a Special Type of Analytic Functions
by Ibtisam Aldawish and Rabha W. Ibrahim
Fractal Fract. 2021, 5(4), 228; https://doi.org/10.3390/fractalfract5040228 - 17 Nov 2021
Cited by 9 | Viewed by 1409
Abstract
The current study acts on the notion of quantum calculus together with a symmetric differential operator joining a special class of meromorphic multivalent functions in the puncher unit disk. We formulate a quantum symmetric differential operator and employ it to investigate the geometric [...] Read more.
The current study acts on the notion of quantum calculus together with a symmetric differential operator joining a special class of meromorphic multivalent functions in the puncher unit disk. We formulate a quantum symmetric differential operator and employ it to investigate the geometric properties of a class of meromorphic multivalent functions. We illustrate a set of differential inequalities based on the theory of subordination and superordination. In this real case study, we found the analytic solutions of q-differential equations. We indicate that the solutions are given in terms of confluent hypergeometric function of the second type and Laguerre polynomial. Full article
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11 pages, 8705 KiB  
Article
Extreme Multistability of a Fractional-Order Discrete-Time Neural Network
by A. Othman Almatroud
Fractal Fract. 2021, 5(4), 202; https://doi.org/10.3390/fractalfract5040202 - 5 Nov 2021
Cited by 10 | Viewed by 1633
Abstract
At present, the extreme multistability of fractional order neural networks are gaining much interest from researchers. In this paper, by utilizing the fractional -Caputo operator, a simple fractional order discrete-time neural network with three neurons is introduced. The dynamic of this model [...] Read more.
At present, the extreme multistability of fractional order neural networks are gaining much interest from researchers. In this paper, by utilizing the fractional -Caputo operator, a simple fractional order discrete-time neural network with three neurons is introduced. The dynamic of this model are experimentally investigated via the maximum Lyapunov exponent, phase portraits, and bifurcation diagrams. Numerical simulation demonstrates that the new network has various types of coexisting attractors. Moreover, it is of note that the interesting phenomena of extreme multistability is discovered, i.e., the coexistence of symmetric multiple attractors. Full article
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21 pages, 372 KiB  
Article
Analytical Study of Two Nonlinear Coupled Hybrid Systems Involving Generalized Hilfer Fractional Operators
by Mohammed A. Almalahi, Omar Bazighifan, Satish K. Panchal, S. S. Askar and Georgia Irina Oros
Fractal Fract. 2021, 5(4), 178; https://doi.org/10.3390/fractalfract5040178 - 22 Oct 2021
Cited by 21 | Viewed by 1371
Abstract
In this research paper, we dedicate our interest to an investigation of the sufficient conditions for the existence of solutions of two new types of a coupled systems of hybrid fractional differential equations involving ϕ-Hilfer fractional derivatives. The existence results are established [...] Read more.
In this research paper, we dedicate our interest to an investigation of the sufficient conditions for the existence of solutions of two new types of a coupled systems of hybrid fractional differential equations involving ϕ-Hilfer fractional derivatives. The existence results are established in the weighted space of functions using Dhage’s hybrid fixed point theorem for three operators in a Banach algebra and Dhage’s helpful generalization of Krasnoselskii fixed- point theorem. Finally, simulated examples are provided to demonstrate the obtained results. Full article
14 pages, 2016 KiB  
Article
An Efficient Stochastic Numerical Computing Framework for the Nonlinear Higher Order Singular Models
by Zulqurnain Sabir, Hafiz Abdul Wahab, Shumaila Javeed and Haci Mehmet Baskonus
Fractal Fract. 2021, 5(4), 176; https://doi.org/10.3390/fractalfract5040176 - 20 Oct 2021
Cited by 48 | Viewed by 1597
Abstract
The focus of the present study is to present a stochastic numerical computing framework based on Gudermannian neural networks (GNNs) together with the global and local search genetic algorithm (GA) and active-set approach (ASA), i.e., GNNs-GA-ASA. The designed computing framework GNNs-GA-ASA is tested [...] Read more.
The focus of the present study is to present a stochastic numerical computing framework based on Gudermannian neural networks (GNNs) together with the global and local search genetic algorithm (GA) and active-set approach (ASA), i.e., GNNs-GA-ASA. The designed computing framework GNNs-GA-ASA is tested for the higher order nonlinear singular differential model (HO-NSDM). Three different nonlinear singular variants based on the (HO-NSDM) have been solved by using the GNNs-GA-ASA and numerical solutions have been compared with the exact solutions to check the exactness of the designed scheme. The absolute errors have been performed to check the precision of the designed GNNs-GA-ASA scheme. Moreover, the aptitude of GNNs-GA-ASA is verified on precision, stability and convergence analysis, which are enhanced through efficiency, implication and dependability procedures with statistical data to solve the HO-NSDM. Full article
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27 pages, 5257 KiB  
Article
A Deep Learning BiLSTM Encoding-Decoding Model for COVID-19 Pandemic Spread Forecasting
by Ahmed I. Shahin and Sultan Almotairi
Fractal Fract. 2021, 5(4), 175; https://doi.org/10.3390/fractalfract5040175 - 19 Oct 2021
Cited by 20 | Viewed by 2893
Abstract
The COVID-19 pandemic has widely spread with an increasing infection rate through more than 200 countries. The governments of the world need to record the confirmed infectious, recovered, and death cases for the present state and predict the cases. In favor of future [...] Read more.
The COVID-19 pandemic has widely spread with an increasing infection rate through more than 200 countries. The governments of the world need to record the confirmed infectious, recovered, and death cases for the present state and predict the cases. In favor of future case prediction, governments can impose opening and closing procedures to save human lives by slowing down the pandemic progression spread. There are several forecasting models for pandemic time series based on statistical processing and machine learning algorithms. Deep learning has been proven as an excellent tool for time series forecasting problems. This paper proposes a deep learning time-series prediction model to forecast the confirmed, recovered, and death cases. Our proposed network is based on an encoding–decoding deep learning network. Moreover, we optimize the selection of our proposed network hyper-parameters. Our proposed forecasting model was applied in Saudi Arabia. Then, we applied the proposed model to other countries. Our study covers two categories of countries that have witnessed different spread waves this year. During our experiments, we compared our proposed model and the other time-series forecasting models, which totaled fifteen prediction models: three statistical models, three deep learning models, seven machine learning models, and one prophet model. Our proposed forecasting model accuracy was assessed using several statistical evaluation criteria. It achieved the lowest error values and achieved the highest R-squared value of 0.99. Our proposed model may help policymakers to improve the pandemic spread control, and our method can be generalized for other time series forecasting tasks. Full article
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13 pages, 311 KiB  
Article
The Solutions of Some Riemann–Liouville Fractional Integral Equations
by Karuna Kaewnimit, Fongchan Wannalookkhee, Kamsing Nonlaopon and Somsak Orankitjaroen
Fractal Fract. 2021, 5(4), 154; https://doi.org/10.3390/fractalfract5040154 - 6 Oct 2021
Cited by 6 | Viewed by 2284
Abstract
In this paper, we propose the solutions of nonhomogeneous fractional integral equations of the form [...] Read more.
In this paper, we propose the solutions of nonhomogeneous fractional integral equations of the form I0+3σy(t)+a·I0+2σy(t)+b·I0+σy(t)+c·y(t)=f(t), where I0+σ is the Riemann–Liouville fractional integral of order σ=1/3,1,f(t)=tn,tnet,nN{0},tR+, and a,b,c are constants, by using the Laplace transform technique. We obtain solutions in the form of Mellin–Ross function and of exponential function. To illustrate our findings, some examples are exhibited. Full article
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