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Boundary Value Problem for the Langevin Equation and Inclusion with the Hilfer Fractional Derivative Langevin方程的边值问题及Hilfer分数阶导数的包含
IF 1.6 Q2 MATHEMATICS, APPLIED Pub Date : 2022-03-11 DOI: 10.1155/2022/3386198
K. Hilal, A. Kajouni, Hamid Lmou
In this work, we discuss the existence and uniqueness of solution for a boundary value problem for the Langevin equation and inclusion with the Hilfer fractional derivative. First of all, we give some definitions, theorems, and lemmas that are necessary for the understanding of the manuscript. Second of all, we give our first existence result, based on Krasnoselskii’s fixed point, and to deal with the uniqueness result, we use Banach’s contraction principle. Third of all, in the inclusion case, to obtain the existence result, we use the Leray–Schauder alternative. Last but not least, we give an illustrative example.
本文讨论了一类Langevin方程边值问题解的存在唯一性,以及包含Hilfer分数阶导数。首先,我们给出了理解手稿所必需的一些定义、定理和引理。其次,我们给出了基于Krasnoselskii不动点的第一个存在性结果,并利用Banach的收缩原理处理唯一性结果。第三,在包含情况下,为了得到存在性结果,我们使用了Leray-Schauder替代。最后但并非最不重要的是,我们给出一个说明性的例子。
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引用次数: 2
Dynamics of Mosquito Population Models with Spatial Diffusion 具有空间扩散的蚊子种群动态模型
IF 1.6 Q2 MATHEMATICS, APPLIED Pub Date : 2021-12-29 DOI: 10.1155/2021/9034274
U. Traoré
In this paper, we study some reaction-diffusion models of interactive dynamics of the wild and sterile mosquitoes. The well-posedness of the concerned model is proved. The stability of the steady states is discussed. Numerical simulations are presented to illustrate our theoretical results.
本文研究了野生蚊子和不育蚊子相互作用动力学的一些反应扩散模型。证明了该模型的适定性。讨论了稳态的稳定性。数值模拟结果说明了我们的理论结果。
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引用次数: 0
Analytical Solutions for the Equal Width Equations Containing Generalized Fractional Derivative Using the Efficient Combined Method 含广义分数阶导数等宽方程的有效组合解法
IF 1.6 Q2 MATHEMATICS, APPLIED Pub Date : 2021-12-22 DOI: 10.1155/2021/7066398
M. Derakhshan
<jats:p>In this paper, the efficient combined method based on the homotopy perturbation Sadik transform method  (HPSTM) is applied to solve the physical and functional equations containing the Caputo–Prabhakar fractional derivative. The mathematical model of this equation of order <jats:inline-formula> <math xmlns="http://www.w3.org/1998/Math/MathML" id="M1"> <mi>μ</mi> <mo>∈</mo> <mfenced open="(" close="]" separators="|"> <mrow> <mn>0,1</mn> </mrow> </mfenced> </math> </jats:inline-formula> with <jats:inline-formula> <math xmlns="http://www.w3.org/1998/Math/MathML" id="M2"> <mi>λ</mi> <mo>∈</mo> <msup> <mrow> <mi>ℤ</mi> </mrow> <mrow> <mo>+</mo> </mrow> </msup> <mo>,</mo> <mi>θ</mi> <mo>,</mo> <mi>σ</mi> <mo>∈</mo> <msup> <mrow> <mi>ℝ</mi> </mrow> <mrow> <mo>+</mo> </mrow> </msup> </math> </jats:inline-formula> is presented as follows: <jats:inline-formula> <math xmlns="http://www.w3.org/1998/Math/MathML" id="M3"> <mmultiscripts> <mrow> <msubsup> <mstyle displaystyle="true"> <mi mathvariant="fraktur">D</mi> </mstyle> <mi>t</mi> <mi>μ</mi> </msubsup> </mrow> <mprescripts /> <none /> <mi>C</mi> </mmultiscripts> <mi>u</mi> <mfenced open="(" close=")" separators="|"> <mrow> <mi>x</mi> <mo>,</mo> <mi>t</mi> </mrow> </mfenced> <mo>+</mo> <mi>θ</mi> <msup> <mrow> <mi>u</mi> </mrow
本文提出了一种基于同伦微扰Sadik变换方法的高效组合方法 (HPSTM)用于求解包含Caputo–Prabhakar分数导数的物理和函数方程。μ∈0,1阶方程的数学模型ℤ + , θ,σ∈ℝ + 表示如下:D tμC u x,t+θuλx,t u x x,t−σu x x tx、t=0时,其中对于λ=1,θ=1,σ=1s和λ=2、θ=3,σ=1时,将方程分别转化为等宽方程和修正的等宽方程。我们用来求解这个方程的分析方法是基于同伦微扰方法和Sadik变换的结合。本文讨论了收敛性和误差分析。给出了三个实例的分析结果图,以表明该数值方法的适用性。并与其它方法进行了比较。
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引用次数: 1
The Method Based on Series Solution for Identifying an Unknown Source Coefficient on the Temperature Field in the Quasiperiodic Media 基于级数解的准周期介质温度场未知源系数识别方法
IF 1.6 Q2 MATHEMATICS, APPLIED Pub Date : 2021-12-22 DOI: 10.1155/2021/2893299
Bingxian Wang, C. Bai, M. Xu, L. Zhang
In this paper, we consider the reconstruction of heat field in one-dimensional quasiperiodic media with an unknown source from the interior measurement. The innovation of this paper is solving the inverse problem by means of two different homotopy iteration processes. The first kind of homotopy iteration process is not convergent. For the second kind of homotopy iteration process, a convergent result is proved. Based on the uniqueness of this inverse problem and convergence results of the second kind of homotopy iteration process with exact data, the results of two numerical examples show that the proposed method is efficient, and the error of the inversion solution r t is given.
在本文中,我们考虑从内部测量中重建具有未知源的一维准周期介质中的热场。本文的创新之处在于利用两种不同的同伦论迭代过程来求解逆问题。第一类仿射迭代过程是不收敛的。对于第二类仿射迭代过程,证明了一个收敛结果。基于这一逆问题的唯一性和具有精确数据的第二类仿射迭代过程的收敛性,两个算例的结果表明,该方法是有效的,并给出了反演解的误差r t。
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引用次数: 0
An Effective Solution of the Cube-Root Truly Nonlinear Oscillator: Extended Iteration Procedure 三根真非线性振子的有效解:扩展迭代法
IF 1.6 Q2 MATHEMATICS, APPLIED Pub Date : 2021-12-21 DOI: 10.1155/2021/7819209
B. Haque, M. Hossain
The cube-root truly nonlinear oscillator and the inverse cube-root truly nonlinear oscillator are the most meaningful and classical nonlinear ordinary differential equations on behalf of its various applications in science and engineering. Especially, the oscillators are used widely in the study of elastic force, structural dynamics, and elliptic curve cryptography. In this paper, we have applied modified Mickens extended iteration method to solve the cube-root truly nonlinear oscillator, the inverse cube-root truly nonlinear oscillator, and the equation of pendulum. Comparison is made among iteration method, harmonic balance method, He’s amplitude-frequency formulation, He’s homotopy perturbation method, improved harmonic balance method, and homotopy perturbation method. After comparison, we analyze that modified Mickens extended iteration method is more accurate, effective, easy, and straightforward. Also, the comparison of the obtained analytical solutions with the numerical results represented an extraordinary accuracy. The percentage error for the fourth approximate frequency of cube-root truly nonlinear oscillator is 0.006 and the percentage error for the fourth approximate frequency of inverse cube-root truly nonlinear oscillator is 0.12.
三根真非线性振子和逆三根真非线性振子是最有意义和最经典的非线性常微分方程,代表了它在科学和工程上的各种应用。特别是振子在弹性力、结构动力学和椭圆曲线密码学的研究中得到了广泛的应用。本文应用改进的Mickens扩展迭代法求解了三根真非线性振子、逆三根真非线性振子和摆方程。对迭代法、谐波平衡法、何氏幅频公式、何氏同伦摄动法、改进谐波平衡法和同伦摄动法进行了比较。通过比较,分析了改进的Mickens扩展迭代法更准确、有效、简单、直观。此外,所得到的解析解与数值结果的比较表明了非凡的准确性。三根真非线性振子四次近似频率的百分比误差为0.006,逆三根真非线性振子四次近似频率的百分比误差为0.12。
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引用次数: 2
Parameter-Uniform Numerical Scheme for Singularly Perturbed Delay Parabolic Reaction Diffusion Equations with Integral Boundary Condition 具有积分边界条件的奇摄动时滞抛物型反应扩散方程的参数一致数值格式
IF 1.6 Q2 MATHEMATICS, APPLIED Pub Date : 2021-12-10 DOI: 10.1155/2021/9993644
Wakjira Tolassa Gobena, G. Duressa
Numerical computation for the class of singularly perturbed delay parabolic reaction diffusion equations with integral boundary condition has been considered. A parameter-uniform numerical method is constructed via the nonstandard finite difference method for the spatial direction, and the backward Euler method for the resulting system of initial value problems in temporal direction is used. The integral boundary condition is treated using numerical integration techniques. Maximum absolute errors and the rate of convergence for different values of perturbation parameter ε and mesh sizes are tabulated for two model examples. The proposed method is shown to be parameter-uniformly convergent.
研究了一类具有积分边界条件的奇摄动时滞抛物型反应扩散方程的数值计算。在空间方向上采用非标准有限差分法构造参数一致数值方法,在时间方向上采用倒推欧拉法求解初值问题。用数值积分技术处理积分边界条件。给出了两个模型实例在不同扰动参数ε值和网格尺寸下的最大绝对误差和收敛速度。该方法具有参数一致收敛性。
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引用次数: 12
Electric Transverse Emissivity of Sinusoidal Surfaces Determined by a Differential Method: Comparison with Approximation of Geometric Optics 用微分法确定正弦波表面的电横向发射率:与几何光学近似的比较
IF 1.6 Q2 MATHEMATICS, APPLIED Pub Date : 2021-11-29 DOI: 10.1155/2021/1506485
Taoufik Ghabara
We present in this paper a numerical study of the validity limit of the optics geometrical approximation in comparison with a differential method which is established according to rigorous formalisms based on the electromagnetic theory. The precedent studies show that this method is adopted to the study of diffraction by periodic rough surfaces. For periods much larger than the wavelength, the mechanism is analog to what happens in a cavity where a ray is trapped and undergoes a large number of reflections. For gratings with a period much smaller than the wavelength, the roughness essentially behaves as a transition layer with a gradient of the optical index. Such a layer reduces the reflection there by increasing the absorption. The code has been implemented for TE polarization. We determine by the two methods such as differential method and the optics geometrical approximation the emissivity of gold and tungsten cylindrical surfaces with a sinusoidal profile, for a wavelength equal to 0.55 microns. The obtained results for a fixed height of the grating allowed us to delimit the validity domain of the optic geometrical approximation for the treated cases. The emissivity calculated by the differential method and that given on the basis of the homogenization theory are satisfactory when the period is much smaller than the wavelength.
本文对光学几何近似的有效性极限进行了数值研究,并与基于电磁理论的严格形式建立的微分方法进行了比较。前人的研究表明,该方法适用于周期性粗糙表面衍射的研究。对于比波长大得多的周期,这种机制类似于在一个腔中发生的事情,在这个腔中,射线被捕获并经历了大量的反射。对于周期远小于波长的光栅,粗糙度本质上表现为具有光学指数梯度的过渡层。这样一层通过增加吸收来减少那里的反射。该代码已实现的TE极化。我们用微分法和光学几何近似两种方法测定了波长为0.55微米的金和钨的正弦形圆柱表面的发射率。对于固定高度的光栅,所得到的结果使我们能够对所处理的情况划定光学几何近似的有效域。当周期远小于波长时,用微分法计算的发射率和根据均匀化理论计算的发射率是令人满意的。
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引用次数: 0
Global Bifurcation of Fourth-Order Nonlinear Eigenvalue Problems’ Solution 四阶非线性特征值问题解的全局分岔
IF 1.6 Q2 MATHEMATICS, APPLIED Pub Date : 2021-11-26 DOI: 10.1155/2021/7516324
Fatma Aydin Akgun
In this paper, we study the global bifurcation of infinity of a class of nonlinear eigenvalue problems for fourth-order ordinary differential equations with nondifferentiable nonlinearity. We prove the existence of two families of unbounded continuance of solutions bifurcating at infinity and corresponding to the usual nodal properties near bifurcation intervals.
本文研究了一类具有不可微非线性的四阶常微分方程的非线性特征值问题的无穷大全局分支。我们证明了在无穷远处分岔的解的两个无界连续族的存在性,它们对应于分岔区间附近的常见节点性质。
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引用次数: 0
A New Conformable Fractional Derivative and Applications 一种新的适形分数阶导数及其应用
IF 1.6 Q2 MATHEMATICS, APPLIED Pub Date : 2021-11-26 DOI: 10.1155/2021/6245435
A. Kajouni, A. Chafiki, K. Hilal, Mohamed Oukessou
<jats:p>This paper is motivated by some papers treating the fractional derivatives. We introduce a new definition of fractional derivative which obeys classical properties including linearity, product rule, quotient rule, power rule, chain rule, Rolle’s theorem, and the mean value theorem. The definition <jats:inline-formula> <math xmlns="http://www.w3.org/1998/Math/MathML" id="M1"> <mfenced open="(" close=")" separators="|"> <mrow> <msup> <mrow> <mi>D</mi> </mrow> <mrow> <mi>α</mi> </mrow> </msup> <mi>f</mi> </mrow> </mfenced> <mfenced open="(" close=")" separators="|"> <mrow> <mi>t</mi> </mrow> </mfenced> <mo>=</mo> <munder> <mrow> <mtext>lim</mtext> </mrow> <mrow> <mi>h</mi> <mo>⟶</mo> <mn>0</mn> </mrow> </munder> <mfenced open="(" close=")" separators="|"> <mrow> <mrow> <mrow> <mfenced open="(" close=")" separators="|"> <mrow> <mi>f</mi> <mfenced open="(" close=")" separators="|"> <mrow> <mi>t</mi> <mo>+</mo> <mi>h</mi> <msup> <mrow> <mi>e</mi> </mrow> <mrow> <mfenced open="(" close=")" separators="|"> <mrow> <mi>α</mi> <mo>−</mo> <mn>1</mn> </mrow>
本文的动机是一些关于分数导数的论文。我们引入了一个新的分数导数定义,它遵循经典性质,包括线性、乘积规则、商规则、幂规则、链式规则、罗尔定理和中值定理。定义Dαft=lim h⟶ 0 ft+h eα−1t−ft/h对于所有t>0,且α∈0,1。如果α=0,这个定义与函数f的一阶的经典定义一致。
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引用次数: 10
Mathematical Analysis and Optimal Control of Giving up the Smoking Model 戒烟模型的数学分析与最优控制
IF 1.6 Q2 MATHEMATICS, APPLIED Pub Date : 2021-11-25 DOI: 10.1155/2021/8673020
Omar Khyar, J. Danane, K. Allali
In this study, we are going to explore mathematically the dynamics of giving up smoking behavior. For this purpose, we will perform a mathematical analysis of a smoking model and suggest some conditions to control this serious burden on public health. The model under consideration describes the interaction between the potential smokers P , the occasional smokers L , the chain smokers S , the temporarily quit smokers Q T , and the permanently quit smokers Q P . Existence, positivity, and boundedness of the proposed problem solutions are proved. Local stability of the equilibria is established by using Routh–Hurwitz conditions. Moreover, the global stability of the same equilibria is fulfilled through using suitable Lyapunov functionals. In order to study the optimal control of our problem, we will take into account a two controls’ strategy. The first control will represent the government prohibition of smoking in public areas which reduces the contact between nonsmokers and smokers, while the second will symbolize the educational campaigns and the increase of cigarette cost which prevents occasional smokers from becoming chain smokers. The existence of the optimal control pair is discussed, and by using Pontryagin minimum principle, these two optimal controls are characterized. The optimality system is derived and solved numerically using the forward and backward difference approximation. Finally, numerical simulations are performed in order to check the equilibria stability, confirm the theoretical findings, and show the role of optimal strategy in controlling the smoking severity.
在这项研究中,我们将从数学上探讨戒烟行为的动力学。为此,我们将对吸烟模型进行数学分析,并提出一些条件来控制这种严重的公共健康负担。所考虑的模型描述了潜在吸烟者P、偶尔吸烟者L、连续吸烟者S、暂时戒烟者Q T和永久戒烟者Q P之间的相互作用。证明了问题解的存在性、正性和有界性。利用Routh–Hurwitz条件建立了平衡的局部稳定性。此外,通过使用合适的李雅普诺夫泛函,实现了相同平衡的全局稳定性。为了研究我们问题的最优控制,我们将考虑两个控制的策略。第一项控制措施将代表政府禁止在公共场所吸烟,从而减少非吸烟者和吸烟者之间的接触,而第二项控制措施则象征着教育运动和香烟成本的增加,从而防止偶尔吸烟者成为连锁吸烟者。讨论了最优控制对的存在性,并利用Pontryagin极小原理对这两个最优控制进行了刻画。利用前向和后向差分近似,推导并求解了最优性系统。最后,进行了数值模拟,以检验平衡的稳定性,证实理论发现,并展示最佳策略在控制吸烟严重程度方面的作用。
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引用次数: 3
期刊
International Journal of Differential Equations
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