Solving the Nonlinear Variable Order Fractional Differential Equations by Using Euler Wavelets

An Euler wavelets method is proposed to solve a class of nonlinear variable order fractional differential equations in this paper.The properties of Euler wavelets and their operational matrix together with a family of piecewise functions are first presented.Then they are utilized to reduce the problem to the solution of a nonlinear system of algebraic equations.And the convergence of the Euler wavelets basis is given.The method is computationally attractive and some numerical examples are provided to illustrate its high accuracy.

Multiple Solutions for a Class of Variable-Order Fractional Laplacian Equations with Concave-Convex Nonlinearity

This paper is concerned with the following variable-order fractional Laplacian equations , where N ≥ 1 and N > 2s(x,y) for (x,y) ∈ Ω × Ω, Ω is a bounded domain in RN, s(⋅) ∈ C (RN × RN, (0,1)), (-Δ)s(⋅) is the variable-order fractional Laplacian operator, λ, μ > 0 are two parameters, V: Ω → [0, ∞) is a continuous function, f ∈ C(Ω × R) and q ∈ C(Ω). Under some suitable conditions on f, we obtain two solutions for this problem by employing the mountain pass theorem and Ekeland’s variational principle. Our result generalizes the related ones in the literature.

NUMERICAL SIMULATIONS FOR A VARIABLE ORDER FRACTIONAL CABLE EQUATION

In this article, Crank-Nicolson method is used to study the variable order fractional cable equation. The variable order fractional derivatives are described in the Riemann- Liouville and the Griinwald-Letnikov sense. The stability analysis of the proposed technique is discussed. Numerical results are provided and compared with exact solutions to show the accuracy of the proposed technique.

Exact Solution to Nonlinear Differential Equations of Fractional Order via (<i>G’</i>/<i>G</i>)-Expansion Method

In this article, a new application to find the exact solutions of nonlinear partial time-space fractional differential Equation has been discussed. Firstly, the fractional complex transformation has been implemented to convert nonlinear partial fractional differential Equations into nonlinear ordinary differential Equations. Afterwards, the (G'/G)-expansion method has been implemented, to celebrate the exact solutions of these Equations, in the sense of modified Riemann-Liouville derivative. As application, the exact solutions of time-space fractional Burgers’ Equation have been discussed.

A New Approach for the Exact Solutions of Nonlinear Equations of Fractional Order via Modified Simple Equation Method

In this article, the modified simple equation method has been extended to celebrate the exact solutions of nonlinear partial time-space differential equations of fractional order. Firstly, the fractional complex transformation has been implemented to convert nonlinear partial fractional differential equations into nonlinear ordinary differential equations. Afterwards, modified simple equation method has been implemented, to find the exact solutions of these equations, in the sense of modified Riemann-Liouville derivative. For applications, the exact solutions of time-space fractional derivative Burgers’ equation and time-space fractional derivative foam drainage equation have been discussed. Moreover, it can also be concluded that the proposed method is easy, direct and concise as compared to other existing methods.

REGULARITY OF SOLUTIONS TO NONLINEAR TIME FRACTIONAL DIFFERENTIAL EQUATION

We find an upper viscosity solution and give a proof of the existence-uniqueness in the space C^∞（t∈（0,∞）;H2^s＋2（R^n））∩C^0（t∈[0,∞）;H^s（R^n））,s∈R,to the nonlinear time fractional equation of distributed order with spatial Laplace operator subject to the Cauchy conditions ∫0^2p（β）D＊^βu（x,t）dβ=△xu（x,t）＋f（t,u（t,x））,t≥0,x∈R^n,u（0,x）=φ（x）,ut（0,x）=ψ（x）,（0.1） where △xis the spatial Laplace operator,D＊^β is the operator of fractional differentiation in the Caputo sense and the force term F satisfies the Assumption 1 on the regularity and growth. For the weight function we take a positive-linear combination of delta distributions concentrated at points of interval （0, 2）, i.e., p（β） =m∑k=1bkδ（β-βk）,0〈βk〈2,bk〉0,k=1,2,…,m.The regularity of the solution is established in the framework of the space C^∞（t∈（0,∞）;C^∞（R^n））∩C^0（t∈[0,∞）;C^∞（R^n））when the initial data belong to the Sobolev space H2^8（R^n）,s∈R.

Exponential-fraction trial function method to the 5th-order mKdV equation

This paper obtains some solutions of the 5th-order mKdV equation by using the exponential-fraction trial function method, such as solitary wave solutions, shock wave solutions and the hopping wave solutions. It successfully shows that this method may be valid for solving other nonlinear partial differential equations.

Blow-Up and Attractor of Solution for Problems of Nonlinear Schrodinger Equations

In this paper, the authors study the blow-up of solution for a class of nonlinear Schrodinger equation for some initial boundary problem. On the other hand, the authors give out some analyses and that new conclusion by Eigen-function method. In last section, the authors check the nonlinear parameter for light rule power by using of parameter method to get ground state and excite state correspond case, and discuss the global attractor of some fraction order case, and combine numerical test. To illustrate this physics meaning in dimension d = 1, 2 case. So, by numerable solution to give out these wave expression.

A LINEARLY-IMPLICIT ENERGY-PRESERVING ALGORITHM FOR THE TWO-DIMENSIONAL SPACE-FRACTIONAL NONLINEAR SCHRÖDINGER EQUATION BASED ON THE SAV APPROACH

The main objective of this paper is to present an efficient structure-preserving scheme,which is based on the idea of the scalar auxiliary variable approach,for solving the twodimensional space-fractional nonlinear Schrodinger equation.First,we reformulate the equation as an canonical Hamiltonian system,and obtain a new equivalent system via introducing a scalar variable.Then,we construct a semi-discrete energy-preserving scheme by using the Fourier pseudo-spectral method to discretize the equivalent system in space direction.After that,applying the Crank-Nicolson method on the temporal direction gives a linearly-implicit scheme in the fully-discrete version.As expected,the proposed scheme can preserve the energy exactly and more efficient in the sense that only decoupled equations with constant coefficients need to be solved at each time step.Finally,numerical experiments are provided to demonstrate the efficiency and conservation of the scheme.

A Hybrided Trapezoidal-Difference Scheme for Nonlinear Time-Fractional Fourth-Order Advection-Dispersion Equation Based on Chebyshev Spectral Collocation Method

In this paper,we firstly present a novel simple method based on a Picard integral type formulation for the nonlinear multi-dimensional variable coefficient fourthorder advection-dispersion equation with the time fractional derivative order a2(1,2).A new unknown function v(x,t)=■u(x,t)/■t is introduced and u(x,t)is recovered using the trapezoidal formula.As a result of the variable v(x,t)are introduced in each time step,the constraints of traditional plans considering the non-integer time situation of u(x,t)is no longer considered.The stability and solvability are proved with detailed proofs and the precise describe of error estimates is derived.Further,Chebyshev spectral collocation method supports accurate and efficient variable coefficient model with variable coefficients.Several numerical results are obtained and analyzed in multi-dimensional spatial domains and numerical convergence order are consistent with the theoretical value 3-a order for different a under infinite norm.

Assorted soliton structures of solutions for fractional nonlinear Schrodinger types evolution equations

Fractional order nonlinear evolution equations have emerged in recent times as being very important model for depicting the interior behavior of nonlinear phenomena that exist in the real world.In particular,Schrodinger-type fractional nonlinear evolution equations constitute an aspect of the field of quantum mechanics.In this study,the(2+1)-dimensional time-fractional nonlinear Schrodinger equation and(1+1)-dimensional time-space fractional nonlinear Schrodinger equation are revealed as having different and novel wave structures.This is shown by constructing appropriate analytic wave solutions.A success-ful implementation of the advised rational(1/φ'(ξ))-expansion method generates new outcomes of the considered equations,by comparing them with those already noted in the literature.On the basis of the conformable fractional derivative,a composite wave variable conversion has been used to adapt the suggested equations into the differential equations with a single independent variable before applying the scheme.Finally,the well-furnished outcomes are plotted in different 3D and 2D profiles for the purpose of illustrating various physical characteristics of wave structures.The employed technique is competent,productive and concise enough,making it feasible for future studies.

能量临界分数阶非线性Schrodinger方程的整体弱解

利用紧性方法给出能量临界分数阶非线性Schr9dinger方程Cauchy问题解的存在性,并证明Cauchy问题存在整体解.通过构造逼近方程,对满足逼近方程的解序列取极限,得到的极限函数即为能量临界分数阶非线性Schr9dinger方程的整体弱解,并证明该弱解满足能量不等式和质量守恒性质.

非线性二阶变系数微分方程的三点边值问题

研究了非线性二阶变系数微分方程的三点边值问题.首先,对非线性二阶变系数微分方程多次积分得到与之等价的Fredholm-Hammerstein积分方程;其次,利用分段泰勒级数得到Fredholm-Hammerstein积分方程的数值解;最后,通过具体算例验证此方法的可行性与有效性,并给出相应的误差估计.

初值奇异性非线性分数阶常微分方程的高阶数值方法

考虑非线性分数阶常微方程高阶格式的精确解具有初值奇异性,从而引入初值变量和逐块方法,再利用拉格朗日插值公式,提出一种新的高阶数值格式。该高阶数值格式为非光滑解条件下的5+α阶。

带有p-Laplacian算子的分数阶积分-微分方程边值问题正解的存在性

研究了带有p-Laplacian算子以及变Riemann-Liouville分数阶积分的分数阶积分-微分方程的边值问题,利用锥上的不动点定理,得到了该边值问题正解的存在性结果.

圆域上变系数二阶椭圆方程有效的谱方法及其在奇异非线性问题中的应用

提出了圆域上二阶变系数椭圆方程的一种有效的谱方法。首先,利用极坐标变换,将原问题转化为极坐标下的一种等价形式,根据极条件、边界条件以及θ方向的周期性,引入了适当的Sobolev空间,建立了极坐标系下二阶变系数椭圆方程的一种弱形式及其离散格式。然后,利用Lax-Milgram引理证明了弱解的存在唯一性。再由非一致带权Sobolev空间中投影算子的逼近性质和傅里叶基函数的逼近性质,证明了逼近解的误差估计。另外,将提出的算法延伸到奇异非线性二阶椭圆方程的计算,并给出了数值算例,数值结果表明该算法是收敛的和高精度的。

分数阶非线性四阶反应扩散方程变步长L 1格式的能量稳定

基于非均匀L1公式对时间分数阶非线性四阶反应扩散方程建立时间方向变步长的有限差分格式.利用离散互补卷积核,得到非均匀L1公式系数核的梯度分解,从而证明该差分格式在任意非均匀时间网格上保持变分能量耗散率.数值算例验证了格式的精度和有效性.

直流微电网中Boost变换器的变阶次分数阶滑模控制

针对直流微电网中Boost电力电子变换器负荷侧波动频繁问题,设计一种新型变阶次分数阶非奇异终端滑模控制(variable order fractional-order non-singular terminal sliding mode control,VO-FNTSMC)策略,对负荷扰动进行精准快速的响应。主要研究该控制策略在Boost变换器启动阶段及负载变化阶段的控制效果,并将研究结果在NI PXIe-ModelingTech实验平台上以硬件在环(hardware in loop,HiL)的方式进行实验验证。结果表明:普通分数阶控制策略在分数阶微积分阶次为1时,具有抖振和输出误差较小的优势;在阶次为1.4时,具有超调量小、响应快速的优点。VO-FNTSMC融合了2个不同阶次分数阶控制器的优点,在启动阶段及负载变化阶段对输出电压都具有更快的响应速度,更小的超调量、稳态误差及滑模抖振,为分数阶控制理论应用于新能源电力电子领域提供了一种深入到变阶次的研究方法。

An Efficient Numerical Solution of Nonlinear Hunter-Saxton Equation

In this paper, the nonlinear Hunter–Saxton equation, which is a famous partial differential equation,is solved by using a hybrid numerical method based on the quasilinearization method and the bivariate generalized fractional order of the Chebyshev functions(B-GFCF) collocation method. First, using the quasilinearization method,the equation is converted into a sequence of linear partial differential equations(LPD), and then these LPDs are solved using the B-GFCF collocation method. A very good approximation of solutions is obtained, and comparisons show that the obtained results are more accurate than the results of other researchers.

Adomian分解法求解非线性分数阶积分微分方程

求一类非线性分数阶Volterra积分微分方程数值解,给出了Adomian分解法.将Adomian多项式与分数阶积分定义有效结合,得到了Adomian级数解.收敛性分析证明了所得级数解收敛于精确解,并给出最大截断误差.结果表明:随着Adomian多项式个数的增加,数值解的精度也越来越高.数值算例表明了该方法的可行性和有效性.与已有的方法相比,Adomian分解法操作更有效、更方便.