闭区间[0,1]上的分形插值函数的分数阶积分

介绍了分形插值函数和迭代函数系统以及v阶黎曼-刘准尔分数阶积分的概念及相关定理.利用这些概念及定理讨论了分形插值函数的分数阶积分在[0,1]上连续性及判定[0,1]上的分形插值函数的分数阶积分也是[0,1]上的分形插值函数,并给予了证明.     

分段函数的连续可导性

讨论了分段函数的连续可导性,得到了一个分段函数具有任意阶导数的充分条件,并介绍了一个求分段函数在其分段点处n阶导数的公式     

一类分形插值函数的分数阶微积分

介绍了分形插值函数和迭代函数系统以及v阶黎曼-刘维尔分数阶积分、微分的概念和相关定理.由于分形插值函数满足应用分数阶微积分处理问题的条件,所以利用这些概念及分步积分的方法讨论了折线段分形插值函数的分数阶积分的连续性,可微性及哪些点是不可微的,进一步说明了该插值函数分数阶微分的连续性并指出其不连续点,用黎曼-刘维尔分数阶微积分与分形插值函数结合起来研究,目的是想设法跟经典微积分一样,能找出函数上在该点的微积分的具体的实际应用意义.这些理论为研究分形插值函数的分数阶微积分的实际应用意义提供了一些理论基础.     

计算Riemann-Liouville分数阶积分和导数的数值算法

研究计算Riemann-Liouville (RL)分数阶积分和导数的数值算法.首先,分析了RL分数阶积分和导数的定义式,由于定义式中包含一个积分瑕点,使RL分数阶积分和导数难于计算.然后,给出了一种去掉积分瑕点的方法,在此基础上设计出计算RL分数阶积分和导数的数值算法,并证明了此数值算法具有一阶精度.最后,给出了计算实例,计算结果说明提出的算法是有效的.     

积分型余项的泰勒公式与分数阶导数

基于将积分和微分统一的思想,并结合高阶积分我们得到了泰勒公式的积分型余项.并从积分型泰勒公式出发,直接推导出Riemann-Liouville分数阶导数计算公式及它和Caputo分数阶导数之间的关系.     

一维连续函数的Riemann-Liouville分数阶微积分

本文主要讨论闭区间上一维连续函数的Riemann-Liouville分数阶微积分.首先,证明一维连续有界变差函数的任意阶Riemann-Liouville分数阶积分仍然是连续有界变差函数.其次,给出无界变差点的定义并构造一个含有无界变差点的一维连续无界变差函数.同时证明该无界变差函数的任意阶Riemann-Liouville分数阶积分的分形维数为1.最后,证明对于任意具有有限个无界变差点的一维连续函数,其任意阶Riemann-Liouville分数阶积分的分形维数仍然是1.文中还给出了一些例子的图像和数值结果.     

高维非齐次时间分数阶扩散-波动方程的解析解问题

分数阶微积分是专门研究任意阶积分和微分的数学性质及其应用的领域,是传统的整数阶微积分的推广,分数阶微分方程是含有非整数阶导数的方程.时间分数阶扩散-波动方程可以用来模拟由传统的扩散-波动方程演变而来的反常扩散方程.考虑在有限区间上高维非齐次时间分数阶扩散-波动方程的初边值问题.利用分离变量法,导出了高维非齐次时间分数阶扩散-波动方程初边值问题的基本解.     

自仿函数分数阶导数的分形维数

研究一类自仿函数的分数阶导数,获得了自仿函数的Weyl-Marchaud分数阶导数的图像盒维数,证明了分数阶导数的阶与分形维数之间的线性关系.     

高阶数值微分的积分方法

本文研究了高阶数值微分问题,利用Groetsch的思想,获得了可以稳定逼近近似已知函数的任意阶导数的积分方法,并在一定条件下,给出了收敛率.给出了二阶、三阶和四阶数值微分问题的数值实验,实验结果表明了方法的有效性.     

Katugampola分数阶积分的阶与Weierstrass函数的分形维数之间的关系（英文）

计算Weierstrass函数的Katugampola分数阶积分的分形维数,如盒维数、K-维数和P-维数.证明了Weierstrass函数的Katugampola分数阶积分的阶与Weierstrass函数的分形维数之间存在线性关系.     

High-order ADI orthogonal spline collocation method for a new 2D fractional integro-differential problem

We use the generalized L1 approximation for the Caputo fractional derivative, the second-order fractional quadrature rule approximation for the integral term, and a classical Crank-Nicolson alternating direction implicit (ADI) scheme for the time discretization of a new two-dimensional (2D) fractional integro-differential equation, in combination with a space discretization by an arbitrary-order orthogonal spline collocation (OSC) method. The stability of a Crank-Nicolson ADI OSC scheme is rigourously established, and error estimate is also derived. Finally, some numerical tests are given.     

Fractal dimensions of fractional integral of continuous functions

In this paper,we mainly explore fractal dimensions of fractional calculus of continuous functions defined on closed intervals.Riemann–Liouville integral of a continuous function f(x) of order v(v0) which is written as D~(-v) f(x) has been proved to still be continuous and bounded.Furthermore,upper box dimension of D~(-v) f(x) is no more than 2 and lower box dimension of D~(-v) f(x) is no less than 1.If f(x) is a Lipshciz function,D~(-v) f(x) also is a Lipshciz function.While f(x) is differentiable on [0,1],D~(-v) f(x) is differentiable on [0,1] too.With definition of upper box dimension and further calculation,we get upper bound of upper box dimension of Riemann–Liouville fractional integral of any continuous functions including fractal functions.If a continuous function f(x) satisfying H?lder condition,upper box dimension of Riemann–Liouville fractional integral of f(x) seems no more than upper box dimension of f(x).Appeal to auxiliary functions,we have proved an important conclusion that upper box dimension of Riemann–Liouville integral of a continuous function satisfying H?lder condition of order v(v0) is strictly less than 2-v.Riemann–Liouville fractional derivative of certain continuous functions have been discussed elementary.Fractional dimensions of Weyl–Marchaud fractional derivative of certain continuous functions have been estimated.     

Fractal Dimension of Graph of Weierstrass Function and Its Derivative of the Fractional Order

In this paper,we obtain the fractal dimension of the graph of the Weierstrass function, its derivative of the fractional order and the relation between the dimension and the order of the fractional derivative.     

Fractal functions with continuous Weil-type derivatives of variable order in control of distributed systems

Properties of fractal functions which are not differentiable in the classical sense but have continuous Weil-type derivatives of variable order at each point are studied. It is shown that the Weierstrass, Takagi, and Besicovitch classical fractal functions have such derivatives. An example of an oscillatory system controlling which requires constructing a fractal control function having a Weil-type derivative of variable order at each point is considered.     

Dimension of the Fractal Curve in Plane and Its Derivative of the Fractional Order

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Probability Interpretation of the Integral of Fractional Order

We establish a relation between stable distributions in probability theory and the fractional integral. Moreover, it turns out that the parameter of the stable distribution coincides with the exponent of the fractional integral. It follows from an analysis of the obtained results that equations with the fractional time derivative describe the evolution of some physical system whose time degree of freedom becomes stochastic, i.e., presents a sum of random time intervals subject to a stable probability distribution. We discuss relations between the fractal Cantor set (Cantor strips) and the fractional integral. We show that the possibility to use this relation as an approximation of the fractional integral is rather limited.     

一类分形函数的Weyl-Marchaud分数阶导数的Hausdorff维数

首先介绍广义Weierstrass型函数的Weyl-Marchaud分数阶导数,得到了带随机相位的广义Weierstrass型函数的Weyl-Marchaud分数阶导数图像的Hausdorff维数,证明了该分形函数图像的Hausdorff维数与Weyl-Marchaud分数阶导数的阶之间的线性关系.     

On turbulence in fractal porous media

We examine three fundamental equations governing turbulence of an incompressible Newtonian fluid in a fractal porous medium: continuity, linear momentum balance and energy balance. We find that the Reynolds stress is modified when a local, rather than an integral, balance law is considered. The heat flux is modified from its classical form when either the integral or local form of the energy density balance law is studied, but the energy density is always unchanged. The modifications of Reynolds stress and heat flux are expressed directly in terms of the resolution length scale, the fractal dimension of mass distribution and the fractal dimension of a fractal’s surface. When both fractal dimensions become integer (respectively 3 and 2), classical equations are recovered.