有限区间上的分数阶扩散-波方程定解问题与Laplace变换

求解了如下的分数阶扩散-波方程定解问题0Dαtu=2ux2,00,0<α≤2,u(0,t;α)=0,u(1,t;α)=θ(t),u(x,0+;α)=0,当1<α≤2时,还有ut(x,0+;α)=0.其中θ(t)是Heaviside单位阶跃函数,0Dαt为关于时间t的α阶Caputo分数阶导数算子,u=u(x,t;α)为时间t的因果函数(即t<0时恒为零的函数).利用Laplace变换的复围道积分反演和离散化反演及FoxH函数理论,给出在计算上对大的t和小的t分别适用的解的表达式.     

带有Riemann-Liouville分数阶导数的边值问题多正解的存在性(英文)

本文运用Avery-Peterson不动点定理研究以下分数阶边值问题Dα0+Dα0+u=f(t,u,u′,-Dα0+u,-Dα+10+u),t∈[0,1],u(0)=u′(0)=u′(1)=Dα0+u(0)=Dα+10+u(0)=Dα+10+u(1)={0至少三个正解的存在性,其中α∈(2,3]是一实数,Dα0+是α阶Riemann-Liouville分数阶导数.文章最后提供一个具体的例子来说明所得到的结论.     

一个分数阶微分方程四点边值问题正解的存在性

本文研究下面的分数阶微分方程四点边值问题Dα0+u(t)+f(t,u(t))=0,0相似文献   

非线性分数阶微分方程非奇异边值问题的多重正解

通过研究非线性分数阶微分方程边值问题D_(0+)~αu(t)+y(t,u(t))=0,0相似文献   

一类非线性分数阶微分方程边值问题的正解

讨论以下非线性分数阶边值问题:^cD_(0+)cD_(0+)^αu(t)+λa(t)f(u(t))=0,0cD_(0+)cD_(0+)^α是Caputo导数,λ>0.利用Krasnoselskiis不动点定理,得到其正解存在与不存在的充分条件,最后给出一个例子验证我们的结论.     

一类带有分数阶微分边值条件的分数阶微分方程在奇异的和非奇异的情况下的唯一正解 [英文]

在这篇文章中,我们研究下列奇异的和非奇异的分数阶微分方程边值问题D^{\alpha}_{0+}u(t)+f(t, u(t))=0, t\in (0,1), 3<\alpha \leq4, u(0)=0, D^{\alpha-1}_{0+}u(0)=0, D^{\alpha-2}_{0+}u(0)=0, D^{\alpha-3}_{0+}u(1)=0.通过计算得到格林函数,通过应用半序集上的不动点定理和u_{0}凸算子不动点定理,得到正解的存在性和唯一性。     

Poisson和公式在分数阶热方程中的应用

本文利用Poisson和公式,证明了如下分数阶热方程(D_t~αlu=D_x~2u u(x1 0)=f(x))当f分别为周期函数和f∈S(■)时(速降函数空间),它们的热核满足关系H_t~α(x)=∑n=-∞H_t~α(x+n)进一步,我们把结论推广到更一般的分数阶微分方程和高维情形     

变时间分数阶扩散方程的非一致时间网格有限差分方法

本文在非一致时间网格上,使用有限差分方法求解变时间分数阶扩散方程?α(x,t)u(x,t)/tα(x,t)-2u(x,t)/x2=f(x,t),0α(x,t)q≤1,证明了该方法在最大范数下的稳定性与收敛性,收敛阶为C(Δt2-q+h2).数值实例验证了理论分析的结果.     

抽象多项Riemann-Liouville分数阶微分方程

该文研究如下抽象多项分数阶微分方程D_t~(α_n)u(t)+(Σ)_(j=1)~(n-1)A_jD_t~(uj)u(t)=AD_t~αu(t)+f(t).t∈(0.τ),(0.1)其中n∈N\{1},算子A,A1,…,A_(n-1)为复Banach空间E上的闭线性算子,0≤α_1…α_n,0≤αα_n,0τ≤∞,f(t)为E-值函数,D_t~α表示α阶Riemann—Liouville分数阶导数~([5]).延续着作者先前在文献[22,24 25]和[34]中的研究工作,该文引入并系统分析了方程(0.1)的若干类新的k-正则(C_1,C_2)-存在和唯一(生成)族,并对抽象的理论性结果给出了丰富的例子来阐明.     

一个新的分数阶微分方程边值问题正解的存在性结果

研究了下面分数阶微分方程边值问题正解的存在性和唯一性D₀₊^αu（t）=f（t,u（t））,00+^α是标准的Riemann-Liouville微分,f:[0,1]×[0,∞)→[0,∞)连续。首先应用压缩映像原理得到解的唯一性,其次应用不动点指数得到正解的存在性,证明中借助了特征值理论。     

Fractional variational integrators for fractional variational problems

In this paper, the fractional variational integrators for a class of fractional variational problems are developed. The fractional discrete Euler-Lagrange equation is obtained. Based on the Grünwald-Letnikov method and Diethelm’s fractional backward differences, some fractional variational integrators are presented and the fractional variational errors are discussed. Some numerical examples are presented to illustrate these results.     

Fractional time-varying energy distributions of ECG signals

We introduce here fractional Cohen class of time-frequency distributions (FCCTFDs) containing fractional modulations which is kernel of fractional Fourier transform (FFT). The fractional modulation depends on angular parameter α and can be interpreted as a rotation by an angle α in time-frequency plane. This distribution promotes to track time-variant energy of a biological signals and represents it in time-frequency domain. It uses the fractional ambiguity function (FAF) of signal multiplied by a suitable kernel which is designed for the biological signals generally having multi-non-stationary components. This result improves and generalizes some of the previous time-frequency distributions derived in the literature.     

Fractional Intertwinings Between Two Markov Semigroups

We define the notion of α-intertwining between two Markov Feller semigroups on and we give some examples. The 1-intertwining, in particular, is merely the intertwining via the first derivative operator. It can be used in the study of the existence of pseudo-inverses, a notion recently introduced by Madan et al. (2008) and Roynette and Yor (2008).      

Fractional Brownian Motion and Sheet as White Noise Functionals

In this short note, we show that it is more natural to look the fractional Brownian motion as functionals of the standard white noises, and the fractional white noise calculus developed by Hu and Фksendal follows directly from the classical white noise functional calculus. As examples we prove that the fractional Girsanov formula, the Ito type integrals and the fractional Black-Scholes formula are easy consequences of their classical counterparts. An extension to the fractional Brownian sheet is also briefly discussed.     

分配格的分式扩张

首先借助整数扩充为有理数的办法构作一个分配格对它的滤子的分式扩张,然后用泛映射性质来刻画由任意分配格所构作的分式扩张,最后讨论了这种扩张的理想结构。     

Fractional covers for forests and matchings

We give polynomial algorithms for the fractional covering problems for forests andb-matchings: min{1·y: yA≥w,y≥0} whereA is a matrix whose rows are the incidence vectors of forests/b-matchings respectively. It is shown that each problem can be solved by a series of max-flow/min-cut calculations, and hence the use of the ellipsoid algorithm to guarantee a polynomial algorithm can be avoided. Visiting professor at the European Institute for Advanced Studies in Management in Brussels and at CORE. Supported in part by the CIM. On leave from New York University, New York, NY 10006.     

Stochastic Fractional Anderson Models with Fractional Noises

The authors are concerned with a class of one-dimensional stochastic Anderson models with double-parameter fractional noises, whose differential operators are fractional. A unique solution for the model in some appropriate Hilbert space is constructed. Moreover, the Lyapunov exponent of the solution is estimated, and its HSlder continuity is studied. On the other hand, the absolute continuity of the solution is also discussed.     

A Fractional Donsker Theorem

We prove a Donsker-type approximation of the fractional Brownian motion which extends a result by Sottinen for the case H > 1/2 to the full range of Hurst parameters H ∈ (0, 1). The convergence is established by a Donsker-type theorem for Volterra Gaussian processes. The approximation is applied to weak convergence of fractional Wiener integrals.     

On the Pseudoconvexity of a Quadratic Fractional Function

In this paper we give a necessary and sufficient condition for the pseudoconvexity of a function f which is the ratio of a quadratic function over an affine function. The obtained results allow to suggest a simple algorithm to test the pseudoconvexity of f and also to characterize the pseudoconvexity of the sum of a linear and a linear fractional function.