一类具有p-Laplacian算子的分数阶差分方程边值问题的正解

该文研究一类具有p-Laplacian算子的分数阶差分方程边值问题.借助离散型Jensen不等式,考虑该问题与相应的不带有p-Laplacian算子的分数阶差分方程边值问题之间的关系,并运用不动点指数理论获得该问题正解的存在性.     

分数阶灰色累减生成算子及其性质研究

给出了分数阶灰色累减生成算子的详细推导过程,并证明了分数阶灰色累减生成算子的不动点定理、信息优先原理、交换律与指数律,为分数阶灰色预测模型提供了理论基础.算例验证了分数阶灰色累减生成算子的特征,在灰色预测模型GM(1,1)中的应用证明了分数阶灰色累减生成算子的有效性.     

基于分数阶混沌时间序列的图像加密算法

基于分数阶logistic映射提出了洗牌加密方法.通过离散分数阶微积分得到分数阶序列并把它作为密钥.利用位异或算子,提出了一种新的图像加密算法.对该算法的密钥空间、密钥敏感性和统计特性进行相应的仿真分析.结果表明,该算法可以达到较好的加解密效果,具有很高的安全性,可以满足图像加密安全性的要求.     

具有线性微分算子的分数阶微分方程积分边值问题

研究一类具有分数阶线性微分算子的非线性微分方程积分边值问题解的存在性与唯一性.利用Schauder不动点定理及压缩映射原理,建立并证明了边值问题解的存在性定理和唯一性定理,并给出两个例子以说明所得结论.     

预解算子控制的无穷时滞分数阶微分方程解的存在性

本文研究了一类预解算子控制的具有无穷时滞的分数阶泛函微分方程.利用解析预解算子理论和不动点定理,得到了具有无穷时滞分数阶微分方程适度解的存在性,推广和改进了一些已知的结果.     

线性分数阶强迫振动的稳态响应

利用分数阶导数算子-∞D_t~β研究线性分数阶振动系统在谐波激励下的稳态响应.采用复指数函数形式的谐波激励,利用待定函数法得到与激励同频率的稳态响应,以及幅频关系和相频关系.讨论了分数阶导数项对刚度和阻尼的影响.     

与由抛物算子生成的分数阶Poisson型算子相关的微分变换算子的有界性

本文考虑如下类型级数:■的收敛性,其中,{P_τ~α}τ>0为由抛物算子L:=?_t-?生成的分数阶Poisson型算子,?为Laplace算子,{v_j}_j∈Z为有界实数序列,{a_j}_j∈Z为递增实数序列.本文将主要证明算子T_N~α及其极大算子T*f (x, t)=sup_N∈Z²|T_N~αf (x, t)|在L^p(Rⁿ⁺¹)空间和BMO(Rⁿ⁺¹)空间上的有界性.本文还证明了极大算子T*对于具有局部支撑的函数f的局部增长性与奇异积分算子的局部增长性具有相同的阶.另外,本文还证明了,如果{v_j}_j∈Z∈?^p(Z),则极大算子T*的局部增长性介于奇异积分与Hardy-Littlewood极大算子的局部增长性之间.     

一类推广的离散分数阶Gronwall不等式

离散不等式,特别是离散的Gronwall不等式已被广泛应用于差分方程的研究.近年来,分数阶微分方程引起很多学者的关注.因此,利用一种新的分数阶和分的定义和不等式的方法,讨论一类更一般的离散分数阶Gronwall不等式.     

分数阶波方程的数值解法

首先,把分数阶波方程转换成等价的积分-微分方程;然后,利用带权的分数阶矩形公式和紧差分算子分别对时间和空间方向进行离散.证明了当权重为1/2时,时间方向的收敛阶为α,其中α(1α2)为Caputo导数的阶数.利用Gronwall不等式,证明了数值格式的收敛性和稳定性.数值例子进一步表明了数值格式的有效性.     

一类涉及分数阶Hardy-Schrödinger算子和Hardy-Sobolev临界指数的方程组

本文研究一类涉及分数阶Hardy-Schr?dinger算子和Hardy-Sobolev临界指数的方程组.在适当的条件下,本文获得该方程组基态解的存在性和相关性结果.为克服紧性缺失,本文考虑一个定义在有界区域上的次临界辅助问题,并证得该辅助问题对应的紧嵌入性结论.     

Monomorphism Operator and Perpendicular Operator

For a quiver Q, a k-algebra A, and an additive full subcategory 𝒳 of A-mod, the monomorphism category Mon(Q, 𝒳) is introduced. The main result says that if T is an A-module such that there is an exact sequence 0 → T _m  → … → T ₀ → D(A _A ) → 0 with each T _i  ∈ add(T), then Mon(Q, ^⊥ T) =^⊥(kQ ? _k T); and if T is cotilting, then kQ ? _k T is a unique cotilting Λ-module, up to multiplicities of indecomposable direct summands, such that Mon(Q, ^⊥ T) =^⊥(kQ ? _k T).

As applications, the category of the Gorenstein-projective (kQ ? _k A)-modules is characterized as Mon(Q, 𝒢𝒫(A)) if A is Gorenstein; the contravariantly finiteness of Mon(Q, 𝒳) can be described; and a sufficient and necessary condition for Mon(Q, A) being of finite type is given.     

Essentially Normal Operator + Compact Operator = Strongly Irreducible Operator

It is shown that given an essentially normal operator with connected spectrum, there exists a compact operator such that is strongly irreducible.

     

Weak Operator Topology, Operator Ranges and Operator Equations via Kolmogorov Widths

Let K be an absolutely convex infinite-dimensional compact in a Banach space χ. The set of all bounded linear operators T on χ satisfying TK ⊃ K is denoted by G(K). Our starting point is the study of the closure WG(K) of G(K) in the weak operator topology. We prove that WG(K) contains the algebra of all operators leaving [`(lin(K))]\overline{{\rm lin}(K)} invariant. More precise results are obtained in terms of the Kolmogorov n-widths of the compact K. The obtained results are used in the study of operator ranges and operator equations.     

Operator Matrices as Generators of Cosine Operator Functions

We introduce an abstract setting that allows to discuss wave equations with time-dependent boundary conditions by means of operator matrices. We show that such problems are well-posed if and only if certain perturbations of the same problems with homogeneous, time-independent boundary conditions are well-posed. As applications we discuss two wave equations in L^p(0, 1) and in L²(Ω) equipped with dynamical and acoustic-like boundary conditions, respectively.     

Operator trigonometry

The purpose of the present paper is to survey, from a historical perspective and including some new results, a theory which I will call operator trigonometry. This theory, which is little known, is closely associated with the numerical range W(A) of an operator A. Among the new results is a beautiful connection to numerical linear algebra, in which gradient descent and conjugate gradient convergence rates are shown to be trigonometric.     

Operator trigonometry

The purpose of the present paper is to survey, from a historical perspective and including some new results, a theory which I will call operator trigonometry. This theory, which is little known, is closely associated with the numerical range W(A) of an operator A. Among the new results is a beautiful connection to numerical linear algebra, in which gradient descent and conjugate gradient convergence rates are shown to be trigonometric.     

Quasi-range-preserving Operator

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