矩阵值函数空间中尺度空间的稠密性

多分辨分析的概念在小波基构造中起着非常重要的作用,并经历了从经典多分辨分析到多重多分辨分析,再到矩阵值多分辨分析的研究历程.本文基于矩阵值多分辨分析,研究并给出了矩阵值函数空间中尺度空间稠密性的两个充要条件,并在此基础之上得到了稠密性的两个充分条件.     

The properties of orthogonal matrix-valued wavelet packets in higher dimensions

In the paper matrix-valued multiresolution analysis and matrix-valued wavelet packets of spaceL ²(R ⁿ ,C ^{s x s}) are introduced. A procedure for constructing a class of matrix-valued wavelet packets in higher dimensions is proposed. The properties for the matrix-valued multivariate wavelet packets are investigated by using integral transform, algebra theory and operator theory. Finally, a new orthonormal basis ofL ²(R ⁿ ,C ^{s x s}) is derived from the orthogonal multivariate matrix-valued wavelet packets.     

一类紧支撑矩阵值正交小波的构造

In this paper,we introduce matrix-valued multiresolution analysis and orthogonal matrix-valued wavelets.We obtain a necessary and sufficient condition on the existence of orthogonal matrix-valued wavelets by means of paraunitary vector filter bank theory.A method for constructing a class of compactly supported orthogonal matrix-valued wavelets is proposed by using multiresolution analysis method and matrix theory.     

二元矩阵有理插值函数的构造

一般构造矩阵值有理函数的方法是利用连分式给出的,其算法的可行性不易预知,且计算量大.本文对于二元矩阵值有理插值的计算,通过引入多个参数,定义一对二元多项式:代数多项式和矩阵多项式,利用两多项式相等的充分必要条件通过求解线性方程组确定参数,并由此给出了矩阵值有理插值公式.该公式简单,具有广阔的应用前景.     

THE NOTE ON MATRIX-VALUED RATIONAL INTERPOLATION

In [3], a kind of matrix-valued rational interpolants （MRIs） in the form of Rn（x） = M（x）/D（x） with the divisibility condition D（x） ｜ ｜｜M（x）｜｜^2, was defined, and the characterization theorem and uniqueness theorem for MRIs were proved. However this divisibility condition is found not necessary in some cases. In this paper, we re- move this restricted condition, define the generalized matrix-valued rational interpolants （GMRIs） and establish the characterization theorem and uniqueness theorem for GMRIs. One can see that the characterization theorem and uniqueness theorem for MRIs are the special cases of those for GMRIs. Moreover, by defining a kind of inner product, we succeed in unifying the Samelson inverses for a vector and a matrix.     

Negative Answer to the Conjecture on the Convexity of the Greatest Eigenvalue

In this note, we show by a counterexample that the conjecture of Seeger on the convexity of the greatest eigenvalue of a real symmetric matrix-valued function does not hold.     

Existence of Matrix-Valued Multiresolution Analysis-Based Matrix-Valued Tight Wavelet Frames

In this article, we introduce and study the matrix-valued tight wavelet frames for analyzing matrix-valued signal based on matrix-valued multiresolution analysis (MMRA). We put our emphasis on the existence of the MMRA-based matrix-valued tight wavelet frames by establishing the correspondence with their the unitary extension principle (UEP). Here in particular we introduce the square brackets product and the quasi-interpolatory operator, which makes the certificating process for UEP become relatively simple. Some interesting byproducts, such as features on the quasi-interpolatory operator 𝒫_n in the matrix-valued function space case, are the critical foundation for our main work.     

Coherent States for Systems of L 2-Supercritical Nonlinear Schrödinger Equations

We consider the propagation of wave packets for a nonlinear Schrödinger equation, with a matrix-valued potential, in the semi-classical limit. For a matrix-valued potential, Strichartz estimates are available under long range assumptions. Under these assumptions, for an initial coherent state polarized along an eigenvector, we prove that the wave function remains in the same eigenspace, at leading order, in a scaling such that nonlinear effects cannot be neglected. We also prove a nonlinear superposition principle for these nonlinear wave packets.     

M-带插值小波包

本文给出M-带插值小波包的构造.M-带插值小波包是根据基插值函数建立的迭代函数序列进行伸缩平移的空间序列.这种小波包可使信号分解更为精细,并具有更好的局部性.由此建立了这种小波包子空间上的近似采样定理.     

Matrix-valued radial basis functions: stability estimates and applications

Radial basis functions (RBFs) have found important applications in areas such as signal processing, medical imaging, and neural networks since the early 1980s. Several applications require that certain physical properties are satisfied by the interpolant, for example, being divergence-free in case of incompressible data. In this paper we consider a class of customized (e.g., divergence-free) RBFs that are matrix-valued and have compact support; these are matrix-valued analogues of the well-known Wendland functions. We obtain stability estimates for a wide class of interpolants based on matrix-valued RBFs, also taking into account the size of the compact support of the generating RBF. We conclude with an application based on an incompressible Navier–Stokes equation, namely the driven-cavity problem, where we use divergence-free RBFs to solve the underlying partial differential equation numerically. We discuss the impact of the size of the support of the basis function on the stability of the solution. AMS subject classification 65D05     

矩阵伸缩的高维向量值小波包

本文给出了对应于任意整数矩阵伸缩的高维向量值正交小波包的定义及其构造方法．并讨论了这种向量值正交小波包的性质,得到向量值函数空间L2(Rs,Cr)的新的正交小波基．     

Meromorphic functions of matrix arguments and applications

Sharp estimates are established for the Euclidean norm of matrix-valued meromorphic functions of a matrix argument. Applications of the obtained estimates to the periodic problem and two-point boundary value problem for vector differential equations are also discussed.     

A CLASS OF BIDIMENSIONAL NONSEPARABLEWAVELET PACKETS

1 IntroductionIn [1], CoifnThu, Meyer, alld Wickerhauser introduced orthogonal wavelet packets for L'(R)and. by using tensor products, collstructed orthogonal wave1et packets iu L'(R'). In [2], Chuial1d Li studied l1onorthogonal wave1et packets and tlieir dual wavelet packets in tlie u11ivariatecase, tl1us generalizing the ortllorgonal wavelet packets of [1]. Ill [3], Slien constructed noutensorwavelet packets in L'(R' ). Applicatious Of wavelet packets in signal processing and compressi…     

多重向量值正交小波包

本文引入多重向量值小波包的概念,提供一类多重向量值正交小波包的构造方法,并运用积分变换和算子理论,讨论了多重向量值正交小波包的性质．利用多重向量值正交小波包,构造了空间L2(R,Cs×s)的新的正交基．     

多元向量值正交小波包的刻画

In this paper,the notion of orthogonal vector-valued wavelet packets of space L2(Rs,Cn)is introduced.A procedure for constructing the orthogonal vector-valued wavelet packets is presented.Their properties are characterized by virtue of time-frequency analysis method,matrix theory and finite group theory,and three orthogonality formulas are obtained.Finally,new orthonormal bases of space L2(Rs,Cn)are extracted from these wavelet packets.     

一类二元半正交小波包的构造

本文给出伸缩矩阵行列式为2的一类二元半正交小波包的构造算法.该小波包是以频域给出的,随着用于小波包分裂的滤波器选取的不同会得到L2(R2)中形态各异的Riesz基,这样使得L2(R2)中小波基的选择更灵活.     

一类二维不可分非正交小波包

Zuowei Shen构造了L^2（R^s)空间的二进制小泡包,与伸缩矩阵M＝（1 1 1 －1）相关的小波适用于二维图像处理中的梅花状子取样,本文给出了一种构造非正交M－小滤包的方法。     

紧支撑多重向量值正交小波包的性质

给出紧支撑多重向量值正交小波包的定义及构造方法.运用矩阵理论与积分变换,研究了多重向量值正交小波包的性质,得到三个正交性公式.进而,得到空间L2(R,Cr)的一个新的规范正交基.     

多元正交小波包

本文利用Ｓｔｏｃｋｌｅｒ在引文（２）中所提供的多元小波矩阵描述的工具，将Ｃｈｕｉ在引文（１）中关于一元正交小波包的结果推广到多元正交小波包。     

二元多重双正交小波包的性质

陈清江等:二元多重双正交小波包的性质 第1期 1引言 小波包川由于拥有优良的特性而受到人们的关注.它己被应用在信号处理{“】，图像 压缩【“】，编码理论【41等工程方面.我们知道，由护(功中的函数生成的正交小波基具有 较差的频率局部化性能，为了克服这一缺陷，Coifman，Me