共查询到19条相似文献,搜索用时 125 毫秒
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《数学的实践与认识》2017,(5)
针对分数阶Fourier变换在信号处理中应用的广泛性,引入了分数阶尺度函数与分数阶小波变换的概念.运用分数阶Fourier变换与时频分析方法研究了分数阶多分辨分析与尺度函数的构造方法,刻画分数阶尺度函数的特征.得到分数阶尺度函数存在的充要条件. 相似文献
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针对Euler小波非正交的缺点,提出了 3-尺度正交Euler小波.利用施密特正交化过程将Euler多项式正交归一化,再根据小波的构造方法得到3-尺度正交Euler小波.分析了 3-尺度正交Euler小波级数的收敛性与误差估计,利用Laplace变换推导了 Euler小波的Riemann-Liouville分数阶积分公... 相似文献
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定义了二维Haar尺度函数,构造了长方形区域上的二维非均匀Haar小波函数,给出了非均匀 Haar 小波的分解和重构公式,最后得到了单值重构算法. 相似文献
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文中研究了对应于α-带尺度函数的小波紧框架,这个小波紧框架是由V1中的n个函数ψ1,ψ2,...,ψn构成. 首先给出了这n个函数构成小波紧框架的充分条件, 并借助尺度函数给出了构造小波紧框架的显式公式. 如果尺度函数的符号是有理函数,则可以构造出符号为有理函数的小波紧框架. 其次给出类似于正交小波的小波紧框架的分解与重构算法,并构造了小波紧框架的数值算例. 相似文献
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《数学的实践与认识》2020,(1)
借助Haar小波正交函数的分数阶积分算子矩阵,通过离散未知变量,将待求Poisson方程转化为大型的线性代数方程组,然后利用Matlab软件进行编程求解,即可求得原问题的未知系数矩阵,代入原方程,从而求得数值解.数值结果表明,当Haar小波采取很小的级数项展开时,即可获得满意的数值精度,而且算法比较稳定,有很强的实际应用价值. 相似文献
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小波的传递函数构造法 总被引:2,自引:0,他引:2
本从小波与尺度函数的传递函数出发,给出了构造小波母函数及尺度函数的构造方法,根据此方法,首先以小波与其尺度函数的传递函数为起点,构造了一个非正交小波,随后以此小波和一个已有的非正交步波为基准,进一步推广得到了一类非正交小波及尺度函数类,在非正交小波的基础上,利用将尺度函数正交化的方法,构造出了相应正交小波的函数值。 相似文献
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Hari M. Srivastava Komal Khatterwani S. K. Upadhyay 《Mathematical Methods in the Applied Sciences》2019,42(9):3103-3122
In the present paper, a fractional wavelet transform of real order α is introduced, and various useful properties and results are derived for it. These include (for example) Perseval's formula and inversion formula for the fractional wavelet transform. Multiresolution analysis and orthonormal fractional wavelets associated with the fractional wavelet transform are studied systematically. Fractional Fourier transforms of the Mexican hat wavelet for different values of the order α are compared with the classical Fourier transform graphically, and various remarkable observations are presented. A comparative study of the various results, which we have presented in this paper, is also represented graphically. 相似文献
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In this paper, the notion of two-direction vector-valued multiresolution analysis and the two-direction orthogonal vector-valued wavelets are introduced. The definition for two-direction orthogonal vector-valued wavelet packets is proposed. An algorithm for constructing a class of two-direction orthogonal vector-valued compactly supported wavelets corresponding to the two-direction orthogonal vector-valued compactly supported scaling functions is proposed by virtue of matrix theory and time-frequency analysis method. The properties of the two-direction vector-valued wavelet packets are investigated. At last, the direct decomposition relation for space L2(R)r is presented. 相似文献
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Sabrine Arfaoui & Anouar Ben Mabrouk 《分析论及其应用》2022,38(4):394-416
In the present paper, by extending some fractional calculus to the framework of Clifford analysis, new classes of wavelet functions are presented. Firstly, some
classes of monogenic polynomials are provided based on 2-parameters weight functions which extend the classical Jacobi ones in the context of Clifford analysis. The
discovered polynomial sets are next applied to introduce new wavelet functions. Reconstruction formula as well as Fourier-Plancherel rules have been proved. The main
tool reposes on the extension of fractional derivatives, fractional integrals and fractional Fourier transforms to Clifford analysis. 相似文献
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向量值双正交小波的存在性及滤波器的构造 总被引:1,自引:0,他引:1
引进了向量值多分辨分析与向量值双正交小波的概念.讨论了向量值双正交小波的存在性.运用多分辨分析和矩阵理论,给出一类紧支撑向量值双正交小波滤波器的构造算法.最后,给出4-系数向量值双正交小波滤波器的的构造算例. 相似文献
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Wavelets for multichannel signals 总被引:1,自引:0,他引:1
In this paper, we introduce and investigate multichannel wavelets, which are wavelets for vector fields, based on the concept of full rank subdivision operators. We prove that, like in the scalar and multiwavelet case, the existence of a scaling function with orthogonal integer translates guarantees the existence of a wavelet function, also with orthonormal integer translates. In this context, however, scaling functions as well as wavelets turn out to be matrix-valued functions. 相似文献
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Recently Fischer and Prestin presented a unified approach for the construction of polynomial wavelets. In particular, they characterized those parameter sets which lead to orthogonal scaling functions. Here, we extend their results to the wavelets. We work out necessary and sufficient conditions for the wavelets to be orthogonal to each other. Furthermore, we show how these computable characterizations lead to attractive decomposition and reconstruction schemes. The paper concludes with a study of the special case of Bernstein–Szegö weight functions. 相似文献
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何永滔 《纯粹数学与应用数学》2012,(1):8-16
基于Householder矩阵扩充,构造了紧支撑正交的二维小波,所构造小波函数的支撑不超过尺度函数的支撑,并且给出了容易实施的显式构造算法.另外,还通过构造反例说明Riesz定理不适用于二元三角多项式.最后,构造了算例. 相似文献
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§ 1. Introduction SinceDAUBECHIES [1 ]gavethewellknownconstructionofunivariatecompactlysup portedorthonormalwavelets,considerableattertionhasbeenspentonconstructingmultivariatecompactlysupportedorthonormalwavelets [2— 5etc.] .Althoughmanyspecialbivariatenon separablewaveletshavebeenconstructed ,itisstillanopenproblemhowtoconstructbivariatecompactlyorthonormalwaveletsforanygivencompactlysupportedscalingfunction .Thepur poseofthispaperistoconstructcompactlysupportedorthogonalwaveletass… 相似文献