广义Moebius变换和算术Fourier变换

离散Fourier变换(DFT)在数字信号处理等许多领域中占有重要地位．近年来，出现一种优于FFT的算术Fourier变换来计算DFT．在广义Moebius变换的基础上，本文采用了一种改进的AFT来计算DFT，这种方法可以直接提取DFT的系数，且用数论的方法阐明了这一过程，并展开了进一步的讨论．这也代表了数论方法应用在计算数学领域的一个新的发展方向．     

Fourier变换的权模不等式

给定 p 和 q,满足1相似文献   

广义离散傅里叶变换的模多项式分解算法(MPDA)及其矩阵表现形式

§1.引言 离散傅里叶变换(DFT)和卷积计算在图象、数字信号处理中起着极为重要的作用,它们是实现数字滤波、进行频谱分析的基本工具.因此,其快速算法的研究异常活跃.在以上众多算法中,由于基-2、基-4快速傅氏变换(FFT)算法具有简洁的蝶式结构,并且可在原置实现等特点,应用极为广泛.70年代末提出的数论变换、多项式变换已发展成完整的理论,成为处理多维DFT和卷积的有力工具.然而它们对一般一     

模糊矩阵的广义一致性变换及其性质

给出模糊矩阵广义一致性变换的定义,并论证模糊矩阵经广义一致性变换后所具有的性质;通过对比分析指出本文的研究结论具有更广的应用范围;从分辨率角度给出参数取值范围的一个合理区间;从而拓展基于模糊一致判断矩阵的层次分析法的应用范围。     

广义M(o|¨)bius变换和算术Fourier变换

离散Fourier变换(DFT)在数字信号处理等许多领域中占有重要地位.近年来,出现一种优于FFT的算术Fourier变换来计算DFT.在广义Mobius变换的基础上,本文采用了一种改进的AFT来计算DFT,这种方法可以直接提取DFT的系数,且用数论的方法阐明了这一过程,并展开了进一步的讨论.这也代表了数论方法应用在计算数学领域的一个新的发展方向.     

广义M(o)bius变换和算术Fourier变换

离散Fourier变换(DFT)在数字信号处理等许多领域中占有重要地位.近年来,出现一种优于FFT的算术Fourier变换来计算DFT.在广义M(o)bius变换的基础上,本文采用了一种改进的AFT来计算DFT,这种方法可以直接提取DFT的系数,且用数论的方法阐明了这一过程,并展开了进一步的讨论.这也代表了数论方法应用在计算数学领域的一个新的发展方向.     

单位阶跃函数在广义Fourier变换中的屏蔽效应

对u(t)在广义傅氏变换的作用进行了探讨,并给出了半屏、翻掩、隐匿、零点对应和对称等相关定理.     

模糊互补矩阵的广义一致性变换及其性质研究

本文给出了模糊互补矩阵广义一致性变换的定义,并论证了模糊互补矩阵经广义一致性变换后所具有的性质;指出相关文献的研究成果只是本文研究结论的特殊情况;深化了对参数β的理解,并给出了该参数取值范围的一个合理区间,从而把模糊一致矩阵及其性质从理论上推广到更大的应用范围之中.     

基于线性算子的广义逆矩阵的几何表示

广义逆矩阵是矩阵理论的重要内容.由于广义逆矩阵的定义众多,计算较为繁杂,使得初学者很难理解和掌握其本质.基于线性方程组求解问题的等价表示,从线性算子的角度展示多种广义逆矩阵定义的背景及其几何直观意义.通过对一个特殊算例的分析与求解,实现了对多种广义逆矩阵的几何解释及其在线性方程组求解中的作用,淡化了广义逆矩阵计算的繁杂,加深初学者对广义逆矩阵的理解与掌握.     

关于广义Fourier级数的若干结论及其应用

讨论Hilbert空间广义Fourier级数收敛的充分和必要条件,并将相关结果应用于数学分析中具体的Fourier级数上.     

广义倒易定理及其应用

推广Betti倒易定理的概念,建立了非耦联系统和耦联系统的广义倒易定理,它们适用于具有不同本构关系的两个变形体。当该两变形体的本构关系相同且为线弹性时,该非耦联系统的广义倒易定理即成为Betti倒易定理。同时,应用该两个广义倒易定理于弹性力学中的模拟计算。     

Generalized Morphic Rings and Their Applications

A ring R is called “left generalized morphic” if for every element a in R, there exists b ∈ R such that l(a)? R/Rb, where l(a) denotes the left annihilator of a in R. The aim of this article is to investigate these rings. Several examples are given. They include left morphic rings and left p.p. rings. As applications, some homological dimensions over these rings are defined and studied.     

广义L-KKM定理及其应用

引入广义L-KKM映射的概念,它包含R-KKM映射,G-KKM映射,H-KKM映射为其特例.在具有(H)性质的拓扑空间中证明了一些新的广义L-KKM型定理,并进一步获得了关于开覆盖的匹配定理.作为广义L-KKM型定理应用,证明了非空交定理.     

非欧空间中的广义度量方程及其应用

本文改进了杨世国关于非欧空间中基本图形的度量方程,建立一个一般意义下的、应用更为方便的广义度量方程,作为其初步应用,导出了非欧空间中两个单形之间的一些有趣的几何关系．     

Applications of the Generalized Fourier Transform in Numerical Linear Algebra

Equivariant matrices, commuting with a group of permutation matrices, are considered. Such matrices typically arise from PDEs and other computational problems where the computational domain exhibits discrete geometrical symmetries. In these cases, group representation theory provides a powerful tool for block diagonalizing the matrix via the Generalized Fourier Transform (GFT). This technique yields substantial computational savings in problems such as solving linear systems, computing eigenvalues and computing analytic matrix functions such as the matrix exponential. The paper is presenting a comprehensive self contained introduction to this field. Building upon the familiar special (finite commutative) case of circulant matrices being diagonalized with the Discrete Fourier Transform, we generalize the classical convolution theorem and diagonalization results to the noncommutative case of block diagonalizing equivariant matrices. Applications of the GFT in problems with domain symmetries have been developed by several authors in a series of papers. In this paper we elaborate upon the results in these papers by emphasizing the connection between equivariant matrices, block group algebras and noncommutative convolutions. Furthermore, we describe the algebraic structure of projections related to non-free group actions. This approach highlights the role of the underlying mathematical structures, and provides insight useful both for software construction and numerical analysis. The theory is illustrated with a selection of numerical examples. AMS subject classification (2000) 43A30, 65T99, 20B25     

Generalized Singular Value Decompositions for Tensors and Their Applications

In this paper, we consider the generalized singular value decompositions for two tensors via the T-product. We investigate and discuss in detail the structures of the quotient singular value decomposition (T-QSVD) and product singular value decomposition (T-PSVD) for two tensors. The algorithms are presented with numerical examples illustrating the results. For applications, we consider color image watermarking processing with T-QSVD and T-PSVD. There are two advantages to T-QSVD and T-PSVD approaches on color watermark processing: two color watermarks can be processed simultaneously and only one key needs to be saved.     

On Generalized Gaussian Quadratures for Exponentials and Their Applications

We introduce new families of Gaussian-type quadratures for weighted integrals of exponential functions and consider their applications to integration and interpolation of bandlimited functions.We use a generalization of a representation theorem due to Carathéodory to derive these quadratures. For each positive measure, the quadratures are parameterized by eigenvalues of the Toeplitz matrix constructed from the trigonometric moments of the measure. For a given accuracy ε, selecting an eigenvalue close to ε yields an approximate quadrature with that accuracy. To compute its weights and nodes, we present a new fast algorithm.These new quadratures can be used to approximate and integrate bandlimited functions, such as prolate spheroidal wave functions, and essentially bandlimited functions, such as Bessel functions. We also develop, for a given precision, an interpolating basis for bandlimited functions on an interval.     

Order-Preserving Transformations and Applications

In this paper, we study the effects of a linear transformation on the partial order relations that are generated by a closed and convex cone in a finite-dimensional space. Sufficient conditions are provided for a transformation preserving a given order. They are applied to derive the relationship between the efficient set of a set and its image under a linear transformation, to characterize generalized convex vector functions by using order-preserving transformations, to establish some calculus rules for the subdifferential of a convex vector function, and develop an optimality condition for a convex vector problem.