Fourier analysis started even before Fourier, but in the context of Fourier’s work on the Analytic Theory of Heat, it began with a claim regarding expansions of functions as trigonometrical series, what we now call Fourier series. Such expansions form the framework for writing down solutions to the heat equation in terms of initial temperature distributions. [refer to Enrique A. Gonzalez-Velasc...

In this paper we devise a so-called cylindrical Fourier transform within the Clifford analysis context. The idea is the following: for a fixed vector in the image space the level surfaces of the traditional Fourier kernel are planes perpendicular to that fixed vector. For this Fourier kernel we now substitute a new Clifford-Fourier kernel such that, again for a fixed vector in the image space, ...

Introduction. The theory of distributions, or generalized functions, provides a unified framework for performing standard calculus operations on nonsmooth functions, measures (such as the Dirac delta function), and even more general measure-like objects in the same way as they are done for smooth functions. In this theory, any distribution can be differentiated arbitrarily many times, a large c...

The theory and instrumentation for Fourier transform infrared spectrometry are discussed. These instruments measure infrared spectra of the same quality as spectra measured on grating spectrometers in about one thousandth of the time. Their sensitivity advantage for spectra measured in equal times is between a factor of 10 and 100. Commercial spectrometers are now available from nine vendors in...

Fast Quaternionic Fourier Transform 1 Acknowledgements I am grateful to all those who contributed to this project, to my professors, especially Gerald Sommer, and other professionals who have taken the time to answer questions and forced me to ask new ones. I particularly appreciate the professional wisdom and assistance of Thomas B ulow, the support in technical details by Udo Mahlmeister and ...

In this paper, some properties of pseudo-differential operators, SG-elliptic partial differential equations with polynomial coefficients and localization operators on space S ν (R), are studied by using fractional Fourier transform. AMS Mathematics Subject Classification (2010): 35S05, 46F12, 47G30.

The DFT can be reduced from exponential time with the Fast Fourier Transform algorithm. Fast Fourier Transform (FFT) One wonders if the DFT can be computed faster: Does another computational procedure an algorithm exist that can compute the same quantity, but more e ciently. We could seek methods that reduce the constant of proportionality, but do not change the DFT's complexity O ( N ) . Here,...

Fourier transform can be generalized into the fractional Fourier transform (FRFT), linear canonical transform (LCT), and simplified fractional Fourier transform (SFRFT). They extend the utilities of original Fourier transform, and can solve many problems that can’t be solved well by original Fourier transform. In this paper, we will generalize the cosine transform. We will derive fractional cos...

In this paper, a new tool that is fractional Fourier Transform is introduced to 3D model retrieval. And we propose a 3D model descriptor based on 3D factional Fourier transform. Fractional Fourier transform is a general format of Fourier transform, and add a variables that is order. Our approach is based on volume. The first step of the approach is that voxelize these 3D models. A coarse voxeli...

The classical method of numerically computing the Fourier transform of digitizedfunctions in one or in ddimensions is the so-called discrete Fourier transform ( D F T ) , efficiently implemented as Fast Fourier Transform ( F F T ) algorithms. In m n y cases the D F T is not an adequate appmximation of the continuous Fourier transform. The method presented in this contribution provides accurate ...