• Title/Summary/Keyword: fourier Transform

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CONDITIONAL FIRST VARIATION OVER WIENER PATHS IN ABSTRACT WIENER SPACE

  • CHO, DONG HYUN
    • Journal of the Korean Mathematical Society
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    • v.42 no.5
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    • pp.1031-1056
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    • 2005
  • In this paper, we define the conditional first variation over Wiener paths in abstract Wiener space and investigate its properties. Using these properties, we also investigate relationships among first variation, conditional first variation, Fourier-Feynman transform and conditional Fourier-Feynman transforms of functions in a Banach algebra which is equivalent to the Fresnel class. Finally, we provide another method evaluating the Fourier-Feynman transform for the product of a function in the Banach algebra with n linear factors.

QUANTUM EXTENSIONS OF FOURIER-GAUSS AND FOURIER-MEHLER TRANSFORMS

  • Ji, Un-Cig
    • Journal of the Korean Mathematical Society
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    • v.45 no.6
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    • pp.1785-1801
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    • 2008
  • Noncommutative extensions of the Gross and Beltrami Laplacians, called the quantum Gross Laplacian and the quantum Beltrami Laplacian, resp., are introduced and their basic properties are studied. As noncommutative extensions of the Fourier-Gauss and Fourier-Mehler transforms, we introduce the quantum Fourier-Gauss and quantum Fourier- Mehler transforms. The infinitesimal generators of all differentiable one parameter groups induced by the quantum Fourier-Gauss transform are linear combinations of the quantum Gross Laplacian and quantum Beltrami Laplacian. A characterization of the quantum Fourier-Mehler transform is studied.

Note on the generalized Fourier-Feynman transform on function space (함수공간에서의 일반화된 푸리에-파인만 변환에 관한 고찰)

  • Chang, Seung-Jun
    • Journal for History of Mathematics
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    • v.20 no.3
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    • pp.73-90
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    • 2007
  • In this paper, we define a generalized Feynman integral and a generalized Fourier-Feynman transform on function space induced by generalized Brownian motion process. We then give existence theorems and several properties for these concepts. Finally we investigate relationships of the Fourier transform and the generalized Fourier-Feynman transform.

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Study of Radix-3 FFT (Radix-3 FFT에 관한 고찰)

  • Jung, Hae-Seung
    • Aerospace Engineering and Technology
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    • v.9 no.1
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    • pp.98-105
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    • 2010
  • Fast Fourier Transform is the fast implementation of Discrete Fourier Transform, which deletes periodic operation of DFT. According to the definition, radix-2 FFT can be implemented byre cursive call which divides the input signal points into 2 signal points. Because of its time-consuming stack-copy operation, this recursive method is very slow. To overcome this drawback, butterfly operation with signal rearrangement was devised. Based on the ideas of signal rearrangement and butterfly operation, this paper applies the signal rearrangement method to the Radix-3 FFT and checks the validity of this method.

Emission Spectroscopy of Unstable Molecules using a Fourier Transform Spectrometer (Fourier Transform 분광기를 이용한 불안정한 분자의 방출분광학)

  • Sang Kuk Lee;Un Sik Kim
    • Journal of the Korean Chemical Society
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    • v.37 no.4
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    • pp.371-377
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    • 1993
  • Fourier Transform UV/VIS spectrometer has been modified for emission spectroscopy with the technique of supersonic expansion, in which the unstable molecular radical $CH_3S$ has been generated in a jet by a high voltage DC discharge. The fluorescence spectra of the supersonically cooled radical have been recorded on a Fourier Transform UV/VIS spectrometer. The ratio of signal to noise of the spectra has been improved substantially. Also the rotational structure has been clearly resolved for $CH_3S$ molecular radical.

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TRANSFORMS AND CONVOLUTIONS ON FUNCTION SPACE

  • Chang, Seung-Jun;Choi, Jae-Gil
    • Communications of the Korean Mathematical Society
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    • v.24 no.3
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    • pp.397-413
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    • 2009
  • In this paper, for functionals of a generalized Brownian motion process, we show that the generalized Fourier-Feynman transform of the convolution product is a product of multiple transforms and that the conditional generalized Fourier-Feynman transform of the conditional convolution product is a product of multiple conditional transforms. This allows us to compute the (conditional) transform of the (conditional) convolution product without computing the (conditional) convolution product.

A CONDITIONAL FOURIER-FEYNMAN TRANSFORM AND CONDITIONAL CONVOLUTION PRODUCT WITH CHANGE OF SCALES ON A FUNCTION SPACE I

  • Cho, Dong Hyun
    • Bulletin of the Korean Mathematical Society
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    • v.54 no.2
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    • pp.687-704
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    • 2017
  • Using a simple formula for conditional expectations over an analogue of Wiener space, we calculate a generalized analytic conditional Fourier-Feynman transform and convolution product of generalized cylinder functions which play important roles in Feynman integration theories and quantum mechanics. We then investigate their relationships, that is, the conditional Fourier-Feynman transform of the convolution product can be expressed in terms of the product of the conditional FourierFeynman transforms of each function. Finally we establish change of scale formulas for the generalized analytic conditional Fourier-Feynman transform and the conditional convolution product. In this evaluation formulas and change of scale formulas we use multivariate normal distributions so that the orthonormalization process of projection vectors which are essential to establish the conditional expectations, can be removed in the existing conditional Fourier-Feynman transforms, conditional convolution products and change of scale formulas.

Analysis of TE-Wave Scattering from Transversal-Shifted Tandem Slits Using Wiener-Hopf Techniques and Fourier Transform Analysis (Wiener-Hopf Technique와 Fourier Transform Analysis를 이용한 병렬 슬릿의 TE파 산란 해석)

  • Seo, Tae-Yoon;Ahn, Sung-Hwan;Lee, Jae-Wook;Cho, Choon-Sik
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.19 no.9
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    • pp.968-977
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    • 2008
  • In this paper, an analysis of TE-wave scattering from transversal-shifted tandem slits using fourier transform analysis and Wiener-Hopf technique are derived and the electrical performances have been compared with a commercially availabel software. In Fourier transform analysis, it is shown that a fast-convergent series solution can be obtained when the distance between the slits is very narrow, while in Wiener-Hopf technique, it is found that the highly-accurate approximation can be obtained when the gap between the slits becomes wider. In addition, this paper has dealt with a good agreement between two analytical solutions.

ANALYTIC FOURIER-FEYNMAN TRANSFORMS ON ABSTRACT WIENER SPACE

  • Ahn, Jae Moon;Lee, Kang Lae
    • Korean Journal of Mathematics
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    • v.6 no.1
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    • pp.47-66
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    • 1998
  • In this paper, we introduce an $L_p$ analytic Fourier-Feynman transformation, show the existence of the $L_p$ analytic Fourier-Feynman transforms for a certain class of cylinder functionals on an abstract Wiener space, and investigate its interesting properties. Moreover, we define a convolution product for two functionals on the abstract Wiener space and establish the relationships between the Fourier-Feynman transform for the convolution product of two cylinder functionals and the Fourier-Feynman transform for each functional.

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MULTIPLE Lp FOURIER-FEYNMAN TRANSFORM ON THE FRESNEL CLASS

  • Ahn, J.M.
    • Korean Journal of Mathematics
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    • v.9 no.2
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    • pp.133-147
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    • 2001
  • In this paper, we introduce the concepts of multiple $L_p$ analytic Fourier-Feynman transform ($1{\leq}p$ < ${\infty})$ and a convolution product of functionals on abstract Wiener space and verify the existence of the multiple $L_p$ analytic Fourier-Feynman transform for functionls in the Fresnel class. Moreover, we verify that the Fresnel class is closed under the $L_p$ analytic Fourier-Feynman transformation and the convolution product, respectively. And we establish some relationships among the multiple $L_p$ analytic Fourier-Feynman transform and the convolution product on the Fresnel class.

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