• 제목/요약/키워드: Fourier Function

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A NOTE ON PROLATE SPHEROIDAL WAVE FUNCTIONS AND PROLATE FUNCTION BASED NUMERICAL INVERSION METHODS

  • Kim, Eun-Joo;Lee, June-Yub
    • Journal of the Korean Society for Industrial and Applied Mathematics
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    • 제12권1호
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    • pp.41-53
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    • 2008
  • Polynomials are one of most important and widely used numerical tools in dealing with a smooth function on a bounded domain and trigonometric functions work for smooth periodic functions. However, they are not the best choice if a function has a bounded support in space and in frequency domain. The Prolate Spheroidal wave function (PSWF) of order zero has been known as a best candidate as a basis for band-limited functions. In this paper, we review some basic properties of PSWFs defined as eigenfunctions of bounded Fourier transformation. We also propose numerical inversion schemes based on PSWF and present some numerical examples to show their feasibilities as signal processing tools.

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Fourier-Galerkin Moment Method를 이용한 접지된 2개 유전체층 위의 완전도체띠 격자구조에 의한 TE 산란의 해 (Solution of TE Scattering by a Perfectly Conducting Strip Grating Over the Grounded Two Dielectric Layers Applying Fourier-Galerkin Moment Method)

  • 윤의중
    • 한국항행학회논문지
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    • 제16권4호
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    • pp.635-640
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    • 2012
  • 본 논문에서는 접지된 2개의 유전체층 위의 도체띠 격자구조에 의한 TE (Transverse Electric) 산란문제를 도체경계조건과 수치해석 방법인 FGMM (Fourier-Galerkin Moment Method)를 적용하여 해석하였으며, 이 때 유도되는 표면전류밀도는 미지의 계수와 단순한 함수인 지수함수의 곱의 급수로 전개하였다. 전반적으로, 제안된 구조에서 영역-2의 유전체층의 비유전율 ${\epsilon}_{r2}$과 유전체 층의 두께 $t_2$가 증가함에 따라 반사전력이 증가하였다. 반사전력의 급변점들은 공진효과에 기인한 것으로 과거에 wood's anomaly라고 불리워졌으며, 수치계산 결과들은 기존 논문의 결과들과 일치하였다.

Lessons from Yeast on Emerging Roles of the ATAD2 Protein Family in Gene Regulation and Genome Organization

  • Cattaneo, Matteo;Morozumi, Yuichi;Perazza, Daniel;Boussouar, Faycal;Jamshidikia, Mahya;Rousseaux, Sophie;Verdel, Andre;Khochbin, Saadi
    • Molecules and Cells
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    • 제37권12호
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    • pp.851-856
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    • 2014
  • ATAD2, a remarkably conserved, yet poorly characterized factor is found upregulated and associated with poor prognosis in a variety of independent cancers in human. Studies conducted on the yeast Saccharomyces cerevisiae ATAD2 homologue, Yta7, are now indicating that the members of this family may primarily be regulators of chromatin dynamics and that their action on gene expression could only be one facet of their general activity. In this review, we present an overview of the literature on Yta7 and discuss the possibility of translating these findings into other organisms to further define the involvement of ATAD2 and other members of its family in regulating chromatin structure and function both in normal and pathological situations.

AN APPROXIMATION OF THE FOURIER SINE TRANSFORM VIA GRÜSS TYPE INEQUALITIES AND APPLICATIONS FOR ELECTRICAL CIRCUITS

  • DRAGOMIR, S.S.;KALAM, A.
    • Journal of the Korean Society for Industrial and Applied Mathematics
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    • 제6권1호
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    • pp.33-45
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    • 2002
  • An approximation of the Fourier Sine Transform via Gr$\ddot{u}$ss, Chebychev and Lupaş integral inequalities and application for an electrical curcuit containing an inductance L, a condenser of capacity C and a source of electromotive force $E_0P$(t), where P (t) is an $L_2$-integrable function, are given.

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PERTURBATION OF NONHARMONIC FOURIER SERIES AND NONUNIFORM SAMPLING THEOREM

  • Park, Hee-Chul;Shin, Chang-Eon
    • 대한수학회보
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    • 제44권2호
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    • pp.351-358
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    • 2007
  • For an entire function f whose Fourier transform has a compact support confined to $[-{\pi},\;{\pi}]$ and restriction to ${\mathbb{R}}$ belongs to $L^2{\mathbb{R}}$, we derive a nonuniform sampling theorem of Lagrange interpolation type with sampling points ${\lambda}_n{\in}{\mathbb{R}},\;n{\in}{\mathbb{Z}}$, under the condition that $$\frac{lim\;sup}{n{\rightarrow}{\infty}}|{\lambda}_n-n|<\frac {1}{4}$.

CONVERGENCE RATE OF HYBRID SAMPLING SERIES ASSOCIATED WITH WAVELETS

  • Shim, Hong-Tae;Kwon, Joong-Sung
    • Journal of applied mathematics & informatics
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    • 제14권1_2호
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    • pp.267-275
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    • 2004
  • While the convergence of the classical Fourier series has been well known, the rate of its convergence is not well acknowledged. The results regarding the rate of convergence of the Fourier series and wavelet expansions can be found in the book of Walter[5]. In this paper, we give the rate of convergence of hybrid sampling series associated with orthogonal wavelets.

CERTAIN RESULTS INVOLVING FRACTIONAL OPERATORS AND SPECIAL FUNCTIONS

  • Aghili, Arman
    • Korean Journal of Mathematics
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    • 제27권2호
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    • pp.487-503
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    • 2019
  • In this study, the author provided a discussion on one dimensional Laplace and Fourier transforms with their applications. It is shown that the combined use of exponential operators and integral transforms provides a powerful tool to solve space fractional partial differential equation with non - constant coefficients. The object of the present article is to extend the application of the joint Fourier - Laplace transform to derive an analytical solution for a variety of time fractional non - homogeneous KdV. Numerous exercises and examples presented throughout the paper.

A GENERALIZED APPROACH OF FRACTIONAL FOURIER TRANSFORM TO STABILITY OF FRACTIONAL DIFFERENTIAL EQUATION

  • Mohanapriya, Arusamy;Sivakumar, Varudaraj;Prakash, Periasamy
    • Korean Journal of Mathematics
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    • 제29권4호
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    • pp.749-763
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    • 2021
  • This research article deals with the Mittag-Leffler-Hyers-Ulam stability of linear and impulsive fractional order differential equation which involves the Caputo derivative. The application of the generalized fractional Fourier transform method and fixed point theorem, evaluates the existence, uniqueness and stability of solution that are acquired for the proposed non-linear problems on Lizorkin space. Finally, examples are introduced to validate the outcomes of main result.

FOURIER SERIES OF A DEVIL'S STAIRCASE

  • Kwon, DoYong
    • 호남수학학술지
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    • 제43권2호
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    • pp.259-267
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    • 2021
  • Given 𝛽 > 1, we consider real numbers whose 𝛽-expansions are Sturmian words. When the slope of Sturmian words varies, their behaviors have been well studied from analytical point of view. The regularity enables us to find the Fourier series expansion, while the singularity at rational slopes yields a new kind of trigonometric series representing 𝜋.

A FUBINI THEOREM FOR GENERALIZED ANALYTIC FEYNMAN INTEGRALS AND FOURIER-FEYNMAN TRANSFORMS ON FUNCTION SPACE

  • Chang, Seung-Jun;Lee, Il-Yong
    • 대한수학회보
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    • 제40권3호
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    • pp.437-456
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    • 2003
  • In this paper we use a generalized Brownian motion process to define a generalized analytic Feynman integral. We then establish a Fubini theorem for the function space integral and generalized analytic Feynman integral of a functional F belonging to Banach algebra $S(L^2_{a,b}[0,T])$ and we proceed to obtain several integration formulas. Finally, we use this Fubini theorem to obtain several Feynman integration formulas involving analytic generalized Fourier-Feynman transforms. These results subsume similar known results obtained by Huffman, Skoug and Storvick for the standard Wiener process.