• Title/Summary/Keyword: Fourier-Gauss transform

Search Result 12, Processing Time 0.02 seconds

QUANTUM EXTENSIONS OF FOURIER-GAUSS AND FOURIER-MEHLER TRANSFORMS

  • Ji, Un-Cig
    • Journal of the Korean Mathematical Society
    • /
    • v.45 no.6
    • /
    • pp.1785-1801
    • /
    • 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.

YEH CONVOLUTION OF WHITE NOISE FUNCTIONALS

  • Ji, Un Cig;Kim, Young Yi;Park, Yoon Jung
    • Journal of applied mathematics & informatics
    • /
    • v.31 no.5_6
    • /
    • pp.825-834
    • /
    • 2013
  • In this paper, we study the Yeh convolution of white noise functionals. We first introduce the notion of Yeh convolution of test white noise functionals and prove a dual property of the Yeh convolution. By applying the dual object of the Yeh convolution, we study the Yeh convolution of generalized white noise functionals, which is a non-trivial extension. Finally, we study relations between the Yeh convolution and Fourier-Gauss, Fourier-Mehler transform.

RELATIONS AMONG THE FIRST VARIATION, THE CONVOLUTIONS AND THE GENERALIZED FOURIER-GAUSS TRANSFORMS

  • Im, Man-Kyu;Ji, Un-Cig;Park, Yoon-Jung
    • Bulletin of the Korean Mathematical Society
    • /
    • v.48 no.2
    • /
    • pp.291-302
    • /
    • 2011
  • We first study the generalized Fourier-Gauss transforms of functionals defined on the complexification $\cal{B}_C$ of an abstract Wiener space ($\cal{H}$, $\cal{B}$, ${\nu}$). Secondly, we introduce a new class of convolution products of functionals defined on $\cal{B}_C$ and study several properties of the convolutions. Then we study various relations among the first variation the convolutions, and the generalized Fourier-Gauss transforms.

Amplitude impulse and superresolution of interferometric imaging system obtained by superposing three Gauss pupils (세개의 Gauss 동을 중첩한 간섭계형 결상계의 진폭임펄스와 초분해능)

  • 송영란;이민희;이상수
    • Korean Journal of Optics and Photonics
    • /
    • v.8 no.1
    • /
    • pp.1-6
    • /
    • 1997
  • The amplitude impulse S(x) of an interferometric optical imaging system for λ=193 nm(ArF laser) and NA=0.5 is derived for the pupil with superposed three Gauss pupils $A_1$($\omega$), $A_{2-}$($\omega$) and $A_{2+}$($\omega$). It is shown that FWHM of S(x) can be far less than the Rayleigh's criterion of resolution $\frac{1}{2}{\epsilon}_R$, where ${\epsilon}_R$ is equal to λ=193 nm in the present case of NA=0.5. The three Gauss pupils are provided in an optical system which consists of a Twyman-Green interferometer and an imaging system. The system is proposed and relevent optical components are discussed. Siloxane polymer is suggested for fabrications of amplitude modulation plates. In the present work, we assumed the system is free from aberration and linear. The case that the system has residual aberrations is important, and further work is necessary.

  • PDF

Continuous and discontinuous contact problem of a magneto-electro-elastic layer

  • Comez, Isa;Karabulut, Pembe Merve
    • Structural Engineering and Mechanics
    • /
    • v.83 no.1
    • /
    • pp.67-77
    • /
    • 2022
  • In this study, frictionless continuous and discontinuous contact problems of a magneto-electro-elastic layer in the presence of the body force were discussed. The layer was indented by a rigid cylindrical insulating punch and supported by a rigid substrate without bond. Applying the Fourier integral transform technique, the general expressions of the problem were derived in the presence of body force. Thanks to the boundary conditions, the singular integral equations were obtained for both the continuous and the discontinuous contact cases. Gauss-Chebyshev integration formulas were used to transform the singular integral equations into a set of nonlinear equations. Contact width under the punch, initial separation distance, critical load, separation regions and contact stress under the punch and between the layer, and substrate were given as a result.

The receding contact problem of two elastic layers supported by two elastic quarter planes

  • Yaylaci, Murat;Birinci, Ahmet
    • Structural Engineering and Mechanics
    • /
    • v.48 no.2
    • /
    • pp.241-255
    • /
    • 2013
  • The receding contact problem for two elastic layers whose elastic constants and heights are different supported by two elastic quarter planes is considered. The lower layer is supported by two elastic quarter planes and the upper elastic layer is subjected to symmetrical distributed load whose heights are 2a on its top surface. It is assumed that the contact between all surfaces is frictionless and the effect of gravity force is neglected. The problem is formulated and solved by using Theory of Elasticity and Integral Transform Technique. The problem is reduced to a system of singular integral equations in which contact pressures are the unknown functions by using integral transform technique and boundary conditions of the problem. Stresses and displacements are expressed depending on the contact pressures using Fourier and Mellin formula technique. The singular integral equation is solved numerically by using Gauss-Jacobi integration formulation. Numerical results are obtained for various dimensionless quantities for the contact pressures and the contact areas are presented in graphics and tables.

Evaluation of Inverse Fourier Integral Considering the Distances from the Source Point in 2D Resistivity Modeling (전기비저항탐사 2차원 모델링에서 송수신 간격을 고려한 푸리에 역변환)

  • Cho, In-Ky;Jeong, Da-Bhin
    • Geophysics and Geophysical Exploration
    • /
    • v.21 no.1
    • /
    • pp.1-7
    • /
    • 2018
  • In the two-dimensional (2D) modeling of electrical method, the potential in the space domain is reconstructed with the calculated potentials in the wavenumber domain using inverse Fourier transform. The inverse Fourier integral is numerically evaluated using the transformed potential at different wavenumbers. In order to improve the precision of the integration, either the logarithmic or exponential approximation has been used depending on the size of wavenumber. Two numerical methods have been generally used to evaluate the integral; interval integration and Gaussian quadrature. However, both methods do not consider the distance from the current source. Thus the resulting potential in the space domain shows some error. Especially when the distance from the current source is very small or large, the error increases abruptly and the evaluated potential becomes extremely unstable. In this study, we developed a new method to calculate the integral accurately by introducing the distance from the current source to the rescaled Gauss abscissa and weight. The numerical tests for homogeneous half-space model show that the developed method can yield the error level lower than 0.4 percent over the various distances from the current source.

A Study on Sound Radiation from Isofropic Plates Stiffened by Symmetrical Reinforced Beams (대칭형 보에 의해 보강된 등방성 평판의 음향방사에 관한 연구)

  • 김택현
    • Journal of the Korean Society of Manufacturing Technology Engineers
    • /
    • v.7 no.1
    • /
    • pp.41-50
    • /
    • 1998
  • The detemination of sound pressure radiated from peoriodic plate structures is fundamental in the estimation of noise levels in aircraft fuselages and ship hull structures. As a robust approach to this problem, here a very general and comprehensive analytical model for predicting the sound radiated by a vibrating plate stiffened by periodically spaced orthogonal symmetric beams subjected to a sinusoidally time varying point load is developed. The plate is assumed to be infinite in extent, and the beams are considered to exert both line force and moment reactions on it. Structural damping is included in both plate and beam materials. A space harmonic series representation of the spatial variables is used in conjunction with the Fourier transform to find the sound pressure in terms of harmonic coefficients. From this theoretical model. the sound pressure levels on axis in a semi-infinite fluid (water) bounded by the plate with the variation in the locations of an external time harmonic point force on the plate can be calculated efficiently using three numerical tools such as the Gauss-Jordan method, the LU decomposition method and the IMSL numerical package.

  • PDF

Lp-Boundedness for the Littlewood-Paley g-Function Connected with the Riemann-Liouville Operator

  • Rachdi, Lakhdar Tannech;Amri, Besma;Chettaoui, Chirine
    • Kyungpook Mathematical Journal
    • /
    • v.56 no.1
    • /
    • pp.185-220
    • /
    • 2016
  • We study the Gauss and Poisson semigroups connected with the Riemann-Liouville operator defined on the half plane. Next, we establish a principle of maximum for the singular partial differential operator $${\Delta}_{\alpha}={\frac{{\partial}^2}{{\partial}r^2}+{\frac{2{\alpha}+1}{r}{\frac{\partial}{{\partial}r}}+{\frac{{\partial}^2}{{\partial}x^2}}+{\frac{{\partial}^2}{{\partial}t^2}}};\;(r,x,t){\in}]0,+{\infty}[{\times}{\mathbb{R}}{\times}]0,+{\infty}[$$. Later, we define the Littlewood-Paley g-function and using the principle of maximum, we prove that for every $p{\in}]1,+{\infty}[$, there exists a positive constant $C_p$ such that for every $f{\in}L^p(d{\nu}_{\alpha})$, $${\frac{1}{C_p}}{\parallel}f{\parallel}_{p,{\nu}_{\alpha}}{\leqslant}{\parallel}g(f){\parallel}_{p,{\nu}_{\alpha}}{\leqslant}C_p{\parallel}f{\parallel}_{p,{\nu}_{\alpha}}$$.