• 제목/요약/키워드: homogeneous field

검색결과 462건 처리시간 0.028초

IVERSON언어의 참고어로의 구성(외부매체의 동질화를 위하여) (A Formalism of Iverson Language as a Reference Language for the Organization of Homogeneous Field using many Extermal Media)

  • 김영택
    • 전기의세계
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    • 제24권4호
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    • pp.71-72
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    • 1975
  • A formalism of reference language and homogeneous field is constructed for Iverson Language to organize a virtual file among external media. To execute some data manipulations among these external media files must be organized homogeneously forming multi-dimensional array like single media. This paper shows some organization of reference language to build the virtual file using many external media and some examples of program and hardware organization is presented for the justification of proposals.

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선형적 물성변화를 고려하는 유한요소법을 이용한 2.5차원 전자탐사 수치모델링 (2.5 Dimensional Electromagnetic Finite Element Numerical modeling using linear conductivity variation)

  • 고광범;서백수
    • 산업기술연구
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    • 제18권
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    • pp.131-138
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    • 1998
  • Numerical modeling for electromagnetic exploration methods are essential to understand behaviours of electromagnetic fields in complex subsurfaces. In this study, a finite element method was adopted as a numerical scheme for the 2.5-dimensional forward problem. And a finite element equation considering linear conductivity variation was proposed when 2.5-dimensional differential equation to couple eletric and magnetic field was implemented. Model parameters were investigated for near-field with large source effects and far-field with responses dominantly by homogeneous half-space. Numerical responses by this study were compared with analytic solutions in homogeneous half-space and compared with other three dimensional numerical results.

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ONE-HOMOGENEOUS WEIGHT CODES OVER FINITE CHAIN RINGS

  • SARI, MUSTAFA;SIAP, IRFAN;SIAP, VEDAT
    • 대한수학회보
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    • 제52권6호
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    • pp.2011-2023
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    • 2015
  • This paper determines the structures of one-homogeneous weight codes over finite chain rings and studies the algebraic properties of these codes. We present explicit constructions of one-homogeneous weight codes over finite chain rings. By taking advantage of the distance-preserving Gray map defined in [7] from the finite chain ring to its residue field, we obtain a family of optimal one-Hamming weight codes over the residue field. Further, we propose a generalized method that also includes the examples of optimal codes obtained by Shi et al. in [17].

불균질 매질에 따른 인공 합성 탄성파 자료 비교 (Comparison of synthetic seismograms referred to inhomogeneous medium)

  • 김영완;장성형;윤왕중;서상용
    • 한국지구물리탐사학회:학술대회논문집
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    • 한국지구물리탐사학회 2007년도 공동학술대회 논문집
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    • pp.197-202
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    • 2007
  • Most of seismic reflection prospecting assumes subsurface formation to be homogeneous media. These models are not capable of estimating small scale heterogeneity which is verified by well log data or drilling core. And those synthetic seismograms by homogeneous media are limited to explain various changes at field data. So we developed a inhomogeneous velocity model which can estimate inhomogeneity of background medium to implement numerical modeling from homogeneous medium and inhomogeneous medium on the model. Background medium using three autocorrelation functions in order to generate inhomogeneous velocity media was according to dominant wavelength of background medium and correlation length of random medium. And then we compared shot gathers. The results show that numerical modeling implemented at inhomogeneous medium depicts complex wave propagation of field data.

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Dynamical behavior of the orthotropic elastic material using an analytical solution

  • Balubaid, Mohammed;Abdo, H.;Ghandourah, E.;Mahmoud, S.R.
    • Geomechanics and Engineering
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    • 제25권4호
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    • pp.331-339
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    • 2021
  • In this work, an analytical solution is provided for the dynamical response of an orthotropic non-homogeneous elastic material. The present study has engineering applications in the fields of geophysical physics, structural elements, plasma physics, and the corresponding measurement techniques of magneto-elasticity. The analytical performances for the elastodynamic equations has been solved regarding displacements. The influences of the rotation, the magnetic field, the non-homogeneity based radial displacement and the corresponding stresses in an orthotropic material are investigated. The variations of the stresses, the displacement, and the perturbation magnetic field have been illustrated. The comparisons is performed using the previous solutions in the magnetic field absence, the non-homogeneity and the rotation.

비균질 사질토 지반에서 단일말뚝의 수평거동 예측을 위한 비선형 해석기법 (Nonlinear Analysis for the Prediction of Lateral Behavior of Single Piles in Non-homogeneous Sandy Soil)

  • 김영수;김병탁;허노영
    • 한국지반공학회논문집
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    • 제16권4호
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    • pp.5-16
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    • 2000
  • 본 연구에서는 지금까지 수행한 일련의 결과들에 근거한 지반력 계수와 극한 지반반력을 역해석적 방법으로 결정하고 이를 이용하여 비균질 지반에서의 비선형 수평거동을 예측할 수 있는 해석기법을 제안하고자 함이 목적이다. Chang이 제안한 해석기법은 비균질 지반의 비선형적인 거동을 예측하기에는 어려움이 있다. 이에 본 연구에서는 말뚝의 비선형 거동 예측을 위하여 Chang 모델에 p - y 곡선을 적용하는 복합적인 해석기법을 제안하고 해석 프로그램을 개발하였다. 그리고 본 해석기법의 적용성 검증을 위하여 모형실험 및 현장실험 결과와 상용 프로그램인 Pentagon2D을 이용한 해석 결과와 비교 검토하였다. 해석상에 이용한 지반반력 계수와 극한 지반반력은 균질지반에서 결정된 값을 비균질 지반에 적용하였으며, 본 해석기법에 의한 거동 예측결과는 모형실험 결과와 잘 일치하였다. 또한 현장실험과의 비교에서도 정도 높은 일치성을 보였다.

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Multi-scale coherent structures and their role in the energy cascade in homogeneous isotropic turbulence

  • Goto, Susumu
    • 한국전산유체공학회:학술대회논문집
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    • 한국전산유체공학회 2008년도 학술대회
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    • pp.355-358
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    • 2008
  • In order to investigate the physical mechanism of the energy cascade in homogeneous isotropic turbulence, we introduce Galilean-invariant energy and its transfer rate in the real space as a function of position, time and scale. By using a database of direct numerical simulations (DNS) of homogeneous isotropic turbulence, it is shown that (i) fully developed turbulence consists of multi-scale coherent vortices of tubular shapes, (ii) the energy at each scale is mainly confined in vortex tubes with the radii of the same order of the length scale, and (iii) the energy transfer takes place around pairs (especially, anti-parallel pairs) of such vortex tubes. Based on these observations, it is suggested that the energy cascade can be caused, in the real space, by the process of the stretching and creation of smaller (i.e. thinner) vortex tubes by the straining field around pairs of larger (i.e. fatter) vortex tubes. Indeed, it is quite easy to find such events (in our DNS fields) which strongly support this scenario of the energy cascade.

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Multi-scale coherent structures and their role in the energy cascade in homogeneous isotropic turbulence

  • Goto, Susumu
    • 한국전산유체공학회:학술대회논문집
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    • 한국전산유체공학회 2008년 추계학술대회논문집
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    • pp.355-358
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    • 2008
  • In order to investigate the physical mechanism of the energy cascade in homogeneous isotropic turbulence, we introduce Galilean-invariant energy and its transfer rate in the real space as a function of position, time and scale. By using a database of direct numerical simulations (DNS) of homogeneous isotropic turbulence, it is shown that (i) fully developed turbulence consists of multi-scale coherent vortices of tubular shapes, (ii) the energy at each scale is mainly confined in vortex tubes with the radii of the same order of the length scale, and (iii) the energy transfer takes place around pairs (especially, anti-parallel pairs) of such vortex tubes. Based on these observations, it is suggested that the energy cascade can be caused, in the real space, by the process of the stretching and creation of smaller (i.e. thinner) vortex tubes by the straining field around pairs of larger (i.e. fatter) vortex tubes. Indeed, it is quite easy to find such events (in our DNS fields) which strongly support this scenario of the energy cascade.

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균일 난류 유동장내에서 연료입자의 퍼짐에 관한 연구 (A Study on the Dispersion of Fuel Particles in the Homogeneous Turbulent Flow Field)

  • 김덕줄;최연우
    • 대한기계학회논문집
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    • 제18권5호
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    • pp.1330-1337
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    • 1994
  • This study is to predict the lateral dispersion of the particles with time in a vertical pipe. Particle is released downward and located in the center of a pipe through which stationary, homogeneous turbulent air is flowing. We assume that gas turbulence velocities have a Gaussian probability density distribution and the presence of particle is not to alter turbulent structures. Particle trajectory is computed by numerically integrating the particle Lagrangian equation of motion, with a random sampling to determine the fluctuating air velocity experienced by each particle, which considered inertia effect and crossing-trajectories effect. The result shows characterestics of particle dispersion according to flow field condition and droplet size by using the parameters and scales, which expressed characterestics of flow field and particle. Predictions agree reasonably with experimental data.