• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 추계학술대회 논문집
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• pp.459-462
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• 2000

A new method for the fabrication of poly-Si films is reported using by alternating magnetic flux crystallization (AMFC) of LPCVD a-Si films. In this work we have studied the crystallization of LPCVD a-Si films by alternating magnetic flux. A-Si films were 1200$\AA$-thick deposited at 48$0^{\circ}C$ at a total pressure of 0.25Torr using Si$_2$H$_{6}$/H$_2$. After this step, these a-Si films were thermally annealed by Alternating Magnetic Flux at 43$0^{\circ}C$ for 1hours. The annealed films were characterized using X-ray diffraction (XRD), Raman Spectra, Atomic Force Microscopy(AFM). Both alternating magnetic flux crystallization and solid phase crystallization were investigated to compare enhanced crystallization a-Si. We have found that the low temperature crystallization method at 43$0^{\circ}C$ by alternating magnetic flux.x.

• 한국안전학회지
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• 제21권1호
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• pp.15-20
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• 2006

The finite element alternating method is a convenient and efficient method to analyze three-dimensional cracks embedded in an infinite or a finite body because the method has the property that the uncracked body and cracks can be modeled independently. In this paper the method was applied for fatigue crack growth simulation. A surface crack in a cylinder was considered as an initial crack and the crack configurations and stress intensity factors during the crack growth were obtained. In this paper the finite element alternating method proposed by Nikishkov, Park and Atluri was used after modification. In the method, as the required solution for a crack in an infinite body, the symmetric Galerkin boundary element method formulated by Li and Mear was used. And a crack was modeled as distribution of displacement discontinuities, and the governing equation was formulated as singularity-reduced integral equations.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 추계학술대회
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• pp.124-129
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• 2004

Finite element alternating method have been suggested and used for assessing the integrity of cracked structures. In the paper, in order to analyze arbitrarily shaped three dimensional cracks, the finite element alternating method is extended. The cracks are modeled as a distribution of displacement discontinuities by the displacement discontinuity method and the symmetric Galerkin boundary element method. Applied the proposed method to three dimensional crack included in the elbow, the efficiency and applicability of the method were demonstrated.

• 한국수학교육학회지시리즈B:순수및응용수학
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• 제15권1호
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• pp.57-72
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• 2008

This paper is concerned with the numerical solutions to steady state nonlinear elliptical partial differential equations (PDE) of the form $u_{xx}+u_{yy}+Du_{x}+Eu_{y}+Fu=G$, where D, E, F are functions of x, y, u, $u_{x}$, and $u_{y}$, and G is a function of x and y. Dirichlet boundary conditions in a rectangular region are considered. We propose alternating direction shooting method for solving such nonlinear PDE. Numerical results show that the alternating direction shooting method performed better than the commonly used linearized iterative method.

• 한국수학사학회지
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• 제30권2호
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• pp.71-86
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• 2017

When looking for solutions of Jisuguimundo with magic number 88~92 and 94~98, alternating method is applied to each possible partitions of each magic number. But this method does not apply in case of finding solutions of Jisuguimundo with magic number 87, 93, and 99. In this study, it is shown that solutions of Jisuguimundo with magic number 87, 93, and 99 can be found by applying alternating method to two partitions. These two partitions are derived partitions obtained by each partitions of magic number 87, 93, and 99. If every number from 1 to 30 which satisfy every unit path of Jisuguimundo can be found in all components of these two derived partitions, that arrangement is just a solution of Jisuguimundo. The method suggested in this study is more developed one than the method which is applied to just one partition.

• Nuclear Engineering and Technology
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• 제15권2호
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• pp.98-109
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• 1983

2차원 다군 확산 이론에 의한 원자로 동특성 방정식의 해를 구하기 위해서 two-step alternating direction explicit method를 도입하였다. Alternating direction implicit method의 특별한 경우로써 이 방법의 정확도 및 안전성을 해석하였다. 이 방법의 타당성을 시험하기 위해서 TWIGL 전산조직에 사용한 implicit difference method와 비교하여 두 방법의 결과가 일치함을 알았다. 이 방법을 이용하여 가압경수형 원자로(PWR)의 제어봉 삽입시의 중성자 신속의 시간변화와, CANDU-PHW 원자로의 가상된 냉각재상실 사고시의 중성자 신속의 시간변화를 계산하여 이들 원자로의 제어능력을 확인하였다.

• 대한기계학회논문집A
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• 제31권10호
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• pp.1009-1016
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• 2007

Finite element alternating method has been suggested and used effectively to obtain the fracture parameters in assessing the integrity of cracked structures. The method obtains the solution from alternating independently between the FEM solution for an uncracked body and the crack solution in an infinite body. In the paper, the finite element alternating method is extended in order to obtain the elastic-plastic stress fields of a three dimensional inner crack. The three dimensional crack solutions for an infinite body were obtained using symmetric Galerkin boundary element method. As an example of a three dimensional inner crack, a penny-shaped crack in a finite body was analyzed and the obtained elastc-plastic stress fields were compared with the solution obtained from the finite element analysis with fine mesh. It is noted that in the region ahead of the crack front the stress values from FEAM are close to the values from FEM. But large discrepancy between two values is observed near the crack surfaces.

• 대한기계학회논문집A
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• 제33권2호
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• pp.145-152
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• 2009

SGBEM(Symmetric Galerkin Boundary Element Method)-FEM alternating method has been proposed by Nikishkov, Park and Atluri. In the proposed method, arbitrarily shaped three-dimensional crack problems can be solved by alternating between the crack solution in an infinite body and the finite element solution without a crack. In the previous study, the SGBEM-FEM alternating method was extended further in order to solve elastic-plastic crack problems and to obtain elastic-plastic stress fields. For the elastic-plastic analysis the algorithm developed by Nikishkov et al. is used after modification. In the algorithm, the initial stress method is used to obtain elastic-plastic stress and strain fields. In this paper, elastic-plastic J integrals for three-dimensional cracks are obtained using the method. For that purpose, accurate values of displacement gradients and stresses are necessary on an integration path. In order to improve the accuracy of stress near crack surfaces, coordinate transformation and partitioning of integration domain are used. The coordinate transformation produces a transformation Jacobian, which cancels the singularity of the integrand. Using the developed program, simple three-dimensional crack problems are solved and elastic and elastic-plastic J integrals are obtained. The obtained J integrals are compared with the values obtained using a handbook solution. It is noted that J integrals obtained from the alternating method are close to the values from the handbook.

• 전기의세계
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• 제26권4호
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• pp.41-53
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• 1977

With the equivalent series circuit analyzed aby revolving field theory and drawn by using the equivalent circuit constant ratios in capacitor motor with windings not in quadrature having space harmonics in its magnetic field (the above ratios are the equivalent circuit constants for the fundamental flux to the magnetizing reactance of the circuit), the equation for the alternating torque with twice line freequency in the motor is directly derived, and the alternating torque is measured with the self-made stator vibration angle amplitude measuring apparatus that is composed of a pickup, filter, photoelectric pickoff etc. The measured values satisfactorily compared with computed values. The properties of the alternating torque characteristics for respective harmonic fluxes and the r5esultant alternating torque characteristic, the effects of the alternating torque characteristics for respective harmonic fluxes on the resultant alternating torque characteristic, the effects of the variation in the motor constants and the equivalent circuit constant ratios for the fundamental flux on the alternating torque characteristics for respective harmonic fluxes and the resultant alternating torque characteristic, are made clear, applying the equation. There exist the optimum values of the motor constants and the equivalent circuit constant ratios for the fundamental flux for decreasing the alternating torque, and the value could be determined in design by the method presented in this paper.

• KIEE International Transactions on Power Engineering
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• 제5A권4호
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• pp.412-415
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• 2005

The recent requirement for faster and more frequent solutions has encouraged the consideration of parallel implementations using decentralized processors. Distributed multi-processor environments can potentially greatly increase the available computational capacity and decrease the communication burden, allowing for faster Optimal Power Flow (OPF) solutions. This paper presents a mathematical approach to implementing distributed OPF using the alternating direction method (ADM) to parallelize the OPF. Several IEEE Reliability Test Systems were adopted to demonstrate the proposed algorithm.