• Proceedings of the KIEE Conference
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• 2000.11a
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• pp.13-16
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• 2000

Continuation power flow has been developed to remove the ill-condition problem caused by singularity of power flow Jacobian at and near steady-state voltage instability point in conventional power flow. When solving large-scale power transmission systems, continuation power flow require large computational costs. Therefore, technique to improve the speed of continuation power flow system was required. In this paper Decoupled Power Flow Method (DPFM), Enhanced Decoupled Power Flow Method (EDPFM), Robust Fast Decoupled Power Flow Method (RFDPFM) are applied to continuation power flow algorithm to improve the speed of continuation power flow system.

• Proceedings of the Korean Information Science Society Conference
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• 2010.06b
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• pp.482-486
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• 2010

Continuation은 운영체제의 실행 흐름을 최적화 하기 위한 수단으로 사용되어 왔다. 특히 Continuation을 이용하면 스택의 내용 없이, 특정 시점 이후의 프로세스의 연산을 그대로 수행 할 수 있는 장점을 가지고 있다. 하지만 이와 같이 스택에 저장된 정보를 사용하지 않을 경우 구조화된 예외 처리 방법(SEH)을 사용하는 운영체제에서는 Continuation을 바로 적용하기에 어려움이 존재한다. 이러한 문제를 해결하기 위해, SEH를 위해 함수에서 수정한 스택의 내용을 저장해 두었다가 Continuation이 끝나고 스택을 복원하여 SEH가 올바르게 실행 되도록 하였다.

• Journal of the Korean Mathematical Society
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• v.55 no.2
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• pp.327-342
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• 2018

In this paper, a homotopy continuation method for obtaining the unique Hermitian positive definite solution of the nonlinear matrix equation $X-{\sum_{i=1}^{m}}A^{\ast}_iX^{-p_i}A_i=I$ with $p_i$ > 1 is proposed, which does not depend on a good initial approximation to the solution of matrix equation.

• Geophysics and Geophysical Exploration
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• v.16 no.1
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• pp.59-62
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• 2013

We formerly reported a new method for the upward continuation of potential field on spherical patch area including Earth's curvature, which has been neglected in most studies on rectangular area with flat Earth assumption. This new method is applicable to downward continuation as well by only assigning corresponding value for the ratio of two radii; $r_2/r_1$, i.e., target radius $r_2$ versus datum radius $r_1$. In addition, the inherent problem of this method due to spherical surface geometry is described, and its one possible remedy is given.

• Journal of the Chungcheong Mathematical Society
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• v.15 no.2
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• pp.25-34
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• 2003

We prove a local unique continuation for Schr$\ddot{o}$dinger equations with time independent coefficients. The method of proof combines a technique of Fourier-Gauss transformation and a Carleman inequality for parabolic operator.

• 제어로봇시스템학회:학술대회논문집
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• 1991.10a
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• pp.93-98
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• 1991

An improved and flexible matrix algorithm for solving interlinked separation problems which is based on the homotopy continuation method has been developed. A flexible model of the interlinked stream in standardized matrix form and JACOBIAN generation I algorithm for homotopy continuation are suggested. Also DOF analysis is performed for easy-understanding of equation based simulation of complex column systems. The Algorithm is tested on several problems of interlinked separation processes and some of results are documented.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2011.10a
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• pp.643-648
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• 2011

This paper deals with the ESM(equivalent source method) with the continuation of acoustic near-field for NAH(near-field acoustic holography) to overcome the finite measurement aperture effect and reconstruct the normal velocity on an arbitrarily shaped structure surface. The continuation method is an extension of the measured sound field into a region outside and is based on the Green's function relating acoustic quantities on the two conformal surfaces. This algorithm is not limited to planar surfaces and can be applied to arbitrarily shaped surfaces. The ESM is an alternative approach of BEM-based NAH for the reconstruction on a general structure. In ESM the acoustic field is represented by a set of point sources located over a surface that is close to the structure surface. The simulation results of this study shows that the reconstruction error of particle velocity on the source surface is 11% and 16% for planar and cylindrical sources separately.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.41 no.7
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• pp.712-722
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• 1992

Several voltage instability/collapse problems that have occurred in the electric utility industry worldwide have gained the attention of engineers and researchers of electric power systems. This paper proposes an effective calculation scheme of the extreme loading point and nose curves(P-V curves) using modified Newton-Raphson(N-R) load flow method and the Continuation Method. This method provides detail and visual information of the power system voltage profile and operating margin ro operators and planners. In this paper, a modified load flow claculation method for ill-conditioned power systems is introduced for the purpose of seeking more precise load flow solutions and nose curves, and the Continuation Method is also used as a part of the solution algorithm for the calculation of extreme loading point and nose curves. The conventional polar coordinate based N-R load flow program is modified to avoid numerical difficulties caused by the singularity of the Jacobian matrix occuring in the vicinity of extreme loading point of heavily loaded systems. Application results of the proposed method to Klos-Kerner 11-bus system and modified IEE-30-bus system are presented to assure the usefulness of the approach.

• Korean Journal of Mathematics
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• v.27 no.4
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• pp.1005-1025
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• 2019

The paper is devoted to study local convergence of a continuation method under the assumption of majorant conditions. The method is used to approximate a zero of an operator in Banach space and is of third order. It is seen that the famous Kantorovich-type and Smale-type conditions are special cases of our majorant conditions. This infers that our result is a generalized one in comparison to results based on Kantorovich-type and Smale-type conditions. Finally a number of numerical examples have been computed to show applicability of the convergence analysis.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.49 no.2
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• pp.78-84
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• 2000

This paper introduces a method of determining the maximum real power transfer limit of interface lines, which connect two areas of a power system, using locally parameterized continuation algorithm. This method traces the path of power flow solutions as interface flow is gradually increased under a certain load demand condition and finds the steady state voltage stability limit, the interface flow limit. Voltage stability index is used to indicate how close the maximum limit is reached. Also, this study presents a procedure to determine the security-constrained interface flow limit using the above method. Contingency ranking index is proposed to identify the severity of contingencies. The case study is performed according to the suggested procedure.