• 대한전기학회논문지:전력기술부문A
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• 제55권3호
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• pp.133-138
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• 2006

This paper presents an Optimal Power Flow (OPF) algorithm using Interior Point Method (IPM) to swiftly and precisely perform the five minute dispatch. This newly suggested methodology is based on Affine Scaling Interior Point Method which is favorable for large-scale problems involving many constraints. It is also eligible for OPF problems in order to improve the calculation speed and the preciseness of its resultant solutions. Big-M Method is also used to improve the solution stability. Finally, this paper provides relevant case studies to confirm the efficiency of the proposed methodology.

• Journal of applied mathematics & informatics
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• 제29권1_2호
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• pp.173-190
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• 2011

In this paper, we construct a new approach of affine scaling interior algorithm using the affine scaling conjugate gradient and Lanczos methods for bound constrained nonlinear optimization. We get the iterative direction by solving quadratic model via affine scaling conjugate gradient and Lanczos methods. By using the line search backtracking technique, we will find an acceptable trial step length along this direction which makes the iterate point strictly feasible and the objective function nonmonotonically decreasing. Global convergence and local superlinear convergence rate of the proposed algorithm are established under some reasonable conditions. Finally, we present some numerical results to illustrate the effectiveness of the proposed algorithm.

• International Journal of Control, Automation, and Systems
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• 제4권3호
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• pp.293-301
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• 2006

A new discretization method for calculating a sampled-data representation of a nonlinear continuous-time system is proposed. The proposed method is based on the well-known Taylor series expansion and zero-order hold (ZOH) assumption. The mathematical structure of the new discretization method is analyzed. On the basis of this structure, a sampled-data representation of a nonlinear system with a time-delayed input is derived. This method is applied to obtain a sampled-data representation of a non-affine nonlinear system, with a constant input time delay. In particular, the effect of the time discretization method on key properties of nonlinear control systems, such as equilibrium properties and asymptotic stability, is examined. 'Hybrid' discretization schemes that result from a combination of the 'scaling and squaring' technique with the Taylor method are also proposed, especially under conditions of very low sampling rates. Practical issues associated with the selection of the method parameters to meet CPU time and accuracy requirements are examined as well. The performance of the proposed method is evaluated using a nonlinear system with a time-delayed non-affine input.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 추계학술대회 논문집 전력기술부문
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• pp.156-158
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• 2005

This paper presents an Optimal Power Flow (OPF) algorithm using Interior Point Method (IPM) to swiftly and precisely perform the five minute dispatch. This newly suggested methodology is based on Affine Sealing Interior Point Method (AS IPM), which is favorable for large-scale problems involving many constraints. It is also eligible for OPF problems in order to improve the calculation speed and the preciseness of its resultant solutions. Big-M Method is also used to improve the solution stability. Finally, this paper provides a relevant case study to confirm the efficiency of the proposed methodology.

• 한국컴퓨터정보학회논문지
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• 제4권2호
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• pp.135-140
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• 1999

본 논문은 영상 부호화시에 걸리는 오랜 시간을 줄이기 위해 스케일링 방식과 탐색영역 제한방식을 이용한 어핀변환 부호화 방식을 제안한다. 제안한 방법의 성능을 평가하기 위해, 제안한 알고리즘과 전통적인 어핀변환 부호화 방식을 사용하는 Jacquin의 방법과 비교하였다. 시뮬레이션 결과, 제안한 알고리즘은 스케일링 방식과 탐색영역 제한 방식을 사용하므로써, 부호화 시간을 상당히 줄일 수 있었다. Jacquin의 방식과 비교해, 복원된 영상의 화질은 약간 저하되었지만 부호화 시간을 많이 단축하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 A
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• pp.858-860
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• 2005

This paper presents an Optimal Power Flow (OPF) algorithm using Interior Point Method (IPM) to swiftly and precisely perform the five minute dispatch. This newly suggested methodology is based on Affine Scailing Interior Point Method (AS IPM), which is favorable for large-scale problems involving many constraints. It is also eligible for OPF problems in order to improve the calculation speed and the preciseness of its resultant solutions. Lastly, this paper provides a relevant case study to confirm the efficiency of the proposed methodology.

• 한국경영과학회지
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• 제17권3호
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• pp.59-65
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• 1992

A modified primal-dual affine scaling algorithm for linear programming is presented. This modified algorithm generates an elipsoid containing all optimal dual solutions at each iteration, then checks whether or not a dual hyperplane intersects this ellipsoid. If the dual hyperplane has no intersection with this ellipsoid, its corresponding column must be optimal nonbasic. By condensing these columns, the size of LP problem can be reduced.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2003년도 추계학술발표회
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• pp.140-143
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• 2003

Air permeabilities in unsaturated fractured tuff at the Apache Leap Research Site (ALRS) near Superior, Arizona, exhibit a self-affine behavior, thus renders a field random fractal. Based up fractal scaling, the observed scale effect has been interpreted [Hyun et al., 2002]. Recently, Frantziskonis and Hansen [2000] presented that fractal scaling can be represented based on wavelets. This study deals with the way of using wavelets for fractal scaling. A numerical study is presented to examine the applicability of wavelet-based approach to determining upscaled air permeability values on various data supports at the site. To characterize the scaling property of self-affine fields generated based upon wavelets, Hurst coefficient, H. was inferred by applying the average wavelet coefficient (AWC) method. The result yielded H = 0.24, which is very close to the result of geostatistical analysis using a power variogram (H = 0.22). The study concludes that wavelet-based scaling is a useful way of determining parameter values on different data supports, which is an essential task for modeling of subsurface flow and mass transport in a numeric grid with different resolutions (grid size).

• 대한산업공학회지
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• 제21권3호
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• pp.429-439
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• 1995

The Interior point method in linear programming is classified into two categories the affine-scaling method and the logarithmic barrier method. In this paper, we integrate those methods and implement them in one shared module. First, we analyze the procedures of two interior point methods and then find a unified formula in finding directions to improve the current solution and conditions to terminate the procedure. Second, we build the shared modules which can be used in each interior point method. Then these modules are experimented in NETLIB problems.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제5권8호
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• pp.1423-1443
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• 2011

Background compensation plays an important role in detecting and isolating object motion in visual tracking. Here, we propose a Genetic Hough Transform, which combines the Hough Transform and Genetic Algorithm, as a method for eliminating background motion. Our method can handle cases in which the background may contain only a few, if any, feature points. These points can be used to estimate the motion between two successive frames. In addition to dealing with featureless backgrounds, our method can successfully handle motion blur. Experimental comparisons of the results obtained using the proposed method with other methods show that the proposed approach yields a satisfactory estimate of background motion.