• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제22권2호
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• pp.125-136
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• 2018

In this article, a homotopy perturbation transform method (HPTM) and the Laplace transform combined with Taylor expansion method are presented for solving Volterra integral equations with a convolution kernel. The (HPTM) is innovative in Laplace transform algorithm and makes the calculation much simpler while in the Laplace transform and Taylor expansion method we first convert the integral equation to an algebraic equation using Laplace transform then we find its numerical inversion by power series. The numerical solution obtained by the proposed methods indicate that the approaches are easy computationally and its implementation very attractive. The methods are described and numerical examples are given to illustrate its accuracy and stability.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1990년도 하계학술대회 논문집
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• pp.96-99
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• 1990

Recently, electric energy consumption pattern shows very high peak load with low load factor. This Load pattern have made electric utilities be interested in Load Management, many studies are reported. But most of these studies are concerned with Rate - Load shape relation, a few of these are concerned with generating cost reduction. In this study, the effect of Load Management is incorporated to establish optimal Generation Expansion Planning. Using avoided cost, optimal generation expansion planning is achieved to make maximum avoided cost of Electric utility. Dynamic programming technique is used to solve this algorithm.

• 한국자동차공학회논문집
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• 제4권4호
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• pp.179-189
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• 1996

An unstructured grid finite-volume method has been applied to predict the linear and nonlinear attenuation characteristics of the expansion chamber silencer system. In order to achieve a grid flexibility and a solution adaptation for geometrically silencer system. In order to achieve a grid flexibility and a solution adaptation for geometrically complex flow regions associated with the actual silencers, the unstructured mesh algorithm in context with the node-centered finite volume method has been employed. The present numerical model has been validated by comparison with the analytical solutions and the experimental data for the acoustic field of the concentric expansion chamber with and without pulsating flows, as well as the axisymmetric blast flowfield with open end. Effects of the chamber geometry on the nonlinear wave attenuation characteristics is discussed in detail.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2014년도 추계학술대회 논문집
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• pp.966-972
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• 2014

The Lattice Boltzmann Method (LBM) has attracted attention as an alternative numerical algorithm for solving fluid mechanics, and its intrinsic unsteadiness and weak numerical damping make it more suitable for aeroacoustic problems. In this paper, applicability of the LBM for solving flow noise problems is tested by applying it to predict transmission loss of a simple expansion silencer. The time history of the static pressure is recorded at the inlet and outlet pipes. The transmission loss (TL) of the muffler is computed by using three point method and two source method, respectively. The TL calculated using the LBM is compared with that computed using finite element method (FEM) and measured data. It is found through these comparisons that the LBM is capable of predicting TL of the simple expansion silencer accurately, which it is difficult to predict using the conventional CFD methods based on the RANS solvers.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 A
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• pp.46-49
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• 2003

This paper proposes a method to solve expansion problem for a transmission network, given future generation and load strategy, and alternative types of lines available, subject to load, reliability and right of way constraints, the problem is formulated as a series of zero one integer programs which are solved by an efficient branch and bound algorithm A study test result on the 63-buses test system shows that the proposed method is practical and efficiently applicable to the transmission expansion planning.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 A
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• pp.139-141
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• 2003

The outage cost has very important position for determination of the optimal level or optimal range of reliability in power system expansion planning. Establishing the worth of service reliability is a very difficult and subjective task. This paper addresses the role, need and assessment algorithm and methodology of the outage cost on power system expansion planning. Furthermore outage cost has been assessed using macro approach for our country 15years(1986-2001) in the case study.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 추계학술대회 논문집 전력기술부문
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• pp.479-483
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• 2003

The outage cost has very important position for determination of the optimal level or optimal range of reliability in power system expansion planning. Establishing the worth of service reliability is a very difficult and subjective task. This paper suggests strategies for the role, need and assessment algorithm and methodology of the outage cost in power system expansion planning. Organization, data collections and method about D/B for outage cost assessment is proposed in the this study.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1993년도 추계학술대회
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• pp.194-197
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• 1993

A technique for fast image reduction or expansion, in which the reduction(expansion) factor is either any integer or any rational number M/L Is represented. The multiresolution is modeled as an interpolation and filtering followed by a decimation. The model enables frequency domain analysts of the muitiresolution representations as well as convenient design of the Kernels(filters). Using any rin linear phase(Type I) filters a fine to coarse multiresolution structure can be generated.

• 대한산업공학회지
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• 제16권1호
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• pp.51-58
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• 1990

A deterministic capacity expansion planning model for a two-capacity type facility is analyzed to determine the sizes to be expanded in each period so as to supply the known demands for two distinct capacity type(product) on time and to minimize the total cost incurred over a finite planning horizon of T periods. The model assumes that capacity unit of the facility simultaneously serves a prespecified number of demand units of each capacity type, that capacity type 1 can be used to supply demands for capacity type 2, but that capacity type 2 can't be used to supply demands for capacity type 1. Capacity expansion and excess capacity holding cost functions considered are nondecreasing and concave. The structure of an optimal solution is characterized and then used in developing an efficient dynamic programming algorithm that finds optimal capacity planning policy.

• Journal of Electrical Engineering and Technology
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• 제8권4호
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• pp.686-693
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• 2013

Generation Expansion Planning (GEP) is one of the most important decision-making activities in electric utilities. Least-cost GEP is to determine the minimum-cost capacity addition plan (i.e., the type and number of candidate plants) that meets forecasted demand within a pre specified reliability criterion over a planning horizon. In this paper, Differential Evolution (DE), and Opposition-based Differential Evolution (ODE) algorithms have been applied to the GEP problem. The original GEP problem has been modified by incorporating Virtual Mapping Procedure (VMP). The GEP problem of a synthetic test systems for 6-year, 14-year and 24-year planning horizons having five types of candidate units have been considered. The results have been compared with Dynamic Programming (DP) method. The ODE performs well and converges faster than DE.