• ETRI Journal
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• 제31권6호
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• pp.806-808
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• 2009

A new computationally efficient algorithm-based propagator method for two-dimensional (2-D) direction-of-arrival (DOA) estimation is proposed, which uses two parallel uniform linear arrays. The algorithm takes advantage of the special structure of the array which enables 2-D DOA estimation without pair matching. Simulation results show that the proposed algorithm achieves very accurate estimation at a computational cost 4 dB lower than that of standard methods.

• 시스템엔지니어링학술지
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• 제8권2호
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• pp.57-67
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• 2012

It is the sensitivity and confidentiality of nuclear power plant decommissioning cost that prevent detailed cost information to be released to the public, which causes some limitation to analyze and reuse the costs. This limitation to access cost information means that the lessons learned from preceding cost estimating may not systematically feed back into following cost estimates. As an alternative, decommissioning cost estimation framework is indispensable to reflecting available experience and knowledge for decommission costs. This study provides the cost estimation framework including data flow and structuralization based on engineering and bottom up approach to enhance decommissioning cost estimation.

• 대한전기학회논문지:전력기술부문A
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• 제49권9호
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• pp.451-458
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• 2000

This paper addresses the issues of the parameter error detection and identification in electric power systems. In this paper, the parameter error identification and estimation is carried out as part of the state estimation. A two stage estimation procedure is used to detect and identify the parameter errors. The suspected parameters are identified by the WLAV state estimator as the first stage. A new WLAV state estimator adding the suspected system parameters in the state vector is used to estimate the exact value of parameter errors. Supporting examples are given by using IEEE 14 bus system.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 A
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• pp.214-215
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• 2006

In power systems, the state estimation takes an important role in security control. At present, the weighted least squares(WLS) method has been widely used to the state estimation computation. This paper presents an application of Adaptive Evolutionary Algorithm(AEA) to state estimation in power systems. AEA is a optimization method to overcome the problems of classical optimization. AEA is employed to solve state estimation on the 6 bus system.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 추계학술대회 논문집 전력기술부문
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• pp.291-293
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• 2006

In power systems, the state estimation takes an important role in security control. At present, the weighted least squares(WLS) method has been widely used to the state estimation computation. This paper presents an application of Particle Swarm Optimization(PSO) to state estimation in power systems. PSO is a modern heuristic optimization method to overcome the problems of classical optimization. PSO is employed to solve state estimation on the IEEE-30 bus system.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1998년도 추계학술대회
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• pp.78-79
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• 1998

This paper describes a real time algorithm for blood flow estimation of LDF(laser Doppler flowmeter). Many algorithms for blood flow estimation are using power spectral density of Doppler signal by blood flow. In these research, the fast Fourier transformation is used to estimate power spectral density. This is a block processing procedure rather than real time processing. The algorithm in this paper used parametric spectral estimation. This has real time capability by estimation of AR(autoregressive) parameters sample by sample, and has smoothing power spectrum. Also, the frequency resolution is not limited by number of samples used to estimate AR parameter. Another advantage of this algorithm is that AR model enhance SNR.

• 한국자동차공학회논문집
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• 제5권1호
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• pp.207-216
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• 1997

We developed the durability estimation and design systems to minimize the volume, considering the durability, efficiency, and design requirements of worm gears. That is, we consider each kind of factors affecting on durability on the basis of AGMA Standard for the cylindrical and double-enveloping worm gears. We also estimate input power on the basis of wear and durability, bending strength and deflection of worm shaft, and we developed the durability estimation and design systems of power transmission worm gears introducing the optimal design method on the personal computer to be easily used in field. Also, we developed a method which converts the design variables obtained from the optimal design method to integer values(number of worm threads, number of worm threads, number of worm wheel teeth, etc.,) to be used in real design and production. The developed durability estimation and design method can be easily applied to the design of worm gears used as power transmission devices in machineries and is expected to be used for weight minimization of worm gear unit.

• 대한전기학회논문지
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• 제43권7호
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• pp.1169-1177
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• 1994

The function estimation characteristics of neural networks can be used sensor signal estimation of the nuclear power plants. In case of applying the neural network to the signal estimation of redundant sensors, it is an important problem that the redundant sensor signals used as the input signals of neural network should be validated. In this paper, we simplify the conventional parity space method in order to input the validated signal to the neural network and lso propose the sensor signal validation method, which estimates the reliable sensor output combining the neural network with the simplified parity space method. The acceptability of the proposed process variable estimation method is demonstrated by using the simulation data in safety injection accident of the nuclear power plant.

• Journal of Electrical Engineering and Technology
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• 제12권4호
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• pp.1427-1434
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• 2017

Since the late 2000s, there has been growing preparation in South Korea for a sudden reunification of South and North Korea. Particularly in the power industry field, thorough preparations for the construction of a power infrastructure after reunification are necessary. The first step is to estimate the peak load demand. In this paper, we suggest a new peak demand estimation methodology by integrating existing correlation analysis methods between economic indicators and power generation quantities with a power supply interruption model in consideration of power consumption patterns. Through this, the potential peak demand and actual peak demand of the Nation, which experiences power supply interruption can be estimated. For case studies on North Korea after reunification, the potential peak demand in 2015 was estimated at 5,189 MW, while the actual peak demand within the same year was recorded as 2,461 MW. The estimated potential peak demand can be utilized as an important factor when planning the construction of power system facilities in preparation for reunification.

• Communications for Statistical Applications and Methods
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• 제15권3호
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• pp.325-332
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• 2008

We consider estimation of reliability P(Y < X) and distribution of the ratio when X and Y are independent uniform random variable and power function random variable, respectively and also consider the estimation problem when X and Y are independent uniform random variable and a half-normal random variable, respectively.