• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 A
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• pp.567-568
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• 2006

Reliable frequency estimation is important for active power control, load shedding and generator protection. Thereby, frequency estimation is researched and some algorithms is proposed. This paper analyzed strength and weakness of each algorithms through comparative analysis of frequency estimation. Used algorithms are Zero Crossing detection, Discrete Fourier Transformation, Least Error Squares.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 B
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• pp.1233-1234
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• 2006

Reliable frequency estimation is important for active power control, load shedding and generator protection. Thereby, frequency estimation is researched and some algorithms is proposed. This paper analyzed strength and weakness of each algorithms through comparative analysis of frequency estimation. Used algorithms are Zero Crossing detection, Discrete Fourier Transformation, Least Error Squares.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 C
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• pp.1693-1694
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• 2006

Reliable frequency estimation is important for active power control, load shedding and generator protection. Thereby, frequency estimation is researched and some algorithms is proposed. This paper analyzed strength and weakness of each algorithms through comparative analysis of frequency estimation. Used algorithms are Zero Crossing detection, Discrete Fourier Transformation, Least Error Squares.

• 한국생산제조학회지
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• 제19권4호
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• pp.498-503
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• 2010

The main purpose of this study strongly concerned micro machining error estimation by using FEM analysis of tool deflection shapes in micro flat end-milling process. For the precision micro flat end-milling process, analysis of micro cutting errors is mandatory. In general, tool deflection is a major factor which causes cutting error and limits realization of the high-precision cutting process. Especially, in micro end-milling process, micro tool deflection generates very serious problems in contrast to macro tool deflection. Methods which deal with compensation of cutting error by tool deflection in macro end-milling process have been studied plentifully but, few researches transact with micro scaled cutting tool deflection in micro cutting process. Therefore, the trend of micro tool deflection was estimated by using FEM analysis in this paper. Cutting forces were acquired by micro dynamometer and these were utilized in FEM analysis. In order to verify FEM analysis results, micro machining processes were carried out and real machined profiles were compared with FEM results. Finally through the proposed approach well suited FEM results were obtained.

• 농촌계획
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• 제12권4호
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• pp.23-32
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• 2006

Recently, Owing to booming of leisure activities and national enforcement of 5-day workweek system, Korean government has been promoting rural tourism policy of which operating project's title is Green Rural Experience Village, Rural Traditional Theme Village, etc. In this study, ken investigation result on Green Rural Experience Village sites, an estimation model of returns by green-tourism activities was developed. The model was constructed through factor analysis and regression analysis method. Regression model developed can estimate green-tourism revenue by investment budget, homepage preengagement sales, homepage visitors, capacity of eating and drinking facilities, capacity of lodging facilities. The model developed was applied in sample villages. With these results, estimation revenue was recorded average 138.3% of survey revenue, and statistical significance was good(correlation coefficient $R^2$ = 0.8255, level of significance : 0.000), and the range of relative error was recorded largely from -7.1% to 158.6%, and average relative error was 38.3% and good. And, the model developed in this study have the critical point in aspects of insufficient data, but the results will be used in green-tourism policies and projects, and revenue estimation about each village in the present and future is limited, but in province or the whole country the application is good.

• 한국항공우주학회지
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• 제41권5호
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• pp.350-356
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• 2013

먼거리에서 접촉하지 않고 측정할 수 있다는 장점으로 인해 사진계측은 항공분야에서도 널리 활용되고 있다. 본 연구에서는 한 대의 카메라로 6자유도 해석을 수행하는 사진계측에서 발생할 수 있는 오차를 분석하였다. 사진계측의 오차 분석 프로그램을 개발하였으며, 사진계측 문제를 공선조건에 기반한 기하학적 문제로 변환하여 프로그램을 검증하였다. 각 좌표계간 6자유도 해석을 위해 필요한 카메라 포즈에 대한 통계량은 정규분포한다는 것을 수치실험을 통해 유추할 수 있었으며, 모표준편차를 이용하여 사진계측의 오차를 정량화하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.854-855
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• 2008

This paper deals with the computation error produced in the time step analysis for a electric machine with eddy current. To investigate the error in quantity, the analytic equations representing the steady state results of time-step analysis are deduced. Using the equations, the characteristics of errors are calculated for a general electric circuit, with variation of the circuit parameters and step size.

• 한국정보전자통신기술학회논문지
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• 제9권3호
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• pp.291-297
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• 2016

본 논문에서는 상관성 신호 시스템에서 원하는 목표물의 도래방향을 추정하기 위한 기존 MUSIC알고리즘과 제안 알고리즘에 대한 성능을 비교 분석한다. 본 논문에서 제안한 알고리즘은 가중치 갱신을 위해서 선형 구속 최소 분산 방법과 도래 방향 오차 확률을 최적으로 감소시키기 위해서 베이스 방법과 최대 사후 확률에 MUSIC알고리즘 적용하여 목표물 도래 방향 추정 오차 확률을 감소하고자 한다. 모의실험을 이용하여 본 연구에서 제안한 알고리즘과 기존의 MUSIC알고리즘의 성능을 비교 분석하였다. 신호대 잡음비가 10dB이고 안테나 배열 개수가 9개와 12일 때, 본 논문에서 제안한 알고리즘이 기존의 MUSIC알고리즘보다 각각 약 11%와 13%의 도래 방향 추정 오차를 감소시켜 본 연구에서 제안한 알고리즘이 우수함을 확인하였다.

• 전기학회논문지
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• 제62권10호
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• pp.1458-1464
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• 2013

This paper proposed a new real time catenary impedance estimation technique using synchronized power data from the measured data of operating vehicle and substation for catenary protective relay and fault locator setting. This paper presented estimation equation of catenary impedance using synchronized power data between substation and vehicle of AT feeding system for the performance verification of the proposed technique. Also AC feeding system is modeled through power analysis program and performance was verified through simulation according to various load changes. We verified that average 2.38%(distance equivalent 23.8 m) error appeared between the proposed estimation equation of catenary impedance and power analysis program simulation output in no connection double track system between up track and down track. Furthermore, We confirmed that estimation error is bigger depending on the increasing the distance from substation and vehicle impedance using only using vehicle current when calculating vehicle impedance in connection double track system between up track and down track. But, We confirmed that the proposed technique estimated accurately catenary impedance regardless of vehicle impedance and distance from substation.

• 대한안전경영과학회:학술대회논문집
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• 대한안전경영과학회 2013년 추계학술대회
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• pp.231-241
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• 2013

In recent years, accident induced by human error is increasing in the chemical plant. Human error analysis of the chemical plant was conducted on the basis of past accident. Some company called by A for the basis of a chemical accident. Factor analysis of human errors was separated in plant operation and work. Agency's work of occupational safety & health was classified into four types. It is based on the work before, during work, recovery work, and discontinue work. It was still separated work of human error by analysis and then was derived factor and issue. The human error factor and priority for accident prevention in the chemical plant is presented.