• 통합자연과학논문집
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• 제8권4호
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• pp.235-243
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• 2015

Rhodium(I)-complex of $[Rh(CO)_2I_2{^-}]$ catalyzed carbonylation of anhydrous-trimethylamine in the presence of methyl iodide to give DMAC (N,N-dimethylacetamide) in no solvent. The catalyst had been reused 20 times, the analyses and distillation of collected products showed that the yields of DMAC, MAA (N-methylacetamide), and DMF (N,N-dimethylformamide) were 82.3%, 12.6%, and 4.4%. The conversion rate of trimethylamine was 99 % and the selectivity of DMAC was 82.3% with TON (Turnover Number) of 700. Stepwise procedure of inner-sphere reductive elimination for the formation of DMAC was suggested instead of acyl iodide intermediate.

• 대한전자공학회논문지
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• 제26권11호
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• pp.1829-1838
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• 1989

This paper is proposed one method of the exact optimal switching pattern of Selected Harmonic Elimination(SHE) Pulse Width Modulation(PWM). It defined Harmonic Elimination Band (HEB) at Constant Voltage(CV) and sought all solutions which are included HEB. Then, it calculated the Generalized Klirr Factor(GKF) beling to this solution and decided the optimal switching pattern which is minimized GKF. This optimal switching solution is used as initial condition of Newto Raphson(NR) method of decided easily switching pattern at Variable Voltage(VV). We desined the inverter by Power Transister(PTR) and implemented variable speed drive of Induction Motor(IM) in order to verify the validity of this theoretical proposition, then shown this results by comparison and analysis.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 F
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• pp.1960-1962
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• 1998

Reference/modulating waveform continuity is not a necessary condition for the implementation of switching patterns for three-phase pulse-width modulated(PWM) converters. This is based on the fact that the converter phase-voltages do not need to be sinusoidal and switching pattern discontinuities do not degrade the quality of output/input voltage/current waveforms by introducing low-order harmonics if certain parameters are optimized. This paper introduces the selected harmonic elimination to reduce the switching frequency and low-order harmonics compared with continuous PWM techniques and some discontinues switching patterns for PWM converter.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 A
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• pp.289-291
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• 2004

ln this paper, A dc-offset elimination novel algorithm based on an An model is proposed. The algorithm can eliminate dc-offset rapidly than other algorithms. The signal of fault current can be presented as a linear equation combined sinusoidal with exponential signals. Then, the linear equation can be presented an auto-regressive(AR) model and do-offset can be calculated by the equation of AR model. So it is possible to be removed the dc-offset from the original current signal. Performance evaluation of the algorithm was tested on condition that A-phase ground fault on 154kV 25km overhead transmission line.

• 동력기계공학회지
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• 제18권5호
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• pp.35-41
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• 2014

The wood pellet, which is one of the woody biomass energy, has very high economic efficiency and combustion efficiency during their combustion. The existing pellet burner have many problems such as low combustion efficiency, flame stabilization, ash problem and ignition time etc. We developed cyclonic wood pellet burner aim to 20,000kcal/hr boiler and measured temperature profiles and exhaust gases in order to investigate the flame stability and optimum combustion condition at any air flow conditions. As results, we confirmed the reappearance and the isotropy of the experimental results in the burner. At the first air flow inlet condition of excess air ratio ${\alpha}=0.02$, second air flow $490{\ell}/min$ had the best combustion condition when pellet supplied 30g. This result means that we need much air supply only for the swirling of second air flow. So we tested various second air flux at first air excess air ratio ${\alpha}=0.7$ condition. At this condition, we could find out that we don't need much second air and total air flux compared to the former condition. We will continuously test this work of air flow distribution, and swirl effect of first air flow, and ash elimination.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1995년도 추계학술대회 논문집
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• pp.324-327
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• 1995

In this research, FEM solution to analysis near field of high Tc superconductor microstrip antenna is presented. This method uses the interpolation function with vector edge triangular element. The advantage of this element is elimination of spurious solutions which are attributed to the lack of enforcement of the divergence condition. The solutions of this method will be used to have a good fundamental data for next reaserch about analysis of HTS microstrip array antenna etc.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 합동 추계학술대회 논문집 정보 및 제어부문
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• pp.278-281
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• 2002

In this paper we propose a controller which has the capability of disturbance measurement calibration for Cds array sensors in a magnetic levitation system. Steady state error due to environment light condition or external disturbance is corrected constantly. The correction is made by the sensors to measure the ball position of the system without additional deployment of sensors.

• 통상정보연구
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• 제6권2호
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• pp.315-335
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• 2004

As one of the 31 e-Government project, BPR/ISP on e-Trade has been carried out during December 2003 and June 2004. The purpose of the project was designed to facilitate e-Trade by establishing Single Window for e-Trade. Elimination of legal obstacles is a condition precedent for activation of e-Trade. Thus this article is focused to present the way to revised the laws relating to e-Trade.

• 한국터널지하공간학회 논문집
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• 제10권4호
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• pp.313-327
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• 2008

화재 발생 시 지하구조물의 열-역학상호거동이 정확히 고려되지 못하고 있으며, 이로 인해 일반적인 열전달 이론에 근거한 수치해석 시 화재로 인한 구조물의 손상정도가 과소 평가될 수 있는 문제점이 있다. 따라서 본 연구에서는 화재 발생 시 지하구조물의 열-역학 상호거동을 모사하기 위한 유한요소 기반의 수치모델을 새롭게 개발하였다. 특히, 화재로 인한 구조물의 단면 손실을 모사하기 위한 요소제거모델을 제안하였고 대류 경계조건을 적용하였다. 이때 요소 내의 최대 온도가 해석 시에 설정한 임계온도 이상이 되면 요소가 제거되도록 설정하였다. 모형 화재시험 결과와 해석 결과를 비교한 변수해석을 통하여, RABT와 RWS 화재 시나리오 조건에 대한 최적의 임계온도, 요소크기, 온도에 따른 대류열전달계수 조건 등을 제시하였다.

• 대한전자공학회논문지SP
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• 제45권3호
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• pp.11-19
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• 2008

영상 내에서 이동하는 객체를 추출하는 전경 분리 방법은 객체의 일치 추적 및 인식에 있어서 필수적인 기술이다. 하지만 이동하는 객체 주변에 그림자가 발생하는 경우 이러한 전경 분리 방법에서는 그림자도 전경 영역으로 잘못 판단하여 분리하게 되어 이동 객체의 정확한 형태를 파악하거나 위치를 추정하기 어려운 문제가 있다. 본 논문에서는 이러한 문제를 해결하기 위하여 색상 정보를 이용하여 그림자를 모델링하고 이를 통해 전경 영역 내의 그림자 화소를 Bayesian 분류법에 따라 제거하는 방법을 제안하였다. 특히 제안하는 방법은 매개변수 갱신 과정을 통해 그림자의 특성이 동적으로 모델링되기 때문에 주변 조명의 지속적인 변화에 적응적으로 대응할 수 있다. 실험 결과 제안하는 방법은 다양한 환경에서 그림자를 효과적으로 제거하는 것을 확인하였다.