• Journal of Power Electronics
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• 제10권3호
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• pp.300-305
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• 2010

This paper presents a two Hall sensor method for rotor angle detection in permanent magnet synchronous motors (PMSM). To minimize the implementation complexity, the system is designed to measure the edge field of permanent magnet pieces. However, there are nonlinearities in the measured values of the edge field. In this work, an angle correction algorithm is proposed, and the improvements in accuracy are verified through experiments. Finally, a field orientation controller is constructed with the proposed angle detection algorithm.

• 전기의세계
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• 제27권3호
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• pp.31-35
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• 1978

In this paper, in order to clarify the mature of traps in polymer, the thermally stimulated current (TSC) measurements were mad on high density polyethylene by changing the condition of the high-field treatment such as the strength of the field (Fe), the treatment time (te) and the heating rate (.betha.). In addition, the TSC measured from the HDPE was compared with that from LDPE having different crystallinity. The obtained results can suggest that the trapping proceeds during the high-field treatment and the trap associated with the peak P$_{2}$ may have the closed relation to drystallinity and the release of trapped charge is enhanced by the molecular motion.

• 한국지반공학회논문집
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• 제33권8호
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• pp.41-52
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• 2017

본 연구에서는 말뚝지지 전면기초의 하중분담률 및 거동분석을 위해 시공단계 별 현장계측을 수행하였다. 현장계측은 시공시작일 부터 약 300일 동안 수행되었으며, 사용된 말뚝지지 전면기초는 $3.1m{\times}3.1m$ 크기의 전면기초와 길이 23m 직경 0.508m의 매입말뚝 5본이 시공되었다. 현장계측을 통해 시공단계에 따라 말뚝지지 전면기초의 하중-침하량 관계를 확인할 수 있었고, 극한하중조건에서 말뚝의 하중분담률은 약 70%에 수렴하였다. 기초의 침하량이 증가함에 따라 말뚝의 하중분담률이 증가하는 경향을 보였으며, 이는 하부 지반인 풍화토의 주면마찰력이 크게 영향을 주었기 때문으로 판단된다. 현장계측 결과를 이용하여 하중전이분석을 수행하였으며, 이를 통해 말뚝-지반 사이의 비선형 하중전이곡선을 산정하고 하중전이기법을 이용한 수치해석 결과에 적용하였다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 1998년도 봄 학술발표회 논문집
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• pp.265-272
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• 1998

• 순환기질환의공학회:학술대회논문집
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• 순환기질환의공학회 2001년도 제1회 학술대회 초록집
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• pp.31-32
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• 2001

• 한국자기학회:학술대회 개요집
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• 한국자기학회 2003년도 somma/kms meeting
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• pp.147-147
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• 2003

• 한국광학회:학술대회논문집
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• 한국광학회 2009년도 동계학술발표회 논문집
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• pp.153-154
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• 2009

• 한국초전도학회:학술대회논문집
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• 한국초전도학회 2004년도 High Temperature Superconductivity Vol.XIV
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• pp.87-87
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• 2004

• 해양환경안전학회지
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• 제17권1호
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• pp.29-37
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• 2011

유속의 변화에 따른 오일펜스 만곡부 후면의 속도장과 압력장, 와도 및 난류 강도를 계측한 PIV 실험의 결과 유속이 증가함에 따라 유동 경계역의 후면부에서의 흐름 방향이 전면부의 흐름 방향에 가까워지는 현상이 나타났고, 압력 분포의 양상이 달라졌으며 난류도 더욱 불규칙적인 형태로 나타났다. PIV 실험과 동일 조건으로 수행한 CFD 해석 결과, 후류의 유동 패턴이 0.3m/s이하의 저속인 경우는 PIV 실험 결과와 유사하게 나타났으나, 유속이 0.4m/s일 때는 오일펜스 자체의 유연성으로 인해 다소 차이가 나타났고, 오일펜스 하단의 압력차로 인한 불규칙한 난류가 수면까지 영향을 주었다.

• Wind and Structures
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• 제26권1호
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• pp.11-24
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• 2018

Full-scale measurements of wind action on the open roof structure of the WuXi grand theater, which is composed of eight large-span free-form leaf-shaped space trusses with the largest span of 76.79 m, were conducted during the passage of Typhoons HaiKui and SuLi. The wind pressure field data were continuously and simultaneously monitored using a wind pressure monitoring system installed on the roof structure during the typhoons. A detailed analysis of the field data was performed to investigate the characteristics of the fluctuating wind pressure on the open roof, such as the wind pressure spectrum, spatial correlation coefficients, peak wind pressures and non-Gaussian wind pressure characteristics, under typhoon conditions. Three classical methods were used to calculate the peak factors of the wind pressure on the open roof, and the suggested design method and peak factors were given. The non-Gaussianity of the wind pressure was discussed in terms of the third and fourth statistical moments of the measured wind pressure, and the corresponding indication of the non-Gaussianity on the open roof was proposed. The result shows that there were large pulses in the time-histories of the measured wind pressure on Roof A2 in the field. The spatial correlation of the wind pressures on roof A2 between the upper surface and lower surface is very weak. When the skewness is larger than 0.3 and the kurtosis is larger than 3.7, the wind pressure time series on roof A2 can be taken as a non-Gaussian distribution, and the other series can be taken as a Gaussian distribution.