• Journal of the Korea Institute of Information and Communication Engineering
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• v.3 no.3
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• pp.639-650
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• 1999

In this paper, a chattering alleviation VSS controller for the sinusoidal type BLDC motor is designed. Dead Zone function is proposed to change the chattering occurring in the transient state from high frequency to low frequency and time-varying gains are applied for the control input to eliminate the steady state excessive chattering in the conventional ISM. The proposed Dead Zone function represents the sliding layer composed of two switching surfaces and if a state vector exists in this layer, the chattering don't occur. Simulation and experimental results confirm the useful effects of the above algorithm.

• 전자공학회논문지 IE
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• v.44 no.1
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• pp.1-5
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• 2007

This experiment was analysed the discharge characteristics of FFL(flat fluorescent lamp). FFL is operated by sine and pulse wave source. We use FFL which has the electrodes covered with dielectric, observed the discharge characteristics of FFL by V-Q Lissajous' figure. When FFL is operated with pulsed, the discharge current flows after the applied voltage is risen. When the duty ratio increases, the number of metastable xenon atoms seem to increase. Consequently, the 172nm radiation becomes strong as the duty ratio increases.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.2 no.2
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• pp.59-63
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• 1988

In a fixed AC power source the PWM techniques were used to vary the voltage and the fundamental frequency. The conventional PWM techniques due to the problem of commutation number and filter size have been studied the PWM output waveforms which applied the motor drive. However in this paper, the carrier frequency with sinusoidal PWM waveform is modulated from 10(KHz) to 45(KHz) using termination devices with high - speed switching capacity and applying LPF(Low Pass Filter) with small capacity to output of inverter and the PAM(Pulse Amplitude Modulation)is obtained. Considering the property of the speed and the control, the sinusoidal PWM control circuit was composed of the microprocessor and analog circuit. In experment result, the system properties are study on the sinusoidal voltage waveform with modulation index changing from 0.6 to 1.0.

• Journal of the Korea institute for structural maintenance and inspection
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• v.18 no.3
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• pp.10-19
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• 2014

Corrugated steel plates are made by fabricating thin steel plates to have trapezoidal or sinusoidal corrugation, and the corrugated plates are able to maintain high out-of-plane rigidity even when they are used instead of thick flat plates. Also, corrugated steel plates have almost no axial rigidity due to the accordion effect. Thus, if they are applied to the webs of plate girders, designing can be easily conducted so that the webs bear only shear stresses. However, unlike flat plates, the shear buckling of corrugated steel plates has very complex characteristics where buckling occurs due to the interaction of local and global buckling, besides local buckling and global buckling. For the investigation of the cause and characteristics of this interactive buckling, studies on sinusoidal corrugated steel plates are fewer than studies on trapezoidal corrugated steel plates. Therefore, in this study, the shear buckling characteristics of sinusoidal corrugated steel plates and the occurrence pattern of interactive buckling were investigated. For the calculation of shear buckling strength, a finite element program was used, and the analysis results were compared with the exact solution. In addition, the characteristics of buckling stress change and the change of buckling mode shape depending on corrugation thickness and shape parameter were analyzed, and by comparing these results with the results of a theoretical equation, the timing of buckling mode change was analyzed.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.8 no.4
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• pp.17-21
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• 1994

레이저 광원을 사용하여 정현적으로 극미세 진동하는 압전소자에 부착된 거울을 대상으로 마이켈슨 간섭계로 부터의 간섭신호를 감지해 변위의 크기와 주파수를 측정할 수 있는 진동측정 방법과 장치를 제시한다. 약 80[nm]~1.2[$\mu\textrm{m}$] 범위의 진폭을 가진 물체의 변위와 주파수를 매우 높은 정밀도로 측정하고, 빔의 파장보다 큰 진동물의 간섭신호를 컴퓨터로 처리하여 진동형태의 개형을 구해다.

• Tribology and Lubricants
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• v.6 no.1
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• pp.89-98
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• 1990

시일의 접촉면이 경사지고, 정현파형이 존재하며 코닝이 있는 경우에 대한 해석을 하였다. 또한 시일링 간극에 존재하는 유체는 비압축성 점성유체이다. 이러한 요소들을 고려한 레이놀즈 방정식의 일반해를 구하기 위하여 멱급수 근사이론을 이용하여 압력분포를 구하였고, 이 결과를 이용하여 시일의 누설 유동량 및 마찰 토오크를 해석하였다. 계산 결과에 의하면 시일 접촉면의 표면파형이나 코닝에 비하여 경사정도가 시일의 성능에 커다란 영향을 주고 있음을 보여주고 있다.

• Proceedings of the Korea Institute of Convergence Signal Processing
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• 2005.11a
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• pp.314-316
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• 2005

본 논문에서는 UWB 통신을 위한 직교 변형 Hermite 파형형성함수와 정현파를 이용한 변조 Hermite펄스함수의 시간과 주파수 영역에서의 특성을 검토하였다. 그리고 이를 이용한 직교 펄스 다원접속 시스템의 송신기와 수신기를 구성하고 그 성능을 분석하였다.

• 건강소식
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• v.10 no.10 s.95
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• pp.2-8
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• 1986

김정현은 9세의 어린학생.(대구시 만촌초등학교 5학년. 여) 언제나 행복한 생활을 하고 있던 정현이는 건협 대구지부에서 심전도 검사를 받았다. 그 결과 요정밀진단 요망이라는 판정을 받고 전진곤 박사(대구지부 심전도 판독의사)로부터 무료정밀진단을 받은 그는 심장 우심방과 좌심방 벽에 구멍이 뚫린 상태였다. 그는 성공적인 수술결과로 건강이라는 광명을 되찾을 수 있었다.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2004.04a
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• pp.169-176
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• 2004

Offshore structure crossing navigation waterways must not only be designed to resist gravity, wind, and earthquake load, but also be capable of resisting ship and barge collision load. Current specifications for offshore structure design provide empirical relationships for computing impact loads generated during barge collision, however, these relationships are based on the limited experimental data. In this paper, the dynamic finite element analysis is used to computing force for vessel collision scenarios to offshore structures. Results obtained from the ANSYS/LS-DYNA are compared to AASHTO bridge design specifications.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2007.11a
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• pp.77-79
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• 2007

터널조명 상황을 안전하고 신속하게 측정하기 위해 고속주행에서도 노면의 조도와 휘도에 대해 다량의 데이터를 수집할 수 있는 '고성능 터널조명 측정시스템'을 개발하였다