http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
동적 부하 특성을 갖는 인버터 TIG 용접기의 역률 개선에 관한 연구
이태원,김재문,원충연,김규식,최규하,목형수 성균관대학교 1998 학술회의지원논문목록집 Vol.1998 No.-
In recent years. A PWM Converter or, Switched Mode Converter with high power factor and sinusoidal input current have got widespread studied. But, Almost. all of studies is based on linear load. This paper reports on research aimed at achieving high power factor and sinusoidal input current waveform for electronic arc welder which has nonlinear dynamic characteristics. It is shown that simulation result yield its property.
Variable Bi-Level Phase-Shifted Driving Method for High-Power RGB LED Lamps
S. K. Ng,K. H. Loo,Y. M. Lai,K. T. Mok,Chi K. Tse 전력전자학회 2011 ICPE(ISPE)논문집 Vol.2011 No.5
Based on the recently proposed bi-level driving method, this paper presents an extended version of the existing method, which is aimed at maximizing the luminous output of high-power LED lamps by piecewise-linear tracing of their luminous output curves under AM (amplitude modulation) driving. The proposed driving method divides the luminous output curve of an AM-driven LED into a multiple sections, where each section is approximated by a straight line with two predefined end-points acting as the lower and upper current levels as used in the existing bi-level driving method. The intermediate current and luminosity values lying between the upper and lower current levels are obtained by duty cycle mixing of the two current levels. The joined multiple sections has enabled a near-maximum luminous output to be extracted from the LED while a linear dimming is realized within each section. The proposed driving method is verified by implementation in a single-driver RGB color LED lighting system with the red, green, and blue LED driven in a time-sequential manner (or shifted in phase). Experimental results show that a significant gain in luminous efficacy, hence energy saving, is achieved compared to the commonly used pulse-width modulation (PWM) driving.
김연수(Kim Y.S.),목재균(Mok J.K.),장세기(Chang S.K.),홍용기(Hong Y.K),김용기(Kim Y.K.),김진완(Kim J.W.),김태형(Kim T.H.) 한국철도학회 2008 한국철도학회 학술발표대회논문집 Vol.- No.-
A bi-modal tram has been developing to consist of articulated-two cars propelled by CNG hybrid (series type) in Korea since 2003. All wheels are driven by electrical motors independently, which can eliminate differential gears to reduce turning radius and make low floor to provide the old and the handicapped with easy access. In the bi-modal tram, therefore, reduction gear unit is key technology to make low floor and drive wheels independently. This study was aimed at performance evaluations of the reduction gear unit for the bi-modal tram. Oil leakage, oil temperature, vibration, acoustic noise in idle operations were measured for the reduction gear unit of the bimodal tram.
Jungmoon Kim,Mok, Philip K. T.,Chulwoo Kim IEEE 2015 IEEE journal of solid-state circuits Vol.50 No.2
<P>A charge pump using 0.13- μm CMOS process for low-voltage energy harvesting is presented. A low-power adaptive dead-time (AD) circuit is used which automatically optimizes the dead-time according to the input voltage. A negative charge pump is also utilized for high efficiency at low input voltages (V<SUB>IN</SUB>). The AD circuit improves efficiency by 17% at V<SUB>IN</SUB> of 0.2 V compared to the fixed dead time circuit as well as enables the charge pump to work at V<SUB>IN</SUB> down to 0.15 V. Dynamic body bias (DBB) and switch-conductance enhancement techniques are applied to a unit stage of the three-stage charge pump. The reverse current flowing through the cross-coupled NMOS switches is prevented and the current transfer is also maximized. Together with the AD circuit and the DBB technique, the maximum output current was improved by 240% as compared to the conventional charge pump design using only the forward body bias.</P>
Observation of the Cosmic Near-Infrared Background with the CIBER rocket
MinGyu Kim,T. Matsumoto,Hyung Mok Lee,T. Arai,J. Battle,J. Bock,S. Brown,A. Cooray,V. Hristov,B. Keating,P. Korngut,Dae-Hee Lee,L. R. Levenson,K. Lykke,P. Mason,S. Matsuura,U. W. Nam,T. Renbarger,A. S 한국천문학회 2012 天文學會報 Vol.37 No.1
하이브리드 전기자동차를 위한 매입형 영구자석 동기전동기의 저속영역 센서리스 제어
이용균(Y.K LEE),박상준(S.J Park),이주석(JS Lee),이광운(K.W LEE),목형수(H.S Mok),이현동(H.D Lee),권태석(T.S Kwon) 전력전자학회 2011 전력전자학술대회 논문집 Vol.2011 No.7
기존에 하이브리드 자동차에 전동기는 레졸버등의 위치센서를 사용하여 제어를 하는데 안전성의 문제로 위치센서가 고장이 발생하게되면 센서없이 모터를 제어하는 방법이 연구되고 있다. 중고속 영역에는 모터의 전압모델을 사용하는 센서리스 방법이 주로 사용되는데 저속과 정지 상태에서는 모터 역기전력의 크기가 작아서 사용하기 어렵다. 본 논문에서는 기존의 방법보다 비교적 간단한 저속역역 센서리스 방법을 소개하고 이 방법의 문제의 해결방안을 제시하고 시험을 통하여 이를 검증하였다.