http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
김기우(Gi-Woo Kim) 한국자동차공학회 2011 한국자동차공학회 학술대회 및 전시회 Vol.2011 No.11
This paper presents a study on the driveline output torque estimation based on two angular velocity sensors: the output and wheel speed sensors. The linear state-space system equations are first derived and the discrete Kalman filter is designed based on the Kalman filter theory to estimate the driveline output torque, and its estimation performance is compared with the in-situ output torque measured by a strain gage type torque transducer. The comparison result show that the discrete Kalman filter can be effective for estimating the output torque without direct torque measurement.
2차 전자방출 효과를 고려한 기체방전의 과도상태 유한요소해석
김남경(Nam-Kyung Kim),정기우(Gi-Woo Jeung),최낙선(Nak-Sun Choi),이세희(Se-Hee Lee),김동훈(Dong-Hun Kim) 대한전기학회 2010 전기학회논문지 Vol.59 No.7
To analyze the gas discharge phenomena in parallel-plane electrodes, the fully coupled finite element method (FEM) considering secondary electron emission effects in discharge column was adopted in this paper. Two coupled equations of the hydrodynamic diffusion-drift equations for three carriers and the Poisson’s equation for electric scalar potential should be solved as a system equation. The proposed method including two secondary electron processes of the photoemission and background ionization has been successfully applied to evaluating the breakdown voltage in parallel-plane electrodes and is verified by comparing its numerical results with the experimental ones. From the obtained results, it is inferred that the proposed numerical scheme will be useful for predicting and understanding streamer transient phenomena.
부드러운 경계 위상 최적설계기법을 이용한 유전체 형상 및 위상 최적설계
정기우(Gi-Woo Jeung),최낙선(Nak-Sun Choi),김남경(Nam-Kyung Kim),김동훈(Dong-Hun Kim) 대한전기학회 2009 전기학회논문지 Vol.58 No.10
This paper deals with a new methodology for topology optimization in which the topology of the design domain may change during the shape optimization process. To achieve this, the concept of the topological gradient is introduced to compute the sensitivity of an objective function when a small hole is drilled in the domain. Based on shape and topological sensitivity values, the shape and topology of the design domain may be simultaneously changed during design iterations if necessary. To verify the advantages and also to facilitate understanding of the method itself, two electrostatic design problems have been tested by using 2D finite element analysis: the first is the inverse problem of a simple dielectric model and the second is the rotor design of a MEMS actuator.
토크 측정을 이용한 차량 변속기용 비틀림 진동 절연 댐퍼 평가
김기우(Kim, Gi-Woo),장재덕(Jang, Jae-Duk) 한국소음진동공학회 2012 한국소음진동공학회 논문집 Vol.22 No.4
This paper presents a proof-of-concept study on the evaluation of torsional vibration isolation performance through in-situ output torque measurement by using a non-contacting magneto-elastic torque transducer installed in the vehicle driveline system. The de-trending processing is first conducted to extract the torsional vibration from the measured driveline output torque. In order to estimate the transmissibility, primary performance indicator of a vibration isolator, the magnitude of transmitted torsional vibration with different frequencies is compared. From the conservative estimation results, the torsional damper built in a lock-up clutch of a torque converter is identified to be a vibration isolator. The evaluation results show that the fluid damping by torque converter outperforms the vibration isolation function of a torsional damper, and the isolation performance needs to be enhanced.