http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
CO₂ Laser에 의한 Polyamide-6 소결과 그 영향에 관한 연구
배성우(S. W. Bae),김동수(D. S. Kim),안영진(Y. J. Ahn),김형일(H. I. Kim),최기섭(K. S. Choi) 한국정밀공학회 2006 한국정밀공학회 학술발표대회 논문집 Vol.2006 No.5월
In the solid freeform fabrication (SFF) system using selective laser sintering (SLS), polyamide-12 powder is currently recognized as general material. In this study, some kinds of polyamide-6 powders with different shape and particlesize were fabricated to investigate the formability, the microstructure and mechanical properties. Also, to develop a more elaborate and rapid system, this study employs a new SLS device with a 3-axis dynamic focusing scanner system instead of the existing f θ lens used in commercial SLS. Polyamide-6 powders having the average size of 100 m were treated thermally in order to keep the spherical symmetry in shape. These polyamide-6 powders were mixed with polyamide-12 powders having the average size of 50 m to give the bimodal distribution of size. These mixed powders showed the better fabrication in the selective laser sintering process because the smaller particles of polyamide-11 played an important role in the compact packing of powders by filling the void space between the large particles of polyamide-6. Also, Experiments have performed to evaluate the effect of a scanning path and sintering parameters by fabricating the various 3D objects.
IGBT 인버터 구동 유도전동기 고정자 권선에서의 과도전압 분포 해석
배성우(S.W. Bae),황돈하(D.H. Hwang),김용주(Y.J. Kim),김동희(D.H. Kim),김민희(M.H. Kim),이인우(I.W.LEE) 전력전자학회 2002 전력전자학술대회 논문집 Vol.- No.-
In this paper voltage distribution in stator windings of induction motor driven by IGBT PWM inverter is studied. To analyze the irregular voltage of stator winding, equivalent 챠rcuit model of inverter-cable-motor was proposed and high frequency parameter is computed by using finite element method (FEM). Electro-magnetic transient program (EMTP) analysis of the whole system for induction motor and PWM inverter is proposed. Induction motor, 50 [HP], and a switching surge generator was built to consider the voltage distribution. The results of EMTP analysis compared with experimental results