비균질 배경매질에 대한 교차시추공 회절 토모그래피

Thesis (master`s)--서울대학교 대학원 :지질과학과 지구물리학전공,1996.Maste

기능지역구분을 위한 향상된 지표를 통한 공간적으로 제약된 통근권의 설정

Thesis(masters) --서울대학교 대학원 :사회교육과(지리전공),2010.2.Maste

CLSVOF 기법을 이용한 이상 유동 시뮬레이션

학위논문(석사)--서울대학교 대학원 :기계항공공학부,2005.Maste

Influnce of Cutting Pressure on Laser Cut Quality (Pressure Distribution of Cutting Gas)

To investigate the influence of the cutting pressure on the laser cutting quality, an expermental facility was constructed which can measure the cutting pressure distribution for various cutting conditions. Flow visualization was performed using the Schlieren photography and the pressure acting on the workpiece surface was measured, corresponding to the important process variables such as the kind of assist gas, nozzle pressure, distance between the nozzle exit and the workpiece surface, and the presence of the secondary nozzle. The cutting pressure acting on the workpiece was largely influenced by the nozzle pressure and nozzle-workpiece distance. The secondary nozzle which is used to raise the effective working pressure had its obvious role only when the angle between it and the main nozzle was small and when the distance between the nozzle exit and the workpiece surface was large