• 대한조선학회 특별논문집
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• 대한조선학회 2008년도 특별논문집
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• pp.54-61
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• 2008

With the development of computer program in calculation for torsional vibration of ship's propulsion shafting it has become possible to calculate all order's vibratory amplitude, vibratory torque, vibratory stress and synthesis value at all concerned revolutions by way of solving the vibratory equation directly. Though this kind of propulsion shafting vibration calculation method makes it possible to get generalized and precise result of calculation, the unexpected critical crankshaft torsional vibration has still appeared in maneuvering range of the engine. A close investigation has been carried out to find out the cause for the 2-node propulsion shafting torsional vibration of the crankshaft that exceeded the limitation value near the MCR 104rpm on the sea trial of the recently delivered 6000TEU class container vessel from HHIC. In conclusion, as the latest super-output engine with heavy crankshaft and propeller mass seems to be liable to 2-node torsional vibration of crankshaft, it is recommend that, in the design stage of propulsion shafting, its torsional vibration condition must be more carefully checked.

• 한국광학회지
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• 제8권6호
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• pp.450-455
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• 1997

Nd:YAG 레이저 제2고조파로 여기되는 Z자형 공진기 구조의 펄스동작 Ti:sapphire 레이저가 개발되었다. 반사율 18%의 출력거울과 3mJ의 여기에너지에서 스펙트럼 반치폭은 90 nm, 파장 가변영역은 740~860 nm에 걸쳐 약 120 nm였다. 복굴절 필터를 설치하여 4 nm의 출력 스펙트럼 반치폭에 $\365mu$J의 출력에너지를 얻어 복구절 필터를 사용하지 않았을 경우보다 약 10배의 발진효율 개선효과를 얻었고, 파장 가변영역은 출력변동율이 $\pm$10%를 넘지 않는 범위에서 720~880 nm까지 약 160 nm로 넓어지는 결과를 얻었다.