• 한국통신학회논문지
• /
• 제27권6B호
• /
• pp.645-651
• /
• 2002

본 논문은 OMS(Optical Multiplex Section) 또는 OCh (Optical Channel) SPRING (Shared Protection Ring)에 적용되는 두 가지 광파장 할당 알고리즘을 제안하고 시뮬레이션을 통해 특성을 비교하였다. 제안한 알고리즘들은 WDM SPRING 네트워크에 적용할 수 있는 최적화 알고리즘과 넌블러킹 알고리즘이며 대부분의 비교에서 최적화 알고리즘이 넌블러킹 알고리즘에 비해 우수함을 보였다. 하지만, 넌블러킹 알고리즘도 몇몇 기존 연결을 재구성하기 위한 광파장 연결이나 할당을 필요로 하지 않는 중요한 잇점이 있다.

• 한국정밀공학회지
• /
• 제30권7호
• /
• pp.741-748
• /
• 2013

A conventional packing ring was designed with a large clearance to prevent damage due to the vibration of the rotor, which can lead to an increase in steam leakage. In this study, a flexible packing ring using winding springs was developed to prevent damage to the rotor teeth by minimizing vibration, while maintaining a smaller clearance than that of conventional rotor designs. Theoretical analysis and finite element analysis (FEA) were used to design the winding spring to satisfy the specified allowable stress limit and minimum load requirements. The shape of the winding spring was designed by applying curves to the center and end parts of a flat spring. Computational fluid dynamics (CFD) analysis was used to predict the leakage of the flexible packing ring. Flow rate measurement tests were performed to verify the leakage reduction efficiency and the reliability of the CFD analysis.

• 소성∙가공
• /
• 제17권5호
• /
• pp.350-355
• /
• 2008

Currently, in the automotive industry, the efforts to reduce the manufacturing cost by changing the manufacturing process are continually performed. In this paper, we proposed a new manufacturing process, the roll bending process of a ring plate of automotive fuel tank instead of conventional press blanking process to reduce material loss and manufacturing cost. Finite element analysis was used to optimize the roll bending process to assure rectangular cross-section of the ring plate. Also, spring-back analysis after the roll bending process was performed and dimension of the bending die considering spring-back was analyzed. Finally, we verified a possibility for realization of the proposed method with prototypes.

• 한국소성가공학회:학술대회논문집
• /
• 한국소성가공학회 2008년도 춘계학술대회 논문집
• /
• pp.311-315
• /
• 2008

Currently, in automobile industry. the efforts to reduce the manufacturing cost by changing the process of manufacturing are continually performed. In this paper, we proposed a new manufacturing process, the roll bending of a ring plate of automotive fuel tank instead of conventional press blanking process to reduce material loss and manufacturing cost. Finite element analysis was used to optimize the roll bending process to assure rectangular cross-section of the ring plate. Also, spring-back analysis after the roll bending was performed and dimension of the bending die considering spring-back was analyzed. Finally, we verified a possibility for realization of the proposed method shape with prototypes.

• Journal of the Korean Wood Science and Technology
• /
• 제49권6호
• /
• pp.550-565
• /
• 2021

본 연구에서는 문경 조령 주흘관(제 1관문) 목부재에 대해 수종과 연륜연대분석을 진행하여 재질과 건축역사를 조사하고자 하였다. 주흘관 목부재(84점)의 수종은 소나무류 76점, 잣나무류 5점, 전나무속 3점으로 확인되었다. 연륜연대분석은 코어링법을 이용하여 시료를 채취하였으며, TSAP프로그램으로 크로스데이팅을 하였다. 연륜연대분석 결과, 소나무류 목부재 59점에 대한 최외각 연도는 1708년 여름-1709년 늦가을, 1792년 여름-1794년 초봄, 1838년 늦가을-1840년 초봄, 1867년과 1872년 초봄-늦가을로 총 4개의 벌채시기가 확인되었다. 이러한 벌채시기들은 조선왕족실록, 주흘관중수기, 주흘관 성벽 각기의 수리기록과 일치한 것을 확인하였다. 일부 부재들은 수리기록과 벌채시기간의 약 10년 정도 차이가 나타나 당시 벌채한 목재를 저장하여 사용한 것으로 판단된다.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2010년도 춘계학술대회 논문집
• /
• pp.1199-1200
• /
• 2010

• 한국가스학회지
• /
• 제12권4호
• /
• pp.46-51
• /
• 2008

본 연구에서는 비선형 디스크 스프링과 고무링으로 구성된 완충장치의 감쇠에 관하여 연구하였다. 고무링의 마찰력과 디스크 스프링의 이력현상을 측정하여, 디스크 스프링의 적층 배열에 따른 이력곡선을 근사하고, 소산되는 에너지의 양을 추산하였다. 마찰력과 소산 에너지에 근거하여 네 종류의 감쇠 해석모델을 제시하였으며, 각각의 모델에 대한 충격응답을 고찰하였다. 고무링의 마찰력보다는 디스크 스프링의 이력현상이 완충장치의 감쇠거동에서 더 큰 영향을 미치었다. 가장 실용적인 감쇠 모델로는 소산되는 총 에너지의 양에 근거한 등가 점성 감쇠 모델이 다른 감쇠 모델보다 적합하다는 결론을 얻었다.

• Structural Engineering and Mechanics
• /
• 제66권6호
• /
• pp.713-727
• /
• 2018

Thin-walled mental tubes under lateral crushing are desirable and reliable energy absorbers against impact or blast loads. However, the early formations of plastic hinges in the thin cylindrical wall limit the energy absorption performance. This study investigates the energy absorption performance of a simple, light and efficient energy absorber called the ring stiffened tube. Due to the increase of section modulus of tube wall and the restraining effect of the T-stiffener flange, key energy absorption parameters (peak crushing force, energy absorption and specific energy absorption) have been significantly improved against the empty tube. Its potential application in the offshore blast wall design has also been investigated. It is proposed to replace the blast wall endplates at the supports with the energy absorption devices that are made up of the ring stiffened tubes and springs. An analytical model based on beam vibration theory and virtual work theory, in which the boundary conditions at each support are simplified as a translational spring and a rotational spring, has been developed to evaluate the blast mitigation effect of the proposed design scheme. Finite element method has been applied to validate the analytical model. Comparisons of key design criterions such as panel deflection and energy absorption against the traditional design demonstrate the effectiveness of the proposed design in blast alleviation.

• 한국윤활학회:학술대회논문집
• /
• 한국윤활학회 2000년도 제31회 춘계학술대회
• /
• pp.87-92
• /
• 2000

In order to improve the instability of Plane journal bearing, it is introduced the leaf spring damper(LSD). The effects of dynamic characteristics of LSD on the stability of a plane journal bearing were investigated theoretically. The improvements on the stability of a plane journal bearing with LSD. are compared with the results of a floating ring journal bearing and of journal bearing without LSD. It found that a plane journal bearing with LSD will be an effective way in the improvement on the stability of rotor system.

• Tribology and Lubricants
• /
• 제17권3호
• /
• pp.179-184
• /
• 2001

In order to improve the instability of plane journal bearing, it is introduced the leaf spring damper(LSD). The effects of dynamic characteristics of LSD on the stability of a plane Journal bearing were investigated theoretically. The improvements on the stability of a plane journal bearing with LSD are compared with the results of a floating ring journal bearing and of journal bearing without LSD. It found that a plane journal bearing with LSD will be an effective way in the improvement on the stability of rotor system.