• Journal of Auto-vehicle Safety Association
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• v.5 no.1
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• pp.31-36
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• 2013

For the robust passenger NCAP 5star and the stable neck injury performance, a new concept of passenger airbag has been required strongly. Especially, the deployment stability and the vent hole control technology of the passenger airbag should be improved. According to these requirements, the deployment stability technique has been studied and the 'Active Vent' technology has been developed. As a result, these technologies have led to achieve the robust NCAP rating and are applied to the production vehicles.

• Transactions of the Korean Society of Automotive Engineers
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• v.4 no.6
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• pp.85-96
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• 1996

Most protection systems such as seat belts and airbags are not effective means for side structure. There has been significant effort in the automobile industries in seeking other protective methods, such as stiffer structure and padding on the door inner panel. Therefore, a car-to-car side impact model has been developed using ATB occupant simulation program and validated for test data of the vehicle. Compared to the existing side impact models, the developed model has a more detailed vehicle side structure representation for the more realistic impact response of the door. This model include impact bar which effectively increases the side structure stiffness without reduction of space between the occupant and the door and padding for absorbing impact energy. The established model is applied to a 4-door vehicle. The parameter study indicated that a stiffer impact bar would reduce both the acceleration-based criteria, such as thoracic trauma index: TTI(d), and deformation-based criteria, such as viscous criterion(VC). Padding on the door inner panel would reduce TTI(d) while VC gives the opposite indication in a specified thickness range. For a 4-door vehicle, the stiffness enhancement of B-pillar is more beneficial than that of A-pillar for occupant injury severity indices.

• Journal of the Society of Naval Architects of Korea
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• v.37 no.3
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• pp.69-77
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• 2000

This study was a part of FSA study which was initiated by IMO and was applied to hatchway watertight integrity of bulk carriers. Hazards which were involved in high risk level were identified as follows. Ship Operation out of Design Criteria(Hatch Coaming Damage) and Poor Maintenance & Inspection(Securing Arrangement Damage). The potential risk was calculated by risk analysis and risk control option was made to reduce potential risk. The potential risk was about U$60,000/ship-year and could be reduced to about U$30,000/ship-year by applying RCO 1(Advanced system directly related to Hatchway Security). In addition, effectiveness of RCOs was shown by cost benefit assessment.

• Proceedings of the ESK Conference
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• 1995.04a
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• pp.51-51
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• 1995

인체 CAD 모델링 시스템은 장비와 인체를 모델링하여설계 초기단계에서 부터 별도의 Mock-up 없이 전 벙위의 운용자에 대한 작업자세의 안락도(Comfort), 동작한계(Reach), 적 합성(Fit), 시계(Vision)등 제반 작업공간 설계 및 평가에 수반되는 고려요소들을 보다 과학적 이고 합리적으로 반영할 수 있는 도구로 인식되고 있다. 본 연구는 크게 한국군 전차병의 인체 CAD 모델의 설계와 설계된 인체 모델을 활용한 한국형 전차 작업공간 평가로 구성되었다. 한국 군 전차병의 인체 CAD 모델링에서는 전차병의 인체 측정자료를 이용하여 5%, 50%, 95%치 전차병 에 대한 선 자세와 앉은 자세의 인체 모델을 설계하였으며, 보다 정확한 인체 모델의 구현을 위 해인체의 기능적 치수에 대한 실측치와 CAD 설계치와의 차이를 비교, 보정하여 줌으로써 작업공 간 평가시 보다 정확한 결과를 얻을 수 있도록 하였다. 한국형 전차 작업공간 평가에서는 설계 된 인체 모델과 한국형 전차 주요 구성품의 CAD 모델을 활용하여 각 승무원의 작업역을 분석하였고, 승무원 해치, 주요 조종장치의 운용 적합성, 판넬류 등의 위치 적합성에 대해 분석, 평가하였다. 본 연구를 통해 무기체계를 대상으로 하여 CAD 프로그램을 이용한 Man-Machine Interface에 대한 검토가 이루어 졌으며, 기존의 도면이나, Mock-up, Prototype에 의존하던 작업공간 타당성 검토가 CAD를 이용하여 3차원적으로 이루어 질 수 있는 기반을 마련하였다는데 의의가 있다.

• Journal of the Korean Society of Costume
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• v.58 no.5
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• pp.102-117
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• 2008

This study shows the badge system for military officials of Joseon dynasty. The badge system for military officials of the 15th century consists of rank badges with tiger and leopard for the first and second ranks and rank badges with bear for the third rank. According to the code of laws, military officials are supposed to wear the rank badges with four different kinds of animals in Joseon dynasty. However, the badge system shown in the code of laws sometimes does not match with the badges in practices. Based on the literature, remaining badges and the badges in portraits, six different kinds of badges with animals are found : First, rank badges with tiger and leopard were used until the late 16th century. Second, rank badges with tiger were found in the period between the early 17th century and the latter 18th century. Third, rank badges with Haechi were found in the early 17th century. Fourth, rank badges with lions can be found in remains of the mid 17th century, the literature and the portrait of the late 18th century. Finally, the rank badges with double leopards or with single leopard were found from a portrait dated the late of 18th century to the last period of Joseon dynasty.

• Journal of Welding and Joining
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• v.28 no.4
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• pp.33-40
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• 2010

The purpose of this study is to establish a predictive equation of transverse residual stress at the thick FCA butt weldment of large container vessel. The variables used were restraint degree, yield strength of base material, thickness of weldment and welding heat input. Restraint degree at the thick weldment of container ship having the various welding sequence was calculated using FEA. From the result, the H-type specimen was designed to reproduce the level of restraint degree at the actual weldment of containership. Based on the results, the predictive equations of the mean value and the distribution of transverse residual stress at each location of the weldment were established using dimensional analysis and multiple-regression method. The predictive equations were verified by comparing with those measured by XRD in the actual weldment of the ship.

• Journal of Welding and Joining
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• v.28 no.4
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• pp.41-48
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• 2010

The purpose of this study is to establish the control method of the global bending distortion caused by fabrication process of hatch-cover in a container ship. In order to do it, the transitional behavior of global bending distortion in the deck of hatch-cover during fabrication process was measured by 3-dimensional measuring instrument. From the results, the principal factor controlling the global bending distortion was identified as the bending moment associated with the longitudinal shrinkage force and transverse shrinkage caused by welding and flame heating and the change of the centroid axis of hatch-cover in each fabrication process. Therefore, in this study, with the predictive equations of the longitudinal shrinkage force and transverse shrinkage caused by welding and flame heating and the simplified thermo elastic method, the predictive method for the global bending distortion was established and verified by comparing with the measured result. Based on the results, the amount of reverse bending distortion of main stiffeners was determined to prevent the global bending distortion of hatch-cover.

• Proceedings of the KWS Conference
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• 2009.11a
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• pp.102-102
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• 2009

The purpose of this study is to establish the predictive equation of transversal residual stress at the thick weldment of large container ship. In order to do it, the variables used for this study were restraint degree, yield strength of base material, thickness of weldment and welding heat input. Here, the level of restraint degree at the thick weldment of container ship having the various welding sequence was calculated using FEA. From the result, the h-type specimen was designed to simulate the level of restraint degree at the actual weldment of containership. With H-type test specimen designed, the effect of the variables on the distribution of transversal residual stress at the weldment in a container ship was evaluated using the comprehensive FEA. Based on the results, the predictive equations of mean value and the distribution of transverse residual stress in each location of residual stress were established using dimensional analysis and multiple-regression method. The validation of predictive equations was verified by comparing with measured results by XRD in the actual weldment of the ship.

• Proceedings of the KWS Conference
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• 2010.05a
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• pp.61-61
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• 2010

The purpose of this study is to prevent the unstable fracture at the FCA butt weldment of hatch coaming deck in the ultra large containership during service life. In order to do it, the behavior of the embedded crack at the weldment under design loading conditions was evaluated in accordance with BS7910. Here, the level of primary stress induced by ship motion was evaluated by the design code of classification society and FEA. The level of residual stress as secondary stress was calculated in consideration of the restraint degree of weldment and welding heat input by using the predictive equation proposed by authors in the previous study. The fatigue crack growth rate at the weldment was evaluated using CT specimen in accordance with ASTM E647. According to the results, although the allowable defect for embedded crack specified in the classification society exists at the weldment, the occurrence possibility of unstable fracture at the weldment could not be negligible, regardless of CTOD value given in this study. So, in this study, the effect of initial defect size, welding heat input, restraint degree and CTOD on the fracture mechanical characteristics of embedded crack at the weldment was evaluated by the comprehensive fracture assessment. Based on the results, the design criteria including allowable defect, residual stress level and CTOD value was established to prevent the unstable fracture at the FCA butt weldment of hatch coaming deck in an ultra large containership during service life of 20years.

• Journal of Navigation and Port Research
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• v.30 no.6 s.112
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• pp.439-446
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• 2006

In ship structures many of the structural plates have cutouts, for example, at inner bottom structure, girder, upper deck hatch, floor and dia-frame etc. In the case where a plate has a cutout it experiences reduced buckling and ultimate strength and at the same time the in-plane stress under compressive load produced by hull girder bending will be redistributed In general, actual ship structure adopted reinforcement of stiffener around the cutout in order to preventing from buckling so it need to examine a buckling and ultimate strength behaviour considering a cutout because In many ship yards used class rule for calculating buckling strength but it is difficult to evaluate perforate stiffened plate with random size. In the present paper, we investigated several kinds of perforated stiffened model from actual ship and then was performed finite element series analysis varying the cutout ratio, web height, thickness and type of cross-section using commercial FEA program(ANSYS) under compressive load.