• Journal of Power System Engineering
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• v.7 no.2
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• pp.51-55
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• 2003

Recently the requirements for light weight and high performance of the automobile have increased. Especially, the plastic fuel tube makers have made their efforts to dove]op the various plastic fuel tube module with not only dimensional accuracy but also cost competitiveness. The experiment is performed to investigate spring backs for PA12 plastic fuel tubes in case of compound bending. In the experiment, steam bending process is adopted as bending method. In this study, the results we obtained are used to design the bending fixtures and the compound bending system.

• Composites Research
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• v.28 no.6
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• pp.378-382
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• 2015

With increasing population density and high-rise expansion of buildings in recent years, elevators have become to play a pivotal role in our everyday lives as most people take an elevator several times even in a day. The elevator penetration and distribution rates in Korea have increased dramatically every year, and the emergence of skyscrapers leads to accelerating the development of elevator industry. Carbon-fiber-reinforced plastics (CFRPs) exhibit better mechanical and thermal properties than steel suitable for uses as elevator wire ropes. In this paper, in order to analyze the properties of CFRPs, the tensile strength of unidirectional (UD) CFRP wire ropes was characterized and finite element analysis was conducted for bending simulation. Simulation results were compared.

• Journal of the Korean Society for Precision Engineering
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• v.25 no.12
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• pp.55-64
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• 2008

This paper describes a research work of developing an automated progressive design system for manufacturing the product with multi processes such as piercing, bending, and deep drawing. An approach to the system for progressive working is based on the knowledge-based rules. Knowledge for the system is formulated from plasticity theories, experimental results and the empirical knowledge of field experts. The system consists of three main modules, which are shape treatment, strip layout, and die layout modules. Based on knowledge-based rules, the system is designed considering several factors, such as material and thickness of a product, piercing, bending and deep drawing sequence, and the complexities of the blank geometry and punch profiles. It generates the strip layout drawing for an automobile product. Die design for each process is carried out through the die layout module from the results of the strip layout module. Results obtained using the modules enable the designers for manufacturing products with multi processes to be more efficient in this field.

• Composites Research
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• v.24 no.2
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• pp.22-29
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• 2011

To increase the performance of thick-walled cylinders recently their length is continually enlarged. For that reason it is important to reduce weight of the thick-walled cylinders. In this paper the FE models to predict and estimate effects on the composite tapes were created with MSC.Nastran/Patran v.2005. First of all a autofrettage method was applied to the 2D model of the AISI4340 cylinder reduced the thick. And then the comparison of the numerical results with analysis results showed and verified by using T300/5208, IM7/PETI5, IM7/8552 tapes. Those are predicted to the effects of the angle of the composite tapes and elastic modulus according to the composite properties.

• Vending industry
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• v.6 no.1 s.16
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• pp.44-57
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• 2006

이보다 더 나쁠 수가 있을 까. 2005년 자판기 산업 전체 매출을 지난 92년 이후 처음으로 1000억대 이하로 떨어지는 부끄러운 성적표를 남겼다. 산업매출이 917억 8천만 원대로 2004년 대비 -12.7% 급락을 한 탓에 산업계는 5년 연속 마이너스 성장을 기록해야 했다. 커피, 복합형자판기의 시장 부진, 뚜렷한 히트상품의 부재 속에 불황에 불황을 거듭해야 했던 게 지난 2005년의 상황이다. 그 결과 적지 않은 중소기업이 좌초되는 아픔을 겪어 산업 기반도 약화되었으며, 경기 불황의 여파는 R&D투자마저 극히 위축시키는 결과를 나았다. 지난해의 부진한 성적표는 자판기 산업의 새로운 분발을 촉구하고 있다. 자판기 시장의 비전을 모색하기 위해서는 지난해의 부진한 성적을 분발의 계기로 삼아야 한다. 한편으로는 혹독한 시장불황을 겪으면서 산업계의 거품이 제거되는 구조조정이 이루어졌다는 점을 주목해야 한다. 이는 시련의 시기를 헤쳐 오며 생존해 온 업체들의 내공과 경쟁력을 강화하게 한 불황의 아이러니한 산물이다. 시련만큼 굳건해 지고 강해진 자판기 산업계의 분발을 기대하며, 지난 2005년 자판기 산업계의 성적표를 살펴보기로 한다.