• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2008년도 춘계학술발표대회 개요집
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• pp.43-43
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• 2008

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1987년도 한국자동제어학술회의논문집(한일합동학술편); 한국과학기술대학, 충남; 16-17 Oct. 1987
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• pp.780-785
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• 1987

The measuring point data of clay model are widely used to design parts whose external features are important design factor such as automobiles and general die products. This paper presents a method for improving the process to generate smooth surfaces from the measuring point data using turnkey CAD/CAM system. The process of smooth-surface generation involves several steps: styline finding, curve fairing, surface generation and filleting. The process is improved by automatic curve fairing, local correction of surface and multi-boundary surface treatment. An automobile bumper and a telephone receiver are measured and modeled to test the new method. Significant time saving is resulted by changing interactive mode to automatic mode and eliminating inefficient loop of surface generation process.

• 소성∙가공
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• 제18권3호
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• pp.256-261
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• 2009

Polyurethane has been one of the most important materials for automobile elastic parts such as bumper, head rest, instrument panel and so on since it covers very wide range of mechanical characteristics with low production costs. The processing variables such as formulation of ingredients and mold temperature, mixing speed, etc. can affect the quality of produced polyurethane foams so that process conditions should be determined appropriately. In this study, foaming behaviors of semi-rigid polyurethane were investigated by conducting cup foam tests with two major processing variables such as environmental temperature and blowing agent content. In addition, it was verified that processing conditions of real practice can be determined effectively by considering foaming characteristics obtained by the cup foam tests.

• 한국자동차공학회논문집
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• 제11권5호
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• pp.127-133
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• 2003

For the purpose of evaluation the damage repairability of a Frame Type Passenger vehicle which experienced a Low Speed 40% Offset front and rear Crash Test. tests were made according to the RCAR testing procedures. Test results concluded ; (1) The deceleration at C.G(center of gravity) off 6.9∼11.39 was similar to that for the vehicle. The airbag system was found to affect neither the passenger's safety nor the savings of the repairing costs. (2) In order to improve the repairability of the Frame Type Passenger vehicle after collision should be a higher crash performance of the bumper on the RCAR standards.

• Journal of Welding and Joining
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• 제26권5호
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• pp.74-78
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• 2008

The laser welding of the car body and components has been spread in the automotive industry. The Nd:YAG laser welding system could be used in 3D welding with robot. However, this system cannot efficiently reduce the welding cycle time according to various welding sequences because the robot's moving time is same that of the resistant spot welding system. But the remote welding system with high power $CO_2$ laser and scanner makes it possible welding cycle time much faster than the robot laser welding system. In the $CO_2$ laser remote welding system, laser beam can be rapidly transferred to a workpiece by moving mirrors of scanner system. So, it makes reducing the cycle time of welding process and shaping various welding patterns easily. Therefore, in this paper, the characteristic of weld strength according to patterns of weld bead on $CO_2$ laser welding was investigated. Also, the relationship between shape of weld bead and value of tensile load was studied. Finally, the optimum remote welding condition for car bumper was investigated.

• 자원리싸이클링
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• 제28권2호
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• pp.23-30
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• 2019

폐자동차 범퍼 파쇄물 재활용을 위하여 색채선별법을 도입하였다. 색채선별법은 기존의 비중, 입도 차이에 의한 선별이 어려운 물질을 색상 차이를 이용한 카메라와 영상 분석기법으로 분리하는 선별법이다. 본 연구에서는 반응표면법 중 BBD (Box-Behnken Design)를 적용하여 실험을 계획하고 최적 조건을 도출하였다. 색채민감도, 피드투입량 및 입자크기의 영향을 분석하였으며, 회귀분석과 통계적인 방법에 기초하여 2차 반응 모델을 획득하였다. $R^2$ 및 p-value는 각각 99.56%, < 0.001로 타당하였으며, 추정된 최적조건은 색채민감도 32%, 피드투입 200 kg/h, 입자크기 33 mm 조건에서 94.1%의 회수율이 나올 것으로 예측하였다. 실제 실험을 통한 회수율은 93.8%로 나타나 해당 모델이 적절함을 확인하였다.

• 한국생산제조학회지
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• 제22권5호
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• pp.806-811
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• 2013

In this study, to prevent the nonhomogeneity of fiber orientation during the molding of GFRP composites, GFRP prepreg was fabricated using roving fiber and polypropylene resin. Analyses on the degree of impregnation, tensile strength, and microstructure were conducted on the fabricated prepregs. A lower pulling speed, higher resin temperature, and longer die length showed a greater degree of impregnation of the prepreg. The scanning electron microscope (SEM) micrograph showed, a homogeneous fiber orientation. As a result, fundamental techniques for improved productivity were suggested for the manufacturing field.

• 제어로봇시스템학회논문지
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• 제18권5호
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• pp.453-464
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• 2012

This is a research of an adaptive longitudinal control system for situated cognition in wide range, traffic accidents reduction and safety driving environment by integrated system which graft a road infrastructure's information based on IT onto the intelligent vehicle combined automobile and IT technology. The road infrastructure installed by laser scanner in intersection, speed limited area and sharp curve area where is many risk of traffic accident. The road infra conducts objects recognition, segmentation, and tracking for determining dangerous situation and communicates real-time information by Ethernet with vehicle. Also, the data which transmitted from infrastructure supports safety driving by integrated with laser scanner's data on vehicle bumper.

• 한국안전학회지
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• 제23권6호
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• pp.21-27
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• 2008

Polypropylene(PP) foams are widely used as protective materials such as automotive bumper and safety helmet, but whose dynamic behaviour are not well defined. In this paper, the compression tests by Split Hopkinson Pressure Bar were conducted to obtain the stress-strain curve and to investigate the effect of density on the absorption of impact energy in the PP foams. Three kinds of foams were chosen depending upon the density. The result of the experiment has revealed that the stiffness of the low-density PP foam is remarkably increased at high strain rate compared with that of the high-density PP foam. And it is also shown that the absorption of impact energy are greatly influenced by the density of PP foam. These results are expected to be utilized for the development of a protective structure with polymer foams.

• Korea-Australia Rheology Journal
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• 제12권1호
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• pp.83-92
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• 2000

In resin transfer molding (RTM) process, preplaced fiber mat is set up in a mold and thermoset resin is injected into the mold. An important interest in RTM process is to minimize cycle time without sacrificing part quality or increasing cost. In this study, the numerical simulation and optimization process in filling stage were conducted in order to determine the optimum gate locations. Control volume finite element method (CVFEM) was used in this numerical analysis with the coordinate transformation method to analyze the complex 3-dimensional structure. Experiments were performed to monitor the flow front to validate simulation results. The results of numerical simulation predicted well the experimental results with every single, simultaneous and sequential injection procedure. We performed the optimization analysis for the sequential injection procedure to minimize fill time. The complex geometry of an automobile bumper core was chosen. Genetic algorithm was used in order to determine the optimum gate locations with regard to 3-step sequential injection case. These results could provide the information of the optimum gate locations in each injection step and could predict fill time and flow front.