• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 1997.04a
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• pp.5-5
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• 1997

Rapidly-solidified P/M aluminium alloys for automobile and home appliance industries were developed. Rapidly-solidification made it possible to refine microstructures and to expand the range of alloy composition. For example, Al-Si alloys containing transition metal have lower thermal expansion coefficient, more excellent wear resistance, higher strength, and better machinability than those of conventional aluminium alloys. Therefore, in Japan, the technologies on powder-extrusion and powder-forging of aluminium alloy powders are developed for fifteen years, and applied to several parts, such as cylinder liners of motor cycle engines, rotors and vanes of compressors for car air conditioner, oil pump rotor for racing car, and so on. In this presentation, applications for automobile are mentioned. In particular, cylinder liners made of particle-dispersed composites with fine alumina and graphite are in detail described.

• Proceedings of the Korean Society of Computer Information Conference
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• 2021.07a
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• pp.443-446
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• 2021

이 연구의 목적은 온라인 상에서 수행된 실습 수업 방식을 분석하는데 있다. 이를 위해 연구자는 예비 교사를 대상으로 '전기 자동차 만들기'수업 주제로 실습 수업을 설계하였으며, 온라인 동영상 강의 컨텐츠 3편을 제작하였다. 동영상 강의 컨텐츠 제작을 위해 교수용 홈페이지 제작, 수업에서 사용할 동영상 제작, 과거 촬영하거나 제작해 두었던 동영상 준비, 실습 재료 준비, 실습 활동 관련 교과서 준비 등 다양한 교수학습자료를 사전에 준비하였다. 동영상 강의 컨텐츠는 CODTRA 분석 방법을 이용 하였으며, 분석 코드는 '동영상에서 제시된 교수학습자료'와 '교수자가 행하고 있는 상태'이었다. 분석 결과는 CODTRA 다이어그램에 의해 분석 코드를 시간에 따라 도식화하여 도시하였다. 이 연구 결과는 중등학교의 기술 교과나 공업계 교과에서 온라인 실습 수업을 위한 동영상 강의 컨텐츠를 제작하고자 하는 교수자에게 참고할 수 있는 자료로 활용될 수 있을 것이다.

• Proceedings of the KSR Conference
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• 2000.11a
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• pp.396-401
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• 2000

There are three examples of noise reduction test by rail welding. One of them is tested at electric car running area and another is tested at expansion joint and long welded rail and the third is tested at open deck bridge. We can know from the result that the noise reduction effect of rail welding is very different to the type of track and the car. The condition of the test has some differences, but it may be useful reference of noise reduction.

• Proceedings of the KSR Conference
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• 2005.11a
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• pp.332-337
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• 2005

In order to investigate performance changes, the acceleration, vibration, and braking performance tests were carried out on the electric multiple units (EMUs) with over 20 years operation. According to the testing results, in vibration and braking performance, the similar performance results were obtained as compared with newly manufactured EMUs. However, in terms of acceleration performance, below reference value (3.0 km/h/s) has been obtained. This is mainly due to performance deterioration including traction motor. The precision diagnosis evaluation of deteriorated EMUs will be provided through the overall evaluation of corrosion testing and structural performance of car body.

• Proceedings of the KIEE Conference
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• 1984.07a
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• pp.272-273
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• 1984

• Proceedings of the KWS Conference
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• 1994.05a
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• pp.89-92
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• 1994

• 한국신재생에너지학회:학술대회논문집
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• 2008.10a
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• pp.162-162
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• 2008

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2003.10a
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• pp.345-351
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• 2003

• Transactions of the Korean Society of Automotive Engineers
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• v.20 no.1
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• pp.61-67
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• 2012

The in-wheel motor used in green car was designed and constructed for an electric direct-drive traction system. It is difficult to connect cooling water piping because the in-wheel motor is located within the wheel structure. In the air cooling structure for the in-wheel motor, a outer surface on the housing is provided with cooling grooves to increase the heat transfer area. In this study, we carried out the analysis on the fluid flow and thermal characteristics of the in-wheel motor under the effects of motor speed and heat generation. In order to check the problem of heat release, the analysis has been performed using conjugate heat transfer (conduction and convection). As a result, flow fields and temperature distribution inside the in-wheel motor were obtained for base speed condition (1250 rpm) and maximum speed condition (5000 rpm). Also, the thermo-flow characteristics analysis of in-wheel motor for vehicles was performed in consideration of ram air effect. Therefore, we checked the feasibility of the air cooling for the housing geometry having cooling grooves and investigated the cooling performance enhancement.

• Journal of the Korean Society of Industry Convergence
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• v.23 no.2_2
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• pp.233-244
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• 2020

A double-parked car is the one that is parked in a crowded parking lot with its transmission gear in neutral position and its auxiliary brake released. A double-parked car can be moved by pushing it but doing so is very difficult and dangerous. In a previous study, we proposed an omni-directional mobile robot for moving a double parked car. In that study we adopted Mecanum wheels. Even though the proposed robot showed successful results, it has some drawbacks such as dependency on a load condition, complexity in control, inefficiency in power use, etc. To overcome those drawbacks, we propose a differential drive robot with ordinary two tire wheels. The proposed robot consists of two parts, one is a wheel part and the other is a body part. By selectively connecting or disconnecting those two parts with the aid of an electric brake, the proposed robot is able to have omni-directional mobility.