• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.411-412
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• 2006

It is very difficult to analyze the dynamic characteristic because railway vehicle is a very complex system which are connected various mass element with railway vehicle system. To realize and analyze actual phenomenon has restriction that usual commercial software calculates creep force under creep theory about wheel-rail contact mechanism as basic analyzing, and approach about contact point are based on two dimensional non-linear contact theory and simplified Hertzian contact which considers just displacement change on the YZ plain. Therefore, to solve these problems there should be a new approach difference with existing one. In this research, a new algorithm for finding wheel-rail contact position, calculation method of contact force and applied force will be presented.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.115-116
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• 2006

In these days, almost urban railway vehicle has been serviced under the random load application. But it is very important that fatigue lift prediction fur structures is major factor of safety. So do this, it is required that fatigue assessment method for cumulative damage approach while Korea domestic regulations only has endurance limit approach. With this endurance limit approach, fatigue lift prediction is impossible. In this research, it will be present that fatigue assessment for urban transit structure by using of cumulative damage approach method and related theories.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.29-30
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• 2006

The interior noise of KTX in tunnel has become an issue since the commercial operating in April 2004. The analysis of the interior noise of KTX in tunnel with concrete track shows sharply increased noise level in the range of 80Hz that is the natural frequency of the KTX carbody. We know that the booming noise inside KTX in tunnel with concrete track is generated by noise outside gangway and rolling noise at the carbody natural frequency. In this Study noise reduction methods are discussed on the basis of the comparison of the KTX and KHST noise characteristics. Alternatively, the effect of the modified mud-flap on the interior noise is introduced.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.32 no.11
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• pp.943-950
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• 2008

A novel nondestructive testing (NDT) system, which is able to detect a crack with high speed and high spatial resolution, is urgently required for inspecting small cracks on express train wheels. This paper proposes a high speed scan type magnetic camera, which uses the multiple amplifying circuits and the crack indicating pulse output system. The linearly integrated Hall sensors are arrayed in parallel, and the Hall voltages from each sensor in the scanning direction are obtained and amplified. High-speed NDT can be achieved by using the exclusive analog-digital converter and micro-processor because the ${\partial}\;V_H/\;{\partial}$ x value, which provides the most important crack information, can be obtained by buffering and calculating. The effectiveness of the novel method was verified by examine using cracks on the wheel specimen model.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2008.04a
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• pp.222-225
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• 2008

To prove a lot of technical difficulties related to the safety management of a railroad fire effectively, we design for the full-scale fire test facility of the railroad vehicle. It will be consist of major 3 part - duct system with smoke cleaning system, measuring section and gas analysis system. The CFD simulation was also carried out to design of the hood and duct system optimization. The results will be help for basic research of the railroad fire safety.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2011.04a
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• pp.155-159
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• 2011

건축법에서 건축마감재료의 연소독성은 설치류(마우스)를 사용한 가스유해성시험으로 평가되고 있다. 최근 동물시험에 대한 최소화 및 대체시험개발의 필요성으로 인해 연소가스의 정량분석을 통한 독성지수연구가 요구되고 있다. 본 연구에서는 이미 철도차량에서 적용되고 있는 BS6853의 연소독성평가를 통해 기존 가스유해성시험결과의 상대적인 비교분석을 수행하여, 건축재료의 연소독성평가에 대한 다양한 가능성을 제시하고자 하였다.

• Transactions of the Korean Society of Automotive Engineers
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• v.12 no.4
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• pp.74-84
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• 2004

In this paper, a theoretical method was derived to redesign carbody members by substituting light-weight materials, and to estimate their structural characteristics. Some performance indices to estimate structural behaviors were derived in order to obtain equivalent designs in case of material substitutions under important design constraints of rolling stock, such as bending stiffness, natural frequency, bending and buckling strength. Validity of the theoretical method was evaluated by comparing its results with finite element results in some examples where the aluminium alloy was substituted for the structural steel. The numerical results of the examples show that the proposed method gives reasonable initial guesses for the material substitution designs.

• Journal of the Korean Society for Precision Engineering
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• v.28 no.5
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• pp.543-550
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• 2011

The development of railway vehicles such as new mechanism of railway vehicle or design parameters of suspension have been used the application of scaled roller rig to the study of railway vehicle dynamics. In this paper, the critical speed was compared between full scale and 1:5 scale of numerical model. And to verify the simulation results, the critical speed was confirmed using the 1:5 scaled roller rig. According to the results, we expect that the developed roller rig will be used in the study for the dynamic characteristics of railway vehicle.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.05a
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• pp.89-89
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• 2004

결정적인 알고리즘과 입력정보의 사용은 평가된 해석과 실제 시스템 값과의 차이로 잘못된 결론을 이끌지도 모른다. 실제 시스템은 대부분 각각의 입력 매개변수들(input parameters)과 관계된 넓은 공차 영역(tolerance band)을 가지고 있어서 입력정보로 하나의 단일한 값을 할당하는 것이 어렵다. 단일 입력에 대한 한가지 해는 변동의 이해 없이 제한된 값이라는 것을 인식할 필요가 있는데 대개 결정론적 설계는 형상과 관련된 치수변동, 항복강도나 부재의 밀도, 탄성계수와 같은 재료 물성치의 불확실성(uncertainty)과 시스템에 작용하는 하중의 변동 등을 직접 고려하지 않고 설계를 수행하기 때문에 수용할 수 있는 오차의 범위 안에서 시스템의 응답을 정확히 평가하기가 쉽지 않았다.(중략)

• Proceedings of the KIEE Conference
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• 2003.04a
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• pp.423-425
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• 2003

철도차량의 유지보수 분야에서 시간, 인력 등의 낭비요소를 제거하기 위한 효율적인 유지보수 업무를 수행할 수 있는 정보화시스템의 도입이 요구되고 있다. 그러나, 정보화시스템을 구축한 후 잘못된 정보의 입력, 이중 작업 등이 발생하면 또다른 시간적, 인적손실을 발생시킬 수 있다. 이를 방지하기 위하여 차상정보 수집을 위한 시스템에 무선통신기술을 적용하여 기초정보수집에 소요되는 인적, 시간적 손실을 최소화 하고 전동차 검 수고에서 전동차를 검수할 때 작업조회에서 작업결과 등록, 부품신청/조회 등에 무선단말기를 이용함으로써 효율적인 유지보수 작업이 될 수 있도록 한다.