• Proceedings of the KSME Conference
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• 2005.11a
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• pp.168.1-168.1
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• 2005

• Proceedings of the KIEE Conference
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• 2003.10b
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• pp.296-299
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• 2003

주어진 운행횟수에서 가능한 많은 승객을 최대한 빠른 시간에 정해진 목적지까지 이동시킬 수 있는 2층 열차의 기본 설계에 필요한 차량내 장치, 신호시스템 및 급전계통에 대하여 전기관련 시스템의 주요 사양을 검토하여 향후 차량을 본격적으로 설계시 기본 자료로 활용할 수 있도록 하였다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.6
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• pp.35-40
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• 2020

The ballast layers play a key role in distributing and supporting a trainload. On the other hand, it settles down by dynamic train loading due to large void ratios. Consequently, it requires continuous maintenance. In this paper, ballast layers mixed with three types of specially shaped artificial ballast (AB) (Rectangular, Tetrapod, Hexagonal) were modeled by using a two dimensional DEM (Discrete Element Method). Repeated loading tests were performed to evaluate the settlement behavior of the ballast layers. The smallest settlement was observed in the case of the ballast layer mixed with Tetrapod AB than in other cases, according to an analysis of the force transfer routes. In addition, contact force analysis showed that the Tetrapod AB, which has a concave shape, could easily make small and multi-channel force-transfer routes. This means that the stress in the ballast layer by the train loading transferred through the sleeper uniformly was distributed well by the AB. Therefore, the settlement of the ballast layer mixed with the concave-shaped Tetrapod AB could be reduced effectively under a repeated train loading. The effects of a decrease in settlement of the ballast layer highlight the possibility of a maintenance-free ballasted track.

• Proceedings of the KSR Conference
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• 2005.05a
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• pp.453-458
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• 2005

Weight minimization of double-deck train carbody is imperative to reduce cost and extend life-time of train. It is required to decide 36 thickness of aluminum extruded panels. However, the design variables are two many to tract. moreover, one execution of structural analysis of double-deck carbody is time-consuming. Therefore, we adopt approximation technique to save computational cost of optimization process. Response surface model is used to apporximate static response of double-deck carbody. To obtain plausible response surface model, orthogonal array is empolyed as design of experiment(DOE). Design improvement by approximate model-based optimization is described. Accuracy and efficiency of optimization by using response surface model are discussed.

• Journal of the Korean Society for Nondestructive Testing
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• v.29 no.5
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• pp.450-457
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• 2009

Periodical thermal shock can introduce defects in thermal barrier coating made by layers of CoNiCrAlY bond coating(BC) and $ZrO_2-8wt%Y_2O_3$ ceramic top coating(TC) on Inconel-738 substrate using plasma spraying. Thermal shock test is performed by severe condition that is to heat until $1000^{\circ}C$ and cool until $20^{\circ}C$. As the number of cycle is increased, the fatigue by thermal shock is also increased. After test, the micro-structures and mechanical characteristics of thermal barrier coating were investigated by SEM, XRD. The TGO layer of $Al_2O_3$ is formed between BC and TC by periodical thermal shock test, and its change in thickness is inspected by eddy current test(ECT). By ECT test, it is shown that TGO and micro-crack can be detected and it is possible to predict the life of thermal barrier coating.

• Composites Research
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• v.32 no.1
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• pp.29-36
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• 2019

The purpose of this paper is to suggest a lightweight design for the aluminum extrusion carbody structure of a double deck high-speed train using material substitution and size optimization method. In order to conduct material substitution, the topology optimization was used to determine the application parts of sandwich composites at the carbody structures. The results of analysis showed that sandwich composites could be applied at roof and 2nd underframe. The size optimization was used to determine thickness of the aluminum extruded and carbon/epoxy composite. The design variable, state constraint and objective function were formulated to solve the size optimization, and then, the feasible design was presented by these conditions. The results of the lightweight design showed that the weight of double deck high-speed train hybrid carbody could be reduced by 2.18(17.70%) tons.

• Journal of the Korean Society for Railway
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• v.7 no.3
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• pp.208-214
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• 2004

In this paper, traction system and electric devices of a double deck train were designed to examine technical reasonableness for driving on the ground and underground. Double deck trains operated in other countries were also considered. For designing the electric devices, two types of accelerations and electric devices arrangements which are based on the current subway system were considered.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.30 no.11 s.254
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• pp.1472-1478
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• 2006

Double-deck train has been attracted growing attention as next generation transportation around metropolis because of high passenger carrying capacity. To develop high-speed double-deck train with low operational costs, the carbody must be designed as light as possible. In addition, the carbody must be strong enough to ensure the safety of passengers. To meet these design requirements, we perform systematically weight minimization that determines thickness of aluminum extruded panels of the carbody. First, to reduce the design variables, we carry out the screening process that select sensitive or/and important design variables through design exploration. Then, weight minimization is accomplished under multi-loading condition such as vertical, compressive and torsional loads, while satisfying strength constraints of the design regulations. Finally, the result of design optimization is discussed by comparison with its initial design.

• Journal of the Korean Society for Railway
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• v.7 no.2
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• pp.22-28
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• 2004

1830년 영국의 리버플 맨체스터철도(영국)의 개통으로 시작된 철도는 선로분기점의파수꾼 설치, 열차신호표기를 위한 전주 사용, 모스전신기를 사용한 "공간 간격법", 1872년 펜실베니아철도(미국)에 최초로 도입된 궤도회로, 연동기 및 CTC 등의 도입으로 철도안전과 효율적인 수송에 크게 공헌하였고, 현재까지 매우 안전하고 정확한 교통수단의 위치를 확보하고 있다. 현재는 무선을 이용한 정보통신 기술을 활용하여 새로운 철도를 개발하기 위한 사업을 국내, 국외에서 추진하고 있어 철도의 경쟁력이 더한층 강화될 것으로 예상된다. 것으로 예상된다.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.1807-1813
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• 2007

The study aims at analyzing an underground station refuge model using EXODUS, one of the refuge simulation programs. The model for simulation is the Daegu Subway (Joongang-ro station). The details of the accident are referred to as the simulation condition the refuge time of traveling from the $3^{rd}$ basement platform to the $1^{st}$ basement is mainly calculated, with passengers numbering 1,000 including 329 at car 1079, 320 at car 1080, and 360 who are not on board. Reference data is used to set up the position of passengers. CFAST fire simulator is also used, and a fast curve among the $t^2$ growth curves, selected as fire growth scenario. The zone is divided into a total of 24 including 18 at the $3^{rd}$ basement platform and 6 at the $2^{nd}$ basement the $1^{st}$ basement is excluded in the fire simulation, however.