• Proceedings of the KSME Conference
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• 2000.11a
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• pp.407-412
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• 2000

In this study, a research for process design in bending of structural frame of AA6061-T6 with rubber pad was conducted. In this process, the conventional lower die made of metal is replaced with a polyurethane pad, resulting in high flexibility during bending. Vulcanized polyurethane rubber with shore A hardness of 60 was used for the pad. Experiments on a newly developed bending machine were carried out by controlling the stroke of the roller and horizontal movement of roller pad lower die. From this, the relation between roller path and geometry of the materials bent was obtained for the process design of producing roof rail part of a passenger car and the experimental result was compared with the target profile. For more accurate process design, it is required to control the roller path interactively. Based on the experience in developing the prototype bending machine, it is construed that a fully automated bending system with rubber pad to produce various light-weight components for automotive body frames can be successfully developed.

• International Journal of Railway
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• v.9 no.1
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• pp.1-9
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• 2016

In order to achieve a comprehensive utilization of railway networks, it is necessary to accurately assess the timetable indicators that effect the train operation. This paper describes the parameter calibration for two timetable indicators: scheduled running time and scheduled dwell time. For the scheduled running time, an existing model is employed and the single timetable parameter (percentage of minimum running time) in that model is optimized. For the scheduled dwell time, two intrinsic characteristics: the significance of stations and the average headway at each station are proposed firstly to form a new model, and the corresponding timetable parameters (the weight of the significance and the weight of the average headway) are calibrated subsequently. The Floyd Algorithm is used to obtain the connectivity among stations, which represents the significance of the stations. A case study is conducted in a light rail transportation system with 17 underground stations. The results of this research show that the optimal value of the scheduled running time parameter can be automatically determined, and the proposed model for the scheduled dwell time works well with a high coefficient of determination and low relative root mean square error through the leave-one-out validation.

• Journal of Korean Society of Transportation
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• v.24 no.3 s.89
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• pp.197-205
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• 2006

The study suggested a demand forecasting method which explicitly reflects transfer between various transport modes especially related light rail transit project with multi-modal transit system. The suggested method classifies several groups depending on characteristic of trips and applies different demand model for each group to explain travel pattern more realistically More specifically. the trips was classified by trips within the LRT route, trips between inside and outside of the LRT route. and through trips via the LRT route. The study also suggested a evaluation measurement of time saving due to the LRT construction, which are consistent along with the do-case and the do-nothing-case even though some mode shift could be happen after introducing the LRT.

• Transactions of the KSME C: Technology and Education
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• v.1 no.1
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• pp.139-145
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• 2013

Light rail transit(LRT) is a public transportation and mainly has an automatic driverless operation system. LRT project is a large scaled project which a construction cost is tens of billions of won per km. Systems engineering(SE) is an interdisciplinary approach and means to enable realization of successful systems. In this paper, we propose the systems engineering processes and their outputs list for the LRT project. And then, we present template and sample case of process output. We also present a case which carried out SE process by SE tool.

• Journal of the Korean Society of Safety
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• v.32 no.5
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• pp.41-46
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• 2017

The coefficient of derailment and the rate of wheel load reduction were used as the index of train running safety that was directly affected the train derailment safety. In aspects of track, the train running safety depends on the complex interaction between wheel and rail, and the track-vehicle conditions (i.e., the curvature, cant, track system, vehicle speed and the operation conditions, etc). In this study, the relationship between the train running safety and the track curvature and vehicle speed for direct fixation concrete tracks currently employed in Korean light rapid transit was assessed by performing field tests using actual vehicles running along the service lines. The measured dynamic wheel load, lateral wheel load and lateral displacement of rail head were measured for same train running on four tested tracks under real conditions, which included curved and tangent tracks placed on the tunnel and bridge, thus increasing the train speed by approximately maximum design speed of each test site. Therefore, the measured dynamic track response was applied to the running safety analysis in order to evaluate the coefficient of derailment, the rate of wheel load reduction and the track gauge widening at each test site, and compare with the corresponding Korean train running safety standard. As the results, the lateral track response of direct fixation concrete track appeared to increase with the decreased track curvature; therefore, it was inferred that the track curvature directly affected the train running safety.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.2182_2183
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• 2009

최근 화석연료에 대한 에너지의존도가 높아지면서 철도차량분야에서 대체에너지를 도입하기 위한 연구가 이루어지고 있다. 본 논문에서는 지자체를 중심으로 활발하게 진행되거나 검토되고 있는 경량전철 시스템에 대해 대체에너지로 각광받고 있는 태양광 발전시스템에 대한 도입 타당성 검토를 연구하였다. 경량전철 전력설비 계통에 태양광 발전시스템을 연계하고자 했을 때, 검토되어야 할 기술적인 사항 등에 대한 조사하였으며, 특히 태양전지판을 경량전철 노선 벽면에 설치하였을 때 발전량이 확보할 수 있는지에 대한 선행연구를 하였다.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.98-103
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• 2010

There should be a need for measures to build up environmentally friendly transport system with new town for residence being built near metropolitan area. In order to promote the development of station influence area, convenience for public transport users and LRT(Light Rail Transit) construction, request for the speed improvement of urban transit is on the rise for easy access to the metropolitan area. This paper delves into the efficient operation of high speed train suitable for passenger demand estimates, and seeks to ensure integrated transportation system with subway Line 9 following the construction of Gimpo urban railway.

• Proceedings of the KIEE Conference
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• 2001.04a
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• pp.413-415
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• 2001

A railroad vehicle(Light weight electric rail car, Urban railroad, High-speed railroad) need to construct propulsion- system capacity experiment equipment to test performance or to estimate confidence. Experiment equipment in interior have been used Flywheel which is equal to the same inertia as railroad straight moment. But mechanical inertia using flywheel don't change inertia and can't embody traveling-struggle which is similar to actual traveling-struggle. We propose the method to embody electric railroad load system with inertia using electric servo motor in order to get the characteristic of real vehicle load, and confirm this algorithm with simulation and experiment.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.1106-1112
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• 2008

Recently many new subway lines and light rail lines are demanded to build as CBTC system for advanced transportation needs. Already several lines are being installed and some other are planned this days. In early 2008, the first korean CBTC project, Bundang Line Intelligent Train Control System was finished successfully then it showed that many advantage of its functionalities to demonstrate. Nowaday, the technology of CBTC in Korea is not standing alone by itself yet, even though a lot of localization was done last decade include ATS (Automatic Train Supervision) and Radio Communication and manufactures and installations, because the core equipment of CBTC is rely on oversea technologies of major railway signal companies. KRRI has been preparing to develop the core equipment of CBTC (wayside ATP and onboard ATO/ATP) with other 14 local railway signal companies. Now they have consisted two consortiums to develop the core equipment by themselves. In this paper, I will mention about how we should focus on the output for viewpoint of interpretabilities between the two groups and review the case study of front developers efforts considering to standardizations we should be following.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.316-320
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• 2008

A light rail transit, using a linear induction motor, is generally composed with reaction plates along railroad track and the three phase primary on the vehicle. This linear induction motor is driven to keep clearance between the primary and the secondary of the ground for preventing any contact. Therefore efficiency and power factor is very low. In addition, the reaction plate installed on the ground throughout entire railway is impossible to keep uniform gap and it may cause system deterioration. In this paper, A rotary-type small-scale model of a linear induction motor for various characteristic analysis is designed. Thrust force, normal force and input current of the model by air-gap variation have been analyzed by using a Finite Element Method (FEM). The effects of air-gap variation on system performance have been considered by analysis results.