• Journal of Korean Tunnelling and Underground Space Association
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• v.18 no.1
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• pp.75-82
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• 2016

As spreading of train concrete ballast leads to the increase resounding friction noise, an porous sound absorbing block is applied in urban train tunnel as a counterparts against the friction noise. Three steps of major variables tests for an optimal mix design of the block are conducted to pursue the light weight of the block. Pilot property tests of the block for the cases of the fly-ash only as lightweight aggregates are carried satisfying KRT(Korean Rail Transit) and new KRS(Korean Railway Standards). Based on the results of pilot tests, required structural strength and admixture effects are evaluated. Additionally, typical lightweight aggregates are replaced so that lightweight and strength are improved for serviceability of poor working conditions and proper maintenance in urban train tunnel.

• Journal of the Korean Institute of Landscape Architecture
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• v.32 no.4
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• pp.105-117
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• 2004

The Pasadena Freeway follows the Arroyo Seco through foothills and scenic passes to link Downtown Los Angeles with Pasadena. The approximately 10 mile road was the first freeway built in the West during the 1930's and is today designated as a Historic Parkway. As it approaches Pasadena, it terminates at a traffic light intersection at Glenarm Street, and then becomes a commercial road the Arroyo Parkway. This one and a quarter mile long, north south road moves significant volumes of traffic both into and out of Pasadena. The Arroyo Parkway is thus a major 'gateway' and an important axis of orientation and movement, terminating in the City's core civic, commercial and retail district. Planting, lighting, signage, paving, furnishing and fixtures ought to all be properly designed and coordinated to create a distinctive 'gateway' experience arriving to Pasadena and driving along the Arroyo Parkway. Alternate design studies, developed in discussion with City officials and others involved in the redevelopment of the area, would need to be done to properly decide on the best direction. Issues of heritage and traditional streetscape will likely have to be reconciled with both the reality of the vehicular character of the road and more contemporary themes. Obviously with such large parcels of property available in the Arroyo Fair Oaks corridor, there is a huge potential for redevelopment and building. This potential would only be strengthened by the Light Rail Line and its stations, the improvements to the Arroyo Parkway, and the redevelopment of the Arts Center College of Design. Guides and controls to the development process, including programming and physical design studies, would need to be developed in order to ensure that the maximum potential for the corridor be realized. This concept proposal suggests that the whole strip might be developed as a Arts and Technology corridor, with special emphases on education, public culture, media and lifestyle. The full programming possibilities need to be further developed. Additionally, appropriate urban design guidelines to ensure high quality development also need to be incorporated into an overall development plan.

• Proceedings of the KSR Conference
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• 2011.05a
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• pp.1572-1581
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• 2011

Since 'The Act on Private Investment of The Infrastructure' was established in 1994, private investment as well as government's investment has been active on transport infrastructure. But investment of transport infrastructure has more risks than others due to overforecast of transport demand for ensuring project validity, and cost uncertainty arising from financial crisis, commodity prices and so on. In the case of Incheon international airport express, after 2 years and 6 months, Incheon international airport express is opened, Korail take over equity stake in private investor due to the problems of MRG(Minimum Revenue Guarantee) be contracted with private investor. Not only that, in other case of Yong-in light rail, it is ongoing for legal disputes between Yong-in local government and private investor on account of opening delaying. On current Investment Assessment System of Transport Infrastructure, Risk Management system on investment of transport infrastructure is inadequate because Sensitivity Analysis in economic efficiency have been performed on the simple method which only changes benefits, expense and social discount rate. For this reason, this study analyze risks for investment of transport infrastructure demand forecast, and rise to the management practice for every particular item.

• Journal of the Korean Society for Railway
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• v.11 no.2
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• pp.203-210
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• 2008

Since hub wheel BLDC Motor consisted of wheel and BLDCM (Brushless DC Motor) without gear reducer has high efficiency and low operation noise, it can be utilized to a driving wheel at some light rail systems. However, installing sensors for speedometer on a Hub-Wheel motor is not easy, so it requires a different speed control mechanism method for speed measurement. This paper introduces a speed control method based on simple mathematical model which uses discrete Kalman Filter to estimate and control the speed of the motor.

• Journal of Electrical Engineering and Technology
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• v.12 no.6
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• pp.2411-2418
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• 2017

This study focuses on the effects of using open stator slots in an interior permanent magnet traction motor with a magnetic slot wedge design in order to increase the power density at its base speed. In addition, such a configuration reduces the torque ripple under field-weakening conditions. Five different wedge models were selected, each of which was evaluated using a finite element analysis (FEA). Based on the initial model, we designed magnetic slot wedges for maximum back-EMF and minimum cogging torque. In addition, the d-q axis inductance was slightly altered due to the magnetic slot wedges. Finally, we analyzed the performance of a traction machine under field weakening control. Moreover, we have outlined the requirements for an ideal magnetic slot wedge design.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1173_1174
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• 2009

Recently, the influence of electromagnetic environment for low frequency range on human body has been being argued. Light Rail Transit (LRT) System is an urban transit system which has approximately an intermediate transportation capacity between conventional subway and bus. The LRT systems have been applied and being operated in about a hundred lines around the world and many projects that apply the LRT systems in Korea are being proceeded and scheduled. LRT system is operated under the electrical circumstance of high voltage and large current and passengers are exposed in those electrical circumstance. In this paper, EMI/EMC for low frequency range of K-AGT system is measured and analyzed comparing with the international standard.

• Journal of the Korean Society of Systems Engineering
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• v.9 no.1
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• pp.47-53
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• 2013

The object of this study is to define systematically for outputs of Verification Process among the system life cycle process based on ISO/IEC 15288 for power supply system, which is one of the importance sub-systems to configure the LRT system. Furthermore, to prevent various problem in advance that can occur in the Transition LRT's power supply to be completed Integration. For this purpose, traceability of verification requirement and outputs. should be managed to use verification for system requirement and data processing tool. by system engineering techniques of system life cycle process based on ISO/IEC 15288 to LRT system.

• Journal of the Korean Society for Railway
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• v.10 no.2 s.39
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• pp.231-242
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• 2007

As railroad industry faces the new Renaissance era, effective and efficient maintenance methods for rolling stock operation are required with advanced railroad technology. All kinds of railroad systems such as high-speed long-distance train, metropolitan mass transit and light rail require systematic maintenance technology in order to maintain the safe railroad operation. Simulation models for regular operations of the example maintenance center are developed. In this study, standard maintenance procedures, layout, equipments, and number of workers of Siheung Metropolitan Railroad Maintenance Rolling Stock Depot are considered. The proposed simulation models are developed using simulation package ARENA. After simulation, four types of observations are analyzed. First, the bottleneck operation is identified. Second, the relationship between maintenance center size, number of workers and cycle time is analyzed. Third, the scheduling performances between PERT/CPM and Critical Chain Project Management(CCPM) are compared. Lastly, the simulation results according to worker's working coverage shows expanding the worker's coverage decreases the cycle time and increases throughput per train. However, workers are to be fully trained to do multiple skill work.

• The Transactions of the Korean Institute of Power Electronics
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• v.14 no.6
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• pp.481-487
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• 2009

This paper proposes a regulation method of DC line voltage for urban transit system fluctuated during the acceleration or deceleration by using supercapacitor. Supercapacitor is modelled electrically under the assumption of three different time constants of RC circuits with variable capacitances depending on the voltage. And its parameters are determined by the experimental measurements. The energy storage system using supercapacitors is installed based on this model, and the proposed model is tested through the simulations and experiments, and the controller for charging and discharging is designed. Finally, it is tested at Kyoungsan test site for the urban light rail road system and the energy saving effect is evaluated economically.

• Proceedings of the KIEE Conference
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• summer
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• pp.541-544
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• 2004

지난 99년 이후 친환경적이며 경제적이고 효율적인 대체 교통수단의 개발이라는 목표 하에, 차세대 근거리 교통수단으로 각광받고 있는 경량전철 시스템 적용을 목표로 무인 변전소 기반의 전력감시제어 시스템(SCADA)을 개발하였다. 차세대 변전소 기술 적용이라는 취지 하에 각종 IED들과의 연계는 모두 통신으로 처리하여 시스템의 고기능화를 추구하였고, Network 이중화를 통하여 시스템의 신뢰성을 제고하였으며, CCTV 및 각종 보안센서를 적용하여 배전반의 무인화 운전 및 원격 상시 감시 기능을 구현하였다. 이로써 신뢰성 있는 시스템 기반의 무인 변전소 기술 확립이라는 측면에서 현재 진행되고 있는 변전소 자동화 기술에 일조하며, 나아가 향후 에너지 IT산업기술의 기반이 되리라 사료된다.