• Proceedings of the KIEE Conference
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• 2005.04a
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• pp.256-258
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• 2005

EMU system is system that o(for target performance and function because various lower part system such as vehicles, signaling, power supply, rail track is consisted as complex. It is important first of all that describe correctly system requirement until configuration of system, design, manufacture, installation and test verification so that the complicated urban transit system is to act safety and reliable and to display target performance and function properly. The system requirement assist the system developer to comprehensive the performance and function of system in basic design. Therefore, In this paper wishes to study way to analyze system of system requirement and apply to Urban transit.

• Proceedings of the KIEE Conference
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• 2003.07a
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• pp.549-551
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• 2003

새로운 대중교통수단의 하나로써 경전철을 도입중이거나 계획중인 도시가 늘어나고 있는 추세이다. 경전철은 장거리 선로상에서 이동하는 부하라는 관점에서 전기철도 및 지하철과 유사성을 가지고 있으나, 전철 설비가 도심의 지상에 설치되는 점과 역사설비가 비교적 간단하며 선로의 긍장이 지하철에 비하여 잘은 경우가 대부분인 경우가 특징이다. 본 논문에서는 경전철을 안전하고 효율적으로 운행하기 위한 전제조건이 되는 전력 계통의 신뢰성확보를 위한 경전철 전력계통 신뢰성평가 및 최적화방안을 도출하였다. 계통공급신뢰도는 확률이론을 이용하여 정량적으로 산출할 수 있으며 정량적 신뢰도 산출법을 이용 개별 계통구성요소의 신뢰도 특성으로부터 전체계통의 신뢰도를 계산할 수 있다. 이로써 신뢰도 측면과, 설치 및 유지보수 비용을 고려한 최적의 계통구성방안이 도출된다.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2004.04a
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• pp.26-29
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• 2004

In order to speed up basic concept is to enhance high speed, curve limit speed, cross limit speed, acceleration/deceleration speed. It is important to optimal interface fundamental technology of vehicle, rail, electrical power, and signal system. Tilting train has advantage minimizing investment cost of infra railway system for increasing train limit speed in curve. the developed tilting train should be operated to commercial service speed 180Km/h of 200Km/h at KNR upgrade railroad. This paper proposed the basic model of system engineering for developing of tilting EMU (maximum operation speed : 180km/h) with speed-up of conventional railway system.

• Journal of the Korean Society for Railway
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• v.8 no.6 s.31
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• pp.610-616
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• 2005

The Incheon International Airport Express(I'Rex) is the railroad that connects Incheon International Airport, Gimpo Airport and Seoul Station. I'Rex is now under construction, and it will be connected to Gimpo Airport by 2007, to Seoul Station by 2010. However, there has been no discussion on how th connect different routes of railway Systems. Therefore it seems likely that rail passenger demand will be lower than that of limousine bus. Therefor, this paper proposes 4 effective connecting methods for I'Rex - (1) Shuttle transport, (2) Short-distance connecting transport (Inside I'Rex, Seoul Subway Line 9, 'Han-River line') (3) Mid-distance connecting transport (Jung-ang, Tae-baek, Young-dong line) (4) Long-distance connecting transport (Korean Train Express (Korean high speed railroad)) These methods can increase the connectivity of I'Rex with existing railroads and the competition power of I'Rex against a highway.

• ETRI Journal
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• v.33 no.5
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• pp.822-825
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• 2011

Level-encoded dual-rail (LEDR) has been widely used in onchip asynchronous interconnects supporting a 2-phase handshake protocol. However, it inevitably requires 2N wires for N-bit data transfers. Encoder and decoder circuits that perform an asynchronous 2-phase handshake protocol with only N wires for N-bit data transfers are presented for on-chip global interconnects. Their fundamentals are based on a ternary encoding scheme using current-mode multiple valued logics. Using 0.25 ${\mu}m$ CMOS technologies, the maximum reduction ratio of the proposed circuits, compared with LEDR in terms of power-delay product, was measured as 39.5% at a wire length of 10 mm and data rate of 100 MHz.

• Journal of Electrical Engineering and Technology
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• v.12 no.3
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• pp.1320-1327
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• 2017

In this paper, a contact loss simulator for a rigid catenary system was designed and used to analyze the effect on the power source according to the conditions of the rigid catenary system and pantograph. R-bar applied to a high-speed train among the real rigid catenary system was used in the contact loss simulator for rigid catenary systems. The excitation frequency generated with the movement of the railway vehicle was simulated. The characteristics according to the frequency and amplitude of the excitation frequency and the presence or absence of pantograph movement were analyzed. This work is considered to be helpful in analyzing the characteristics of contact loss in the interface between a real rigid catenary system and a rail vehicle.

• Journal of Biosystems Engineering
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• v.34 no.2
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• pp.77-81
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• 2009

Our nature is facing with serious problems related to the air pollution from automobiles in these days. Specially, the exhaust emissions from the diesel engine are recognized as a main cause influencing the environment severly. In this study, the potential possibility of biodiesel fuel is investigated as an alternative fuel for a naturally aspirated CRDi type diesel engine. The smoke emission of biodiesel fuel 5 vol-% was reduced by approximately 40% at 3000 rpm and full load in comparison with diesel fuel. On the other hand, the power, torque and brake specific energy consumption didn't show significant differences. NOx emission of biodiesel fuel was, however, increased compared with commercial diesel fuel.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.12 no.4
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• pp.20-28
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• 1998

This study proposes a new method to estimate voltage unbalance more exactly using Thevenin's equivalent circuit. The conventional simple formula were easily applied to evaluate voltage unbalance. Because the formula was derived on the assumption that traction load would be directly connected to the secondary windings of the main transformer, they could not consider the detailed characteristics of traction power supply system, for example, self and mutual impedances of rail, catenary and return feeder. So, the ac쳐racy of the results could not be guaranteed. The proposed algorithm is applied to a standard autotransformer-fed test system to analyze unbalance phenomena. Through simulations, we could evaluate voltage and current unbalance factors and compare the voltage unbalance of the three transformer connection schemes : single phase, V- and Scott-connections which are required for suitable train operation schedules. Additionally, we could determine the combinations of trains which can be operated under the unbalance factor limits.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1179-1180
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• 2007

Urban transit is system that offer target Performance and function because various lower part system such as vehicles, signaling, power supply, rail track is consisted as complex. It is important first of all that describe correctly system requirement until configuration of system, design, manufacture, installation and test verification so that the complicated urban transit system is to act safety and reliable and to display target Performance and function properly. The system requirement assist the system developer to comprehensive the performance and function of system in basic design. Therefore, In this paper wishes to study way to analyze system of system requirement and apply to Urban transit.

• Proceedings of the KIEE Conference
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• 2005.10c
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• pp.296-298
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• 2005

Urban transit is system that offer target Performance and function because various lower part system such as vehicles, signaling, power supply, rail track is consisted as complex. It is important first of all that describe correctly system requirement until configuration of system, design, manufacture, installation and test verification so that the complicated urban transit system is to act safety and reliable and to display target Performance and function properly. The system requirement assist the system developer to comprehensive the performance and function of system in basic design. Therefore, In this paper wishes to study way to analyze system of system requirement and apply to Urban transit.