• Proceedings of the KSR Conference
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• 2005.05a
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• pp.320-325
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• 2005

Power of fuel cell tram is supplied by only fuel cell system or hybrid system of fuel cell and battery/super capacity. Fuel cell is operated by hydrogen, which is fed directly from hydrogen tank or by reforming gasoline or methanol into hydrogen. Power system is preferred with hybrid of fuel cell and battery/super capacity since it improves total energy efficiency through interaction of hybrid components and restores energy regenerated by braking. Also, power supply system by fuel cell hybrid should be designed to output optimum energy efficiency depending on driving mode of fuel cell tram.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.1126-1131
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• 2010

Experimental studies for the high damping rubber bearing, lead rubber bearing and natural rubber bearing, those are often used to improve the seismic capacity if the structure recently, are conducted to evaluate the seismic capacity of the seismic isolation bearings. The shear stiffness of the bearings decrease and the shear strain amplitude or the constant axial load level increase, but not sensitive to the strain rate effect. Bearings are strong for the axial compression but weak for the axial tension.

• Proceedings of the KSR Conference
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• 2002.10a
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• pp.104-112
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• 2002

The Honam conventional railroad was already exceseed the limit capacity of transportal ion at some sect ion. Therefore Honam railroad axis needs new high speed railroad line for increasing of transportal ion capacity now. This report was studied about the system technical specification of rolling stock based on new technology or high speed train or advenced countries, KHST and KTX for Honam high speed railroad.

• Proceedings of the Korean Geotechical Society Conference
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• 2002.03a
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• pp.533-540
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• 2002

Recently, geogrid reinforcement has been applied tn the subgrade of the roadway and the railway on the compressible layered soil, and the relevant reserch on the reinforcing mechanism has been performed. In this study, mechanics of geogrid reinforcement and the parameters for the improvement of bearing capacity are evaluated and presented based on the case histories of the field load test on the geogrid-reinforced layered subgrade

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.1819-1826
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• 2007

This study results of performed field load test in order to estimate the best pile length assessment and allowable bearing capacity of the pile foundation. End of initial driving(EOID) and restrike of pile dynamic loading tests were performed to calculate allowable bearing capacity of the experimental pile side and results were compared with the allowable bearing capacity estimated by theory. The results of allowable bearing capacity by EOID test is $1.08{\sim}1.21$ in the range of compared to the capacity calculated by the Structure Foundation Design Criterion. Allowable bearing Capacity by restrike of pile dynamic loading test is $1.32{\sim}1.48$ in the range of compared to the Structure Foundation Design Criterion. The Foundation Design Criterion underestimated the pile capacity. If the bearing capacity calculated by Structure Foundation Design Criterion is 100, EOID of pile dynamic loading test is 116, restrike of pile dynamic loading test is 138 for 20m pile used in this experimental.

• Proceedings of the KSR Conference
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• 2011.05a
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• pp.1473-1479
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• 2011

In this paper, speed control of IPMSM drives for the next generation domestic high speed railway system using multilevel inverter is presented. Multilevel inverter is suitable for the high-voltage high-capacity motor drive system because noise and switching frequency of power semiconductor devices is reduced. For the speed control of IPMSM using multilevel inverter, maximum torque control is applied in a constant torque region, and field weakening control is applied in a constant power region. Simulation programs based on Matlab/Simulink are developed. Finally the designed system is verified by simulation and their characteristics are analyzed by the simulation results.

• Proceedings of the KSR Conference
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• 2011.05a
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• pp.1242-1247
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• 2011

This study investigates vertical vibration control method for railway structure by using vertical vibration control device. The device consists of high stiffness polyurethane spring and friction damper recognized by National Center for Earthquake Engineering Research of USA for durability. To confirm the capacity of vertical vibration control, at first, behavior equation is established by considering correlation among the components. Then, hysteresis curve is drawed from behavior equation. By considering both dynamic behaviors and material nonlinearities, more reasonable behavior of the device can be simulated. After that, the Validity of the vibration control trend is proved by FEM(Finite Element Method).

• Proceedings of the KSR Conference
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• 2003.10b
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• pp.297-304
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• 2003

As the high speed rail to be opened at 2004, the. railroad will dominate over the transportation market in the Seoul-Busan corridor compared to road transport. But, it is obvious that the LOS(level of service) of railroad at 2004 will be worse in the areas that are not served KTX. For the speed-up of conventional line, it is a worldwide trend that tilting trains are served on the conventional railway line. That is the reason serving tilting trains is very efficient to use existing facilities and improve cruise time when capacity is available. In this paper, we suggest 10 routes are replaced with present operating trains(saemaeul, mugunghwa) by the tilting train.

• Proceedings of the KSR Conference
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• 2005.05a
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• pp.115-122
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• 2005

This study analyzed the characteristics of four kinds of bridge rubber pads and suggested how to determine the stiffness the pads. The stiffness of rubber pads can be estimated by a direct static test. In the procedure to estimate the stiffness of a pad, the dead load(preload) of a bridge and live load of a vehicle are considered. The polyurethane rubber pads have larger hardness than natural and chloroprene rubber pads and thus carry larger load bearing capacity. In addition, they showed higher stiffness with the same shape factor than the others and thus are more avaliable as for bridge bearings. Although natural and chloroprene rubber pads are elongated to large deformation in horizontal direction due to vertical loads, polyurethane rubber pads almost do not generate horizontal deformation due to vertical loads regardless to the thickness and hardness of the pads. Therefore, they do not need reinforced plate to restrict horizontal deformation.

• Journal of the Korean Society for Railway
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• v.3 no.3
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• pp.161-169
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• 2000

AGT(Automated Guide-way Transit System) was introduced to satisfy the every increasing need for improved urban transportation. The AGT system is classified as medium distance and demand capacity mass transit being introduced for such area with inadequate passenger demand for railway construction but excessive demand for bus service. To decrease initial investment cost it is important that we have to secure the technology system of Light Rail Transit for Korea environment. By utilizing the finite element analysis, the result in this paper is enough to satisfy the strength whish is required. Also for the purpose of safety, it is decided the thickness and frame structure of the undeframe section through the analysis. It is known that carbody is no problem for required design conditions.