• Proceedings of the KSR Conference
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• 2008.11b
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• pp.358-363
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• 2008

Through this study, 2D multibody dynamics models for analysis of train collisions have been developed to evaluate the crashworthiness requirements of the TSI regulation. The crashworthiness regulation requires some performance requirements for two heavy collision accident scenarios; a train-to-train collision at the relative speed of 36 kph, and a collision against a standard deformable obstacle of 15 ton at 110 kph. The complete train set will be composed of hybrid model with 2D and 1D model. Using numerical analysis of the hybrid model, some crashworthy design were evaluated in terms of mean crush forces and energy absorptions for main crushable structures and devices. especially, 2D model can evaluate overriding effect in train collisions. It is shown from the simulation results that the suggested hybrid model can easily evaluate the crashworthiness requirements.

• Journal of Electrical Engineering and Technology
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• v.12 no.1
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• pp.117-125
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• 2017

Research on Maglev (Magnetic Levitation) train is currently being conducted in Korea, concerning Urban Transit (110 km/h of maximum speed), semi-high-speed (200 km/h of maximum speed), and high-speed (550 km/h of maximum speed) trains. This paper presents a research study on the levitation and guidance systems for the Korean semi-high-speed maglev train. A levitation electromagnet was designed, and the need for a separate guidance system was analyzed. A guidance electromagnet to control the lateral displacement of the train and ensure its stable operation was then also designed, and its characteristics were analyzed. The dynamic performance of the designed levitation and guidance electromagnets was modeled and analyzed, using a linearized modeling of the system equations of motion. Lastly, a test setup was prepared, including manufactured prototypes of the designed system, and the validity of the design was verified and examined with performance evaluation tests.

• Journal of the Korean Society for Precision Engineering
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• v.29 no.6
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• pp.593-599
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• 2012

To analyze the effect of the track structure on the running performance of the railway vehicle, we studied on the vibration and ride characteristics of the high speed train. As results, vibration and ride level of high speed train on the concrete bed track is more reduced than on the ballast bed track. Peak-peak value of carbody vibration on the concrete bed track at 300km/h is half of the peak-peak value of carbody vibration on the ballast bed track. Ride level on the concrete bed track at 300km/h is same level as that on the ballast bed track at 250km/h. Thus, Vibration and ride performance of the high speed train on the concrete bed track is greatly improved compared with that on the ballast bed track.

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.1227-1232
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• 2008

High-speed train of push-pull type called as G7 train has been developed and chosen as the model of KTX-II which will be operated on Honam Line nexr year. However, the EMU-type high-speed train appeared to be the recent trend that foreign markets have shown. Also, in the near future, a great number of new train sets are needed to accommodate the increased passengers in our country. Thus, development of the high-speed EMU was decided, planned, and started. In the development, included were almost all fundamental key technologies such as noise and vibration reduction in a passenger cabin, running characteristics, aerodynamic analysis, crashworthiness evaluation, EMI/EMC analysis, design of the cooling system for the propulsion control system, enhanced performance of transformer and switching converters, synchronous traction motor with permanent magnets, new design of front nose and ergonomic interiors, application of advanced information technology(IT) and smart sensors and the cost reduction of construction of railway bridges, etc. Each key technologies are carried out as sub-project independently but under the supervision of a project. The project will develop the high advanced level of technologies and provide necessary know-why's and support the team in charge of the development of the high-speed EMU, Hyundai Rotem Co. Ltd. The high-speed EMU will be successfully developed with the support of the project.

• The Journal of the Korea institute of electronic communication sciences
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• v.11 no.8
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• pp.743-750
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• 2016

The conventional track to train communication is commonly using radio based equipment such as transponder or balise to transmit the data. However, there are some drawbacks of the conventional equipment, for example multipath fading, source of bandwidth limitation, and interference from other users. Moreover, the radio based equipment is very expensive when installed in large numbers. To address these problems, we propose infrared system for trackside to train communication system. Infrared system offers a transmission of data to train and it can be processed to obtain at least a train location. Infrared communication protocol provides practical wireless data communication for direct dedication configuration. Furthermore, on the pole configuration the infrared system provides an abundant bandwidth, an economically sensible, minimalized installation of equipment on the trackside and reliability for heavy rain environment. This paper concentrates on the communication function and measurement performance evaluation. The proposed trackside to train communication system covers about 6 meters between infrared receiver and infrared transmitter, whereas the half angle of the transmitter is set to $19.65^{\circ}$ and the receiver angle is $15^{\circ}$.

• Journal of the Korean Society for Railway
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• v.16 no.3
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• pp.169-174
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• 2013

The effect of modifying the shape of a high-performance EMU train on the aerodynamic drag is studied here using Computational Fluid Dynamics(CFD) based on three dimensional Steady-state Navier-Stokes equation and two equation turbulence modeling. FLUENT 12 and Gambit 2.4.6 are employed for a numerical simulation of the aerodynamic drag of a streamlined-shape train as well as a proto type train. The characteristics of the aerodynamic drag of trains in tunnels are analyzed in a comparison with these characteristics in an open space. The contribution of the aerodynamic drag of each case is also investigated to establish principal pertaining to drag reduction for urban trains in tunnels. The aerodynamic drag of a streamlined train was reduced to 9.8% relative to a proto-type train with a blunt nose and a protruding roof facility and underbody shape: the running resistance is expected to be reduced by as much as 4% at a running speed of 80km/h.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.415.2-415.2
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• 2016

Triboelectric nanogenerator (TENG) is one of ways to convert mechanical energy sound, waves, wind, vibrations, and human motions to available electrical energy. The principal mechanism to generate electrical energy is based on contact electrification on material surface and electrostatic induction between electrodes. The performance of TENG are dependent on amount of the input mechanical energy and characteristics of triboelectric materials. Furthermore, the whole TENG system including mechanical structure and electrical system can effect on output performance of TENG. In this work, we investigated the effect of gear train on output performance and power conversion efficiency (PCE) of TENG under a given input energy. We applied the gear train on mechanical structure to improve the contact rate. We measured the output energy under a constant input energy by controlling the size of the working gear. We prepared gears with gear ratios (rin/rw) of 1, 1.7, and 5. Under the constant input energy, the voltage and current from our gear-based TENG system were enhanced up to the maximum of 3.6 times and 4.4 times, respectively. Also, the PCE was increased up to 7 times at input frequency of 1.5 Hz. In order to understand the effect of kinematic design on TENG system, we performed a capacitor experiment with rectification circuit that provide DC voltage and current. Under the input frequency of 4.5 Hz, we obtained a 3 times enhanced rectifying voltage at a gear ratio of 5. The measured capacitor voltage was enhanced up to about 8 fold in using our TENG system. It is attributed that our gear-based TENG system could improve simultaneously the magnitude as well as the generation time of output power, finally enhancing output energy. Therefore, our gear-based TENG system provided an effective way to enhance the PCE of TENGs operating at a given input energy.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.204-210
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• 2011

This paper present investigation of interoperable process and interaction-facts between urban and new ATS signalling system for degrading, improvement or replacement in wireless communication-based train control system of urban driverless transit, and investigate interoperable requirement from joint program of cooperation-"wireless communication-based train control system's standard process construction and performance evaluation on urban transit" of first year result.

• Proceedings of the KIPE Conference
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• 2000.07a
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• pp.543-547
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• 2000

Power factor and harmonics are increasingly important for high speed train auxiliary block. This paper presents experimental results of the power factor and harmonic performance of two parallel PWM circuits under various supply and load conditions. For reducing harmonics the harmonic content is eliminated by the phase shift between two converters switching phase. Experimental results show the usefulness of the proposed method and applicability to PWM converter in auxiliary block of high speed train.

• Proceedings of the KIPE Conference
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• 2000.07a
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• pp.274-277
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• 2000

Power factor and harmonics are increasingly important for high speed train auxiliary block. This paper presents experimental results of the power factor and harmonic performance of four parallel PWM converter circuits under various supply and load conditions. For reducing harmonics the harmonic content is eliminated by the phase shift between four converters switching phase. Experimental results show the usefulness of the proposed method and applicability to PWM converter in auxiliary block of high speed train.