• Proceedings of the KIPE Conference
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• 2001.07a
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• pp.405-408
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• 2001

This paper investigates the problem of the speed estimation of conventional speed sensorless stator flux-oriented induction machine drive in the field weakening region and proposes a new speed estimation scheme to estimate speed exactly in transients in the field weakening region. The error included in the estimated rotor speed is removed by not a low pass filter but Kalman filter.

• Proceedings of the KSR Conference
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• 1999.11a
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• pp.534-541
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• 1999

The purpose of this study is to suggest the effective analytical procedure using finite element model for the crashworthiness of motorized trailer of high speed train. In the analysis of end-on collision of Motorized Trailer for Korean High Speed Train., deformed pattern, rigidwall force, internal energy and each part section force is obtained. From those indices, we evaluate crashworthiness of motorized trailer for Korean High Speed Train in planning. The numerical results are applied to the design of motorized trailer of Korean high speed train.

• Proceedings of the KSR Conference
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• 1999.11a
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• pp.130-138
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• 1999

This study was carried out about interior design of trailer car for Korean High speed Train of Maximum operating speed of 350km/h. The interior main item design of high speed train is performed in order to satisfy the function of speed, safety and comfort concerning the RAMSH, ENVIRONMENT, ACTIVITY AND INFORMATION, This paper focuses on what is the design principle concerning the above mentioned factors and how did we apply that in the korea high speed train.

• Proceedings of the KSR Conference
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• 1998.11a
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• pp.313-320
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• 1998

The critical speed of a train running on the straight railway track is investigated by in-house program. The program is developed to find out nonlinear critical speed and it bases on the bifurcation theory. As a result, it is found that nonlinear critical speed exists on the lower speed band than linear critical speed and this fact imply a possibility of induction of a big accident.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.2306-2309
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• 2011

With the opening of 1st phase and 2nd phase in Gyeongbu High Speed Line, KTX(The Korea Train Express) and Sancheon(2nd generation of High Speed Train) are operating commercially on entire line. Gyeongbu High Speed Line can be separated as several sections. In this entire line, a few types of train has operating by it's own pattern. However, commercial speed of the line compared with the maximum speed of Train is rather slow. Through this study, I found the reason of the slow speed on the Catenary system and suggested a solution.

• Proceedings of the IEEK Conference
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• 2003.07c
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• pp.2769-2772
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• 2003

This paper presents results of the development of the Turbo-generator system with structure which is HSG(High Speed Generator) installed to high speed gas-turbine engine directly. Turbo-generator with high speed motor-generator directly has many advantages aspects of weight, size, lubrication system and complexity of the system compared of conventional turbo-generator system with gear-box. But because of direct high speed operation of the high speed generator, we have to need stable high speed motor driving algorithm for perfect engine ignition when gas turbine starting. Also we have to need design of the PCU(Power Conditioning Unit) for converting high speed AC output power to conventional AC power or needed DC power.

• Journal of Electrical Engineering and Technology
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• v.11 no.6
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• pp.1548-1555
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• 2016

This paper presents an application of time series analysis in hourly wind speed simulation and forecast in Jeju Island, Korea. Autoregressive - moving average (ARMA) model, which is well in description of random data characteristics, is used to analyze historical wind speed data (from year of 2010 to 2012). The ARMA model requires stationary variables of data is satisfied by power law transformation and standardization. In this study, the autocorrelation analysis, Bayesian information criterion and general least squares algorithm is implemented to identify and estimate parameters of wind speed model. The ARMA (2,1) models, fitted to the wind speed data, simulate reference year and forecast hourly wind speed in Jeju Island.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.11 no.8
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• pp.349-356
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• 2001

The dynamic behavior of high speed train is very Important because the railway should be safe and Is satisfied tilth the rode comfort of passengers. The train is composed of many suspension components. such as 1st springs, 1st dampers, 2nd springs and 2nd dampers, that have an influence on the dynamic characteristics of high speed train. Also, the wheel/rail shapes, the track conditions and geometry and many environmental factors, such as rain, snow and wind. affect the dynamic behavior of high speed train. This paper reviews the effect of wind and track conditions on the dynamic behavior of high speed train. The VAMPIRE program Is used for this simulation. The result of simulation shows that the high speed train should not be operated when the wind velocity is beyond 34.5 m/sec.

• Journal of Power System Engineering
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• v.13 no.6
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• pp.88-94
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• 2009

In this paper, vibration characteristics after applying variable speed control to fans with a rated speed used in a power plant are studied by performing experiments and analyzing finite element models. Then the campbell diagram is presented to verify the reason of the abnormal vibration measured from fan structure during variable operation of Forced Draft Fan & Induced Draft Fan. According to results, it is found that amplitude of acceleration increases abruptly when a 2X harmonic component meets the natural frequency of fan rotor. Therefore it is very important thing that investigate exactly dynamic characteristics for the rotor at variable speed zone before applying variable speed control to a rotor with a rated speed.

• Journal of the Korean Society for Railway
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• v.11 no.2
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• pp.115-119
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• 2008

Korean Train Express (KTX) has opened to commercial traffic since 2004 at maximum speed 300km/h. As the speed of the train becomes higher, the conditions of the rail affect the behavior of the running train. To secure the safety and reliability of high speed railway, it is necessary to inspect rail irregularities and to maintain the rail regularly. The authors designed the high speed rain measurement system over 300km/h. And we installed the system to Korea High-speed Railway (HSR 350x). In this paper, we introduce the high speed rail measurement system for HSR 350x and show verification of the performance of the system through test runs.