• The KSFM Journal of Fluid Machinery
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• v.17 no.5
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• pp.54-59
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• 2014

The new high speed combi train prototype project was developed which named HSB. It runs over the speed of 330km/h. As the speed of the train exceeds over 300km/h, due to pressure change in tunnel, aerodynamic problems such as sudden drag increase, severe acoustic noise, passenger discomfort and tunnel pressure sonic boom were occurred. This aerodynamic characteristics in tunnel should be reviewed in early design state to enhance the performance and driving quality of new high speed train. In this paper, the aerodynamic characteristics in tunnel for HSB such as pressure waves in tunnel, a rate of pressure change in cabin and micro pressure wave that cause sonic boom outside tunnel are analyzed by 2D axisymmetric CFD simulations. The results are also compared with the value for ordinary high speed train like the KTX-Sancheon. It is helpful how to design the configuration of HSB train. Finally it shows that the HSB train was well designed in tunnel condition because all values fulfill the criterions on UIC code and Korean national regulations.

• The Korean Journal of Emergency Medical Services
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• v.1 no.1
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• pp.100-111
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• 1997

This is the first Korea study to evaluate the effects od the safety of ambulance driving and the occurrence of ambulance traffic accidents and to provide basic informaion for the description of various factors to reduce the ambulance traffic accidents. The major insturment of this study were Krean Self-Analysis Driver Opinionnaire. Questionnaire contains 8 items which measure driver's opinions or attitudes : driving courtesy, emotion, traffic law, speed, vehicle conditions, the use of drugs, high-risk behaviors, and human factors. To take the analysis of data, the total of 350 divers were investigated ambulance divers and others in Taejon City and others (6 City) from 1996. 1. July to 1996. 31. July. The data were analyzed by the descriptive statistics and the logistic regression - path analysis - with SPSS and SAS package program. The result are as follows : 1. There was desirable attitude group(16.2%) and undesirable attitude group(17.6%) on safety ambulance driving. 2. It have suggested that risk factors of ambulance traffic accidents much affected with emotion and speed control on safety ambulance driving < Y(Accdient) = -2.64 + 0.57 $X_1$ (Emotion Control) + 0.30 $X_2$(Seed control) + E > and motor traffic acident much affected with emotion control and high-risk behavior on safety driving < Y(Accident) = -1.11 + 0.33 $X_1$(Emotion Control) + 0.29 $X_2$(High-risk Behvior) + E > 4. The primary emphassis of ambulance drivers was make us realized that improthatnt factors on safety ambulance driving were 1)making way for emergent ambulance, 2)driver's career, 3)The ability of emergency medical technics, and the knowledge or under standing of ambulance way difficut(or easy) of accdess. 5. Almost 96.6% of respondents have agreed to necessity of emergency medical technics for ambulance drivers. 6. Almost 94.6% of respondents have consented to necessity of emergtency medical technicians for ambulance driving. 7. It have suggested that the proportion of traffic accident proportion by desitable attitude group(16.7%) was much less than that of undesirable attitude group(30.8%) on safety ambulance driving(P < 0.05)/Ps) Accidents are unplanned, unforesen incidents which can lead to harmful or unfortunate outcomes, Collisons are not accidents, since the basic cause of the majority of collisons invovles high-risk human behavior. Although there are many factors which contribute to accident causation, four basic factors seem to predominate in most traffic related situations. These four factors include: the human factor, the vehicle factor, the environmental factors and destination factor(Peto G. et al. 1995).

• IEMEK Journal of Embedded Systems and Applications
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• v.8 no.3
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• pp.129-136
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• 2013

In this paper, a motion control system based on 2-axis gimbal system is designed and implemented to drive a high speed and precision. The proposed system consists of the RS-422 interface, 2-axis gimbal platform, servo control unit integrated with a high speed DSP chip-set, servo amplifier unit, potentiometer sensor unit, and resolver sensor unit. The servo control unit using the high speed DSP firmware is designed to get a fast response without an overshoot with step input and a RMS error of low probability with ramp input. The servo amplifier unit using a voltage control is designed to resolve the zero-crossing distortion for precise motion. To verify the performance and stability of the implemented system, experiments are performed through a measurement of the time and frequency domain response in a laboratory environment by using a PXI(PCI eXtentions for Instrumentation).

• Journal of Institute of Control, Robotics and Systems
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• v.18 no.8
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• pp.787-793
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• 2012

This paper introduces the autonomous vehicle Pharos, which participated in the 2010 Autonomous Vehicle Competition organized by Hyundai-Kia motors. PHAROS was developed for high-speed on/off-road unmanned driving avoiding diverse patterns of obstacles. For the high speed traveling up to 60 km/h, long range terrain perception, real-time path planning and high speed vehicle motion control algorithms are developed. This paper describes the major hardware and software components of our vehicle.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.60 no.3
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• pp.138-143
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• 2011

Electric locomotive is adapted to high speed driving and mass transportation due to obtaining high traction force. The electric locomotive is operated by motor blocks and traction motors. Train speed is controlled by suppling power from motor blocks to traction motors according to reference speed. Speed control of the electric locomotive is efficient by spending energy between motor blocks and traction motors. Currently, switched reluctance motors have been studied because the efficient is higher than induction motors. In this paper, model of the switched reluctance motor is presented and the PID controller is applied to the model for the speed control by using Simulink. Asymmetry converter is used for real-time control and system performance is demonstrated by simulating the speed of switched reluctance motor including PID controller.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.712_713
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• 2009

This paper deals with the analysis on eddy current looses of high speed permanent magnet synchronous motor (PMSM) for turbo compressor according to voltage source driving. This paper presents analytical procedures for calculation of the eddy current losses using Poynting theorem. On the basis of the magnetic vector potential and a two-dimensional (2-D) cylindrical coordinate system, this paper derived analytical solutions of the eddy current looses using phase current analysis. The eddy current losses of each harmonic obtained by fast Fourier transform (FFT) analysis of phase current are with results obtained from finite-element method (FEM).

• Proceedings of the KIEE Conference
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• 1994.07a
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• pp.229-231
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• 1994

In recent years, as the industry has been highly developed and precised, its driving and control system have been changed, what is more, revolutionized. The requirements of these change are more accuracy, more high efficiency, more miniaturized size and more servo functions. Step motor has been adopted for driving servo systems, because of easier controllability, open-loop control, high position accuracy at low speed. In this paper, we deal with developing step motor system, and describe the procedure that contains design, analysis. testing characteristics.

• Proceedings of the KSR Conference
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• 1998.05a
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• pp.458-465
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• 1998

This paper presents an inverter-driven induction motor used as the traction motor for a high speed drive system that is required safety, reliability and performance and so on, In the respect of traction motor design, it is mainly showed the weight reduction inclination and characteristic investigation due to V/f driving pattern variation of inverter. Particularly, the reduction of V/f ratio pattern effects on the weight of traction motor and badly on the increase of phase current of traction motor in starting point. This method of weight reduction design have to be reached the decision with not only motor but also the consideration of inverter system because of the heat capacity, weight and material cost of inverter according to the increase of current.

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.1479-1482
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• 2006

Potentials and advantages of recently proposed raised bus electrode plasma display panel is discussed in terms of luminous efficiency, addressing speed. Detailed experimental and simulation results, which shows mechanisms of high efficiency driving mechanism, will also be given. Apart from the cell structure, we introduce new high efficiency driving method that can be applicable to conventional ac Plasma Display Panel.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08a
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• pp.479-482
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• 2007

For high performance driving carbon nanotube backlight units, their phosphor must be well studied. This paper experimentally evaluates their activating speed and persisting duration properties. They are proven to be the most efficiency related factors. High performance driving schemes are derived from them and implemented in this paper.