• Journal of Electrical Engineering and Technology
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• v.12 no.2
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• pp.632-642
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• 2017

This paper presents an improved approach towards reducing the switching loss of insulated gate bipolar transistors (IGBTs) for a medium-capacity-class power conditioning system (PCS). In order to improve the switching performance, the switching operation is analyzed, and based on this analysis, an improved switching method that reduces the switching time and switching loss is proposed. Compared to a conventional gate drive scheme, the switching loss, switching time, and delay are improved in the proposed gate driving method. The performance of the proposed gate driving method is verified through several experiments.

• Journal of Power System Engineering
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• v.16 no.2
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• pp.60-65
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• 2012

Pneumatic actuators are clean, lightweight, and can be easily serviced, whereas low energy efficiency has been considered as a critical shortcoming compared with corresponding hydraulic and electrical actuators. This study describes a new design method of pneumatic cylinder driving apparatus by lowering a supply pressure. The simulation study demonstrates that the designed system with the proposed method can operate at the smaller energy consumption state compare to the designed system with the conventional method for the specified working conditions.

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.409-412
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• 2006

A high data accuracy and low power consumption driving method and output stage of the source driver are proposed for the LTPS TFT-LCD in mobile applications. The proposed driving method is insensitive to the variations of the electrical characteristics of TFTs, which enables the output errors of the source driver are under 1/2 LSB in all gray levels. In addition, the power consumption of the driver with the method is decreased to 9.9mW which is 55.9% of that of the conventional source driver by reducing unnecessary charge waste.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.11
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• pp.2723-2731
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• 2000

Ultrasonic motors(USM) has been emerging as one type actuators, which possess many advantages such as high torque, low weight, compact size and no magnetic field generation. In spite of these features, there are several problems to be solved, which are temperature rise in case of long term operation, non -linearity, and hysteresis. Among these, hysteresis cause the most serious problem in force/torque control applications. To cope with this paper we propose a new PWM driving method which can be applied to force/torque control applications. To cope with this problem, in this paper we propose a new PWM driving method which can applied to force/torque control of USM. To verify the proposed method, an experimental setup was built and several experiments were performed.

• Journal of Power System Engineering
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• v.11 no.4
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• pp.98-102
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• 2007

In this study, a measurement method of leakage flow-rate for pneumatic driving apparatus is proposed. The existing measurement methods of leakage flow-rate of air need disassemble the test component. Therefore, there is no effective method to measure the leakage flow-rate while operating pneumatic driving apparatus. In this study, the leakage flow-rate is measured from the pressure change in an isothermal chamber that can realize isothermal conditions by stuffing the steel wool into it. Therefore, a wide range of flow-rate could be measured only from the pressure response and the leakage flow-rate can be measured during operating pneumatic driving apparatus. The effectiveness of the proposed method is proved by experimental results.

• Transactions of The Korea Fluid Power Systems Society
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• v.3 no.1
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• pp.15-19
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• 2006

In this study, a measurement method of leakage flow-rate for pneumatic driving apparatus is proposed. The existing measurement methods of leakage flow-rate of air need disassemble the test component. Therefore, there is no effective method to measure the leakage flow-rate while operating pneumatic driving apparatus. In this study, the leakage flow-rate is measure from the pressure change in an isothermal chamber that can realize isothermal conditions by stuffing steel wool into it. Therefore, wide range of flow-rate could be measured only from the pressure response and the leakage flow-rate can be measured during operating pneumatic driving apparatus. The effectiveness of the proposed method is proved by experimental results.

• Proceedings of the KIEE Conference
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• 2004.11a
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• pp.123-125
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• 2004

In order to achieve high efficiency and low cost, new high-speed addressing method is suggested. This can be achieved by reducing the address discharge delay time through the priming effect. This paper suggests a new ADR (Address During Reset) driving method which provides priming particles by using a separated driving method without adding auxiliary electrode or auxiliary discharge. The experimental results show an approximately loons reduction in the formative delay time of address discharge and a reduction in jitter of over 200ns. Also, due to enough time being available for reset, there was a reduction in light emitted during reset of about 29% which improved the dark contrast ratio considerably.

• International Journal of Highway Engineering
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• v.7 no.4 s.26
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• pp.185-202
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• 2005

In this research, to get over restrictions of a field expreiment, we modeled a planning road through the 3D Virtual Reality and achieved data about dynamic response related to sector fluctuation and about driver's visual behavior on testers' driving the Driving Simulator Car with Eye Camera. We made constant efforts to reduce the non-reality and side effect of Driving Simulator on maximizing the accord between motion reproduction and virtual reality based on data Driving Simulator's graphic module achieved by dynamic analysis module. Moreover, we achieved data of driver's natural visual behavior using Eye Camera(FaceLAB) that is able to make an expriment without such attaching equipments such as a helmet and lense. In this paper, to evaluate the level of road's safety, we grasp the meaning of the fluctuation of safety that drivers feel according to change of road geometric structure with methods of Driving Simulator and Eye Camera and investigate the relationship between road geometric structure and safety level. Through this process, we suggest the method to evaluate the road making drivers comfortable and pleasant from planning schemes.

• Phonetics and Speech Sciences
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• v.5 no.2
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• pp.93-97
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• 2013

This paper is on designing an indoor driving simulator to evaluate the performance of in-car speech recognizer when influenced by the elements, which lower the success rate of speech recognition. The proposed simulator simulates vehicle noise which was pre-recorded in diverse driving environments and driver's speech. Additionally, the proposed Lombard effect conversion module in this simulator enables the speech recorded in a studio environment to convert into various possible driving scenarios. The relevant experimental results have confirmed that the proposed simulator is a feasible approach for realizing an effective method as it achieved similar speech recognition results to the real driving environment.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.17 no.3
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• pp.65-70
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• 2008

Capacitive position sensing with modulation technique is widely used in electrostatic actuator applications. To maximize the electrostatic force and the position-sensing gain, capacitors for driving and capacitors for sensing are shared, i.e, after applying the driving voltage with high-frequency modulating signals using op amps, the position is demodulated from the modulated signal. In high-voltage applications, however, low bandwidth of a high-voltage op amp hinders adding the high-frequency modulating signal to the driving voltage. In this paper, new and very simple driving and sensing method is proposed, in which the pulse-width modulated driving voltage eliminates the need of the high-frequency modulating signal for position sensing. This new algorithm is proved by the simulation results using Matlab/SIMULINK.