• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.5
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• pp.72-81
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• 2018

In this study, the sinusoidal-wave driving method, six-step driving method, and twelve-step driving method, which can be used in an inverter for permanent-magnet synchronous motors, were simulated, and the results were compared to review their operating performance. These driving methods were classified according to the electrical conduction angle and phase current of the motor. Conventionally, only the transition control technique between the sinusoidal-wave driving method and six-step driving method was studied for the efficiency of the inverter. In this paper, however, comparative analysis was focused on a variety of transition control applications to use the advantages of each driving method. For this purpose, computer simulations for these driving methods were carried out to obtain the motor torque, speed control characteristics, and THD of the motor phase currents. As a result, the sinusoidal-wave driving method showed the best performance in all respects. The six-step driving method has better speed control characteristics than the twelve-step driving method, and the twelve-step driving method has a lower THD of the motor phase currents than the six-step driving method.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.20 no.9
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• pp.11-17
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• 2006

We have theoretically investigated the effects of the interplay between the driving voltage of Mach-Zehnder(MZ) modulators and the bandwidth of low-pass filters(LPF) in 10[Gb/s] duobinary modulation systems. For the change of driving voltage ratios(driving voltage/switching voltage), the transmission performance has been evaluated over 200[km] of single-mode fiber(SMF) systems. For driving voltage ratios with smaller than 100[%], the transmission performance has been maintained and greatly affected by the bandwidth of LPFs than the driving voltage. For driving voltage ratios with larger than 100[%], the transmission performance has been degraded and is not sensitive to the bandwidth of LPFs. To see the limitation of driving voltage, we have reduced the driving voltage ratio to 50[%]. Our results suggest that 10[Gb/s] duobinary signals with driving voltage ratio with smaller than 100[%] have been transmitted over 200[km] SMF within 2[dB] power penalty without dispersion compensation. For the driving voltage ratio with 50[%], we have verified that the transmission performance was maintained.

• The Transactions of the Korean Institute of Power Electronics
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• v.25 no.2
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• pp.79-86
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• 2020

This study examines the power generation characteristics of a vehicle rooftop photovoltaic module with urban driving conditions. Actual test data with an illuminometer and a thermometer were used to analyze the power generation characteristics of the vehicle rooftop photovoltaic module. In addition, the power generation characteristics were analyzed in terms of urban driving conditions, irradiance, ambient temperature, and photovoltaic module temperature. This study also analyzes the power generation characteristics of the vehicle rooftop photovoltaic module with urban driving conditions through a wavelet transform filtering method. The power generation characteristics of the vehicle rooftop photovoltaic module with urban driving conditions depend on the change in irradiance rather than that in photovoltaic module temperature.

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.1495-1498
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• 2008

We proposed driving method with variable integration time for ambient light sensing. One operation period of the proposed driving method consists of several sub-integration periods with variable integration time which can enlarge dynamic range of ambient light sensing circuit. Temperature dependent characteristic of p-intrinsic-metal (p-i-m) diode can be compensated using the proposed driving method.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 1999.11a
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• pp.181-183
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• 1999

This paper is about the design of half-bridge inverter controller with low cost and simple configuration for low power single-phase induction motor driving. The simple controller is composed of MCU and PLD. Also, to limit the overcurrent at initial driving, auxiliary function is added, and stabilizes the system. In order to verify the performance of the proposed methode, we design 500W inverter system, and in result, the response time of the proposed method compared with line voltage driving method is reduced by 200[msec].

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.24 no.11
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• pp.915-919
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• 2011

We analyzed various forces affective to the charged particles in closed space, to explain the image degradation and lifetime-shortening phenomena because of particle lumping which is one of the serious problems in reflective displays. It is possible to predict the quantity of q/m which is the most important parameter in determining the optical and electrical characteristics, by calculating the image force and kinetic energy. For stable driving, the quantity of q/m must be in the defined range but it changes during the fabrication process, so we added the filtering process to solve this problem and obtained the well-defined nonlinear driving voltage coinciding with the threshold voltage. And we obtained the fully-driving property which prevents the particle lumping and decides the image quality and lifetime of panel from the optical characteristics and occupation surface of moving particles.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.4
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• pp.646-652
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• 2015

Increasing needs for rapid driving vehicles during rush hour, there are various researches how to operate or allocate rapid driving vehicles with the existing normal driving vehicles. In the aspect of power system, it should be preceded by an analysis for power equipment capacity. Also, it should be studied whether the added rapid driving vehicles gives a bad effects for stable operation of railway systems or not. In order to derive the results for these analysis processes, this paper suggest a novel analysis algorithm which can implement integrated analysis including rapid and normal driving railway vehicles simultaneously. This algorithm has been verified using Seoul Metro 7 Line data.

• Journal of IKEEE
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• v.25 no.4
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• pp.728-734
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• 2021

In recent years, there has been a strong interest in the end-to-end autonomous driving based on deep reinforcement learning. In this paper, we present a reward function of latent SAC deep reinforcement learning to improve the longitudinal driving performance of an agent vehicle. While the existing reward function significantly degrades the driving safety and efficiency, the proposed reward function is shown to maintain an appropriate headway distance while avoiding the front vehicle collision.

• 한국정보디스플레이학회:학술대회논문집
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• 2003.07a
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• pp.726-729
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• 2003

A new driving method is proposed to reduce the address period. The scan time of new driving method overlaps with the next scan time during the discharge lag time. Thus, without reducing the address pulse width and the scan pulse width, the new addressing method can reduce the address period. The results show that the scan time of about 100ns ${\sim}$ 300ns can be overlapped without the misfiring,.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.26 no.8
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• pp.1-7
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• 2012

In this paper, a new LED driving circuit which is able to control dimming of LED is proposed using charge pump. The proposed LED driving circuit steps down the input voltage to operate LED without DC-DC converter. The operation of this driving circuit is verified by P-Spice simulation, and the characteristics of the driving circuit is measured and evaluated in the experiments. As a result, the driving circuit efficiency of 88.5[%] is obtained when all LEDs are turned on by digital control method at the highest dimming level(255/255).