• Journal of IKEEE
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• v.19 no.2
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• pp.168-175
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• 2015

In this paper, we propose FPGA design technique for rotating LED display device which is capable of displaying videos with the use of the afterimage effect. The proposed technique is made up of image data correction process based on inverse gamma correction and error diffusion, block interleaving process, and data serial output process. The data correction process based on inverse gamma correction and error diffusion is an image data correction step in which image data received are corrected by inverse gamma correction process to convert the data into linear brightness characteristics, and by error diffusion process to reduce the brightness reduction phenomenon in low-gray-level which is caused by inverse gamma correction. In the block interleaving process, the data of the frames entered transversely are first saved in accordance with entrance order, and then only the longitudinal image data are read. The data serial output process is applied to convert the parallel data in a rotating location into serial data and send them to LED Driver IC, in order to send data which will be displayed on high-speedy rotating LED Bar. To evaluate the accuracy of the proposed FPGA design technique, this paper used XC6SLX45-FG484, a Spartan 6 family of Xilinx, as FPGA, and ISE 14.5 as a design tool. According to the evaluation analysis, it was found that goal values were consistent with simulation values in terms of accurate operation of inverse gamma and error diffusion correction, block interleaving operation, and serialized operation of image data.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.4 no.1
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• pp.23-31
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• 2011

In this paper, the intelligent smart monitor system is implemented for the next generation vehicle. to mitigate the numerous effects of distractions within the vehicle, it is vital to put critical information where the driver can use it without affection focus on the road ahead. Audible alarms are useful supplements when used in conjunction with visual displays. But driving is an overwhelmingly visual task. To optimize a vehicle's active safety systems, more than just audible alarms are necessary. The driver needs a visual interface that focuses his or her attention on the road ahead. The most commonly viewed information in a vehicle is from the instrument cluster, where speed, tachometer, fuel, engine temperature, fuel gauge, turn indicators and warning lights provide the driver with an array of fundamental information. TFT LCD, LCD Back light led, plane mirror, lens and controllers parts were designed to intelligent integrated smart monitor system. Finally, in this paper, we analyze intelligent integrated smart monitor system for driver safety vehicles.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.9
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• pp.2003-2008
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• 2012

A drive system is necessary to operate LED by an LED illumination system. Because Switched Mode Power Supply (SMPS) is higher in efficiency in the large capacity than Linear Regulator, it is used mainly and controls this in an analog form or digital method. A MCU and a DSP of the digital control central processing unit were higher in a unit price than existing analog control chip, so that an approach was not easy for application of SMPS. But it can take the earnings by it lets you integrate various digital control features like an LED illumination system in one MCU, and realizing a whole system. In this paper, we suggest the algorithm that can improve LED driving current in applying such a digital control method using low-priced type MCU.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.65 no.4
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• pp.285-291
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• 2016

A light-emitting diode (LED) has been increasingly applied to various industrial fields and general lightings because of its high efficiency, low power consumption, environment-friendly characteristic and long lifetime. To drive the LED lighting, a power converter with the constant output current is needed. Among many power converters, the flyback converter is chosen by many converter designers due to high power density, structural simplicity, and miniaturization. In this converter, an electrolytic capacitor is generally chosen for the stabilization of the DC voltage because of having the large capacitance and the low price. However, the disadvantages are the short expected life time and 120Hz ripple currents on the converter output node. In this paper, a single-stage dimmable PFC DCM flyback converter without the electrolytic capacitor is proposed to prolong the lifetime of the LED driver. For the long lifetime of the converter, the polyester film capacitor with the small capacitance is substituted for the electrolytic capacitor on the output node and an LC resonant filter is added to damp 120Hz ripple current. The proposed converter is verified through the simulation and the experimental works.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.27 no.2
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• pp.84-94
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• 2013

In case when the existing TRIAC phase controlled dimmer is drove for the LED lighting equipments, there are many problems such as the LED flicker in low phase-angles, the acoustic noise and elements damage by increase of the peak voltage in the input filter capacitor, mulfunction by insufficiency of the TRIAC holding current, and the abnormal oscillation by LC resonant. In this paper, we proposes the single-stage quasi-resonant PSR(Primary Side Regulation) PWM converter, and the design, the simulation and experiment are performed. As a result, it could confirm that the proposed PWM converter is the lighting equipments for LED drive which can alternate the existing 60W class incandescent bulbs and it has the high drive performance of the efficiency 80% and over, the power factor 0.95 and over under the normal voltage 220V. Finally, total harmonic distortion(THD) is gratified with a standard[1] of the lighting equipments and the durability is evaluated as the high reliablilty of 150,000 hours and over.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.16 no.2
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• pp.151-155
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• 2016

In this paper, we present the LED dimming control system by using ADPCM (Adaptive Differential Pulse Code Modulation). This ADPCM apparatus accurately controls the LED current with high resolution reducing the RFI (radio frequency interference) due to the spreading out of the harmonics of current of pulses. Additionally, this makes it easier to increase the accuracy of control operation. This study introduces to make a digitally controlled circuit for controlling LED with high-energy efficient by adopting pulse current to LED. The LED current drive system we designed are two systems, the digitally-controlled unit and analog switching mode power supply unit, can be developed separately. The simulation shows the sigma delta modulation of digital to analog converter's output when the input level is 0.7. From this simulation, the output is approached to accurately 0.15% to target value with 510 pulses.

• Proceedings of the KIPE Conference
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• 2013.11a
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• pp.73-74
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• 2013

본 논문은 LED Driver 휘도(Luminance) 제어 방식인 펄스폭 변조(PWM), 진폭변조 방식(PAM)을 조합한 스마트디밍 알고리즘에 대해 제안한다. 제안된 방식은 LED 구동 순방향 전류($I_f$)양에 따라 순방향 전압($V_f$)이 비례적으로 변화되는 특성을 이용한 것으로, LED Backlight 적용 LCM의 소비전력을 저감할 수 있다. 본 논문에서는 스마트 디밍 (CPWAM=Conditional Pulse Width Amplitude Modulation) 알고리즘에 대해 소개하고 실험을 통해 제안된 알고리즘의 타당성을 검증한다.

• Proceedings of the KIPE Conference
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• 2011.07a
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• pp.224-225
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• 2011

본 논문은 하나의 제어 IC로 이중출력 각각 독립 제어가 가능한 LLC 공진형 컨버터를 제안한다. 기존의 이중출력 LLC 공진형 컨버터의 경우 master 출력전압만 제어가 가능하므로, slave 출력의 정밀제어를 위해 별도의 DC/DC 컨버터가 필요하며, 이는 시스템의 전력 변환 효율을 떨어뜨리고 제작단가를 증가시키는 단점이 있다. 반면, 제안된 회로는 LLC 공진형 컨버터의 이중출력을 하나의 제어 IC로 주파수 및 시비율 각각 가변하는 방식으로 개별적 제어가 가능하므로 부하 및 입력전압 조건과 무관하게 모든 출력 전압의 제어를 정밀하게 할 수 있는 장점이 있다. 따라서 별도의 DC/DC 컨버터 사용이 불필요하므로 고효율 및 저가격의 특징을 가질 수 있다. 본 논문에서는 제안된 회로의 타당성 검증을 위해 이론적 분석결과를 제시하고 40W급 LED 조명회로에 적용한 실험 결과를 바탕으로 그 우수성을 확인한다.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1017_1018
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• 2009

LLC 하프브리지 공진형 컨버터는 일반적으로 게이트 구동드라이버, 구형파 발생부, 공진회로 및 정류회로로 구성되어 있다. 구형 파발생기는 두 개의 스위치 소자가 각각 50%의 주기와 약간의 데드타임을 가지고 반복하여 동작함으로써 구형파 전압을 발생하며, 공진회로에 구형파 전압이 인가되어도 높은 차수의 고주파 전류를 필터링하여 기본적으로 정현파 전류만 흐르도록 한다. 본 연구에서는 LLC 컨버터를 이용하여 LED를 구동을 하였고 시뮬레이션 결과를 실제 실험을 통해서 비교하였다.

• KIEAE Journal
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• v.7 no.6
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• pp.53-64
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• 2007

The idea that city culture can be employed as a driver for urban development has become part of the new orthodoxy by which cities seek to enhance their competitive position. Such development reflect not only the rise to prominence of the cultural sphere in the city development, but also how the meaning of culture has been refined to include new uses in order to meet the main objectives of sustainable development. This study focuses on the procedure how the cultural infrastructure and historical context can be applied for urban regeneration strategy. Two successful cases (Bilbao, Spain and Yokohama, Japan) were selected for analysis of strategies as a whole, background, main characteristics of culture-led urban regeneration strategies and their effect for urban regeneration have been analyzed in detail. In conclusion, lessons for the future development were suggested in terms of resources, planning and linking strategies.