• Journal of information and communication convergence engineering
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• v.21 no.1
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• pp.45-53
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• 2023

This study constructs various scenarios required for landscape lighting; furthermore, a large-capacity general-purpose multifunctional controller is designed and implemented to validate the operation of the various scenarios. The multi-functional controller is a large-capacity general-purpose controller composed of a drive and control unit that controls the scenarios and colors of LED modules and an LED display unit. In addition, we conduct a computer simulation by designing a control system to represent the most appropriate color according to the input values of the temperature, illuminance, and humidity, using the neuro-control system. Consequently, when examining the result and output color according to neuro-control, unlike existing crisp logic, neuro-control does not require the storage of many data inputs because of the characteristics of artificial intelligence; the desired value can be controlled by learning with learning data.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.4A
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• pp.573-578
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• 2000

This paper presents a noble optical access system using shared laser and LED light sources, which is based on WDM-PON technologies. This system adopts an external modulation of the shared laser sources for high-speed downstream and a direct modulation of the LED sources for low-speed upstream. To split or combine the transmission channels, AWG(Arrayed Wave-guide Grating) devices are used in the optical cable section. The proposed system is attractive for low cost implementation. The laser light sources can share the optical carriers in the downstream scheme. Also, in upstream, the LED sources can afford to make simple of the circuits for controlling light source and of standardization for ONU(Optical Network Unit). The feasibility of the proposed system is demonstrated by several experiments. Our results show that the system operates well at 2.SGbps for downstream and up to 622.08Mbps for upstream.

• Transactions of the Society of Information Storage Systems
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• v.9 no.1
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• pp.10-16
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• 2013

Through the rapid development of LED TV, a large-area edge-lit backlight unit is widely researched in the display industry for enhancing the optical efficiency, luminous uniformity and slim design. In addition, an edge-lit backlight unit includes many optical sheets such as reflection sheet, prism sheet and diffuser sheet. However the function can be replaced by the carefully patterned light guide plate (LGP). Micro patterns which located on the top and bottom surface of light guide plate was designed by ray-tracing optical simulation. The designed patterns improved the light characteristics of LGP, including optical extraction efficiency and intensity distribution uniformity. These results suggest that it is very effective method to design edge-lit LGP with micro-patterns on both sides for large-area display and to reduce the fabrication cost.

• Journal of Industrial Technology
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• v.30 no.B
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• pp.75-81
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• 2010

This paper presents the development of LED street light lamp which is controled by central command system. This system includes a lamp unit controller, data repeater and command repeater as well as the LED lamps. These devices enable the individual power control and partial on/off control of the LED lamps by the control repeater through full duplex communication line. Also, they have the ability to control the brightness and period of on/off timing by detecting the car's existence. As a result of this development, it is founded that the performances of the system have been satisfied to apply for the actual road test.

• The Optical Journal
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• s.155
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• pp.66-80
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• 2015

본 논문은 지식경제부 한국산업기술평가관리원의 LED시스템조명 기술개발사업(10042947, 멀티센서 기반의 데이터 통신모듈과 드라이버 IC/프로세서 제어부품 등을 탑재한 200cc 이하의 LED 시스템조명 기술개발) 연구사업의 일환으로 작성되었음. 세계 각국은 자국의 안정적인 에너지 공급과 저탄소 녹색성장을 위해 장 단기적인 정책을 다양하게 펼치고 있다. 그 중 고효율, 친환경 광원인 LED는 국가의 에너지 정책 추진의 중요한 부분을 차지하고 있다. LED 조명은 기존 백열등 형광등 할로겐을 대체 할뿐만 아니라 휴대전화, 자동차, BLU(Back Light Unit) 등 다양한 분야에 적용할 수 있기 때문에 시장잠재력이 크다. 본고에서는 미국, 유럽, 중국, 일본의 LED 조명산업 관련 정책을 살펴보고 정책적 시사점을 도출하고자 한다.

• Journal of Industrial Technology
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• v.32 no.A
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• pp.109-114
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• 2012

In this paper, We studied LED(Light Emitted Diode) sensor lights system using PIR(Pyroelectric Infrared Ray) sensor, CdS and MCU(Micro Controller Unit). And applied the valley fill circuit to improve the power factor. We designed the amplifier for each sensor and the LED driver for constant current which is the buck converter. Also, we proposed the algorithm of LED control by each sensors using MCU. Experimental results showed that power factor is 92% with valley fill circuit.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1556-1557
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• 2007

LCD BLU에 광원의 수명을 측정하고, 고장모드를 분석하기 위해서는 광원을 구성하고 있는 각각의 성분 중에서 광원 자체를 구성하고 있는 R/G/B 광원에 대한 Burn-in test 및 고장모드를 분석하였다. LCD BLU에 있어서 R/G/B LED광원의 역할은 BLU 자체의 수명과 성능에 가장 큰 영향을 미친다. 서로 각각 사용조건하에서의 수명과 성능의 차이에 따라서 BLU 자체의 수명이 결정된다. 이를 평가가기 위해 LED device에 대한 가속수명테스트를 위한 Burn-in test를 실시하였으며, 발생한 고장모드를 분석하였다. 분석결과 누설전류 증가로 인한 불량이 주로 발생하였다. 누설전류 증가를 평가하기 위해 Photo emission microscope(PHEMOS-1000, MoDooTEK Inc.)을 이용하여 저전류에서의 LED chip의 누설전류에 의한 발광을 관찰함으로 인해, LED chip의 신뢰성 및 평가 기준이 됨을 알 수 있다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.11a
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• pp.375-376
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• 2007

In this work, we have simulated a 42-inch LED BLU which was based on 300 RGB LEDs. We have done an adjustment of LEDs' strip distance and a height of the top of the LED to the back of the LCD to get white color uniformity. So, we have changed simultaneously the distance between the top of the LEDs and the back of the LCD. Moreover, we set a fixed position for the horizontal of LED's pitch. And then, we have experimented and compared to our simulation data.

• The Journal of the Korea Contents Association
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• v.10 no.5
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• pp.62-69
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• 2010

LCD panel need BLU(Back Light Unit) that is outside source of light because can not emit light voluntarily. BLU is used in LCD module and is used in tester that examine LCD panel's badness. Lately, BLU had changed from CCFL(Cold Cathode Fluorescent Lamp) to LED(Light-Emitting Diode) fast. CCFL need extra-high tension power and produce much heat and is difficult to keep fixed brightness. LED is few electric power wastage and keeps fixed brightness. But, BLU that is used to detector that examine the LCD module is using CCFL until recently. This paper develops LED BLU that can examine LCD panel's badness. Also, this manufactures LED BLU to 24 inch size to examine all LCD panels(12~24 inch), and develops so that LED BLU may operate according to LCD panel's size.

• Journal of the Korea Concrete Institute
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• v.12 no.4
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• pp.103-111
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• 2000

The influence of the improvement of grain shape of the coarse aggregate to the unit powder content of concrete and the fine aggregate ratio for the increase of the flowability and segregation resistance of high performance concrete was examined. According to the experimental results, flowability and compacting of concrete presents best states in the S/a which has the smallest 패야 ratio. The coarse aggregate after improvement of grain shape, that has changed from the 0.68 of spherical rate of disk shape to 0.73, led fine aggregate ratio to be down 6% (i.e from 47% to 41%). The improvement of grain shape of the coarse aggregate also led the lowest unit powder content to be down 60kg/㎥ (ie from 530kg/㎥ to 470kg/㎥). And approximate 10% of unit water content has been reduced as unit powder content was down. However, the compressive strength after the improvement of grain shape of the coarse aggregate decreased to 5% due to decrease of adhesiveness of the aggregate and cement paste.