• 한국진공학회지
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• 제16권6호
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• pp.424-432
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• 2007

32인치 WXGA급 (해상도 1366$\times$768) LCD-TV용 백라이트를 구성하는 외부전극 형광램프 및 각 광학 부품들에 대한 휘도 특성을 조사하고, 광학시트들의 빛의 투과율을 계측하였다. 12등식과 18 등식의 백라이트에 대한 휘도 특성을 조사하였다. 휘도 균일도는 12등식 백라이트에서도 85 %의 휘도 균일도를 갖지만, 광학 부품들의 휘도 값과 백라이트의 효율은 18 등식의 백라이트에 비하여 낮다. 외부전극 형광램프 12 등식과 18 등식의 백라이트에 대하여 램프의 휘도를 100 %로 규격화하면, 확산판, 확산시트, 프리즘시트 (BEF) 및 편광시트 (DBEF)의 상대 휘도는 램프의 휘도 값과 무관하게 정량화된다. 광학 부품의 상대 휘도 값은 12등식은 18등식보다 낮다. 백라이트의 휘도 100 %에 대한 액정 패널의 투과도는 DBEF와 BEF를 사용한백라이트는 7.14 %, DBEF만을 사용하면 6.12 %, 그리고 BEF만을 사용하면 3.21 %이다. 본 실험에서 얻어진 광학 부품들의 상대 휘도의 정량화 데이터와 액정의 투과도는 백라이트 설계를 위한 기초 자료이다.

• 조명전기설비학회논문지
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• 제25권2호
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• pp.24-31
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• 2011

The purpose of this study is to find an efficient way using dimmable LED lamps to describe specific target illuminance and color temperature. This study used 14 dimmable LED lamps as same or different color temperature. The method of study is to measure of electric power consumption using different color temperature of dimmable LED lamps that were combination of two or three dimmable LED lamps by simultaneously dimming. Through this method, the electric power consumption was compared with all combinations of the illuminance and color temperature.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 1992년도 추계학술발표회논문집
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• pp.16-21
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• 1992

Incandescent lamps and discharge lamps are generally used as light sources and special ballasts are needed thor stable operation of discharge lamps. In this paper, the author proposes the electronic ballast thor metal hallide lamps, experiments with high frequency square wave of frequency 22.52 KHz to avoid the acoustic resonance phenomenon and proves the usefulness of the proposed ballast. Furthermore, the author uses 220 AC voltage as a input voltage source of the proposed ballast. By examining the proposed ballast, lamp voltage of 139 V(max.) and lamp current of 1.4 A(max) can be measured. Furthermore, stable operation antral great luminouse fluxes are recognized.

• 전기학회논문지P
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• 제58권4호
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• pp.546-551
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• 2009

In this paper, we studied insulation characteristics of LED lamps for load and street lighting. LED lamps can be divided into internal type and external type according to converter type. In this study, we analyzed technology standard, K(Electrical Appliances Safety Standards) and KS(Korean Industrial Standards) about insulation resistance for LED lamps for load and street lighting, and measured insulation resistances for each measured point. Mostly, insulation resistances were measured high more than regulation value but some measured points were measured badly. We expect that the results of these experiments would be helpful for electrical safety of LED lighting installation, manufacture, construction and maintenance.

• Journal of Information Display
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• 제10권3호
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• pp.97-100
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• 2009

A backlight unit for a 42-inch LCD TV was manufactured with red, green, and blue LED lamps. The luminous and light extraction efficiencies of the LED lamps were increased by improving their light reflection structures and thermal properties. The blue, green, and red LED lamps showed different luminous efficiencies as a function of the input current. Compared to the conventional red LED lamp, however, the developed red LED lamp showed very high luminous efficiency in a low drive current. Taking these luminous efficiencies into account, the fabricated backlight unit showed high energy efficiency, low power consumption, and a wide color gamut.

• Asia Pacific Journal of Business Review
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• 제2권2호
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• pp.1-15
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• 2018

The purpose of this paper is to find out the factors responsible for purchase of LED (light-emitting-diodes) bulbs & tubes among Indian consumers and how much they are ready to replace their existing lighting system with LED fittings. A multiple regression model has been employed to investigate the factors affecting the buying decision of LED lamps in place of CFL and incandescent lamps. Eleven motives for adopting LED lamps has been identified viz. price, quality, energy saving, durability, brand, promotion, CSR, & environmental consciousness. In addition the effect of demographic variables like gender, age, household income on the purchasing decision of LED has also been examined. A total 150 respondents were contacted visiting different outlet of electrical shops of Northern Delhi. The study may helpful for the companies to decide their marketing strategies to promote LED Lamps among the consumers with an aim to save energy and save environment.

• 조명전기설비학회논문지
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• 제27권7호
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• pp.1-7
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• 2013

LED lamps are appropriate to the light source for use in broadcasting lighting. When the lighting frequency of LED lamp is different from the shutter frequency of camera, however, the flicker appears on the moving image which is taken by the camera under the dimmed light of LED lamp with conventional dimming methods. In this study, a new dimming method for the LED lamps used as the broadcasting lighting is proposed to minimize the flicker. A lighting period in the proposed dimming method is divided into the several sub-periods which have weight of the bits. Also, the proposed dimming method has characteristics that are optimizing the turn-on timings of two LED lamps to reduce the turn-off periods of the lamps and not to overlap the turn-on periods of the lamps. In the experiments, the incidence of the flicker is taken by the camera under several lighting conditions of the conventional dimming methods and the proposed dimming method. In addition, the brightness values of the frames are obtained in the moving image, and incidence of the flicker is evaluated and compared with conventional methods. From the results, the incidence of the flicker in the proposed method is more improved than the conventional methods.

• 한국안전학회지
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• 제7권3호
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• pp.30-34
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• 1992

This study is conducted to evaluate the airborne concentration of mercury, as well as installation and efficiency of local exhaust ventilation system for 57 factories manufactured fluorescence lamps, mercury lamps and thermometers for July and August 1990. Results and conclusion are as fellows : 1) Mercury treatment factories are 32 among 57 ones, which are 18 fluorescence lamp manufacturing ones and 6 mercury lamp ones and 3 thermometer ones and 5 other ones. 2) Mean airborne concentrations of mercury for factories manufactured mercury lamps are 0.01 mg/ ㎥ in injection process and 0.0155mg/㎥ in exhaust process, and mean airborne concentration of mercury for factories manufactured thermometer are 0.023mg/㎥ in injection process and 0.012mg/㎥ in selection process. All of these airborne concentrations of mercury are lower than PEL(Permissible Exposure Limit ), 0.05mg/㎥. 3) Mean airborne concentrations of mercury for factories manufactured fluorescence lamps are 0.094mg/㎥ in injection process and 0.087mg/㎥ in exhaust process, and 0.052mg/㎥ in sealing process and 0.085mg/㎥ in other process, respectively. All of these air borne concentrations of mercury are exceeded to PEL. More than 60% among 32 factories manufactured mercury are exceeded to PEL. 4) Nine factories among 18 factories manufactured fluorestence lamps are equipped with local exhaust ventilation system, and 7 factories among 9 factories are required for the improvement of suction capacity and structure. Five factories among 14 factories manufactured mercury lamps and the other ones are equipped with local exhaust ventilation system, and 2 factories are required for the improvement of suction capacity and structure.

• 전기학회논문지
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• 제66권6호
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• pp.935-941
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• 2017

This paper proposes a method for estimating the distance betweeen vehicles in a moving situation using the image ratio of the distance between the tail lamps of a front vehicle. The actual distance between the tail lamps of a front vehicle was transmitted by LED tail lamps using visible light communication. As the distance between the front vehicle and the rear vehicle changes, it calculates the ratio of the pixel width between the tail lamps of the front vehicle projected on the image. The calculated values are used to derive a distance-mapping function through non-linear regression technique. Then, the distance between vehicles in the moving situation is estimated based on this function.

• 한국전자통신학회논문지
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• 제10권5호
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• pp.615-622
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• 2015

반도체 제조기술의 발달로 고효율 및 고휘도의 LED가 개발됨에 따라 재래식 조명들로부터 LED를 이용한 조명으로 조명산업이 이동하는 추세이다. LED 조명등은 에너지 효율이 재래식 조명보다 뛰어나지만 많은 열이 발생한다는 단점이 있다. 특히 대형 LED 조명등에서는 이러한 발열문제가 심각한 실정으로, LED에 의한 메탈기판의 열은 납땜 부분을 열화시켜 조명등의 수명을 단축시키는 주된 원인이 된다. 따라서 대형 조명등을 개발하기 위해서는 이러한 열 문제를 해결하는 것이 매우 중요하다. 본 연구에서는 대형 LED 조명등에서 열문제를 해결하기 위한 방법을 제시하였고, 제시한 방식으로 1200W급 LED 조명등을 개발하였다. 본 연구에서 이용한 방법은 LED 조명등에 워터재킷을 설치하여 냉각수를 채웠으며, 소형의 수중펌프를 이용하여 냉각수를 순환시키는 방법을 이용하였다.