• 광학세계
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• 제10권3호통권55호
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• pp.36-40
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• 1998

• 전기학회논문지
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• 제61권11호
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• pp.1625-1633
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• 2012

In the lighting industry, a Lighting Emitting Diode (LED) is increasingly used because of many advantages and a eco-friendly product comparing with the conventional lighting. However, the LED lighting has to include various AC/DC converters because the direct current is used for the LED lighting. Among a lot of power converters, the flyback converter is widely used for the LED lighting and includes some electrolytic capacitors for the voltage regulation. But the electrolytic capacitor has shorter lifetime than the LED element. It makes the expected life-time of the converter having the electrolytic capacitor shorter than the LED element. This paper proposes the single-stage PFC flyback converter without electrolytic capacitors. To verify the performance of the proposed converter, simulated and experimental works were carried out.

• 한국전기전자재료학회논문지
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• 제36권3호
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• pp.255-260
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• 2023

In order to spread LED lighting, LED lighting technology directly driven by alternating current (AC) commercial power has recently been introduced. Since current does not flow at a voltage lower than the threshold voltage of the LED, a non-conductive section occurs in the current waveform, and the higher the threshold voltage of the LED, the more discontinuous current waveforms are generated. In this paper, multi-LED modules are connected in series so that the threshold voltage can be adjusted according to the number of LED modules. A small number of LED modules are driven at a low instantaneous rectified voltage, and a large number of LED modules are driven at a high instantaneous rectified voltage to lengthen the overall lighting time of AC-LED lighting, thereby minimizing the luminance deviation of AC-LED lighting. In addition, the load current flowing through the LED module is adjusted to be the same as the design current even at the maximum rectified voltage higher than the design voltage, so that the light brightness of the LED module is kept constant. Therefore, even if the rectified voltage applied to the LED module changes, the AC-LED lighting in which the light brightness is constant and the luminance deviation is minimal has been realized.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 하계학술대회 논문집 B
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• pp.1126-1128
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• 2002

In proportion to the development of various cultural contents industry, although the lighting tools with advanced control system are needed, the fields of the lighting tools are not competitive in techniques because they are limited in small businesses and have been lost their markets to foreign companies in the high value added industry. Accordingly, the technique that is better than current lighting tools is needed urgently. So, for the new lighting tools, this paper presents a new dimming method using IGBT(Insulated Gate Bipolar Transistor) devices. There are three procedures in this study. For the first, the authors verify superiority of IGBT Dimmer with simulation using EMTDC in former step for development of IGBT dimmer. Secondly, the authors made IGBT dimmer directly with the basis of simulation results. For the last, the efficiency, the Total Harmonic Distortion(THD) current, temperature characteristic, noise characteristic, voltage drop, heat losses between the IGBT dimmer and the Thyristor dimmer that is being used popularly in the industries the stages, and the theaters were tested and compared..

• 한국산학기술학회논문지
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• 제11권4호
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• pp.1233-1238
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• 2010

현재의 조명 산업은 반도체 LED를 이용한 R(빨강), G(초록), B(파랑)를 각각 제어 연출하여 대형화, 시스템화 되어가고 있다. 조명 산업의 통신 제어 표준인 DMX512(ANSI E1.11) 프로토콜은 기본적으로 조명 단말기를 구별할 수 있는 주소가 필요하다. 기존의 방식은 이 주소를 조명 단말기에 어떠한 형태(Dip Switch, EEPROM에 저장, PROM에 저장)로든 부여하여 서로를 구별하고, 통신으로 전송되어온 자신의 색상 데이터를 통신 선로에서 얻을 수 있었다. 또한, 통신 규약에 의하면 DMX512 통신 프로토콜의 전기적인 특성상 조명 단말기 32개 마다 스프리터(splitter)가 필요하게 된다. 즉, 512채널이 전부 연결된다면 최대 16개의 스프리터가 필요하게 된다. 본 논문은 DMX512 프로토콜에서 이러한 단점을 해결하기 위하여 모든 단말기를 직렬로 연결하여 조명제어용 Auto-Addressing 갖는 지능형 조명 단말기를 개발하였다. 각 단말기에 주소 부여에 대한 불편함을 해소하였고, 스프리터의 사용 또한 필요없게 하였다. 또한 이 개발품을 반도체 LED 조명 단말기에 적용하여, ON-OFF제어, 디밍제어, 순차제어, 무지개제어 등이 동작하는 것을 확인하였고, 이를 바탕으로 상용화하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 A
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• pp.795-797
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• 2005

This paper describes a measurement & verification scheme for the high efferent lighting program in Demand Side Management (DSM), which was Introduced in the beginning of the 1980's in Korea With the dramatic changes in the circumstance of power industry in Korea. It is required the reviewing for the existing process of DSM programs and the development of the new process methods/standards on the evaluation of DSM programs. To design an accurate evaluation scheme for the high efficient lighting program. In this paper, we develop an evaluation prototype for the high efficient lighting program using measurements and stipulated factors. The proposed scheme is tested by practical measurements and modified stipulated factors Results from the case studios show the proposed scheme could provide the practical performance evaluation results with promising accuracy.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2008년도 춘계학술대회 논문집
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• pp.93-96
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• 2008

Recently, as development of the luminaire industry, many people are interest of the outdoor and indoor lighting environment. Also, as increasing of people activity at night, the role of lighting is more important. In these days, the issue of LEDs lighting environment is using loud colors of LEDs which are the most of primary colors (R, G, B). It is often disliked by same people. Therefore, it is necessary to use of natural color in lighting design using LEDs. The colors of the LEDs are composed of combination of R, G, B diodes. This paper performs to investigate preference of various colors and color patterns of LEDs. The purposes of this study are to suggest standardization and natural colors instead of primary colors using LEDs.

• International Journal of Advanced Culture Technology
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• 제7권4호
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• pp.260-267
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• 2019

Harvested de-astringent persimmon 'Fuyu' were treated with various lighting sources under low (3℃) and high (22℃) temperatures. The weight loss rate of fruits was lower in those with Red LED than Fluorescence and Blue LED under both temperature conditions. Hardness and soluble solid content of fruits were higher in those with 3℃ / Blue LED or mixed LED (Blue+Red LEDs). Beta-carotene and lycopene content of fruit peel were higher in those with 3℃ than 22℃ and with Red LED or light sources with mixed red wavelength under both temperatures. When the fruits treated with light and temperature were stored for 4 days under 3℃ / dark condition, the hardness of the fruits did not significant difference among the treatments. Taken together all the results, it would be best to treat it light sources mixed red wavelength under 3℃.

• 대한기계학회논문집A
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• 제21권1호
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• pp.1-11
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• 1997

Austomated visual inspection(AVI) capability has become an important key component in the automated manufacturing system. In such a visual inspection system an intensity(or color) image of a scene is quickly affected by optical property of objects, condition and roughness of surface, lens and filters, image sensor property and lighting system. In particular, the lighting system disign is the most important factor, since it affects overall performance of the visual system. For fast and cheap automated visual inspection system it is important to obtain the good image quality which results from careful attention to the design of the lighting system. In this paper, the lighting subsystem of AVI system is analysed for the inspection of printed circuit board(PCB) patterns. The spectral reflectance of materials, which are composed of PCB, is measured for choosing the light source. The reflection property is theoretically obtained by a reflection model and also obtained by experiments which measure intensity with varying the viewing direction of image sensor and the lighting direction of illuminator. The illumination uniformity of a ring-type illuminator. The lighting system is designed based upon the experimental results and theoretial analysis.

• 조명전기설비학회논문지
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• 제23권4호
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• pp.8-15
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• 2009

본 논문은 전력시장 환경에서 수요관리 자원으로서 조광제어의 잠재량과 가치평가 방안을 제시한다. 일반적으로 수요자원의 경제성 평가를 위해 캘리포니아 테스트가 널리 사용되고 있다. 하지만 전력산업의 규제완화 및 구조개편으로 인한 새로운 시장 환경에서 캘리포니아 테스트를 적용하는데 한계가 있다. 특히 UC 테스트는 수직통합 전력회사에 적합하지만 발, 송, 배전이 분할된 전력회사에는 적합하지 않다. 따라서 본 논문에서는 전력시장 환경에서 전력판매회사 관점에서 수요관리 자원으로서 조광제어의 경제성을 평가하는 새로운 방법을 제시한다. 먼저 조광제어 자원의 잠재적 가치를 분석하고, 2006년 전력시장 데이터를 이용하여 판매회사 관점에서 조광제어의 경제성을 평가한다. 본 논문의 결과는 조광제어 자원이 전력판매회사 관점에서 비용-효과적인 수요관리 자원임을 보여 준다.