• Journal of the Optical Society of Korea
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• 제19권4호
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• pp.421-426
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• 2015

This paper presents a hybrid single optical system for an LED surgical light that combines the advantages of both lens- and reflector-type single optical systems. The proposed hybrid single optical system includes a lens in the center and the LED light originating from the lens is redirected using a reflector to achieve a high beam spread. Iterative optical software simulations are used to provide data for the design of the lens and reflector for a single optical system, and for a complex optical system for the LED light assembly. The resulting data is also used to fabricate a prototype system. Experiments using the prototype of the hybrid single optical system and a mock-up LED surgical light confirm the system's shadow dilution performance and its applicability to surgical operations.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2007년도 추계학술대회 논문집
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• pp.107-109
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• 2007

LED is expected as an environmentally friendly light source with its good reliability and long lifetime. A few ten mW white LED can substitute for the indicator light source, and it is required to study several watt multi-chip semiconductor light sources in order to replace the light sources for general illumination such as incandescent lights and fluorescent lamps. Since the optical technology used for several mW white LED light source uses only 30% to 50% of the light, it is required to develop the design technology of optical system and lens to improve the efficiency more than 80% for insuring the high power of white LED. In this paper, we designed and fabricated new structure reflector to increase the efficiency.

• 한국광학회지
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• 제13권4호
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• pp.324-331
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• 2002

LED 램프의 기본 설계이론을 제시하였다. 설계된 LED 램프에 사용된 reflecting cup과 렌즈는 몇몇의 설계 변수에 의하여 다양한 형태로의 모양의 변화가 가능하다는 특징을 갖는다. Monte Carlo 기법을 이용하여 설계된 램프를 해석한 결과 다양한 응용분야에서 요구되는 빔 패턴특성을 손쉽게 구현할 수 있음을 확인할 수 있었다.

• JSTS:Journal of Semiconductor Technology and Science
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• 제16권1호
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• pp.1-10
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• 2016

Drivers for LED MR16 retrofit lamps need to be compatible with the dimmers and electronic transformers which originally operated with the halogen lamps to be replaced. We present a two-stage MR16 LED driver consisting of a boost converter in the first stage and a buck converter in the second stage. Our design has been analyzed in the frequency domain using simulations to demonstrate that it effectively suppresses the high-frequency components of the AC output of the electronic transformer. Experiment results with a driver prototype verify the simulation results as well as dimmability.

• 한국마린엔지니어링학회:학술대회논문집
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• 한국마린엔지니어링학회 2011년도 전기공동학술대회 논문집
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• pp.186-186
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• 2011

This paper presents the design guide of a LED red-light for naval vessels. Power consumption, luminous flux and optical characteristics of a conventional FL red-light were analyzed. Spectrum of the red-light is in ranges of 600~780 [nm]. Power consumption and luminous efficacy are 26.9 [W] and 1.1 [lm/W], respectively. From the experimental results, we proposed a 5 [W] LED red-light which save power consumption by 80 [%] and increase luminous flux over 500 [%].

• 산업기술연구
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• 제30권A호
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• pp.83-88
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• 2010

Recently, the LED lighting is widely used to illumination purpose due to its high luminous efficiency and the long life time. However, the light power and lifetime is reduced by junction temperature increment of LED. So it is important to measure the junction temperature accurately. In this paper, we proposed a new design and implementation method of high power LED junction temperature measurement circuit. The proposed circuit has two current sources which are a driving current source and a measurement is verified by experiment, and the result shows that the proposed circuit is appropriate to practical use.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2006년도 춘계학술대회 논문집
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• pp.154-156
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• 2006

A few ten mW white LED can substitute for the indicator light source and it is required to study several watt multi-chip semiconductor light sources in order to replace the light sources for general illumination such as incandescent lights and fluorescent lanes. Since the optical technology used for several mW white LED light source uses only 30% to 52% of the light it is required to develop the design technology of optical system and lens to improve the efficiency more than 80% for insuring the high power of white LED. In this paper, we designed and fabricated new structure reflector to increase the efficiency and is easy to make high power multi-chip LED lamp.

• 한국철도학회논문집
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• 제18권2호
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• pp.111-116
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• 2015

LED 조명은 고효율과 장시간의 수명 특성으로 각광받고 있지만 LED소자의 구동전류와 열에 의한 특성으로 예측된 수명에 미치지 못하는 경우가 많다. 특히 철도차량의 전조등의 운행환경은 주변온도 변화에 민감한 구조를 지니고 있다. LED소자에 대한 수명을 예측하기 위한 시험방법 및 예측방법이 북미조명학회에서 LM-80과 TM-21 등으로 제시되고 있지만 수명 확인을 위해 장기간이 소요되며 전류와 온도 등의 다양한 스트레스로 인하여 LED제품에 대한 수명시험 표준이 구체적으로 정립되어 있지 않다. 본 논문에서는 실제품의 수명을 예측할 수 있는 방안과 시험방법의 적합성을 확인하여 궁극적으로 LED제품에 대한 수명시험 표준으로 타당성을 검증하기 위한 선행연구로서 철도차량의 운행환경을 반영한 조건에서 수명 시험이 가능한 측정 설비의 개념 설계안을 제시하고 이에 대한 설계 타당성을 검토한다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2012년도 춘계학술대회 논문집
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• pp.983-984
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• 2012

• 복식
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• 제65권6호
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• pp.48-62
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• 2015

Practice is essential in art and design. Through practice, artists gain tacit knowledge that is hard to acquire from conventional academic studies. This paper characterizes practice-led research in the study of fashion and textile design through the investigation of practice-led research theses in the UK. According to relevant literature, which includes four exemplary case studies, the following features can be drawn: First, the methodology is different in each case and the use of practice is unconventional. Second, the research is not always aimed at making products. Third, the structure follows an iterative process. Fourth, the ratios of theory and practice are different and various theories are used. Fifth, a personal journal or diary is used for reflection as a major aid to research. Lastly, the process should be recorded by a thorough academic method. Practice-led research can have unexpected outcomes in theory and practice. It can be a good option for fashion practice research to develop a better evaluation method and reduce the gap between subjectivity and objectivity.