• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.4
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• pp.1203-1209
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• 2010

LED lights as a newly-growing industry are highly energy-efficient and have drawn lots of attention due to higher illuminance and longer life compared to other light sources. In this study, MR16 lights with one high-power LED were considered for the replacement of the previous halogen lights or LED lamps with many LEDs. Thus, fundamental experiments of LED on a MCPCB, 3-dimensional numerical analysis for heatsink design and performance tests of the prototype lights have been done and the MR16 LED lights have been successfully developed.

• Korean Institute of Interior Design Journal
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• v.21 no.6
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• pp.129-136
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• 2012

As the importance of eco-friendly and energy saving issues are emphasized in lighting as consciousness about energy saving is elated worldwide, demand for natural resources such as gas increases, supply of LED lighting is spread. Owing to white LED's development and price fall. It is expected to LED High Luminance Emitting Diode. LED's brightness and long life-time that surpass fluorescent light in the latest as well as is used by back light source of thin film LCD, low electric power attrition rate by advantage do and widen the market at the world lighting lamp market that is potential market. Accordingly, study about suitability of LED lighting is activated but space that apply actual LED lighting fixtures yet is less and advanced researches about LED fixtures' applied apaces are slight compared to existing light source up to now because is not many on this. The result of the experiment shows similar tendency with the existing light sources'. Through a psychological reaction experiment in the LED lighting experiencing space that can control of color temperature and lighting level, this study is wished to use to the data for lighting design of space that LED lighting fixtures are applied hereafter.

• Journal of Applied Reliability
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• v.16 no.4
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• pp.331-337
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• 2016

Purpose: The purpose of this study is the analysis of the failure mechanisms effect of circuit design characteristics of the ballast for LED Lamp Methods: Recently, electronic circuit of ballasts for LED lamp are being occurred on various failure mechanisms (whiskers, ion migration, heat dissipation problem, switching element damage) because electronic ballast circuit design characteristics are becoming more and more diverse. Results: we analysis failure mechanisms that occurs in accordance with the circuit design characteristics The ballast for LED lamp were divided into three different types (Type A, Type B, Type C) considering circuit design characteristics (thermal design, PCB patten spacing, element material) and it was experimented in the acceleration test conditions ($85^{\circ}C$, 85% R.H). Conclusion: We confirmed that failure mechanism of the ballast for LED Lamp had occurred differently in accordance with the circuit design characteristics.

• Journal of Advanced Marine Engineering and Technology
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• v.35 no.5
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• pp.654-660
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• 2011

This paper dealt with a design guide of LED luminaires to replace the surface and watertight fluorescent lamp (FL) fixtures for naval vessels. Several standards such as Korean Industrial Standard (KS), Korea Defence Standard (KDS) and US Military Standard (MIL) were compared in terms of safety and performance of lighting fixtures. The electrical and optical characteristics like power consumption, total luminous flux, and illumination distribution of the FL fixtures were experimentally analyzed to acquire design rules for LED luminaires. Based on the results, four types of LED luminaires were fabricated, and we proposed a design guide of LED luminaires for naval vessels which save power consumption of 44~51 [%] and increase total luminous flux of 8~13 [%].

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.20 no.3
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• pp.361-367
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• 2011

In this paper, it was attempted to analyze the optimal design of light emitting diode (LED), a source of back light unit (BLU). LED is beginning with commercialized red LED which is made by GaAsP compound semiconductor, and has been developed focusing on liquid crystal panel. In order to get the optimal design, optical simulation was made by analyzing luminosity shape, reflector angle, chip depth, and chip position of LED lighting. Final results show that the proposed LED characteristics were useful to increase light efficiency and it has been proven by distribution chart for actual exposed light on the light guide panel (LGP).

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.9
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• pp.3141-3147
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• 2010

The most important cause for shortening LED lighting efficiency and life is the junction temperature rises and, to solve this problem, various studies such as thermally efficient packaging, highly conductive material development, contact resistance improvement or heat sink optimization have been studied. However, most studies so far assumed that the LED lights are in the atmosphere, and thermal performance has not been therefore reported when the LED lights are mounted on the ceiling with ceiling unit. Thus, this study investigates the variation of junction temperature of the MR16 LED light under actual installation conditions and more accurate thermal design for the efficiency and life of LED lights is therefore achieved.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.21 no.6
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• pp.26-32
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• 2007

Design methods of LED optic system includes point source assumption and imaginary focus approaches. However, these methods make significant error if the position of LED approachs that of optic system. This paper suggests a new design approach that LED is equally divided, light distribution of each division is predicted and confirmed through reverse tracing of light wave, and then each divided segment is separately designed, Using new design method, two kinds of example optic system were designed and light distribution and efficiency of the systems were evaluated.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2016.11a
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• pp.197-198
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• 2016

최근 RGB LED 조명은 다양한 장점으로 이를 활용한 연구가 진행되고 있으며 단순 조명이 아닌 정보전달 및 공간연출의 디자인적 요소의 역할을 이행하기도 한다. RGB의 혼합으로 다양한 색상이 표현 가능한 LED를 사용하여 개별적으로 LED를 제어해 여러 가지 색상 및 모양이 표현 가능한 LED 도트 매트릭스를 제작하였으며, 이를 활용해 다양한 콘텐츠를 출력하고자 한다. 다양한 모양의 콘텐츠에선 개별적으로 LED를 제어하고, 그 외의 콘텐츠에선 원하는 LED를 그룹지어 제어한다. 본 논문에서 제작한 LED 도트 매트릭스는 많은 정보를 전달 할 수 있으며, 다양한 콘텐츠 제공으로 인한 상업화 및 효율성의 확대를 꾀할 수 있다.

• The Transactions of the Korean Institute of Power Electronics
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• v.24 no.3
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• pp.207-214
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• 2019

In this study, discrete-time domain analysis is proposed to investigate the input current of a buck AC/DC light-emitting diode (LED) driver. The buck power factor correction converter can operate in both discontinuous conduction mode (DCM) and continuous conduction mode (CCM). Two discontinuous and two continuous conduction operating modes are possible depending on which event terminates the conduction of the main switch in a switching cycle. All four operating modes are considered in the discrete-time domain analysis. The peak current-mode control with slope compensation is used to design a low-cost AC/DC LED driver. A slope compensation design of the buck AC/DC LED driver is described on the basis of a discrete-time domain analysis. Experimental results are presented to confirm the usefulness of the proposed analysis.

• The Research Journal of the Costume Culture
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• v.18 no.3
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• pp.488-498
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• 2010

This study was intended to develop a multi-purpose, multi-functional design for safety vest to enhance the safety and user's availability. With a limited scope to LED-applied safety vest, this study contemplates on the problems of safety vest on the market and directions for design development with a view to develop its prototype. This is a significant study because it has been conducted concerning a prototype, a cut above the study method of constructing a basic theory. For study method, theoretic considerations on LED and safety vest are followed by case study for LED-applied safety vest currently on the market to draw out problems. Then, solutions for problems with LED safety vest will be found, while planning for a design direction in consideration of safety, functionality and beauty. Scope of study was limited to cases of LED safety vests currently on sale online and offline, excluding cases of common-form luminosity such as HB luminous vest without LED. Accordingly, results of study will help develop the prototype for LED safety vest with an increase of the wearer's safety, and be used as a basic data for developing high-value-added fashion prodcts to meet his aesthetic sense and functionality. This study has limitations. Restricted scope for LED-applied safety vest should be extended to an outdoor wear in follow-up research for the foundation of higher value added.