• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2008.10a
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• pp.161-164
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• 2008

ELS(Edge Light System)을 이용한 40W조명 시스템을 개발하기 위하여, ELS에 적합한 LED를 선정하고, 색온도 제어라 광색제어를 위한 구동회로 및 제어회를 설계 제각 하였으며, 0.5W R,G,B 4 IN 1 Package 를 적용하여 LED 180EA를 사용하여 LED Lighting System을 개발하였다. ELS LED Lighting System은 40W급 LED SMPS 구동회로 및 광색/색온도 제어회로 설계, 면발광을 위한 ELS 설계, 방열 설계 및 기구 구조 설계를 통하여 개발되었으며, 직접 시제품을 제작하고 그 성능을 측정하였다.

• Journal of the Semiconductor & Display Technology
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• v.10 no.1
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• pp.17-22
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• 2011

LEDs(Light Emitting Diodes) are becoming widely used and increasingly in demand. Quality inspection of the LEDs has become more important. Two-dimensional inspection systems are limited in inspection capability, so threedimensional(3-D) inspection systems are needed. In this paper, a cost-effective and simple 3-D measurement system of LED packages using phase measuring profilometry(PMP) is proposed. The proposed system uses a pico projector to project sinusoidal fringe patterns and to shift phases instead of piezocrystal. It was evaluated using extremely accurate gauge blocks, yielding excellent repeatability of about 12 um(3-sigma). 3-D measurements of various LED packages were performed to demonstrate the applicability and efficiency of the proposed system.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2009.10a
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• pp.197-200
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• 2009

주광의 색온도와 일치하는 실내 전반 조명용 60W급 LED 조명제품 개발하기 위하여 실내 주광에 적합한 LED를 선정하고, 색온도, 광색제어를 위한 구동회로 및 제어회로를 설계 제작 하였다. 그리고 1W급 Cool White, Warm White Package LED 총 168 EA를 적용하여 주광의 색온도와 일치하는 실내전반 조명용 LED 조명 System 을 개발하였다. 주광의 색온도와 일치하는 실내 전반용 LED 조명제품은 60W급 LED SMPS 구동회로 및 광색/색온도 제어회로 설계, 면발광을 위한 방열 설계 및 기구 구조 설계를 통하여 개발되었으며, 직접 시제품을 제작하고 그 성능을 측정하였다. 그 결과 회로 효율은 85% 이상, 색온도는 $3,000{\sim}7,000K$에서 실시간으로 제어 가능 하고, 원하는 색온도을 구현 할 수 있도록 하였으며, 발산각 또한 최대 광도의 1/2 기준으로 $100^{\circ}$ 이상을 만족시켰다.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.26 no.10
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• pp.778-784
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• 2013

In order to develop a LED luminaire for naval-submarines which can replace a conventional one with two-compact fluorescent lamp (CFL) of 18 W, we analyzed the electrical and optical performance of the conventional luminaire. A LED luminaire was fabricated as compact as possible based on the analyzed data. The weight of the prototype LED luminaire is 1.8 kg, reducing up to 58% of the conventional one. The use of LED package for the submarine luminaire could reduce the power consumption from 38 W to 14.5 W with the same optical performance. The reason is that the optical efficacy of the LED luminaire improved by 2.47 times as 61.9 lm/W, compared to 25.1 lm/W for the conventional one.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1611_1612
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• 2009

접합온도의 증가는 PN 접합 부분에서 생성된 열이 외부로 원활하게 방출되는 것을 저하시키고, 칩 내부에 남은 열이 전자와 정공의 비발광 재결합을 증가시켜 LED의 신뢰성과 내구성에 큰 영향을 미친다. 본 논문에서는 PMS-50과 KEITHLEY 2430을 이용하여 FR4 PCB의 Via hole 구성에 따른 LED 패키지의 열적 광학적 특성을 분석하였다. Via hole 0.6 [mm]일 때 열 특성과 광 출력 특성이 가장 우수하였으며 Via hole 1.2 [mm]는 열 특성, 광 특성이 가장 떨어졌고, 열 특성은 곧바로 광 특성에 영향을 미치는 것을 알 수 있었다.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1613_1614
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• 2009

In this paper, thermal movement of high power LED on the MCPCB is analyzed with structural function and CFdesign V10 program. thermal resistance is decreased as 10.1 [$^{\circ}C$/W] in MCPCB from 12.2 [$^{\circ}C$/W] in LED package. Junction temperature which is calculated with thermal computational analysis program shows 85.113 [$^{\circ}C$] and almost same to measured data.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.27 no.10
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• pp.673-677
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• 2014

In this paper, thermal analysis of HDU (Heat Dissipation Unit) for infrared CCTV is performed by using SolidWorks Simulation (Thermal analysis) package, in order to change the part materials and HDU shape is optimized. Furthermore, HDU disperses the aggregated heat around the LED inside the housing. The junction temperature of infrared LED checked by HDU check was $65.83^{\circ}C$, $42.02^{\circ}C$, respectively. In addition, the Thermoelement by changing the shape of the HDU was possibly designed and equipped with. Comparison with simulation and prototype measurement results, without HDU model was $65.83^{\circ}C$, $61.99^{\circ}C$, respectively. In addition to with HDU model was $42.02^{\circ}C$, $39.01^{\circ}C$, respectively. Only HDU mounted into infrared CCTV is usable in the ordinary house or outdoors. Also HDU with thermal element, fan mounted into infrared CCTV is usable in a blast furnace workplace or high temperature workplace.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.26 no.7
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• pp.1-8
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• 2012

In this paper, we improved the light extraction efficiency by structural change of LEDs on conventional LEDs. We simulated the LEDs light emission as functions of LED side wall angle, various refractive indices the geometrical structures and analyzed the condition improved the light efficiency. We present the results of experimerns and simulations for light output power from LEDs for various refractive indices and the geometrical structures of the LED encapsulants. When the side wall angle range was from 40[$^{\circ}$] to 30[$^{\circ}$], the LED emission increased. LED side wall angle onto LED using the simulation system with a fine tuning of the structure of the LEDs side wall angle is fabricated. Additionally, we changed the side wall angle of LED package with spherical structure and flat structure. The result of spherical structure ray tracting is higher compared with flat structure about 14[%].

• Journal of Fashion Business
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• v.27 no.2
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• pp.108-123
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• 2023

Recent increase of eco-conscious trends and pleasure from Do It Yourself (DIY) activities have led to a surge in sales of package products bundling together clothing patterns and raw materials. However, a well-structured market system is yet to be established. We surveyed 460 women with sewing as a hobby who had purchased these DIY clothing pattern packages. The survey revealed that majority of respondents had their hobby for over five years. Choosing the right fabric to match clothing patterns presented a common challenge. Most participants owned a sewing machine and an overlocker, with price being the primary concern when purchasing a package. For guidance during the sewing process, participants preferred print materials featuring real-life images. Those with less sewing experience leaned towards video tutorials. Items of interest or those commonly created included blouses, shirts, and dresses. Desire for further learning in sewing and pattern-making was prominent, with a clear preference for online classes. Several strategies are recommended to enhance the appeal of DIY clothing package products, including broadening range of packages that incorporate fabric, offering supplementary educational resources to improve users' skills, implementing affordable pricing structures, supplying comprehensive creation guidelines, and making available design modification guides. These considerations could significantly boost customer satisfaction. This research intends to lay groundwork for understanding DIY clothing creation market, ultimately fostering production of highly desirable products. Insights of this study will prove instrumental in refining product development and devising effective marketing tactics, leading to a more rewarding consumer experience.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.1
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• pp.135-140
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• 2014

Pre-storage ultra-violet (UV) light treatment on fresh produce is known to inactivate the contaminated microorganisms, activate the defense system, and delay ripening extending the shelf life. As UV light emitting diode (LED) becomes available at a relatively low price, continuous or intermittent UV treatment during chilled storage is possible in a container or package. This study attempted an in situ UV LED treatment on fresh produce stored under a refrigerated container in order to see its potential in the fresh produce storage and further optimize its application conditions. The effect of in-container UV LED irradiation on the quality preservation of shredded carrots was investigated in the air and modified atmosphere (MA) conditions. Two sets of experiment with Escherichia coli inoculation and with natural microbial flora in the air (two 30 minute on-off cycles of 1 $diode/dm^2$ per day at a location above 2 cm) showed a clear and significant effect of the UV LED irradiation on the suppression of microbial growth: 280 nm was the most effective by maintaining a lower microbial count by at least 0.5 log (CFU/g) throughout the 6 day storage period. The carotenoids content of shredded carrots subjected to UV LED treatment at 365 and 405 nm in the air was higher than that of the control shredded carrots. In MA condition of $O_2$ of 1.2~4.3% and $CO_2$ of 8.4~10.6% being indifferent with LED wavelengths, 280 nm UV LED irradiation was also effective in inhibiting the microbial growth. While there was no observed difference in the carotenoids content between untreated and UV LED-treated shredded carrots in MA, UV LED irradiation at 365 and 405 nm was slightly better in DPPH radical scavenging activity. The use of UV LED in storage container or package seems to give the benefits of preserving the microbial and nutritional qualities of minimally processed fruits and vegetables.