• Journal of the Semiconductor & Display Technology
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• v.23 no.1
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• pp.84-87
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• 2024

A water sterilization system is developed utilizing a 275 nm-wavelength LED light source equipped with a TIR lens. The system's light source is constructed by combining a 275 nm-wavelength UVC LED, known for its germicidal properties, with a TIR lens having a direction angle of 6.8 degrees. The optical simulation software 'LightTools' is employed to design and optimize the intensity of deep ultraviolet sterilizing light irradiation, its distribution, and sterilization capacity. In the inactivation experiment with E. coli, the water sterilizer system achieved a sterilization rate of 78.92 % while maintaining a water flow capacity of 50 L/min. Compared to the conventional mercury lamp light source water sterilizer system, the UVC LED water sterilizer system addresses environmental concerns related to mercury usage and offers advantages in terms of lifespan and durability.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.45 no.1
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• pp.25-30
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• 2008

In this study, the Fourier-Domain optical measurement system, which use a commercial high power white LED as a light source and a CCD linear-array as a detector is realized. The proposed system shows the axial measurement range over $125{\mu}m$ and the axial resolution below $1.24{\mu}m$. This system has the advantage of the cost effective and compact structure and also the better resolution than the existing technologies, which have a resolution above a few of ${\mu}m$ and use bulky and/or expensive broadband light sources.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.10a
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• pp.15-16
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• 2012

General lighting will be replaced into LED due to the high efficiency, low power consumption, long life than conventional light, moreover, since it is a basically semiconductor device that can convert the electric energy to visible light at a very high speed, using these characteristics can be performed communication modulation via the high-speed ON-OFF switching. Recently, visible light communication (VLC: Visible Light Communication) technology is received attention and there have been many researches. This paper is implemented media signal transmission by combining LED with VLC, a transmitter used the LED light-emitting device and receiver used an infrared sensor. In order to increase the efficiency of the communication system to improve the existing LED visible light communication driver of power conversion efficiency and thermal issues that is applied to the visible light communication in order to improve the speed of transmission media to research a new way of LED driver.

• Journal of Satellite, Information and Communications
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• v.9 no.2
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• pp.69-73
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• 2014

Recent interest in the worldwide energy to increase, and energy savings of the energy for effective operation of the IT technology there is a demand. By using a low-power LED energy efficient energy use worldwide for a variety of studies have been conducted. In Korea, 20-30% of the domestic electricity consumption corresponding to the illumination in order to conserve energy used by various sensors associated with illumination control studies are underway. That is the next generation of energy began to pay attention to the LED light source, LED and Arduino In this paper, an ultrasonic sensor to control and want to maximize the energy efficiency of the management. Paper, the user is directly operating the separate controller that controls the LED light, instead of being recognized through human body detection LED light on / off to control the experiment and study verified. In this paper, we develop an interface that also allows them to maximize the efficiency of energy management and efficiency, accompanied by expansion of commercialization can be achieved.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.10
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• pp.4725-4732
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• 2012

This paper studies MR16 that can strengthen the strength and make up for the weakness of MR16 by replacing halogen light source using multifaceted Reflector(MR16) with LED light source. To achieve this, developed MR16 for LED applying optical system that four aspheric lens is one sheet. Optical system is designed by optics software and lighting performance of the designed data is predicted lighting simulation program. Also, heatsink's heat radiation analysis program to predict the thermal performance. Finally, optical prototype system based on simulation analysis data is manufactured and the results comparing performance of the developed system and the designed data are follows: Radiation angle was around $50^{\circ}{\sim}60^{\circ}$ in results of simulation analysis and the test of the prototype system. Also, temperature measurement result indicates that the thermal equilibrium is realized after one minute and thirty seconds and heat is generated up $60^{\circ}C$ in all of simulation analysis and the test of the prototype system. Finally, simulation analysis result on light disturbance curve of MR16 is similar to that of performance of the prototype system.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.10
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• pp.4398-4404
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• 2012

This thesis was conducted a numerical analysis on the radiant heat performance according to factors of design of heat sink for cooling of the automotive LED head lamp. The heat sinks were designed with 5 different types to fit the limited internal space by formula based on an existing product (Type 1). Designed heat sinks of five types were analyzed by ANSYS CFD V12.1, and the analysis results were compared with the existing type. The results of simulation were analyzed temperature distribution and average temperature, air flow characteristic, heat flux etc. This thesis was researched on the correlation of the cooling performance according to the heat sink structure and the fin shape. Through numerical analysis, could be confirmed heat sink Type 2 as the best results.

• Journal of the Korean Applied Science and Technology
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• v.37 no.6
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• pp.1798-1805
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• 2020

This study attempted to numerically verify specific effects on skin condition improvement by measuring and comparing changes in skin conditions such as pores, wrinkles, and sebum of LED masks for beauty devices with low output among light sources. 18 healthy women (4 weeks in the control group and 4 weeks in the experimental group) were conducted once a week for 8 weeks. As a result of measuring the skin condition of pores, wrinkles, and sebum, it was confirmed that the skin condition improved significantly as the LED irradiation progressed, and the difference between the groups by measurement period of the experimental group and the control group also showed significant differences in pores, wrinkles, and sebum (p< .001, p<.05). This is meaningful in that it can be presented as clinical information and quantitative data by preparing continuous data in an academic sense by proving the effect of improving the LED mask as a beauty device. It is also suggested that in the future, follow-up studies to prove more effective skin improvement will be conducted.

• The Optical Journal
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• s.136
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• pp.36-41
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• 2011

OLED는 유기발광 물질에서 나오는 빛을 이용하는 소자로 현재는 주로 디스플레이분야에서 LCD와 경쟁하고 있다. OLED 조명은 백색을 내는 OLED 소자를 조명으로 이용하는 것으로 휘도가 높고 낮은 전압에서 구동되며 유리 기판위에 제작됨으로 얇다는 장점을 가지고 있다. 특히 OLED는 수 mm 이하의 두께로 구현이 가능하여 경량 박형의 광원이 가능하므로 실치 장소에 대한 제약이 거의 없다는 장점을 까지고 있다. 시장전망 기관들에 따르면 OLED 조명 시장은 2012년을 전후로 본격적으로 시작될 것으로 예상하고 있다.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.17 no.5
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• pp.143-150
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• 2018

With the rapid development of RF based high speed wireless communication technology, devices that can be applied to IoT networks based on RF bandwidth are rapidly spreading, nevertheless, the development speed of the RF communication is not possible to keep up with the spread of the RF band for wireless communication. In this situation, OWC technology that uses visible light source as a transmitter is attracting attention as a technology that can overcome the band exhaustion problem of RF based wireless communication technology. Although, due to the distortion of the LED illumination shape by camera exposure time and LED blinking period, the LED illumination detection rate is degraded and the RoI setting is inaccurate. In this paper, we propose an adaptive median filter applied LED illumination detection algorithm for low rate CamCom, it is possible to detect a clear RoI and LED illumination. This research will be able to play a role as a complementary material of RF based wireless communication technology efficiently.

• Horticultural Science & Technology
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• v.32 no.3
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• pp.330-339
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• 2014

Growth and anthocyanins of lettuce (Lactuca sativa L., 'Mid-season') grown under LED lamps with blue light in the range of 430-470 nm or with red light in the range of 630-670 nm were analyzed in this study. Cool-white fluorescent light was used a s the control. P hotosynthetic photon flux, p hotoperiod, air temperature, relative humidity, and $CO_2$ concentration in a closed plant production system were $201{\pm}2\;{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, 16/8 hours (day/night), $22/18^{\circ}C$, 70%, and $400{\mu}mol{\cdot}mol^{-1}$, respectively. At 21 days after light quality treatment, growth characteristics and anthocyanins content of lettuce as affected by the peak wavelength of blue or red LED were significantly different. Among peak wavelengths treated in this stusy, R1 treatment (peak wavelength 634 nm) and R6 treatment (peak wavelength 659 nm) were effective for increasing leaf width, leaf area, shoot fresh weight, and photosynthetic rate of lettuce. B5 treatment (peak wavelength 450 nm) and B4 treatment (peak wavelength 446 nm) increased the anthocyanins concentration and chlorophyll content in lettuce leaves, respectively. Anthocyanins in lettuce leaves increased linearly with decreasing hue value of leaf color and with increasing SPAD value of lettuce leaves. From these results, it was concluded that the red LED with peak wavelengths of 634 nm and 659 nm and the blue LED with peak wavelengths of 450 nm can be used as potential light spectra for increasing the yield and anthocyanins accumulation of leafy vegetable.