• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.05a
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• pp.563-565
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• 2010

LED is low power and pro-environment semiconductor element. That can be used not only as the lighting function but also for Visible Light Communication(VLC). The VLC is the communication technology that can send data by blinking a fluorescent or LED using visible spectrum. That velocity of blinking can not be usually recognized by eyesight. Visible Light Communication using LED can be used in many fields. In the field of ITS(Intelligent Transportation System), Under construction on the road, Emitting traffic signs can be applied to transfer the vehicle information. In this paper, Emitting traffic signs in addition to the VLC give information about road condition, safety distance and the lane change. We design Communication protocol to provide safety service and verify protocol by experiment.

• The Korean Journal of Mycology
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• v.39 no.3
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• pp.175-179
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• 2011

Light wavelength is the major factor of fruit body development associated with mushroom cultivation, but its wavelength range in Pleurotus eryngii is poorly understood. Using four kinds of light emitting diode (LED) including blue (475 nm), green (525 nm), yellowed (590 nm) and red (660 nm), we investigated to elucidate suitable light wavelength during primordium formation and fruit body development of P. eryngii on bottle cultivation. Primordia formation did not occur in blue light and red light. The morphological properties of fruit body in fluorescent lamp and blue light irradiation were showed thicker and larger pileus than those in other LEDs. However, length of stipe in fluorescent lamp and blue light was shorter than that of other LEDs. The DPPH radical was high in blue light, green light, and yellow light except for red light, and the polyphenol was high in four kinds of LED sources. And ergosterol was the highest in the green light. Thus, the high-quality mushroom production of P. eryngii is possible to green light condition considering productivity and functional materials.

• Journal of the Korean GEO-environmental Society
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• v.13 no.10
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• pp.63-68
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• 2012

This study was performed to determine optimum conditions of batch type cultivation of Isochrysis galbana cultivated under various wavelengths of light emitting dioes (LEDs). Among LEDs used in the cultivation, white LED was found to be the most effective light source, and light intensity of 3,000Lux resulted in the most effective for the cultivation of Isochyrysis galbana. Comparison with common light source, fluorescent light, showed less effective than that with white LED. Four different air flow rates were tested to overcome shading effects due to denser cell concentration in the solution. In results, cell growth rates and maximum cell concentrations were similar regardless of air flow rates. Three times greater cell concentrations, however, were observed when air was applied.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.247-247
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• 2012

기존형광등보다 에너지소비가 적고, 수명이 길다는 장점을 가진 LED소자는 조명분야뿐만 아니라 선박 및 해양플랜트시장에까지 적용분야가 확대되고 있다. 그러나 LED소자의 수명연장 및 제품신뢰성을 위해서 방열에 관한 연구가 필수적이며 특히, 해양환경적용을 위해서는 내부식성을 요구하는 방열 재료개발에 대한 연구가 필요하다. 일반적으로 방열판소재로 사용되는 알루미늄의 경우 열전도도가 우수하며, 대기 중에서 쉽게 생기는 자연산화막보다 내부식특성을 향상시키기 위해 현재 국내 외의 표면처리 방법으로 전기화학적 방법을 이용한 Anodizing기술을 적용하고 있다. 하지만, Anodizing에 사용되는 질산과 황산액을 처리하는 과정에서 유독물질을 발생시킴으로 유해물질사용제한 등 국제적으로 환경규제가 강화되고 있어 Anodizing기술의 적용이 제한적인 단점이 있다. 본 연구에서는 친환경적 기술인 Plasma Immersion Ion Implantation (PIII)방식을 사용하여 알루미늄표면에 $Al_2O_3$을 형성하였다. 최적의 산화막증착 조건을 찾기 위해 Gas Flow양, Pulse Voltage, 공정온도, 시간 등을 변수로 실험을 진행하였다. SIMS (Secondary ion mass spectroscopy)를 통해 $Al_2O_3$ 박막두께 및 Oxygen의 정량분석을 하였으며, Anodizing처리된 알루미늄시편과 열전도특성과 내부식특성을 비교하기 위해 각각 Hot Disk 열전도율측정기와 Salt water tester chamber를 사용하였다.

• 한국HCI학회:학술대회논문집
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• 2009.02a
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• pp.1145-1149
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• 2009

In the 1960s, light art using neon or fluorescent lamp, etc and 'light and space art' appeared with kinetic art. Light art that is an extension of kinetic art tends to be digitalized art and focus on movement, while light and space art emphasizes psychological side and focuses more on phenomenal experience than movement itself. Light art generally tends to offer visual play, but light and space art offers not only visual play but also deep impression on audience's mind. In this paper, LED control method using sound and how color change influences people's mind are studied based on my works try to supplement shortcoming of light art. The main goal of my work is to make more effective and empathic interaction between audience and light in order to avoid cold and mechanical impressions that light art has. Based on its contents, this study seeks method to stimulate people's emotion, and suggests applying mentality on the color and sound interaction together to media art. In conclusion, it is believed that new model of media art is suggested through this study.

• Journal of Advanced Marine Engineering and Technology
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• v.40 no.9
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• pp.812-817
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• 2016

This paper dealt with electrical and optical requirements of naval vessel's LED luminaires. And the products have been tested to determine whether the products meet these requirements or not. This study analyzes the cost-effectiveness of the LED luminaires which have been implemented for the application to naval vessel since 2012. The LED requirements were proposed based on comparison among other standards/specifications such as Korean Industrial Standard(KS), Korean Defense Specification(KDS) and US Navy Military Specification(MIL). Application of the proposed requirements were then be verified by analyzing and testing the electrical and optical characteristics of both fluorescent Luminaires and LED luminaires, and the LED luminaires were installed to A1 naval vessels according to the proposed requirements. As results, approximately 40% of power consumption was saved by using LED luminaires compared to using fluorescent luminaires while luminous flux was increased by 10~15%. Moreover, using LED luminaires of the proposed requirements exhibited the effect of reducing approximately 4,900 fluorescent luminaires in 10 naval vessels in the time period between 2012 to 2015, which is equivalent to cost reduction of \0.56M approximately. Such cost reduction is further expected considering the LED luminaires will continue to be applied to naval vessels in the future.

• Fire Science and Engineering
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• v.16 no.2
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• pp.1-7
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• 2002

In the normally, exit sign is always lighting on status by the connected to normal electrical source. So, there are happened to rise of the economical cost such as power consumption, maintenances and repair replacement of lamp etc. This paper are study on the new exit sign circuits by using high efficiency LED that is available for remote control and reduceible to power consumption, maintenance cost by the way of compensation fluorescent and incandescent lamps. As a results on the study, exit sign lamp is capable of control and supervisory in trigger angle by the remote control switch, widely and easily. And then, the response time was very fast in 600〔$\mu$s〕and also it can be find that the rising and fall time of oscillate circuit is maximum 200〔ns〕 as high sensitively. Finally, it obtain to the result that reducible of electrical power consumption and not required for replacement of lamp by using the high efficiency LED lighting source.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.14 no.1
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• pp.23-30
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• 2014

Recently, Light Emitting Diode(LED) light is changing the light equipment, which was considered just as a power-controlled device in home-network, into a IT convergence device by combining illumination function with wireless communication. As a result, Visible Light Communication(VLC) becomes a more practical solution to ubiquitous networks due to the more spread of LED light. One of representative applications using VLC is a VLC-based indoor navigation system which can provide high-accuracy indoor localization. In this paper, we model and implement a VLC based-indoor navigation system in which a fluorescent light type of LED lamp, which is normally used in large buildings, and smart devices, which are usually used by users, are utilized as main components for indoor navigation. Subsequently, it is expected that the paper can contribute to make VLC applications be more active.

• Journal of Bio-Environment Control
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• v.23 no.4
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• pp.356-363
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• 2014

This work was conducted to investigate the field growth and yield of the sweetpotato (Ipomoea batatas) slips grown under different light emitting diodes (LEDs). Sweet potato cuttings of 3 cultivars ('Matnami', 'Shinhwangmi', and 'Yeonhwangmi') were cultivated under fluorescent lamp (FL) and several LEDs (PPF $150{\pm}5{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ at 20cm distance) in deep flow culture system for 20 days. The plants were acclimatized under sunlight for 10 days, and then cuttings (30cm length) were planted with $75{\times}25cm$ planting density on June 10th, covered with black vinyl film during growth period. Length and diameter of vine, number of root were excellent in the red plus blue (7:3) LED than the other treatments. At 30 days after planting, the survival rate in red plus blue (7:3) LED was significantly higher than that in FL and red LED, and it was not different among cultivars. Vine length, vine diameter, and number of node were not significant among LED light qualities and cultivars. After 120 days in the field cultivation, vine length, vine diameter, number of node, number of branch, and fresh weight of shoot were not significant among LED light qualities, but those except the number of branch showed significant differences among cultivars. Yield characteristics among LED light colors were not significant, but weight of storage root per plant, mean weight of storage root, and yield showed significant differences among cultivars. The yield per 10a in 'Matnami', and 'Yeonhwangmi' was significantly higher than that in 'Shinhwangmi'.

• Korean Journal of Environmental Agriculture
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• v.38 no.4
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• pp.225-236
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• 2019

BACKGROUND: Hydroponics is one of the methods for evaluating plant production using the inorganic nutrient solutions, which is applied under the artificial light conditions of plant factory system. However, the application of the conventional inorganic nutrients for hydroponics caused several environmental problems: waste from culture mediums and high nitrate concentration in plants. Organic nutrients are generally irrigated as a supplementary fertilizer for plant growth promotion under field or greenhouse conditions. Hydroponic culture using organic nutrients derived from the agricultural by-products such as dumped stems, leaves or immature fruits is rarely considered in plant factory system. Effect of organic or conventional inorganic nutrient solutions on the growth and nutrient absorption pattern of green and red leaf lettuces was investigated in this experiment under fluorescent lamps (FL) and mixture Light-Emitting Diodes (LEDs). METHODS AND RESULTS: Single solution of tomatoes (TJ) and kales (K) deriving from agricultural by-products including leaves or stems and its mixed solution (mixture ration 1:1) with conventional inorganic Yamazaki (Y) were supplied for hydroponics under the plant factory system. The Yamazaki solution was considered as a control. 'Jeockchima' and 'Cheongchima' lettuce seedlings (Lactuca sativa L.) were used as plant materials. The seedlings which developed 2~3 true leaves were grown under the light qualities of FL and mixed LED lights of blue plus red plus white of 1:2:1 mixture in energy ratio for 35 days. Light intensity of the light sources was controlled at 180 μmol/㎡/s on the culture bed. The single and mixture nutrient solutions of organic and/or inorganic components which controlled at 1.5 dS/m EC and 5.8 pH were regularly irrigated by the deep flow technique (DFT) system on the culture gutters. Number of unfolded leaves of the seedlings grown under the single or mixed nutrient solutions were significantly increased compared to the conventional Y treatment. Leaf extension of 'Jeockchima' under the mixture LED radiation condition was not affected by Y and YK or YTJ mixture treatments. SPAD value in 'Jeockchima' leaves exposed by FL under the YK mixture medium was approximately 45 % higher than under conventional Y treatment. Otherwise, the maximum SPAD value in the leaves of 'Cheongchima' seedlings was shown in YK treatment under the mixture LED lights. NO₃-N contents in Y treatment treated with inorganic nutrient at the end of the experiment were up to 75% declined rather than increased over 60 % in the K and TJ organic treatment. CONCLUSION: Growth of the seedlings was affected by the mixture treatments of the organic and inorganic solutions, although similar or lower dry weight was recorded than in the inorganic treatment Y under the plant factory system. Treatment Y containing the highest NO₃-N content among the considered nutrients influenced growth increment of the seedlings comparing to the other nutrients. However effect of the higher NO₃-N content in the seedling growth was different according to the light qualities considered in the experiment as shown in leaf expansion, pigmentation or dry weight promotion under the single or mixed nutrients.