• 한국신뢰성학회지:신뢰성응용연구
• /
• 제11권2호
• /
• pp.127-140
• /
• 2011

This paper presents an accelerated life test of aviation taxiway lights installed in the airport to help safe navigation of airplanes at night or in bad weather. Recently halogen lamps of taxiway lights are replaced by LED ones and their reliability needs yet to be verified. Thus, effective test conditions are designed reflecting the failure modes and mechanisms from the previous studies on LED, which include the accelerated degradation process. The test is performed under the temperature $70^{\circ}C$ and $90^{\circ}C$ for two types of LED lights, taxiway center line lights(TCLL) and taxiway edge lights (TEDL). The failure time data were analyzed using lognormal distribution and Arrhenius model to find the life-stress relationship, acceleration factor and life characteristics under the normal condition temperature $30^{\circ}C$.

• 한국산학기술학회논문지
• /
• 제11권4호
• /
• pp.1203-1209
• /
• 2010

신성장 동력 산업으로 분류된 LED 조명제품은 고효율 에너지 제품으로 기존 광원보다 조도가 높고 수명이 길어 많은 주목을 받고 있다. 본 연구에서는 기존의 할로겐 MR16 조명등이나 다수의 LED를 사용한 MR16 조명등을 대체할 단일 LED를 사용하는 MR16 조명등을 개발하고자 하였다. 이를 위해 LED 패키지 MCPCB 장착 기초 실험, 3차원 방열 수치해석 및 시제품에 대한 방열 성능실험을 수행하여 성공적으로 고출력 단일 LED MR16 조명등을 개발하였다.

• 한국전기전자재료학회논문지
• /
• 제25권9호
• /
• pp.743-749
• /
• 2012

In this paper, we designed and fabricated LED navigation lights which can replace the existing ones immediately and overcome disadvantages due to use of conventional lamps. To decide the best arrangement and position of a LED module, optical systems of existing navigation lights were analyzed and refracted routes of rays were simulated. The electrical and optical characteristics of the fabricated LED navigation lights were measured and analyzed with a goniophotometer. To calculate ranges of visibility, the vertical and horizontal luminous intensity distributions were evaluated in accordance with the COLREGs (convention on the international regulation for preventing collisions at Sea). From the results, the proposed LED navigation lights showed suitable characteristics for marine environment with the power consumption reduced by 90% and the maximum luminous intensity increased by 20% compared to the existing navigation lights.

• 수산해양기술연구
• /
• 제48권4호
• /
• pp.346-351
• /
• 2012

The fuel cost of fishing lights for squid jigging fishing vessels takes about 30% of total fishing costs and over 65% of total fuel costs, which indicates the necessity of development of cost-reducing and high efficient fishing light system. This study aimed to analyze the economic effectiveness of LED fishing light systems in combination with metal halide lamp for the squid jigging fishery. Analytical results showed that the level of fishing profits of vessels using LED lights could be different with those of vessels using metal halide lights. That is, when a fuel cost could be reduced by 30%, fishing profits of vessels using LED lights might be the same as those of vessels using metal halide lights, and fishing profits of vessels using LED lights could be higher than those of vessels using metal halide lights when a fuel cost could be reduced by 50%.

• Fisheries and Aquatic Sciences
• /
• 제26권8호
• /
• pp.514-523
• /
• 2023

The visible threshold of Oreochromis niloticus responded to high light intensity under short wavelengths, whereas the response to low light intensity under long wavelengths was low, with a minimum visual threshold of 574 nm of LED lights. Movement distance of O. niloticus was dropped at 31℃ and increased abnormally at 37℃ under natural light. Comparing movement distance under red (622 nm) and green (518 nm) lights of LED, movement distance and swimming speed under red and green lights were higher than under natural light. However, the movement distance decreased rapidly at 31℃ under red light and lowest at 33℃ under green light. After that, there was a tendency to adapt to high water temperatures gradually. Consequently, red and green lights may be recommended for O. niloticus's aquaculture because the red and green lights have a positive effect on growth performance, survival rate, and metabolism, as shown in previous studies. It is necessary to control the water temperature below 32℃ because abnormal behavior above 32℃ revealed under red and green LED lights and natural light.

• KIEAE Journal
• /
• 제10권6호
• /
• pp.33-39
• /
• 2010

Visual Environment and productivity are correlated. So we need to create a comfortable visual environment and maintain proper workplane illumination level. We can obtain lighting energy savings and comfortable visual environment using daylight and LED lights. In this study, we characterized the indoor illuminance level according to the sky condition and proposed dimming control strategy of LED lights. Energy savings in On/Off control mode are 40% at clear sky and 28% at intermediate sky. In dimming control mode, energy savings are 77.2% at clear sky and 64.1% at intermediate sky. Then we obtain the appropriate dimming control strategy of LED lights based on data. Dimming rates are 0-14.2-80(min-avg-max, %) for LED 1, 0-19.9-60% for LED 2 and 30-61.4-90% for LED 3. Lighting energy savings are 68.2% for LED dimming system applied this control method.

• 한국식품저장유통학회지
• /
• 제19권5호
• /
• pp.645-651
• /
• 2012

LED광의 파장을 달리하여 재배한 새송이버섯의 식품기능적 특성과 무기질 및 유리아미노산의 함량을 분석하였다. 총 가용성 고형분의 함량은 청적, 청녹, 적녹 혼합광을 제외한 모든 구에서 대조구에 비해 유의적으로 높게 나타났다. 유리아미노산 분석 결과, 31종의 아미노산이 검출되었으며 총 유리아미노산은 대조구에서 함량이 다소 높게 나타났으나 8종 필수 아미노산의 함량은 청색광을 포함한 모든 구(Blue, $B^*R$ $B^*G$, $B^*R^*G^*U$) 및 녹색광에서 재배한 구에서 대조구보다 높게 나타났다. 아미노산 중 arginine, glutamic acid, alanine, ornithine, lysine 등의 순으로 함량이 높았으며, ${\beta}$-alanine, ${\beta}$-aminoisobutyric acid, 1-methylhistidine, citrulline 등은 낮은 함량을 나타내었다. 새송이버섯의 무기질은 K이 대부분을 차지하였고, Na, Mg, Ca, Fe의 순으로 그 함량이 높았으며 Mn의 함량이 가장 낮은 것으로 나타났다. Ca은 청색광을 제외한 모든 LED 처리구에서 대조구보다 그 함량이 유의적으로 증가하였으며, Fe은 녹색광과 청적 혼합광, K은 적색광과 UV-A, Mg은 적색광, UV-A, 적녹 혼합광에서 함량 증진이 나타났다. 총 페놀 함량은 청색광, 적색광, 녹색광, 청적 및 청녹 혼합광에서, DPPH radical 소거능은 적녹 혼합광을 제외한 모든 구에서 대조구보다 유의적으로 높은 것으로 나타났다.

• 한국정보통신학회:학술대회논문집
• /
• 한국정보통신학회 2014년도 추계학술대회
• /
• pp.971-974
• /
• 2014

본 논문은 최근의 에너지 절감의 사회적 관심을 반영한다. LED 시장은 지속적 성장을이어가고 있다. 그러나 현재 led 조명은 빛 에너지 변환율이 높지 않다.이러한 LED 조명에 대하여 빛 변환 에너지 절감 방법을 제시하고자 한다. 현재의 LED 조명은 전력 변화를 각각의 조명에서 이루어지므로 인한 변환 손실의 누적이 발생한다. 손실 누적 발생을 최소화 하여 에너지 손실 성능 개선을 얻을 수 있도록 한다.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2011년도 춘계학술대회 논문집
• /
• pp.1457-1465
• /
• 2011

The saloon light is the device that can offer convenience and comfort to the driver and passenger when the train is operated at night or in the tunnel. Generally, The fluorescent type saloon for the rolling stock have been used, but the problems that are short life and the generation of heat have been brought about because the saloon lihgts of rolling stock are supposed to operated continuously long time, and high power consumption. So, the development of new type of saloon lights has been requested in order to solve these problems. And recently the various LED type lights have been developed and LED type saloon lights for rolling stock also has been developed. Therefore, we survey the characteristic, function and needed condition of the LED type saloon lights for rolling stock, and analyze the good and bad point, and then research the complement of weak point. We want to find the direction and develop the design of future LED saloon light type.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2012년도 춘계학술대회 논문집
• /
• pp.695-696
• /
• 2012