• 한국자원식물학회지
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• 제32권3호
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• pp.228-236
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• 2019

This study is conducted to investigate the effects of growth characteristics (GC) and DPPH radical scavenging activity (DRSA) of the heading lettuce 'Fidel' depending on four concentrations of activated mineral groups (AMG: 1.6% active minerals and 0.03% CaO) added to basic nutrient solutions (diluted by 0, 0.05, 0.1, and 0.2%) and on four different light-emitting diodes (LED; B:R:W ratio = 0:1:12, 0:1:9, 0:5:5, and 2:3:5). Both 0.1 and 0.2% AMG showed better GC of lettuce in plant width, plant length, leaf width, leaf length, and the number of leaves than those of other AMG, while leaf thickness and chlorophyll value did not show significant difference among all AMG. Moreover, 0.1 and 0.2% AMG showed heavier shoot fresh weights than those of other AMG. As for the combinations of AMG and LED, B0:R5:W5 showed the best lettuce GC regardless of AMG compared to other AMG and LED combinations. As shown in the above results of LED, although there was a difference in lettuce growth by LED, the differences of lettuce growth by AMG were statistically significant. The DRSA was the highest at 82.8% in B2:R3:W5, followed by B0:R5:W5 at 77.8%. LED showed differences but AMG did not affect DRSA. Therefore, the optimal conditions in plant factory for GC and DRSA of the lettuce were 0.1% AMG and B0:R5:W5.

• 한국버섯학회지
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• 제13권2호
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• pp.125-128
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• 2015

광조사 유무에 따른 수량성 조사 결과 수량은 점등처리구에서 많았으나 상품수량은 소등처리구에서 많았고, 생육특성은 점등처리구가 소등처리구 보다 갓과 대의 형태 모두 작은 경향이었다. LED광원에 따른 생육특성을 조사한 결과 자실체의 발육기간은 주황색광 및 적색광에서 길었고, 수량은 청색광 및 녹색광에서 많았다. 그리고 유효 경수는 청색광에서 많았으나 상품수량은 주황색광과 적색광에서 많았다. 이와 같은 결과 잣버섯의 경우 파장이 짧을수록 갓의 크기가 커지는 경향이었고, 파장이 길수록 대의 길이는 커지는 경향이었다.

• KIEAE Journal
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• 제14권2호
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• pp.37-46
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• 2014

University buildings are energy-guzzling facility that consume more than 10,000TOE within a campus annually. Even the consumption is on an upswing trend. Behind such high consumption are there cheap power rates for education facility, lack of high-efficiency equipment and ever-increasing use of various information equipment. Being keenly aware that greenhouse gas emission increases due to such rise of energy consumption, the present study carried out a case study. In the case study, the study chose the buildings of E university from top 10 universities that consume energy most in Seoul and examined the current status of their energy consumption and greenhouse gas emission. And then it set the reduction target of greenhouse gas by year. Putting aside a middle and long-termed strategy for later endeavor, it first established the 1st year's implementation plan (2014) for energy saving and greenhouse gas reduction with limited budget and according to greenhouse gas reduction target. The plan is specified as follows. Targets for energy saving are mainly divided into two sectors: machine equipment and electric equipment. 7 ideas were proposed. Three ideas to improve machine equipment are to replace with high-efficiency boilers and chillers and to adjust the position of the cooling tower. By doing so, it was estimated that energy could be saved by 176.34TOE in total and greenhouse gas could be reduced by 370.771t$CO_2$-eq. Four ideas to improve electric equipment include the replacement with LED lights, LED emergency lights and high-efficiency motors and the installation of motion sensors. It was calculated that such replacement could conserve 1,076.08TOE (electric energy) and reduce 2,181.420t$CO_2$-eq (greenhouse gas).

• 생태와환경
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• 제53권3호
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• pp.304-310
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• 2020

Smart farm is a high-tech type of plant factory that artificially makes environmental conditions suitable for the growth of plants and manages them to automatically produce the desired plants regardless of seasons or space. This study was conducted by identifying the effects of Hertz and Duty ratio on the photosynthetic rate of ginseng, a medicinal crop, to find the optimal conditions for photosynthetic responses in smart farms. The light sources consisted of a total of 10 chambers using LED system, with 4 R+B(red+blue) mixed lights and 6 R+B+W (red+blue+white) mixed lights. In addition, the Hertz of the R+B mixed light was treated at 20, 60, 180, 540, 1620 and 4860 hz respectively. The R+B+W mixed light was treated with 60, 180, 540, and 1620 hz. Afterwards, experiments were conducted with the duty ratio of 30, 50, and 70%. As a result, the photosynthetic rate of ginseng according to duty ratio and Hertz was the highest at 60 hz when duty ratio was set to 50%. On the other hand, that was the lowest when the duty ratio was 30% at the same 60 hz. In addition, the photosynthetic rates were highest in the R+B mixed light and R+B+W mixed light at 60 hz. Therefore, the condition with the highest photosynthetic rate of ginseng in smart farms is 60 hz when the duty ratio in R+B mixed light is 50%.

• 조명전기설비학회논문지
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• 제30권2호
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• pp.1-10
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• 2016

A system which provides multispectral near-IR and visible gray images of objects is constructed and an algorithm is derived to acquire a natural color image of objects from the gray images. A color image of 24 color patches is obtained by recovering their CIE (International Commission on Illumination) LAB color coordinates $L^*$, $a^*$, $b^*$ from their gray images using the algorithm based on polynomial regression. The system is composed of a custom-designed LED illuminator emitting multispectral near-IR illuminations, fluorescent lamps and a monochrome digital camera. Color reproducibility of the algorithm is estimated in CIELAB color difference ${\Delta}E^*_{ab}$. And as a result, if yellow and magenta color patches with around 10 ${\Delta}E^*_{ab}$ are disregarded, the average ${\Delta}E^*_{ab}$ is 2.9, and this value is within the acceptability tolerance for quality evaluation for digital color complex image.

• 한국전자파학회논문지
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• 제21권10호
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• pp.1136-1142
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• 2010

본 논문에서는 조명용 LED를 광원으로 사용한 무선 광통신 시스템에서 광전 궤환을 이용한 ASK 변조 방식을 사용하여 잡음 광의 간섭을 소거하였다. 광전 궤환 회로의 발진을 이용하여 70 kHz의 반송파를 자체적으로 생성하였으며, 입력 신호를 사용하여 궤환 회로의 단락과 개방을 반복함으로써 9.6 kbps의 데이터 속도로 출력광을 ASK 변조하였다. 주변의 잡음 광이 존재하는 환경에서 광전 궤환을 이용한 ASK 변조 방식을 사용함으로써 신호대 잡음비가 약 25 dB 개선되었다.

• 센서학회지
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• 제25권2호
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• pp.155-159
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• 2016

In this work, we have developed a test system to examine whether the charge indicator of the plug-in hybrid electric vehicle (PHEV) works properly or not. In PHEV, the driver should charge the necessary electricity by plugging in manually and be able to know the charging status through the charge indicator conveniently located for the charging individual. Our system used the CAN bus to transmit the same commands from ECU to the indicator to test the proper operation of the indicator lights. It measured the electric current values during operation and analyzed to determine the quality of the indicators. The inspection items included the proper packaging, the electrical shorts, the LED lighting during charging, the LED lighting for charging failure, and the LED lighting when errors occur. We developed the system for the operators in the factory allowing them to approve the test results at the site. We developed the hardware, the control software, and the software to store the test results and the history of the products in the database. Serial numbers were given to the good quality products and the bar code labels were printed to trace the products afterwards. Through this work, we developed a system to inspect the electric parts in real time upon fabrication. We are planning to further improve our system to inspect the brightness of the indicator by adding the vision inspection in future.

• 한국응용곤충학회지
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• 제61권4호
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• pp.615-622
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• 2022

본 연구는 콜레마니진디벌의 품질확인장치에 적용할 수 있는 LED 광원을 선발하기 위하여 수행되었다. 4개의 LED 광원(385, 405, 450, 및 660 nm)을 대조구로 5,000k 백색 LED를 사용하여 Y자관 시험에서 선택시험을 수행한 결과, 385 nm LED 광원만 콜레마니진디벌에 대한 유인효과가 있었다. 하지만 3개의 LED 광원(385, 405, 및 450 nm)과 대조구로 5,000k 백색 LED를 사용하여 비선택시험을 수행한 결과, 450 nm > 385 nm > 405 nm 광원 순으로 유인효과가 높았으나 450 nm와 385 nm 광원간 유의차는 없었다. UV-A에 속하는 385 nm LED 광원은 피부질환을 초래할 수 있는 우려가 있어 제외하였고, 최종 450 nm LED 광원을 콜레마니진디벌 품질확인장치에 적용할 광원으로 선발하였다. 450 nm LED 광원을 콜레마니진디벌 우화기구에 적용한 결과, 87.4%의 높은 유인효과를 확인 할 수 있었다. 이러한 결과는 천적 품질관리에 유용하게 활용될 수 있을 것으로 생각된다.

• 컴퓨터교육학회논문지
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• 제15권6호
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• pp.83-89
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• 2012

노령 인구가 늘어가는 나라일수록 다가오는 u-health 사회를 준비하는 것은 중요한 문제로 대두되고 있다. U-health 기술은 장소와 시간에 구애받지 않고 노인들의 건강을 관리하는 일을 도울 수 있는데, 그 이유는 유비쿼터스 기술은 그 핵심 개념을 건강 관리 문제와 결합할 수 있기 때문이다. 이 연구에서는 u-health 시대에 대비하여 인체 체액에 대한 자동화된 진단 시스템을 구성할 수 있는 설계 방법을 제안한다. 구체적으로 이 시스템은 임베디드 시스템, 빛 발생 시스템, 광 감지 시스템으로 이루어지는데, 화학적 시료 패드에 조사되는 빛으로부터 분산되는 빛을 분석하며 구체적 질병에 따라 미리 정의된 색상 값에 의하여 다양한 질병을 진단하는 기능을 한다. 제안된 시스템은 실제 하드웨어로 구현되었으며 95%의 신뢰성으로 정확하게 측정할 수 있는 성능을 보인다.

• 한국기계가공학회지
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• 제12권4호
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• pp.61-68
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• 2013

As an advance study for the development of a heat sink for special purpose high power illumination, an investigation was made to find feasibility for the application of copper plated EP to a heat sink of small LED light of less than 10W installed in commercial product. In this study, the plated heat sink with EP copper was fabricated for the conventional LED light. It was used actually for finding heat radiation property and effectiveness of the heat sink accompanied with measurement of luminous intensity. The heat is radiated by transfer and dissipation only through the copper plated surface due to extremely low heat conductivity of EP in case of EP heat sink; however the total area of the plate plays the function of heat transfer as well as heat radiation in case of the aluminum heat sink. It seems that the volume difference of heat radiating material is so big that the temperature $P_1$ is 9.0~12.3% higher in 3W and 42.7~54.0% higher in case of 6W volume difference of heat radiating material is so big that the temperature $P_1$ is 9.0~12.3% higher in 3W and 42.7~54.0% higher in case of 6W even though heat transfer rate of copper is approximately 1.9 times higher than that of aluminum. It was thought that this is useful to utilize for heat sink for low power LED light with the low heating rate. Also, the illumination could be greatly influenced by the surrounding temperature of the place where it is installed. Therefore, it seems that the illumination installation environment must be taken into consideration when selecting illumination. Further study was expected on order to aims at development of an exterior surface itself made into heat radiation plate by application of this technology in future.