• Journal of Conservation Science
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• v.31 no.4
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• pp.443-455
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• 2015

To verifying the stability of Natural pigments for Dancheong which is available on the market was carried out as light resistance and gas corrosion test. In this particular case, we will confirm the characteristics of the only pigments except of Dancheong technique and influence of substance. Medium using for coloring are animal glue and synthetic resin that widely used for Dancheong in currently. Selected to artificial light source is a xenon arc lamp, contaminated gas is nitrogen dioxide gas in experiment. Degree of degradation of pigment were compared by measuring the degree of color change. The result of light resistance test, mineral pigments were good; color is green and blue type, soil pigments also good; color is yellow ocher, white clay, red clay etc. Gamboge, unghwang, cinnabar, red lead were confirmed not good. The result of gas corrosion test, most of the natural pigments were good condition except the red lead. Generally, animal glue samples had better than a synthetic resin samples.

• Korean Journal of Environmental Agriculture
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• v.34 no.1
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• pp.38-45
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• 2015

BACKGROUND: For commercial production of greenhouse crops under shorter day length condition, supplementary radiation has been usually achieved by the artificial light source with higher electric consumption such as high-pressure sodium, metal halide, or incandescent lamps. Light-Emitting Diodes (LEDs) with several characteristics, however, have been considered as a novel light source for plant production. Effects of supplementary lighting provided by the artificial light sources on growth of Kale seedlings during shorter day length were discussed in this experiment. METHODS AND RESULTS: Kale seedlings were grown under greenhouse under the three wave lamps (3 W), sodium lamps (Na), and red LEDs (peak at 630 nm) during six months, and leaf growth was observed at intervals of about 30 days after light exposure for 6 hours per day at sunrise and sunset. Photosynthetic photon flux (PPF) of supplementary red LEDs on the plant canopy was maintained at 0.1 (RL), 0.6 (RM), and $1.2(RH){\mu}mol/m^2/s$ PPF. PPF in 3 W and Na treatments was measured at $12{\mu}mol/m^2/s$. Natural light (NL) was considered as a control. Leaf fresh weight of the seedlings was more than 100% increased under the 3 W, Na and RH treatment compared to natural light considering as a conventional condition. Sugar synthesis in Kale leaves was significantly promoted by the RM or RH treatment. Leaf yield per $3.3m^2$ exposed by red LEDs of $1.2{\mu}mol/m^2/s$ PPF was 9% and 16% greater than in 3W or Na with a higher PPF, respectively. CONCLUSION: Growth of the leafy Kale seedlings were significantly affected by the supplementary radiation provided by three wave lamp, sodium lamp, and red LEDs with different light intensities during the shorter day length under greenhouse conditions. From this study, it was suggested that the leaf growth and secondary metabolism of Kale seedlings can be controlled by supplementary radiation using red LEDs of $1.2{\mu}mol/m^2/s$ PPF as well as three wave or sodium lamps in the experiment.

• The Journal of Korea Robotics Society
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• v.7 no.2
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• pp.142-149
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• 2012

The camera has limitations of poor visibility in underwater environment due to the limited light source and medium noise of the environment. However, its usefulness in close range has been proved in many studies, especially for navigation. Thus, in this paper, vision-based object detection and tracking techniques using artificial objects for underwater robots have been studied. We employed template matching and mean shift algorithms for the object detection and tracking methods. Also, we propose the weighted correlation coefficient of adaptive threshold -based and color-region-aided approaches to enhance the object detection performance in various illumination conditions. The color information is incorporated into the template matched area and the features of the template are used to robustly calculate correlation coefficients. And the objects are recognized using multi-template matching approach. Finally, the water basin experiments have been conducted to demonstrate the performance of the proposed techniques using an underwater robot platform yShark made by KORDI.

• Journal of the Korean Institute of Educational Facilities
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• v.4 no.3
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• pp.31-39
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• 1997

The purpose of this study was to improve the lighting environment of the VDT workspaces in computer laboratory. This study was carried out through the field measurements on the computer laboratory and a survey using the questionnaire about the VDT workspaces. The major findings of the study were as follows: (1) It was unbalanced among the illumination, luminance, and color distributions in the the VDT workspaces. (2) The difference of brightness between the CRT screen and its surroundings have presented on the whole unbalanced. (3) It was proved that the artificial light source of the ceiling lighting should use the parabolic louver luminaire limiting the radiant luminance.

• Proceedings of the KIPE Conference
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• 2006.06a
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• pp.178-180
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• 2006

광은 식물의 광합성 작용뿐만 아니라 조직이나 기관의 분화, 종자의 발달 등 식물의 형태형성에도 관여하는 중요한 요인 중 하나이다. 불량한 광환경조건 하에서는 작물의 생육부진 뿐만 아니라 다양한 생리장해 및 병발생 등을 유발하기 때문에 경제적으로 광효율을 증가시키기 위하여 적절한 시설구조를 채택해야 한다. 또한 작물의 생육과 품질을 향상시키기 위하여 보광 및 차광 등 광환경 관리기술 개발이 요구된다. 본 연구에서 도입한 적외선램프는 새로운 인공광원으로서 태양광과 80% 정도 유사하고 용도에 따라 근적외선, 중적외선 및 원적외선이 방사되도록 할 수 있으며, 적은 전력소모량과 발생되는 열원은 겨울철 온풍난방기를 보조하거나 대체할 수 있어 에너지 절감효과를 동시에 기대할 수 있다. 따라서 본 연구는 인공광원에 대한 기초연구로서 인공광원의 종류별 분광특성을 비교 분석하고, 일몰 후 적외선램프의 조사 시간이 배추와 상추 유묘의 생장에 미치는 영향을 구명하고자 실시하였다.

• Proceedings of the KIPE Conference
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• 2006.06a
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• pp.194-196
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• 2006

본 논문은 신재생에너지 분야 중 태양광/풍력발전시스템의 모니터링에 관한 것으로서, 500W 태양광 발전시스템 1기와 풍력발전시스템 2기를 각각 설치하고, LabVIEW를 이용하여 원격 모니터링 시스템을 구축한 후, 이를 이용하여 동시 다채널 모니터링 하는 것에 관한 것이다. 모니터링을 위하여 각 시스템 별로 센서를 부착하고, 출력되는 아날로그 데이터를 실시간으로 네트워크를 통하여 모니터링 함으로써 각 발전원별 출력특성을 분석하고자 하였다.

• The Bulletin of The Korean Astronomical Society
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• v.45 no.1
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• pp.67.1-67.1
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• 2020

Adaptive Optics (AO) is the technology for ground-based telescopes to overcome the interference caused by atmospheric turbulence. We are developing an AO system for the 1-m telescope at Seoul National University Observatory (SNUO). The seeing size of the SNUO is 2 arcseconds on average, and 0.85 arcseconds at best condition. Our system is based on MEMS deformable mirror and Shack-Hartmann wavefront sensor. We developed the wavefront sensor using a cheap CMOS camera, and measured phase disturbance at SNUO. To verify the performance of the AO system, we designed an artificial phase disturber that produces similar scale phase error, measured at SNUO. We carried out laboratory tests in which the AO system measures and corrects the wavefront using the phase disturber and an F/6 light source, the same as that of SNUO telescope. The control system was developed in C++. The system performs closed-loop PI correction up to 100 Hz at a consumer-grade PC.

• Korean Journal of Environment and Ecology
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• v.34 no.1
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• pp.63-71
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• 2020

This study characterized the spatial and seasonal patterns of light pollution in the Deogyusan National Park and examined the potential effects of light pollution on ecosystems in the park using light intensities derived from VIIRS (Visible Infrared Imaging Radiometer Suite) DNB (Day and Night Band) nightlight images collected in January and August 2018. Results showed that the Muju Deogyusan resort had the greatest light intensity than other sources of light pollution in the park, and light intensity of the resort was much higher in January than in August, suggesting that artificial lights in ski slopes and facilities were the major source of light pollution in the park. An analysis of an urban-natural light pollution gradient along a neighboring urban area through the inside of the park indicated that light radiated from a light pollution source permeated for up to 1km into the adjacent area and contaminated the edge area of the park. Of the legally protected species whose distributions were reported in literature, four mammals (Martes flavigula, Mustela nivalis, Prionailurus bengalensis, Pteromys volans aluco), two birds (Falco subbuteo, Falco tinnunculus), and nine amphibians and reptiles (Onychodactylus koreanus, Hynobius leechii, Karsenia koreana, Rana dybowskii, Rana huanrenensis, Elaphe dione, Rhabdophis tigrinus, Gloydius ussuriensis, Gloydius saxatilis) inhabited light-polluted areas. Of those species inhabiting light-polluted areas, nocturnal species, such as Prionailurus bengalensis and Pteromys volans aluco, in particular, were vulnerable to light pollution. These results implied that protecting ecosystems from light pollution in national parks requires managing nighttime light in the parks and surrounding areas and making a plan to manage nighttime light pollution by taking into account ecological characteristics of wild animals in the parks.

• Korean Journal of Environment and Ecology
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• v.30 no.5
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• pp.821-828
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• 2016

We examed physiological and flowering response of S. capitata, the endangered plant in Korea, under LED light conditions in plant factory to cultivate artificially for conservation. We cultivated S. capitata and measured its physiological responses and the number of flowers under red, blue, white, red+far-red mixed, red+blue mixed, and red+blue+white mixed light. The results showed that its photosynthetic rate and chlorophyll content were recorded relatively high in red+blue+white and red+blue mixed light respectively. Transpiration rate and stomatal conductance appeared relatively high in the white single light while water use efficiency was no difference. Photochemical efficiency of photochemical photosystem II by minimum and maximum chlorophyll fluorescence was the highest in the red+blue+white mixed light condition than other ones. The number of flowers of S. capitata was at its peak under the red light or red+far-red mixed light. Therefore, we conclude that the most efficient way to grow for flowering of S. capitata is to provide red light or red+far-red mixed light in the plant factory.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.20 no.1
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• pp.27-33
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• 2006

Evaluating comfort of illumination environment of building interior is recognizing the degree of glare causing discomfort. Currently, to use the experimental formula for discomfort glare studied abroad it would be not appropriate because each races feel about the degree of glare differently. Therefore, this study aim to make up prediction formula for evaluating discomfort glare reasonably from Koreans' vision and it proceeded with 4 stages as follows: First, after reviewing the existing discomfort glare evaluation formula, I selected experimental variables. Second, I made a mock-up that I can control experimental variables and conditions according to the purpose of this study. Third, 1 conducted discomfort glare evaluation experiment. Finally, compared with UGR evaluation method suggested for Westerner in prior studies. In conclusion, 1) it's proved that discomfort glare is influenced highly by a light source luminance, background luminance and location of testee and the line of vision. 2) In interior discomfort glare experiment whether the glare light source is placed within range of vision or not has more significant influence than the distance between the light source and testee. 3) I compared and analyzed with UGR, the most representative discomfort glare evaluation system and I found there is a little difference in the results. This shows discomfort glare of Koreans and Westerners are different.