• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.3
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• pp.333-338
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• 2021

This study determined the characteristics of LED illumination and photosynthetically active radiation flux density (PPFD) for LED lighting design in an indoor plant factory. This was done based on the light wavelength and PPFD intensity required for plant growth. It has been found that the wavelength and intensity are decreased according to the measuring distance, and green light has an important role in illumination characteristics, while blue light has an important role in the PPFD characteristics. Considering only the photosynthetic properties of plants, the effective order of photosynthesis was blue>red>white>green. When the measurement distance was 30 [cm], it was found that reduction levels of 60 [cm], 90 [cm], and 120 [cm] decreased to about 36 [%], 18 [%], and 10 [%], respectively. As a result of the characteristics of mixed light (red:blue=2:1, 3:1, 4:1) and the measurement distance, when the measured value at 30 [cm] is 100%, the measured value at 120 [cm] is 10-11 [%]. From the obtained results, an optimal structure was proposed for maximizing the light efficiency of an indoor greenhouse for future research.

• Korean Chemical Engineering Research
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• v.53 no.6
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• pp.755-761
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• 2015

Photocatalytic VOCs removal test in gas phase is generally performed by placing the light source on the outside due to maintaining a constant temperature inside the test chamber. The distance between light source and photocatalysts is importantin the VOC degradation test since the intensity of light is rapidly decreased as the distance farther. Especially, for the choice of light source as UVLED, this issue is more critical because UVLED light source emits lots of heat and it is hard to measure the exact concentration of VOCs due to changed temperature in the test chamber. In this study, we modified VOC removal test chamber base on the protocol of air cleaner test and evaluated the efficiency of photocatalystunder UVLED irradiation. Photocatalystsof two different samples (commercial $TiO_2$ and the synthesized vanadium doped $TiO_2$) weretested for the p-xylene degradation in the closed chamber system and compared with each other in order to exclude any experimental uncertainties. During the VOC removal test, VOC concentrations were monitored and corrected at regular time intervals because the temperature in the chamber increases ${\sim}20^{\circ}C$ due tothe heat of UVLED. The results showed that theconversion ratio of p-xylene has 40~43% difference before and after the temperature correction. Based on those results, we conclude that the VOC concentration correction must be required for the VOC removal test in a closed chamber system under UVLED light source and obtained the corrected efficiencies of various photocatlysts.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.9
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• pp.4038-4045
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• 2011

To investigate whitening Effects of Angelica dahurica Radix Ethanol Extract (ADEE), we used melan-a cell line, brown guinea pig, and HMB-45. We treated with ADEE of 6.25, 12.5, 25, and 50 ${\mu}g/m{\ell}$ concentration in order to evaluate the effect of ADEE on cell viability and on morphological observation of melan-a cells. Also we were induced the artificial tanning spots by 1,500 mJ/$cm^2$ of ultraviolet B radiation on the backs of brown guinea pigs (approximately 450~500g) and then the test agent of $30{\mu}{\ell}$ was applied on the spots twice a day, five days a week, for five weeks respectively. The visible whitening effect was evaluated once a week. At the end of the experiment, the animals were sacrificed under anesthetization. The artificial tanning spots were obtained by biopsy punch and stained with HMB-45 to observe the gp100 proteins which were melanosomes. Our results show that cell viability was not reduce at ADEE concentrations between 6.25 and 50 ${\mu}g/m{\ell}$, melanin synthesis and melanocyte dendricity were decreased in ADEE treated melan-a cells increasing ADEE concentration. In the gross observation, ADEE treated groups had lower pigmentation than the vehicle control groups. And in the histological observation, ADEE treated groups had lower melanocytes than the vehicle control groups. Also in the quantitative analysis of the gp100 proteins using image analysis software, ADEE treated groups had a significantly lower value (p<0.001) than the vehicle control group and this resultsagreed with the results of observation under microscope. From these results, weconcluded that ADEE had positive whitening effect.

• Journal of the Korean Association of Geographic Information Studies
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• v.8 no.2
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• pp.44-54
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• 2005

In this study the tidal area in Seo han bay, North Korea was detected and extracted by using various satellite images (ASTER, KOMPSAT EOC, Landsat TM/ETM+) and GIS spatial analysis. Especially, the micro-landform was classified through the spectral characteristic of each satellite image and the change of tidal flat size was detected on passing year. For this, the spectral characteristics of eight tidal flat area in Korea, which are called as Seo han bay, Gwang ryang bay, Hae iu bay, Gang hwa bay, A san bay, Garorim bay, Jul po bay and Soon chun bay, were analyzed by using multi band of multi spectral satellite images such as Landsat TM/ETM+. Moreover, the micro-landform tidal flat in Seo han bay, North Korea was extracted by using ISODATA clustering based on the result of spectral characteristic. In addition, in order to detect the change of tidal flat size on passing years, the ancient topography map (1918-1920) was constructed as GIS DB. Also, the tidal flat distribution map based on the temporal satellite images were constructed to detect the tidal flat size for recent years. Through this, the efficient band to classify the micro-landform and detect its boundary was clarified and one possibility of KOMPSAT EOC application could be also introduced by extracting the spatial information of tidal flat efficiently.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.10 no.2
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• pp.113-123
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• 2005

Samples were collected to investigate the effect of salinity change on biological interaction between primary producers and herbivores in water column of the Youngsan estuary (Mokpo Harbor) at 8 stations from October 2003 to September 2004. The highest river freshwater inputs were introduced into the estuary from the Youngsan dike during summer (June and July 2004). Ranges of salinity were between 6 and 28.9 psu when the gates of dike were open whereas the ranges were between 24.4 and 30.3 psu when the gates were closed. Algal bloom occurred in February and July when the gates were not open at the upper region of the Youngsan estuary and the bloom was dominated $(70\%)$ by large cells of phytoplankton $(micro-sized;>20{\mu}m).\;Nano-sized (2-20{\mu}m)$ and pico-sized phytoplankton $(<2{\mu}m)$ were dominant in October, November 2003, June, August and September 2004 when the gates were open suggesting that size structure was affected by river discharge from the dike. Micro-and meso-zooplankton (herbivores) displayed the similar pattern to that of phytoplankton. The biomass of zooplankton was higher when the gates were closed than when the gates open and also the biomass was higher at the upper region of the harbor system. This results suggest that freshwater inputs affect size structure and biomass of phytoplankton by changing salinity, nutrient inputs, turbidity or light level In water column resulting in the change of the interaction between primary producters and herbivores in the Youngsan estuary.

• Korean Journal of Environment and Ecology
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• v.32 no.4
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• pp.392-412
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• 2018

This study was conducted from 2012, which was a year before forest road construction in Minjujisan, to 2015 to verify effects on flora and vegetation change annually before and after the construction, and to provide strategies to examine and manage flora changes. The plant communities in the investigated area around the forest road is separated by the slopes into Quercus mongolica community is on the northwestern slope and Quercus variabilis and Larix kaempferi communities is on the southwestern slope. The annual investigation of flora change before and after the construction showed that there were 209 taxa that had 71 families, 153 genera, 178 species, 27 varieties, and 4 forma in 2015 while there were 66 taxa that had 44 families, 59 genera, 51 species, 13 varieties, and 2 forma in 2012 before the construction, indicating an increase of 143 texa before and after the construction. The investigation of the slope area adjacent to the forest road constructed in 2013, in particular, showed increasing coverage and taxa each year after the construction. This was caused by significantly increased light transmittance after the construction. The investigation in 2015 showed increased coverage of herbaceous layer the year after development of the forest road and the remarkable increase of the coverage of shrub layer in 2015. Further, the coverage on the slope adjacent to the forest road increased more in 2015 than in 2013 and 2014. Therefore, we expect supplementary studies will help to generate a detail manual on flora and vegetation change before and after forest road construction.

• Journal of Bio-Environment Control
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• v.17 no.4
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• pp.283-287
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• 2008

To investigate the effects of different wavelengths of photosynthetically active radiation on the morphology and leaf color changes of a single tomato (Lycopersicon esculentum) seedling, we stored the seedling at $10{\pm}0.5^{\circ}C$ under eight different wavelengths (peak wavelengths; 405, 450, 505, 545, 600, 645, 680, and 700 nm) with a constant photosynthetic photon flux of $3{\mu}mol\;m^{-2}s^{-l}$ for 28 d. Under the 405, 450, and 505 nm wavelength conditions, the leaves of the seedlings showed vigorous shape with an upright morphology. Rachis elongation was suppressed and hence compact appearance was observed under the 450 and 505 urn conditions. Although the difference in leaf color between before storage and on 28 days after storage was observed under all wavelength conditions, the 405 and 700 um irradiations changed the leaf color to light green. Application of light-emitting diode (LED) light irradiated from around 450 to 545 nm can contribute to vigorous shape with an upright morphology of tomato seedlings during low light irradiation-low temperature storage.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2012.05a
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• pp.5-5
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• 2012

들깨는 아직 식물학적으로 분류는 되어 잇지 않으나 일반 식물분류학상 꿀풀과(진형과(唇形科); Labiatae)에 속하는 1년생 초본으로 동부 아시아지역이 원산지로 한국, 일본, 중국 동북부 등의 저위도 지역에서 광지역성 작물로 생육온도가 $10{\sim}15^{\circ}C$ 사이에서는 광합성 속도가 거의 변화가 없고 $20^{\circ}C$에서 최대에 이르며 $25^{\circ}C$ 이상의 온도에서는 급격히 떨어지는 것으로 보고되어 있다. 들깨의 생육 적온은 $20^{\circ}C$ 전후로 벼, 옥수수 등 다른 여름작물에 비해 낮으며, 온도에 대한 반응은 매우 둔감한 반면, 광량에는 아주 민감하게 반응하는 기름작물이다. 우리나라의 농서에는 이조시대인 1429년 정초(鄭招)의 농사직설(農事直說)에서 들깨를 유마(油麻), 수임자(水荏子)로 기록한 이래 여러 문헌에 임(荏), 임자(荏子), 수임(水荏), 수소마(水蘇麻), 유마(油麻), 지마(脂麻) 등으로 불리워져 왔다. 예로부터 들깨는 쓰임새도 다양하여 식용기름, 등화용 이외에도 잎에서 나는 독특한 냄새를 가축들이 싫어하여 농작물을 보호하기 위한 목적으로 밭 둘레에 심거나 기상재해로 소득 작물 재배가 어려울 때 대파작물(代播作物)로 이용되어 왔다. 세계적으로 한국인만 식용으로 즐겨 사용하는 들깨가 근래에는 경제성장으로 국민 소비형태가 다양화되는 추세로 들깨를 종실뿐 아니라 신선 잎채소로 이용하는 양이 크게 증가하고 있으며 들깨기름에 들어있는 ${\alpha}$-리놀렌산이 오메가-3 지방산으로서 고혈압 등의 성인병 예방과 학습능력향상에 효과적이라는 사실이 밝혀짐에 따라 들깨를 이용한 오메가3 계란, 오메가3 두유 등 다양하게 건강식품으로 응용되고 최근 동물성 어류에서 추출하던 오메가-3 해양 오염. 프랑크톤의 먹이사슬 등의 환경문제로 들깨기름의 식물성 오메가-3로 대체하는 영향이 세계적으로 인식되기 시작하여 우리 한국 들깨의 우수성을 세계인들에게 널리 알리는데 노력하여야 하고 국내에서 농촌에 들깨 심기을 보다 확대하여 소득작물로 육성하여야 한다고 본다. 들깨는 식물 유지류 작물중 오메가-3가 가장 많은 60%이상의 함유량으로 기능성 건강 보조식품의 원료 및 사료로 이용되는 등 새로운 소득 작물로 자리 잡아가고 있다.

• Journal of Navigation and Port Research
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• v.33 no.6
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• pp.381-385
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• 2009

Generally power system of ocean facility composes a solar generation system.The power to be generated by the solar system is changed according to the amount of sunlight of weather conditions. Output power of solar system is decreased with weather condition such as cloudy day and rainy day. And the power shortage of the ocean facility can occur due to the lack of solar energy. To solve this problem, this paper proposes the power control system for solar-wave hybrid system Wave generation system consists of wells turbine and permanent magnet synchronous generator(PMSG). This propose system set the specific area and measures the solar generation power and wave generation power. As a result of experiment, the solar power is a more static source than wave power, but the wave power provides energy during periods of no sunshine. The power characteristic of propose hybrid system have been obtained high reliability than a solar generation system.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.8
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• pp.5195-5200
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• 2014

White LEDs are expected to be applied widely as a lighting system. To make white LED chips, one requires a mixture with silicon and a phosphor coating on a LED blue chip. The process of preparing a mixture with silicon using phosphor involves the use of discarded phosphor in the chip process. Reducing the costs of chip production depends on many factors, such as the mixture errors, exposure over time of silicon, and changes in the characteristics of blue chip. This paper reports the characteristics of a white LED chip manufactured through a reproduction process of derelict phosphor. This method was applicable to a real LED flashlight. A derelict phosphor chip showed similar results to a normal white chip for the degradation of cd 3.2[Cd] and 3.6[Cd], color temperature, 57[K] and 58[K], and maximum white wavelength 444.3[nm] and 449.8[nm]. These results are expected to make ea great contribution to cost reduction.