• Proceedings of the KAIS Fall Conference
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• 2009.05a
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• pp.636-640
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• 2009

태양광발전과 같은 분산형전원이 기존의 어떤 보호협조체제하의 배전선로에 도입될 경우는 계통에 대한 역 조류에 의해 사고 시 고장 구간의 분리 및 선로재구성에 따른 차단기 및 개폐기 제어알고리즘, 그리고 순시정전 시 분산형전원의 기동정지, 개폐기의 기능, 차단용량 등에 악영향을 끼칠 우려가 다분히 있다. 또한, 사고 시 일시적으로 분리된 건전구간 내에 분산형전원이 존재하여 그 구간내의 부하와 평형을 이루며 운전되고 있는 경우가 있을 수 있는 데, 이 경우는 인체 및 전기설비에 위험을 초래하게 될 뿐만 아니라 사고의 신속한 복구에도 저해의 요인이 된다. 특히, 태양광발전이 배전선로에 연계되어 운전되는 경우, 동일 뱅크의 타 배전선로에서 사고가 발생하면 태양광발전이 연계된 건전한 배전선로의 보호협조기기(리클로져)가 오동작하는 사고가 발생하는 경우가 실 계통에서 빈번하게 발생하고 있다. 이에 의하여 건전한 선로의 부하가 정전을 경험하는 심각한 문제점이 발생한다. 따라서 본 논문에서는 이론적인 계산식인 대칭좌표법을 이용하여 모델링과 시뮬레이션을 수행하여, 상기의 보호기기의 오동작 메카니즘과 문제점을 분석하고, 이에 대한 개선 방안을 제시하였다.

• Journal of Korean Society of Water and Wastewater
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• v.29 no.3
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• pp.319-323
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• 2015

This study investigated the effects of the light conditions on the productivity of scenedesmus dimorphus in the continuous mass cultivation system. To compare the algal productivity according to the light conditions, S. dimorphus was cultivated continuously under the wide range of light intensity(200-600 PPFD) and various light wavelength(white light and red-blue mixed light). After 100 days of cultivation under the different light intensity, the productivity of S. dimorphus increased as light intensity decreased. So, the productivity was maximized as 100 mg/L/d when light intensity was 200 PPFD. In case of light wavelength, the productivity of S. dimorphus was enhanced about 20% with the white light compared to that of the red-blue mixed light. Consequently, the optimal light conditions for the continuous mass cultivation of S. dimorphus were 200 PPFD as light intensity and white light as light wavelength.

• Korean Journal of Environmental Agriculture
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• v.15 no.3
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• pp.316-324
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• 1996

The four tolerant and one susceptible plant to oxyfluorfen were selected from 26 species and investigated for the inhibition of protox activity, the PPIX accumulation, and the activity of antioxidative enzymes by oxyfluorfen treatment. When treated, the oxyfluorfen-tolerant plant species showed a less decrease in fresh weight and height than the susceptible one. The susceptible barnyardgrass showed more inhibition of protox activity due to the treatment of oxyfluorfen than the tolerant species. Especially at the concentration of $10^{-6}M$, protox activity of the susceptible barnyardgrass was inhibited completely, but tolerant species maintained $25{\sim}45%$ of the activity. Under the light and dark condition, the susceptible barnyardgrass showed more PPIX accumulation than the tolerant.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.30 no.2
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• pp.227-233
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• 2004

Chronic exposure to solar radiation, particularly ultraviolet (UV) light, causes a variety of adverse reactions on human skin, such as sunburn, photoaging and photocarcinogenesis. Free radicals and reactive oxygen species (ROS) caused by UV exposure or other environmental facts play critical roles in cellular damage. And, repeated-UV irradiation activated the expression of the matrix metalloproteinase (MMP) and induced skin irritation. Therefore, the development of effective and safe photoprotectants that can reduce and improve the skin damage has been required. The purpose of this study was to investigate the photo-protective effect of several chinese medical plants (Juniperus chinensis) on the UV -induced skin cell damages. We tested free radical and superoxide scavenging effect in vitro. Fluorometric assays of the proteolytic activities of MMP-1 (collagenase) were performed using fluorescent collagen substrates. UVA induced MMP-1 synthesis and activity were analyzed by enzyme-linked immunosorbent assay (ELISA) and gelatin-based zymography in skin fibroblasts. We also examined anti-inflammatory effects by the determination test of proinflammatory cytokine, interleukin 6 in HaCaT keratinocytes. Expression of prostaglandin E$_2$ (PGE$_2$) after UVB irradiation was measured by competitive enzyme immunoassay(EIA) using PGE$_2$ monoclonal antibody. In the human skin we tested anti-irritation effect on the SLS-induced damage skin after appling the extract containing emulsion. We found that Juniperus chinensis extract had potent radical scavenging effect by 98% at 100$\mu\textrm{g}$/mL. The extract of Juniperus chinensis showed strong inhibitory effect on MMP-1 activities by 97% at 100 $\mu\textrm{g}$/mL and suppressed the UVA induced expression of MMP-1 by 79% at 25$\mu\textrm{g}$/mL. This extract also showed strong inhibition on MMP-2 activity in UVA irradiated fibroblast by zymography. In the test of proinflammatory cytokines of human keratinocytes Juniperus chinensis extract decreased expression of interleukin 6 about 30%. The amount of PGE$_2$ by HaCaT keratinocytes was significantly increased at the doses of above 10 mJ/$\textrm{cm}^2$ of UVB (p < 0.05). At the concentrations of 3.2-25$\mu\textrm{g}$/mL of this extract, the production of PGE$_2$ by HaCaT keratinocytes (24 h after 10mJ/$\textrm{cm}^2$ UVB irradiation) was significantly inhibited in culture supernatants (p < 0.05). In SLS-induced skin irritation model in vivo, we found to reduce skin erythema and improve barrier recovery after appling Juniperus chinensis extract containing emulsion when compared to irritated non-treated and placebo-treated skin. Our results suggest that Juniperus chinensis extract can be effectively used for the prevention of UV and SLS-induced adverse skin reactions and applied as anti-aging and anti-irritation cosmetics.

• Environmental and Resource Economics Review
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• v.28 no.4
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• pp.467-495
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• 2019

Uncertainty of renewable energy such as photovoltaic(PV) power is detrimental to the flexibility of the power system. Therefore, precise prediction of PV power generation is important to make the power system stable. The purpose of this study is to forecast PV power generation using meteorological data including particulate matter(PM). In this study, PV power generation is predicted by support vector machine using RBF kernel function based on machine learning. Comparing the forecasting performances by including or excluding PM variable in predictor variables, we find that the forecasting model considering PM is better. Forecasting models considering PM variable show error reduction of 1.43%, 3.60%, and 3.88% in forecasting power generation between 6am~8pm, between 12pm~2pm, and at 1pm, respectively. Especially, the accuracy of the forecasting model including PM variable is increased in daytime when PV power generation is high.

• Electronics and Telecommunications Trends
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• v.27 no.3
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• pp.175-185
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• 2012

최근, 지난 2009년 설비제공제도 개선에도 불구하고 여전히 병목설비가 해소되지 않았다는 문제점이 제기되었고, FTTx(Fiber to the x) 기술 보급 확대로 가입자망이 고도화되고 있는 현시점에서, 광케이블의 개방에 대해 재검토가 필요하다고 생각된다. 따라서, 본고에서는 서유럽 국가 및 미국, 일본의 광가입자망 개방에 대한 동향을 살펴보고 국내 설비제공제도 정책에 주는 시사점을 살펴보고자 한다. 유럽은 SMP(Significant Market Power) 사업자에게 NGA(Next Generation Access Network) 구축에 필요한 물리적 망 요소 제공 의무를 권고하는데, 기존의 동선 개방 규제에서 벗어나 광가입자망(FTTx)의 개방(광회선 및 광케이블)까지 명시하고 있다. 미국은 광가입자망 개방을 의무화하지 않고 있는데, 이는 광가입자망 개방 시 투자유인 저해를 보완할 수 있는 제도적 장치가 반드시 필요함을 시사한다. 일본의 사례를 살펴볼 때, 국내에서도 설비제공제도뿐만 아니라 가입자선로 공동활용제도를 통해서 광회선을 개방하는 방식도 검토되어야 함을 시사하고 있다.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.35 no.4
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• pp.293-300
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• 2009

In this study, we investigated the antioxidative activity and inhibitory effects on elastase and tyrosinase of Persicaria hydropiper L. extracts. The free radical (1,1-diphenyl-2-picrylhydrazyl, DPPH) scavenging activities ($FSC_{50}$) of ethyl acetate fractions of Persicaria hydropiper L. was $5.23\;{\mu}g/mL$. Reactive oxygen species (ROS) scavenging activities ($OSC_{50}$) of some Persicaria hydropiper L. extracts on ROS generated in $Fe^{3+}$-EDTA/$H_2O_2$ system were investigated using the luminol - dependent chemiluminescence assay. The ROS scavenging activities ($OSC_{50}$) of ethyl acetate fractions of Persicaria hydropiper L. was $0.40\;{\mu}g/mL$. The protective effects of extract / fractions of Persicaria hydropiper L. on the rose-bengal sensitized photohemolysis of human erythrocytes were investigated. The Persicaria hydropiper L. extracts suppressed photohemolysis in a concentration dependent manner ($1\;{\sim}\;10\;{\mu}g/mL$). Inhibitory effects ($IC_{50}$) on tyrosinase of aglycone fraction of Persicaria hydropiper L. extracts was $8.90\;{\mu}g/mL$. Inhibitory effects ($IC_{50}$) on elastase of aglycone fraction of Persicaria hydropiper L. extracts was $2.37\;{\mu}g/mL$. These results indicate that extract / fractions of Persicaria hydropiper L. can function as antioxidants in biological systems, particularly skin exposed to UV radiation by anti-oxidative activity and protect cellular membranes against ROS. Persicaria hydropiper L. extract / fractions could be used as a new cosmeceutical for whitening and anti-wrinkle products.

• Korean Journal of Weed Science
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• v.31 no.3
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• pp.240-249
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• 2011

The potential of juglone a plant naphthoquinone as a natural herbicide on new target, 7-keto-8-amino pelargonic acid synthetase (KAPAS) in the early step of biotin biosynthesis pathway, was performed in vitro and in vivo. Juglone effectively inhibited KAPAS activities in vitro and the $IC_{50}$ was $9.5{\mu}M$. Foliar application of juglone showed very good herbicidal activity to the eight-tested weed species. Among them, Solanum nigrum was completely controlled at a concentration of $250{\mu}g\;mL^{-1}$ with main symptoms of desiccation or burndown. Digitaria sanguinalis and Aeschynomene indica were also sensitive to juglone treatment. All eight weed species were controlled by 90~100% at a concentration of $500{\mu}g\;mL^{-1}$. However, soil application of juglone to Digitaria sanguinalis did not show any herbicidal symptoms. Cellular leakage from cucumber leaf squares treated with juglone increased depending on the concentrations increased from 6.25 to $100{\mu}M$ after 24 hours incubation with or without light. However, chlorophyll loss in cucumber leaf squares was negligible. Biotin supplements significantly rescued the inhibition of germination rate of Arabidopsis thaliana seeds previously inhibited by the juglone. Our results suggest that the juglone is a possible environmental friendly herbicide candidate with a new target KAPAS inhibiting activity.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 1994.05a
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• pp.102-103
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• 1994

원예작물의 개화는 일장이나 생장조절제 처리 이외에도 광도, 관수량, 그리고 시비수준 등 재배환경에 따라 영향을 받는다. 차광처리는 광합성률을 낮추어 개화를 지연시키며, 관수처리는 건조시 양분흡수가 저해되거나, 수분부족 자체가 스트레스로 작용하여 종자생산을 촉진시키는 생식생장으로의 전환을 유도할 가능성도 있다. 쑥갓은 국내에서 엽채류로 4계절을 통해 많이 이용되나 개화생리에 대한 연구가 미비하다. (중략)

• Journal of Practical Agriculture & Fisheries Research
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• v.22 no.1
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• pp.99-112
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• 2020

A edible mushroom, Hypsizygus marmoreus is commercially cultivated. However, the researches of cultivation and physiological characteristics were not conducted in Korea. In this study, we conducted on artificial cultivation of H. marmoreus and elucidated the effect of light on the mycelial growth and fruit body development using LED light sources with different wavelength; blue (peak wave length 460nm), green(peak wave length 530nm), yellow(peak wave length 590nm), red(peak wave length 630nm), and white as positive control. Mycelial growth of H. marmoreus strains were inhibited about 30~40% in inhibition ratio under the illumination with blue, green, yellow LED light. However, red LED light was not inhibited. Elongation of stipe was effective under the long wave length such as yellow and red light. Abnormal fruit body was produced under the long wavelength and dark. However, development of pileus was effective under the short wavelength such as green and blue light. Also, as a result of cultivation with mixed light for high quality and harvest, many effective numbers and yields of fruiting bodies were obtained in the mixed treatment of blue and white light, and pileus developed well.