• Journal of The Korean Society of Grassland and Forage Science
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• v.9 no.3
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• pp.148-152
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• 1989

This field experiment was carried out to determine the effects of fertilizer application time in early spring on growth, dry matter (DM) yield, crude protein (CP) content, crude protein yield (CPY), N recovery, acid detergent fibej (ADF) content and DM digestibility (DMD) of grasses for hay. Application times of fertilizer were March 10, 20, 30, April 9. 19, and control (non-fertilized) plot was involved. The fust harvesting data for hay was May 9 (early heading stage) and the regrowth yields were investigated for soiling, 1989. In all fertilized plots, the growth, DM yield, CP, CPY and N recovery of grasses were significantly increased compared with control, and the best grass growth, DM yield, CP, CPY, N recovery and DMD were observed on March 20 and 30 among all fertilized plots. On March 20 and 30 in this experiment, the accumulated temperature was 200 and 280^{\circ}C.$, and the subsoil temperature at 10 cm depth was 8 and 10^{\circ}C.$. Considering the average meteorological condition in Suwon area, the optimum application time of early spring for hay may be recommended from April 10 to 15. i\ulcornerfW3U% (L. westock Experiment Station, RDA. Suwon 440 - 350. Korea)

• Korean Journal of Organic Agriculture
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• v.26 no.4
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• pp.719-729
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• 2018

Green manure crops can be efficient replacements of high nutrient materials such as livestock compost, organic fertilizers, etc. in organic farming. Grass-legume mixtures or mixed cropping of legumes with non-legumes can aid in abating the shortcomings of each plant type under monoculture (i.e. legumes have low biomass yields while grasses are poor at fixing nitrogen). This study was conducted to investigate the effects of barley (B) and hairy vetch (H) mixtures on green manure yield in nutrient accumulated organic upland soils of Korea. In one cropping season, single crops of barley and hairy vetch (Barley: 160 kg/ha, Hairy vetch: 90 kg/ha) as well as mixtures of both crops at different seeding rates (B66:H33, B33: H66) were grown and the obtained results are as shown below. The biomass yield and nutrient productivities were higher in barley-hairy vetch mixture. The biomass yield and total phosphorus content were higher for the mixed crops by 78~132% and 200% respectively than those of the hairy vetch monoculture. Total nitrogen content of the mixed crops was also higher than those of the barley monoculture by 43~44%. The biomass yield (5.60 Mg/ha) and nutrient contents (87.7 kg N/ha, 23 kg $P_2O_5/ha$) were highest in the case of B66:H33 seeding rate. Accordingly, this study concludes that the barley-hairy vetch mixtures cropped at B66:H33 seeding rate is efficient in increasing green manure productivity due to complementary effects observed and the highest biomass yield and nutrient contents.

• Clean Technology
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• v.27 no.1
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• pp.85-92
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• 2021

A solar water battery is a system that generates power using solar energy. It is a combination of photoelectrochemical cells and an energy storage system. It can simultaneously convert and store solar energy without additional external voltage. Solar water batteries consist of photoelectrodes, storage electrodes and counter electrodes, and their properties and combination are important for the performance and the efficiency of the system. In this study, we tried to find the effect that changing the components of solar water batteries has on its system. The effects of the counter electrode during discharge, the kinds of photoelectrode and storage electrode materials, and electrolytes on the solar energy conversion and storage capacitance were studied. The optimized composition (TiO2 : NaFe-PB : Pt foil) exhibited 72.393 mAh g-1 of discharge capacity after 15 h of photocharging. It indicates that the efficiency of solar energy conversion and storage is largely affected by the configuration of the system. Also, the addition of organic pollutants to the chamber of the photoelectrode improved the battery's photo-current and discharge capacity by efficient photoelectron-hole pair separation with simultaneous degradation of organic pollutants. Solar water batteries are a new eco-friendly solar energy conversion and storage system that does not require additional external voltages. It is also expected to be used for water treatment that utilizes solar energy.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.62 no.1
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• pp.60-65
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• 2017

This study was conducted to dentify the optimum plantlet type of 'Solara' potatoes (Solanum tuberosum L.) for growth in an aeroponics system. Plantlets of 'Solara' were transplanted on March 16, 2015 in a greenhouse, and growth and yield characteristics were investigated at 70 and 78 days after transplanting, respectively. Stem length was shorter in plantlet of 15-day-old stem cuttings and acclimatization of culture, and the stem length of plantlets of stem cuttings tended to increase with increasing stem cutting age. The fresh weight of plants was the highest in the plantlets of 40-day-old stem cuttings and the lowest in non-rooted stem cuttings and acclimatization of culture. The highest number of first stolons was obtained in 35-day-old stem cuttings. The number of second stolons was the highest in plantlets of 35-day-old stem cuttings, acclimatization of culture, and 30- day-old stem cuttings. The total number of tubers was higher in plantlets of 35-day-old stem cuttings and acclimatization of culture, and the number of tubers above 3 g was the highest in plantlets of 35-day-old stem cuttings. The weight of tubers above 3 g was the heaviest in plantlets of 35-day-old stem cuttings(1,947 g per 10 plants), followed by plantlets of 30-day-old stem cuttings. These results indicate that plantlets of 30 to 35-day-old stem cuttings could be the best for production of 'Solara' potato tubers in an aeroponics system.

• Fire Science and Engineering
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• v.31 no.6
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• pp.107-111
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• 2017

The purpose of this study was to develop a Eco smoking booth that can effectively reduce hazardous pollutants generated during smoking and evaluate the efficiency and effectiveness of removing hazardous pollutants. The design and manufacture of an eco-friendly automatic smoking booth equipped with deodorizing facilities, such as inlet - HEPA filter - electrostatic precipitator (EP) - impregnated activated carbon - exhaust port, etc., and the efficiency of removing hazardous pollutants from inside and outside was measured and evaluated. The complex odor removal efficiency was 95.37% inside the smoking booth, and 97.38% at the exit of the preventive facility. The carbon monoxide removal efficiency was 94.25% in the inside and 98.32% in the outlet. In addition, the removal efficiency of particulate matter, (PM1, PM2.5, and PM10) inside the smoking booth was 98.59%, and 98.85% at the outlet. The total volatile organic compounds (TVOCs) decreased from $26,000{\mu}g/m^3$ to $5,203{\mu}g/m^3$ in the smoking booth, resulting in 79.99% removal efficiency. After the ventilator was operated, the measured effluent concentration was $5,019{\mu}g/m^3$, and the removal efficiency was 80.70%. Therefore, the smoking booth designed and manufactured through this study can be applied to the removal of harmful pollutants even in the small working environment in the future.

• Korean Journal of Agricultural and Forest Meteorology
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• v.1 no.2
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• pp.97-102
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• 1999

This study was conducted to compare seasonal changes of height, diameter at root collar, biomass and chlorophyll contents of Abies holophylla seedlings grown in Sangju National University Nursery under different light intensities. Four light intensities were adopted using nylon net such as 100% sunlight(1800 $\mu$㏖ m$^{-2}$ s$^{-1}$ ), 75% of sunlight (1350 $\mu$㏖ m$^{-2}$ s$^{-1}$ ), 50% of sunlight (900 $\mu$㏖ m$^{-2}$ s$^{-1}$ ) and 25% of sunlight (450 $\mu$㏖ m$^{-2}$ s$^{-1}$ ). Planting density in four light intensities was 30 cm$\times$30 cm. In each treatment, 100 trees were planted and height, diameter at root collar, biomass and chlorophyll contents were measured. The highest height, diameter at root collar and biomass in Abies holophylla seedlings were observed at 100% full sunlight. Lowest chlorophyll contents (Chlorophyll a, b and total) were shown at 25% of sunlight, lowest light intensity treatment in this study. Growths and chlorophyll contents of Abies holophylla seedlings were strongly associated with light intensity. Photosynthesis has to be investigated in near future because photosynthesis and chlorophyll contents were strongly related to tree growth with long periods.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.44 no.1
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• pp.95-101
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• 2018

The epidermis which is stratified by epithelial tissue renewal based on keratinocyte differentiation protects the organism from various environmental insults by forming a physical barrier. Autophagy is a mechanism which mediates lysosomal delivery and degradation of protein aggregates, damaged organelles and intracellular microorganisms. Recent reports have shown that autophagy has critical roles for proper terminal differentiation to stratum corneum via removing metabolic organelles and nuclei. However, whether increasing autophagy can activate epidermal differentiation is unknown. Here, we screened a library of natural single compounds and discovered that betaine specifically increased the LC3 positive cytosolic punctate vesicles and LC3-I to LC3-II conversion in HaCaT human keratinocyte cell line, indicating increased autophagy flux. mTOR pathway, which negatively regulates autophagy, was not affected by betaine treatment, suggesting betaine-induced autophagy through an mTOR-independent pathway. Betaine-induced autophagy was also observed in primary human keratinocyte and skin equivalent. Furthermore, epidermal thickness was increased in skin equivalent under betaine treatment. Overall, our finding suggests that betaine as a novel regulator of autophagy may induce epidermal turnover and improve the skin barrier abnormality of the aged epidermis.

• Proceedings of the Korean Information Science Society Conference
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• 2006.06b
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• pp.238-240
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• 2006

네트워크상에서 발생하는 다양한 형태의 대량의 데이터를 정확하고 효율적으로 분석하기 위해 설계되고 있는 마이닝 시스템들은 목표지향적으로 훈련데이터들을 어떻게 구축하여 다룰 것인지에 대한 문제보다는 대부분 얼마나 많은 데이터 마이닝 기법을 지원하고 이를 적용할 수 있는지 등의 기법에 초점을 두고 있다. 따라서, 점점 더 에이전트화, 분산화, 자동화 및 은닉화 되는 최근의 보안공격기법을 정확하게 탐지하기 위한 방법은 미흡한 실정이다. 본 연구에서는 유비쿼터스 환경 내에서 발생 가능한 문제 중 복잡하고 지능화된 침입패턴의 탐지를 위해 데이터 마이닝 기법과 결함허용방법을 이용하는 개선된 학습알고리즘과 후처리 방법에 의한 RTPID(Refinement Training and Post-processing for Intrusion Detection)시스템을 제안한다. 본 논문에서의 RTPID 시스템은 active learning과 post-processing을 이용하여, 네트워크 내에서 발생 가능한 침입형태들을 정확하고 효율적으로 다루어 분석하고 있다. 이는 기법에만 초점을 맞춘 기존의 데이터마이닝 분석을 개선하고 있으며, 특히 제안된 분석 프로세스를 진행하는 동안 능동학습방법의 장점을 수용하여 학습효과는 높이며 비용을 감소시킬 수 있는 자가학습방법(self learning)방법의 효과를 기대할 수 있다. 이는 관리자의 개입을 최소화하는 학습방법이면서 동시에 False Positive와 False Negative 의 오류를 매우 효율적으로 개선하는 방법으로 기대된다. 본 논문의 제안방법은 분석도구나 시스템에 의존하지 않기 때문에, 유사한 문제를 안고 있는 여러 분야의 네트웍 환경에 적용될 수 있다.더욱 높은성능을 가짐을 알 수 있다.의 각 노드의 전력이 위험할 때 에러 패킷을 발생하는 기법을 추가하였다. NS-2 시뮬레이터를 이용하여 실험을 한 결과, 제안한 기법이 AOMDV에 비해 경로 탐색 횟수가 최대 36.57% 까지 감소되었음을 알 수 있었다.의 작용보다 더 강력함을 시사하고 있다.TEX>로 최고값을 나타내었으며 그 후 감소하여 담금 10일에는 $1.61{\sim}2.34%$였다. 시험구간에는 KKR, SKR이 비교적 높은 값을 나타내었다. 무기질 함량은 발효기간이 경과할수록 증하였고 Ca는 $2.95{\sim}36.76$, Cu는 $0.01{\sim}0.14$, Fe는 $0.71{\sim}3.23$, K는 $110.89{\sim}517.33$, Mg는 $34.78{\sim}122.40$, Mn은 $0.56{\sim}5.98$, Na는 $0.19{\sim}14.36$, Zn은 $0.90{\sim}5.71ppm$을 나타내었으며, 시험구별로 보면 WNR, BNR구가 Na만 제외한 다른 무기성분 함량이 가장 높았다.O to reduce I/O cost by reusing data already present in the memory of other nodes. Finally, chunking and on-line compression mechanisms are included in both models. We demonstrate that we can obtain significantly high-performanc

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2017.05a
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• pp.165-165
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• 2017

지난 수 십 년 동안, 전 세계적으로 자원의 소비가 급격히 증가하게 되면서 최근 자원 고갈은 물론 환경오염이 커다란 이슈로 문제가 되고 있다. 이에 따라 재료 관련 분야에 있어서는 보다 효율적이고 친환경적인 방법으로 자원을 활용해야 된다는 필요성이 대두되었고 이와 같은 관점에서 목적하는 성분이 우수하고 환경 친화적인 표면처리 재료 개발연구가 활발하게 진행되고 있는 실정이다. 그 중 플라즈마 전해 산화(Plasma Electrolytic Oxidation, PEO)는 알루미늄, 마그네슘 등의 경금속의 경도를 향상시키고 높은 내마모성, 내식성을 갖게 하는 표면처리로써 그 관심이 증가하고 있다. 이 플라즈마 전해 산화는 일반적으로 공정비용 대비 효과적이고 환경 친화적이며 코팅 성능 면에서 우수하다고 알려져 있다. 이러한 고유한 특성으로 인해 플라즈마 전해 산화 코팅은 최근 몇 년 동안 기계, 자동차, 우주항공, 의학 및 전기 산업 등의 분야에서 그 적용이 점차 증가하고 있는 상황이다. 한편, 플라즈마 전해 산화 코팅을 하는 모재들의 경우 부동태 산화피막을 용이하게 형성할 수 있는 특성의 모재에 한정되고 있어서 그 응용확대에 한계가 있는 것이 사실이다. 따라서 본 연구에서는 플라즈마 전해 산화법을 사용하여 용융알루미늄도금 강판 상에 산화피막 형성을 시도하였다. 전원공급 장치의 양극은 전해질 속에 잠겨있는 작동전극에 연결하고 음극은 대전극 역할을 하는 스테인레스강 전해질 용기에 연결되었다. 전해질은 Sodium Aluminate 및 기타 첨가제를 함유한 것을 사용하였고 온도는 열교환기를 사용하여 $30^{\circ}C$ 이하로 유지되었다. 또한 여기서 전류밀도는 $5{\sim}10A/dm^2$, 실험 주파수는 700Hz, Duty cycle은 30 및 90%의 각 조건에서 공정처리 시간을 각각 30분 및 60분 동안 진행하였다. 이와 같은 조건에서 형성한 막들에 대해서는 주사형전자현미경(SEM)을 이용하여 코팅 막의 표면 및 단면의 모폴로지를 관찰하였음은 물론 EDS 및 XRD 측정을 통하여 원소조성분포 및 결정구조를 각각 분석하였다. 또한 이 코팅 막들에 대한 내식성은 5% 염수분무 환경 중 노출시험(Salt spray test), 3% NaCl 용액에서의 침지 시험 및 전기화학적 동전위 양극분극(Potentiodynamic Polarization) 시험을 진행하여 평가하였다. 이상의 실험결과에 의하면, 제작조건별 플라즈마 전해 산화 코팅 막의 모폴로지 및 결정구조가 상이하게 나타나는 것을 알 수 있었다. 코팅 막의 모폴로지 관찰 결과, 공정 시간에 비례하여 표면에 존재하는 원형 기공의 수는 감소하였으나 그 크기가 커지고 크레이터의 직경 또한 커진 것이 확인되었다. 이 기공은 마이크로 방전에 의해 형성된다고 알려져 있는데 공정 시간이 증가함에 따라 코팅 두께가 점차 증가하여 마이크로 방전의 빈도수가 줄어들고 그 강도는 증가하게 되어 기공 크기가 증가한 것으로 사료된다. 또한 공정시간이 긴 시편에서 표면에 크랙이 다수 존재하는 것으로 확인되었다. 이것은 방전에 의해 고온이 된 소재가 차가운 전해질과 만나게 되어 생긴 큰 온도구배로 인해 강한 열응력이 발생하여 균열을 초래한 것으로 보인다. 조성원소 분석 결과 원형 기공 주변의 크레이터 영역에는 알루미늄이 풍부하였으며 그 주변에 결절상을 갖는 구조에서는 전해질 성분의 원소가 포함되어 있는 것이 확인되었다. 이러한 코팅 막의 표면 특성은 내식성에 영향을 주게 된 원인으로 사료된다. 동전위 분극측정 결과에 의하면 플라즈마 전해 산화 공정 시간이 길어질수록 부식전류밀도가 증가하였다. 이것은 공정시간이 길어짐에 따라 강한 방전이 발생하여 기공의 크기가 증가하고 크랙이 발생하게 되면서 내식성이 저하된 것으로 판단된다. 종합적으로 재료특성 분석 및 내식성 평가를 분석한 결과, 플라즈마 전해 산화의 공정 시간이 너무 길게 되면 오히려 내식성은 저하되는 것이 확인되었다. 이상의 연구를 통하여 고내식 특성을 갖는 플라즈마 전해 산화 막의 유효성을 확인하였으며 용융알루미늄강판 상에 실시한 플라즈마 전해 산화 처리에 대한 기초적인 응용 지침을 제시할 수 있을 것으로 사료된다.

• Journal of Life Science
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• v.31 no.12
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• pp.1110-1119
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• 2021

The purpose of this study was to investigate whether the inflammatory response in lipopolysaccharide (LPS)-treated RAW 264.7 macrophages could be promoted by particulate matter 2.5 (PM_2.5) stimulation. To this end, the levels of inflammatory parameters, reactive oxygen species (ROS) and inflammation-regulating genes were investigated in RAW 264.7 cells treated with PM_2.5 in the presence or absence of LPS. Our results showed that the production levels of pro-inflammatory mediators (nitric oxide and prostaglandin E₂) and cytokines (interleukin-6 and -1β) were significantly increased by PM_2.5 stimulation in LPS-treated RAW 264.7 cells, which was correlated with increased expression genes involved in their production. In addition, when LPS-treated RAW 264.7 cells were exposed to PM_2.5, nuclear factor-kappaB (NF-κB) expression was further increased in the nucleus, and the expression of inhibitor of NF-κB as well as NF-κB in the cytoplasm was decreased. These results suggest that the co-treatment of PM_2.5 and LPS further increases the activation of the NF-κB signaling pathway compared to each treatment alone, thereby contributing to the promotion of transcriptional activity of inflammatory genes. Furthermore, although the generation of ROS was greatly increased by PM_2.5 in LPS-treated RAW 264.7 cells, the NF-κB inhibitor did not reduce the generation of ROS. In addition, when the generation of ROS was artificially suppressed, the production of inflammatory mediators and the activation of NF-κB were both abolished. Therefore, our results suggest that the increase in the NF-κB-mediated inflammatory response induced by PM_2.5 in LPS-treated RAW 264.7 macrophages was a ROS generation-dependent phenomenon.