• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2010.03a
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• pp.109-109
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• 2010

• Journal of Powder Materials
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• v.21 no.5
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• pp.377-381
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• 2014

This work describes the coloration, chemical stability of $SiO_2$ and $SnO_2$-coated blue $CoAl_2O_4$ pigment. The $CoAl_2O_4$, raw materials, were synthesized by a co-precipitation method and coated with silica ($SiO_2$) and tin oxide ($SnO_2$) using sol-gel method, respectively. To study phase and coloration of $CoAl_2O_4$, we prepared nano sized $CoAl_2O_4$ pigments which were coated $SiO_2$ and $SnO_2$ using tetraethylorthosilicate, $Na_2SiO_3$ and $Na_2SiO_3$ as a coating material. To determine the stability of the coated samples and their colloidal solutions under acidic and basic conditions, colloidal nanoparticle solutions with various pH values were prepared and monitored over time. Blue $CoAl_2O_4$ solutions were tuned yellow color under all acidic/basic conditions. On the other hand, the chemical stability of $SiO_2$ and $SnO_2$-coated $CoAl_2O_4$ solution were improved when all samples pH values, respectively. Phase stability under acidic/basic condition of the core-shell type $CoAl_2O_4$ powders were characterized by transmission electron microscope, X-ray diffraction, CIE $L^*a^*b^*$ color parameter measurements.

• Journal of the Korean Ceramic Society
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• v.46 no.1
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• pp.69-73
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• 2009

We report the preparation of nanocrystalline cobalt ferrite, $CoFe_2O_4$ particles and their surface coating with silica layers using micro emulsion method. The cobalt ferrite nanoparticles with the size 7nm are firstly prepared by thermal decomposition method. Hydrophobic nanoparticles were coated with silica using micro-emulsion method with surfactant, $NH_4OH$, and tetraethylorthosilicate (TEOS). Monodispersed and spherical silica coated cobalt ferrite nanoparticles have average particle diameter of 38 nm and narrow sized distribution.

• Journal of the Korean Applied Science and Technology
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• v.37 no.6
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• pp.1627-1634
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• 2020

In this study, water-based acrylic adhesives as copolymers with acrylic acid, 2-hydroxyethyl acrylate were synthesized using ethyl acrylate, 2-ethylhexyl acrylate, and lauryl methacrylate as the main monomers. Prepared water-based acrylic adhesive was compared to physical properties such as solid content, average particle size distribution, initial adhesive force, maximum adhesive force, peel strength, and heat resistance.

• Journal of Environmental Science International
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• v.19 no.2
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• pp.217-227
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• 2010

This paper was studied $CO_2$ respiration rate with physicochemical properties of soils at wetland, paddy field and forest in Nongju-ri, Haeryong-myeon, Suncheon city, Jeollanam-do. Soil temperature and $CO_2$ respiration rate were measured at the field, and soil pH, moisture and soil organic carbon were analyzed in laboratory. Field monitoring was conducted at 6 points (W3, W7, W13, W17, W23, W27) for wetland, 3 points (P1, P2, P3) for paddy field and 3 points (F1, F2, F3) for forest in 10 January 2009. $CO_2$ concentrations in chamber were measured 352~382 ppm for wetland, 364~382 ppm for paddy field and 379~390 ppm for forest, and the average values were 370 ppm, 370 ppm and 385 ppm, respectively. $CO_2$ respiration rates of soils were measured $-73{\sim}44\;mg/m^2/hr$ for wetland, $-74{\sim}24\;mg/m^2/hr$ for paddy field and $-55{\sim}106\;mg/m^2/hr$ for forest, and the average values were $-8\;mg/m^2/hr$, $-25\;mg/m^2/hr$ and $38\;mg/m^2/hr$. $CO_2$ was uptake from air to soil in wetland and paddy field, but it was emission from soil to air in forest. $CO_2$ respiration rate function in uptake condition increased exponential and linear as soil temperature and soil organic carbon. But, it in emission condition decreased linear as soil temperature and soil organic carbon. $CO_2$ respiration rate function in wetland decreased linear as soil moisture, but its in paddy and forest increased linear as soil moisture. $CO_2$ respiration rate function in all sites increased linear as soil pH, and increasing rate at forest was highest.

• Korean Journal of Agricultural and Forest Meteorology
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• v.22 no.4
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• pp.299-311
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• 2020

This paper analyzes the distribution of water vapor pressure and relative humidity in complex terrains by collecting weather observation data at 6 locations in the valley in Jungdae-ri, Ganjeon-myeon, Gurye-gun, Jeolla South Province and 14 locations in Akyang-myeon, Hadong-gun, Gyeongsang South Province, which form a single drainage basin in rural and mountainous regions. Previously estimated water vapor pressure used in the early warning system for agrometeorological hazard and actual water vapor pressure arrived at using the temperature and humidity that were measured at the highest density (1.5 m above ground) at every hour in the valley of Jungdae-ri between 19 December 2014 and 23 November 2015 and in the valley of Akyang between 15 August 2012 and 18 August 2013 were compared. The altitude-specific gradient of the observed water vapor pressure varied with different hours of the day and the difference in water vapor pressure between high and low altitudes increased in the night. The hourly variations in the water vapor pressure in the weather stations of the valley of Akyang with various topographic and ground conditions were caused by factors other than altitude. From the observed data of the study area, a coefficient that adj usts the variation in the water vapor pressure according to the specific difference in altitude and estimates it closer to the actual measured level was derived. Relative humidity was simulated as water vapor pressure estimated against the saturated water vapor pressure, thus, confirming that errors were further reduced using the derived coefficient than with the previous method that was used in the early warning system.

• Proceedings of the Korean Society of Computer Information Conference
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• 2013.01a
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• pp.99-101
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• 2013

본 논문에서는 사춘기 여고생들의 기능성 화장품의 신상품 개발과 성능 향상을 위한 효율적인 정보의 분석과 생산 정책을 위한 SNS 분석시스템을 제안한다. 제안하는 시스템은 여고생들의 기능성 화장품에 관한 SNS 내용을 분석하기 위한 효율적 알고리즘과 방법론을 제안하여 시스템의 처리량을 최대화하고, 각 작업의 수행시간을 최소화한다. 또한 여고생들의 기능성 화장품에 대한 기호 상태를 파악하여, 그 분석 결과를 제품의 개발 및 생산에 반영하기 위한 비주얼 방법론을 함께 제안한다. 따라서 본 논문에서 제안하는 시스템은 단지 화장품에 대한 분석뿐만 아니라 이와 비슷한 소비자의 기호가 빠르게 변화하는 제조업 분야에서 다양하게 응용이 가능하다.

• Journal of Species Research
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• v.5 no.3
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• pp.309-312
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• 2016

Cleantioides rotundata (Kussakin, 1982) is reported for the first time in South Korea. Specimens of C. rotundata were collected with a small hand net from the intertidal zone of Opo-ri, Yeongdeok-gun in South Korea. This species makes tubes using seagrass debris at our sampling location and distinguished by the following characteristics: pleotelson long, length almost 1.6 times as long as width; dorsum of distal one third with deeply bilobed depression on plane. In this paper, we provide descriptions of diagnostic characteristics and illustrations of morphology of C. rotundata. Additionally, a key to the Korean species of the genus Cleantioides is provided and the partial sequences of the mitochondrial cytochrome c oxidase subunit 1 (CO1) are provided as molecular characteristics.

• Bulletin of the Korean Chemical Society
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• v.35 no.11
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• pp.3232-3238
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• 2014

Mollugin has been reported to have various biological activities including antineoplastic, antitumor, antiviral against the hepatitis B virus, anti-aging and antimutagenic activities. An effective and concise synthesis of mollugin in two steps including kinetic control from the cheap starting material 1,4-naphthoquinone has been introduced, and mollugin derivatives thus prepared are screened for their inhibition ability against the hepatitis C virus (HCV) and the dihydrobenzochromene structure might be an additional anti-HCV agent as a new leading compound.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2011.11a
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• pp.314-317
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• 2011

최근 국내 장애인 복합시설의 증가와 함께 많은 사고 사례가 발생하고 있다. 하지만 장애인 시설 화재시 재실자가 장애인으로 비장애인 보다 피난 효율이 저하되어 수 많은 인재가 발생하고 있다. 따라서 장애인시설 피난 방화와 관련하여 강화된 규정이 필요하고 많은 연구가 이루어져야 할 것이다. 이에 따라 국내 장애인복합시설을 대상으로 가연물 조사와 Cone Calorimeter 실험을 통해 화재하중과 가연물 연소성상 등을 연구 분석한 결과 장애인 시설의 화재하중이 공동주택보다 높다는 것을 확인하였다. Cone Calorimeter 실험을 통해서 6개 시료 중 4개의 시료가 기준치 이상의 발열량을 보였고, 방염블라인드의 경우 Co, $CO_2$ 유해연기의 검출량이 기준치 이상으로 그 위험성을 확인 할 수 있었다.