• 해양환경안전학회지
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• 제18권6호
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• pp.610-616
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• 2012

세계는 지금 본격적인 에너지 기후시대로 도래했으며 녹색성장을 이끌 강력한 에너지 정책이 선진국가 진입의 초석으로 신재생에너지를 활용하여 미래의 에너지 자원으로 동력화하는 것이 21세기 에너지 수요를 충족시키는 개발 목표가 되고 있다. 최근 신재생에너지 개발의 필요성에 따라 해양에너지가 주목을 받고 있다. 해양에너지는 아직 개발되지 않은 가장 유망한 재생 및 청정에너지 자원 중 하나이다. 이에 따라 각 해역에 적합한 조류에너지 변환장치의 개발이 매우 필요하다. 본 연구에서는 조류발전용 터빈에 작용하는 유입각, 해저면 효과 및 공동현상 발생에 따른 효율의 변화를 후류유동특성을 통해 파악하였다. 계산 조건하에서 해저면 효과에 의한 효율저하는 크게 나타나지 않았고, 유입각은 10도 이상부터 효율 저하가 나타났고 45도에서는 출력계수가 7 % 낮게 계산되었다. 유입속도가 증가할수록 토크와 출력계수가 증가하였으나, 공동현상이 발생하는 3 m/s이상부터 오히려 출력저하가 나타났다. 또한 유동특성의 고찰을 통해 유입각이 크고 공동현상이 나타날수록 출력감소의 원인이 됨을 확인하였다.

• 대한원격탐사학회지
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• 제34권6_3호
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• pp.1383-1398
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• 2018

해상풍은 복잡한 해양 현상을 이해하는 데 가장 기초 요소 중 하나이다. 1990년대 초부터 산란계를 활용하여 전세계 바람장 자료를 생산해왔지만, 낮은 해상도로 인해 해양 연구에 제한적으로 사용되었다. Synthetic Aperture Radar(SAR)는 이러한 한계점을 보완하여 고해상도의 바람장 자료 생산이 가능하다. KOMPSAT-5는 한반도 최초의 X-band SAR 탑재 인공위성으로 고해상도 해상풍 산출이 가능하다. 본 연구는 KOMPSAT-5 후방산란계수 자료를 활용하여 산출한 해상풍의 검증 결과를 최초로 제시하였다. 18장의 KOMPSAT-5 ES 모드 자료를 수집하여 해양 부이와의 일치점 데이터베이스를 생산하였다. 정확한 해상풍 산출을 위해 육지 화소, 스페클 잡음, 선박 화소를 제거하는 전처리 과정을 거쳤고, 해양 부이 실측 자료에 Liu-Katsaros-Businger (LKB) 모델을 통해 10-m 중성 바람으로 변환하여 기준 자료로 활용하였다. XMOD2를 활용하여 산출한 해상풍은 후방산란계수 산출식에 따라 $2.41-2.74m\;s^{-1}$의 평균 제곱근 오차를 보였다. 분석 결과 KOMPSAT-5 후방산란계수 자료를 활용하여 해상풍을 산출하는 경우, 대기 중력파, 파랑, 내부파를 포함한 해양 기상 환경과 레인지 모호성(range ambiguity), 입사각의 이산적 불연속적 분포를 포함한 영상 품질에 의한 잠재적 오차 요인이 존재함을 규명하였다.

• Asian-Australasian Journal of Animal Sciences
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• 제16권2호
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• pp.234-238
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• 2003

This experiment was conducted to measure nutrient digestibility and performance in broiler chicks fed diets based on normal and low viscosity rye or barley fed with and without enzyme (pentosanase and $\beta$-glucanase) during a 17 day growth trial. A total of 150 one-day old, male broiler chicks (5 birds per pen and 5 pens per treatment) were randomly assigned to one of six dietary treatments in a $3{\times}3$ factorial design experiment (3 cereals${\times}$2 enzyme levels). Digestibility coefficients were determined using chromic oxide. Digestibility coefficients for dry matter and crude protein were significantly (p=0.0001) higher for the barley-based diets than for any of the rye-based diets. Digestibility coefficients for gross energy did not differ (p>0.05) due to cereal grain. There were no differences in the digestibility coefficients for dry matter and gross energy between chicks fed normal and low viscosity rye. However, the digestibility coefficient for crude protein was higher (p=0.01) for the low viscosity rye compared with the normal viscosity rye. Addition of enzyme to the diet significantly (p=0.0001) increased digestibility coefficients for dry matter, crude protein and energy. There were no significant differences in weight gain, feed intake or feed conversion between birds fed barley or rye or between birds fed normal or low viscosity rye. Enzyme supplementation significantly improved (p=0.0001) weight gain, intake and feed conversion. The overall results of this experiment indicate that unsupplemented barley and rye do not support adequate growth rates in poultry. Enzyme supplementation dramatically improved broiler performance. In addition, genetic selection to reduce the viscosity of rye had only a modest effect on the nutritive value of rye for broilers.

• Bulletin of the Korean Chemical Society
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• 제32권11호
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• pp.4035-4040
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• 2011

Long $TiO_2$ nanotube (NT) arrays, prepared by electrochemical anodization of Ti foils, have been utilized as dye-adsorbing electrodes in dye-sensitized solar cells (DSCs). By anodizing for 1-24 hr and subsequent annealing, highly crystallized and tightly-adhered NT arrays were tailored to 11-150 ${\mu}m$ lengths, ~90 nm innerpore diameter and ~30 nm wall thickness. I-V curves revealed that the photovoltaic conversion efficiency (${\eta}$) was proportional to the NT length up to 36 ${\mu}m$. Beyond this length, the ) was proportional to the NT length up to ${\eta}$ was still steadily increased, though at a much lower rate. For example, an ${\eta}$ of 5.05% at 36 ${\mu}m$ was increased to 6.18% at 150 ${\mu}m$. Transient photoelectron spectroscopic analyses indicated that NT array-based DSCs revealed considerably higher electron diffusion coefficient ($D_e$) and life time (${\tau}_e$) than those with $TiO_2$ nanoparticles (NP). Moreover, the electron diffusion lengths ($L_e$) of the photo-injected electrons were considerably larger than the corresponding NT lengths in all the cases, suggesting that electron transport in NT arrays is highly efficient, regardless of tube length.

• 임상간호연구
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• 제22권2호
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• pp.205-216
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• 2016

Purpose: This study was performed to develop a valid and reliable Korean Patient Classification System for Neonatal care nurses (KPCSN). Methods: The study was conducted in tertiary and general hospitals with 1~2 grade according to nursing fee differentiation policy for NICU (neonatal intensive care unit) nurse staffing. The reliability was evaluated for the classification of 218 patients by 10 nurse managers and 56 staff nurses working in NICUs from 10 hospitals. To verify construct validity, 208 patients were classified and compared for the type of stay, gestational age, birth weight, and current body weight. Nursing time was measured by nurses, nurse managers, and nurse aids. For the calculation of conversion index (total nursing time divided by the KPCSN score), 426 patients were classified using the KPCSN. Data were collected from September 5 to October 28, 2015, and analyzed using t-test, ANOVA, intraclass correlation coefficient, and non-hierarchial cluster analysis. Results: The final KPCSN consisted of 11 nursing categories, 71 nursing activities and 111 criteria. The reliability of the KPCSN was r=.83 (p<.001). The construct validity was established. The KPCSN score was classified into four groups; group $1:{\leq}57points$, group 2: 58~80 points, group 3: 81~108 points, and group $4:{\geq}109points$ in the KPSCN score. The conversion index was calculated as 7.45 minutes/classification score. Conclusion: The KPCSN can be utilized to measure specific and complex nursing demands for infants receiving care in the NICUs.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.427-427
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• 2016

Organic-inorganic hybrid perovskite have attracted significant attention as a new revolutionary light absorber for photovoltaic device due to its remarkable characteristics such as long charge diffusion lengths (100-1000nm), low recombination rate, and high extinction coefficient. Recently, power conversion efficiency of perovskite solar cell is above 20% that is approached to crystalline silicon solar cells. Planar heterojunction perovskite solar cells have simple device structure and can be fabricated low temperature process due to absence of mesoporous scaffold that should be annealed over 500 oC. However, in the planar structure, controlling perovskite film qualities such as crystallinity and coverage is important for high performances. Those controlling methods in one-step deposition have been reported such as adding additive, solvent-engineering, using anti-solvent, for pin-hole free perovskite layer to reduce shunting paths connecting between electron transport layer and hole transport layer. Here, we studied the effect of alkali metal halide to control the fabrication process of perovskite film. During the morphology determination step, alkali metal halides can affect film morphologies by intercalating with PbI2 layer and reducing $CH3NH3PbI3{\cdot}DMF$ intermediate phase resulting in needle shape morphology. As types of alkali metal ions, the diverse grain sizes of film were observed due to different crystallization rate depending on the size of alkali metal ions. The pin-hole free perovskite film was obtained with this method, and the resulting perovskite solar cells showed higher performance as > 10% of power conversion efficiency in large size perovskite solar cell as $5{\times}5cm$. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and inductively coupled plasma optical emission spectrometry (ICP-OES) are analyzed to prove the mechanism of perovskite film formation with alkali metal halides.

• Journal of Pharmaceutical Investigation
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• 제31권3호
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• pp.143-150
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• 2001

Butyrolactone ester of ceftezole (CFZ-BL) was synthesized by esterification of ceftezole (CFZ) with ${\alpha}-bromo-{\gamma}-butyrolactone$. The synthesis was confirmed by spectroscopic analysis. CFZ-BL was more lipophilic than CFZ when the lipophilicity was assessed by partition coefficients between n-octanol and water at various pH. CFZ-BL itself did not show any microbiological activity in vitro, but serums taken after oral administration of CFZ-BL showed substaintial microbiological activity indicating that CFZ-BL is converted to microbiologically active metabolite, probably CFZ, in the body. The conversion was confirmed by in vitro incubation study, in which CFZ-BL was incubated in some body tissues of rabbit. Liver homogenate showed fastest conversion of CFZ-BL among the tissues tested (blood and intestine). Thus, CFZ-BL appeares to be rapidly metabolized in the liver to CFZ following oral administration. The metabolism process appears to be hydrolysis of the ester to CFZ, the parent drug of CFZ-BL. In vivo metabolism of CFZ-BL to CFZ was confirmed by analying CFZ by HPLC. CFZ concentration in the serum samples taken after oral administration of CFZ-BL were higher than those in the serum samples taken after oral administration of equivalent amount of CFZ. Oral bioavailability of CFZ-BL, a prodrug of CFZ, was 1.45-fold higher than that of CFZ in rabbits possibly due to enhanced lipophility and absorption of the prodrug.

• 해양환경안전학회지
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• 제17권1호
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• pp.75-82
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• 2011

해양에너지는 아직 개발되지 않은 가장 유망한 재생 및 청정에너지 자원 중 하나이다. 특히 우리나라는 세계적으로 보기 드문 조류발전의 적지이며, 이를 이용하기 위해서는 각 해역에 적합한 조류에너지 변환 장치의 개발이 매우 필요하다. 따라서 본 연구에서는 조류발전 방식 중 수평축 로터 블레이드의 최적형상 설계 및 성능평가를 목적으로 날개 끝 손실 모델을 포함하는 날개요소 운동량이론을 적용한 조류터빈 설계기법을 제안하고, 100 kW급 로터 블레이드를 설계하였다. 또한 블레이드 국부위치에서 주속비에 따른 Prandtl의 날개 끝 손실 변화를 비교하였으며, 정격 날개 끝 속도비에서 NACA63812를 사용하여 설계된 로터 블레이드의 동력계수는 0.49로 우수한 성능을 나타내었다.

• 폴리머
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• 제24권2호
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• pp.201-210
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• 2000

에폭시 수지의 삼차원 망목상 구조 형성에 관한 근본적이고 화학구조에 바탕을 둔 미세구조 및 물성 발현에 대한 연구의 일환으로, 말단 관능기가 같은 아민 경화제의 주쇄에 포함된 질소 및 탄소원자의 개수가 반응특성, 열적 특성, 그리고 기계적 특성에 미치는 영향을 조사하였다. 열적 특성을 측정하기 위하여 DSC, TGA, TMA 분석을, 기계적 특성 및 파단특성 분석을 위하여 인장 시험, 삼점 굴곡시험, 광학현미경 분석을 행하였다. 그 결과, 주쇄의 사슬길이가 짧을수록 반응열이 크고 최대 발열온도와 열안정성이 낮아졌다. 또한 최대 반응전환율은 주쇄의 사슬길이가 길어질수록 증가하였다. 경화물의 경우 밀도는 주쇄의 사슬길이와는 큰 관계가 없으나, 인장탄성율은 주쇄의 사슬길이가 짧을수록 크고, 인장강도는 그와 반대의 경향을 보인다. 그 외의 shrinkage, 유리전이온도, 굴곡탄성율, 굴곡강도는 주쇄의 사슬길이와는 일견 무관한 불규칙한 형태를 보였다. 이는 최대 반응전환율의 차이가 이러한 특성에 큰 영향을 미치는 것을 나타낸다. 굴곡 파단특성은 최대 반응전환율과 밀접한 관계를 나타내었다.

• 농촌계획
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• 제9권1호
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• pp.65-75
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• 2003

As a pre-step research to make land-use planning in the region level, this study aims to analyze some probability pattern representing transition probabilities from farmland to others using the sequential detailed digital land-use maps. Kinki and Chubu regions of Japan, which have Osaka and Nagoya cities as their center places respectively, were selected as test regions in this study. The 10m grid land-use maps for four time series at every 5 year from 1977 to 1992 were used. In this study, the regions were divided into three sub-areas 10km, 20km, and 30km according to distance from center cities, respectively. The correlation coefficient (CC) between sub-areas with same distance in the two regions was calculated to analyze whether or not the two regions have common points in the pattern of land-use conversion probability from farmland to other types. The probability distribution of the converted areas which were moved to the urbanized area (residential, commercial, industrial, road, park and public facility areas) was about $40{\sim}70%$ for both all periods and sub-areas. According to distance from city centers, the probability moved to the urbanized area was about 60% at 10km area, and 40% at the 30km area, which means that the values we decreased gradually, while in the case moved to the forest and the etc areas, the values were increased slightly. The CC analysis from the paddy field and the dry field to the others separately showed that there is high correlation in the probability pattern between the two regions.