• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2000년도 봄 학술발표회 논문집
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• pp.57-61
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• 2000

This experimental study was carried out to estmate the effects of mixing dosage rate and blain on the compressive strength properties of antiwashout underwater concrete admixed with finely ground granulated blast furnace slag. The experimental parameters are slag contents(0, 20, 30, 40, 50, 60%). As a result the compressive strength have a high correlation with slag blended ratio. Thus, it is possible to calculate the modulus of modified age using compressive strength of antiwashout underwater concrete blended with slag.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2000년도 가을 학술발표회 논문집(II)
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• pp.861-866
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• 2000

This experimental were investigated on the influence of steel fiber reinforcement on flexural behavior characteristics of slabs with various steel fiber contents $V_f$ and aspect ratio($\ell $/$\phi$). Deflection, crack widths, and strains of steel bar were measured with every load step. In the results of this experimental, the addition of steel fibers to conventionally reinforced concrete slab increased the ultimate load, reduced the creak width, the average crack spacing, and deflection.

• 대한공업교육학회지
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• 제45권2호
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• pp.1-20
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• 2020

이 연구의 목적은 화학공업을 공부하는 학생들이 액위제어를 쉽게 이해할 수 있도록 하기 위해, 조립형 액위제어 실험장치를 제작하고 이를 수업에 적용할 수 있는 체험활동과제를 개발하는 것이다. 이를 위해 2015 개정 교육과정 화학공업 실무과목에서 액위제어와 관련된 내용요소를 분석하여, 조립형 액위제어 실험장치를 활용하는 체험 활동과제를 개발하여 전문가 검증을 마친 후, 16차시의 체험활동과제를 S 마이스터고등학교 학생 19명에게 적용하였다. 이 연구에서 얻은 결과는 다음과 같다. 첫째, 기존 완성형 액위제어 실험장치를 분석하고, 이를 토대로 학생 수준에서 조립 가능하며 실습에 활용할 수 있는 새로운 조립형 액위제어 실험장치를 설계·제작하였다. 둘째. 2015 개정 교육과정의 NCS기반 '화학공정유지운영' 실무과목의 내용을 분석하여 액위제어와 관련된 학습 내용들을 추출하였다. 이 액위제어 관련 내용 중에서 공정 흐름도의 이해, 액위제어 실험장치 제작, 유량 측정, 액위제어 현상 확인 등의 실습을 위 조립형 액위제어 실험장치로 진행하여 액위제어 관련 내용을 체계적으로 학습할 수 있도록 하였다.

• 산업기술연구
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• 제24권A호
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• pp.157-164
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• 2004

Air voids in hardened concrete have an important influence on concrete durability such as resistance of freezing and thawing, permeability and surface scaling resistance. Linear traverse method and point count method in ASTM standard method have been widely used to estimate the air void system in hardened concrete. However, these methods are not used at present time, because they are is exhausted much time and effort. In previous study, air voids system of concrete was estimated by spacing factor. The purpose of this study organizes image analysis method by analyzing air contents, air voids distributions by diameters, air voids system as well as spacing factors after hardened concrete. The experimental variables institute of depth of specimen(top, middle, bottom), air contents(AE contents 0, 0.01, 0.03%).

• 한국구조물진단유지관리공학회 논문집
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• 제4권3호
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• pp.129-136
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• 2000

In the side of military purpose, the explosion proof concrete, which contributes to protect the military facilities from damages due to the explosion of bomb and to maintain their shapes, is required to develop, Therefore. in this paper, mechanical and explosion-proof properties of concrete are tested under various steel fiber contents and member size. According to the experimental results, compressive, tensile and flexural strength gain higher levels with an increase in fiber contents. It shows that energy bearing capacities are higher with an increase in fiber contents. Especially. it is confirmed that slurry infiltrated fiber concrete(SIFCON) gains high strength and has high energy bearing capacities. SIFCON is expected to be applied in the construction of explosion proof structures.

• 한국식품영양과학회지
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• 제23권1호
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• pp.1-6
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• 1994

The present study was conducted to evaluate the effect of dietary levels of vitamin A on the lipid composition in rats fed Zn-deficient diets. Fifty male Sprague-Dawley rats were fed 5 experimental diets for 7 weeks. Rats were fed Zn-and vitamin A-deficient diet or the same diets supplemented with various levels of vitamin. A liver total lipid, cholesterol and triglycerides contents tended to decrease in Zn-deficient rats, but the supplementation of excess vitamin A enhanced those contents. Plasma cholesterol content was significantly higher in feeding Zn-deficient and excess vitamin A diet. Plasma triglyceride and phospolipid contents were higher in Zn-deficient groups, but not influenced by dietary levels of vitamin. A . Plasma HDL-cholesterol content was not changed by Zn-deficient diets. Plasma alkaline phosphatase activity was significantly reduced in Zn-deficient groups. Zinc contents of plasma and liver were influenced by the dietary level of zinc, but not changed by supplementation of vitamin A.

• 한국수산과학회지
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• 제44권2호
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• pp.149-154
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• 2011

Two experiments were conducted to investigate the effects of dietary moisture content on the growth and gastrointestinal evacuation of sub-adult olive flounder (Paralichthys olivaceus) in the summer and winter seasons. In the first experiment, three experimental diets containing different moisture levels (7%, 15%) and additives were prepared by adding water and commercial additives (1% nutrients, 1% digestives) to commercial extruded pellets. Fish (initial weight: $332{\pm}9.2$ g) were distributed randomly into six 3000 L tanks (25 fish/tank) in a flow-through tank system. Two replicate groups of fish were fed the experimental diets to satiation for 14 weeks during the summer season ($21.4{\pm}2.5^{\circ}C$). Survival, weight gain, feed efficiency, and daily feed intake did not differ significantly among groups. In the second experiment, two experimental diets containing different moisture levels (8%, 23%) were prepared by adding water to commercial extruded pellets. Fish (initial weight: $646{\pm}6.7$ g) were randomly distributed into six 3000 L tanks (20 fish/tank) in a flow-through tank system. Three replicate groups of fish were fed the experimental diets to satiation for 19 weeks during the winter season ($12.2{\pm}1.2^{\circ}C$). Weight gain, feed efficiency, and daily feed intake did not differ significantly among groups. Gastrointestinal evacuation rates were determined after the end of the winter feeding trials. The stomach contents of fish fed diets containing different moisture levels peaked within 3 h after feeding and then decreased gradually over 40 h to approach pre-feeding levels. Intestinal contents began to accumulate 3 h after feeding and reached a maximum at 32 h, then declined until nearly complete evacuation around 56 h. The stomach contents reached moisture levels of approximately 70% within 3 h after feeding and then increased gradually. No considerable difference in moisture levels was observed in the stomach contents of fish fed diets with different moisture contents. The results of this study suggest that the gastric evacuation of sub-adult olive flounder was not affected by dietary moisture level and the addition of water to the diet had no beneficial effect on the growth of sub-adult olive flounder in the summer and winter seasons.

• 한국콘텐츠학회논문지
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• 제13권9호
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• pp.504-514
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• 2013

본 연구는 인천 소재 G 대학 간호학생을 대상으로 e.learning기본간호실습 콘텐츠를 이용한 자기주도 학습을 했을 때 지식, 자신감과 교육만족도에 미치는 효과를 파악하고자 시도되었다. 비동등성 대조군 전후 실험설계로 연구대상은 실험군 31명, 대조군 32명, 총 63명의 1학년 간호학생이었고, 연구기간은 2011년 9월 1일부터 11월 30일까지였다. 중재 기간 2주 동안 실험군에게는 기존의 강의 중심의 전통적 실습교육과 더불어 e-learning기본간호실습 콘텐츠를 이용한 자기주도학습(Mosby's Nursing Skills 중 피부와 점막의 투약, 수혈 및 중심정맥관 간호에 관한 9개 항목)을 주 3회 이상씩 총 120분 이상 제공하였으며, 대조군에게는 전통적 실습 교육만을 제공하였다. 연구결과 실험군은 대조군에 비해 지식과 교육만족도가 증가되었으나 유의한 차이는 없었고, 자신감은 유의하게 향상되는 것으로 나타났다. 따라서 피부와 점막의 투약, 수혈 및 중심정맥관 간호의 기본간호 실습에서 전통적인 실습과 함께 e-learning기본간호실습 콘텐츠를 이용한 자기주도학습은 간호학생의 기본간호 술기에 대한 자신감을 향상시키는 효율적인 교수학습 전략이 될 수 있다.

• Journal of Nutrition and Health
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• 제36권7호
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• pp.699-710
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• 2003

This study was performed to investigate the effect of chamomile, sage, and green tea intakes on anti oxidative capacity in 15-month-old rats. Dried powders of three plants were analyzed to determine the amount of total flavonoids, $\beta$-carotene, vitamin C, vitamin E, and dietary fibers. In order to examine the change of antioxidative capacity in old rats, forty-eight Sprague-Dawley male rats weighing 621.2$\pm$9.5 g were divided into four groups according to body weight and fed for four weeks with each experimental diet of three dried powders and control diet. Plasma and liver thiobarbituric acid reactive substances (TBARS) levels and xanthine oxidase (XO) activities, erythrocyte and liver superoxide dismutase (SOD) activities and plasma vitamin A, C, E, and total carotenoids levels were measured. The total flavonoids and vitamin C contents were the highest in green tea powder. Beta-carotene and vitamin E contents were not significantly different among all three dried powders. Total dietary fiber contents also were not different among all three dried powders, but soluble dietary fiber contents of chamomile was higher than other two dried powders. Plasma TBARS level was found to be significantly lower in all the experimental groups as compared to control group. Chamomile powder group, especially, showed the lowest level among all experimental groups. Liver TBARS levels of experimental groups were also lower than that of control group and significant differences were observed in chamomile and green tea groups compared to control. Plasma XO activity of green tea group was significantly lower than control group. Liver XO activities of green tea and chamomile groups were significantly lower than control group. Erythrocyte SOD activity was not significantly different among all the groups. However, liver SOD activities of sage and green tea groups showed a significant increase as compared to control group. Plasma vitamin A level was not significantly different among all the groups. Plasma total carotenoids levels were found to be significantly higher in experimental groups as compared to control group. Plasma vitamin E level of chamomile group and vitamin C level of green tea group showed the highest level among all the groups. In conclusion, chamomile, sage, and green tea intakes had an effect on improving antioxidative capacity in 15-month-old rats. Effects of green tea and chamomile powders, especially, were higher than sage powder.

• 디지털콘텐츠학회 논문지
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• 제16권2호
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• pp.275-282
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• 2015

2001년 지상파 디지털방송 시작 이후, 디지털방송의 장점 중 하나인 다채널방송 서비스 도입에 대한 논의가 계속되던 중, 2013년 10월 정부기관, 방송사, 가전사가 참여하는 지상파 다채널 실험방송 추진반이 구성되어 2014년 1월부터 4월 사이에 지상파 다채널 실험방송이 실시되었다. 이 실험방송 결과를 바탕으로 EBS에서는 2015년 2월 11일 국내 최초로 2HD MMS 시험방송을 시작하였다. 본 연구는 압축 기술의 발전으로 기존 6MHz 대역에 2개의 HD 채널을 MPEG-2 코덱기반으로 운영하기 위하여 실시하였다. 1080i 와 720p 주사방식에 따른 변화 및 효율적 데이터 사용을 위한 가변 비트율(Variable Bit Rate) 적용 실험을 통하여 화질 최적화 연구를 실시하고 2HD MMS 시험방송에 적용하였다.