• International Journal of Ocean System Engineering
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• 제2권4호
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• pp.250-258
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• 2012

The distribution of wave heights is assumed to be a Rayleigh distribution, based on the assumption of a narrow band and Gaussian distribution of wave elevation. The present study was started with doubts about the narrow band assumption. We selected the wave spectra widely used to simulate irregular random waves. The wave spectra used in this study included the Pierson-Moskowitz spectrum, Bretschneider-Mitsuyasu spectrum, and JONSWAP spectrum. The directionality of the waves was considered. The cosine 2-l type directional spreading function and mixed form of the half-cosine 2-s type with Mitsuyasu type directional spreading are considered here to investigate the effects of a directional spreading function on random waves. The simulated wave height distribution is compared with a Rayleigh distribution.

• KIEAE Journal
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• 제13권5호
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• pp.5-15
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• 2013

104 village has kept the landscape of low-income settlements at hillside village as called 'Daldongnae' since 1960s. It has high urban and social values in modern housing history of Korea. This study is to analyze the basic type, transformed type of street facade and also the meaning in the modern housing history. It analyzes basic elements(building elevation, gate, fence) and subsidiary elements(roof form, door, window), and the type of street facade by the composition of the element.

• 한국토양환경학회지
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• 제5권3호
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• pp.65-75
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• 2001

본 연구는 제주도의 전체 지하수공 중 수역별로 대표성이 있는 150공을 선정하여 고도에 따른 수질 특성을 파악하는데 목적을 두었다. 수질특성의 평가는 물리.화학적 특성과 통계분석을 이용하였다. Piper diagram에 의한 수질 유형은 표고 50m이하 지역은 $Na^{+}$＋ $K^{+}$-C $l^{-}$ 형태를 보이고 있다. 40~100 m에 위치한 지하수에서는 $Na^{+}$＋ $K^{+}$-HC $O_3$$^{-}$ ＋C $O_3$$^{2-}$ 형태와 일부 $Na^{+}$＋ $K^{+}$-C $l^{-}$ 형태의 군을 이루고 있다. 그리고 100 m이상의 지역에서는 $Na^{+}$＋ $K^{+}$-HC $O_3$$^{-}$ ＋C $O_3$$^{2-}$ 형태에 속하고 있다. 요인분석 결과, 50 m이하와 100 m이상 지역에서 공통적으로 TDS와 오염물질 2개 요인이 추출되었다. 50~100m지역에는 3개의 요인이 추출되었으며, 요인1에는 TDS함량으로 요인2는 오염의 영향과 광물용해로 볼 수가 있다. 그리고 요인 3에는 HC $O_3$$^{-}$ 함량으로 나타났다..

• 한국수자원학회논문집
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• 제50권2호
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• pp.111-119
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• 2017

치성천의 홍수범람이 빈번하게 발생하는 구간을 대상으로 하단배출형 가동보를 다단으로 배치하여 가동보의 관리수위별 저류 및 홍수조절 효과를 기존 고정보의 설치 경우와 비교분석하였다. 분석 결과를 기반으로 인공신경망 모형을 구축하여 목표하는 저류량과 하류부 홍수위 조절을 위한 가동보의 관리수위를 제안하였다. 하단배출형 가동보를 다단으로 배치할 경우 고정보 대비 하류부에서의 첨두 홍수위가 68.28%가 감소하였고, 대상구간의 총 저류량이 216%가 증가하였다. 인공신경망 학습모델의 구축을 위해 수치모의 결과 216개의 data 중 60%, 20%, 20%를 각각 학습, 검증 및 시험에 사용하였다. 학습결과 평균제곱오차가 $0.1681m^2$, 결정계수가 학습, 검증 및 시험에서 각각 0.9961, 0.9967, 0.9943으로 높게 나타났다. 인공신경망을 이용하여 목표하는 저류량과 하천의 하류부에서의 홍수위에 대한 각각 가동보의 관리수위의 결정방안을 제시하였다.

• 대한방사선기술학회지:방사선기술과학
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• 제33권4호
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• pp.335-340
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• 2010

T형 금속판을 이용한 요골 원위부 골절 수술 후 나사못의 요골구 관통 유무를 확인하기 위한 요골구 촬영 방법을 알아보고자 하였다. Wrist CT 환자 51명의 3D 영상과 건조된 요골 표본 20본에서 요골구 각도를 분석하였고, 석고를 이용하여 요골 모형을 제작 한 다음 나사못이 요골구를 2.4 mm 관통 하도록 하고 요골구 원위부 거상 각도 및 외회전 각도를 0~30도까지 5도씩 변화시켜 X-선 영상으로 촬영하였다. 그 결과 요골구 각도는 Wrist CT 영상에서 평균 14.4도, 건조된 요골 표본에서 평균 16.3도였다. 요골 모형에서 요골구를 관통한 나사못의 길이는 거상 각도 및 외회전 각도에 따라 묘출 정도가 다름을 알 수 있었다. 결론적으로 T형 금속판을 이용한 요골 원위부 골절 수술 후 나사못의 요골구 관통을 알기 위한 접선방향촬영에서 요골 원위부 거상각은 $5^{\circ}$, 외회전 각은 $20^{\circ}$를 추천한다.

• KIEAE Journal
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• 제8권3호
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• pp.13-18
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• 2008

Recently it is urgent issue in every department that problem from environmental disruption such as global warming. As the case of streetscape works essentially at city scenery, it is inevitable that changing from present view, which centers facilities and buildings, to environmental harmonic scenery. This study plans climate adjusting ability and improvement of thermal efficiency by putting ecological elements to buildings on a street which are essential factors of streetscape. Ultimately, this not only makes a pleasant environment but also revives being withered earth. Street-environment on eco-scape will take a part in designing sustainable city. This study acquires the way how buildings on a street get applied ecological elements as following. Roof level part : the greening surface of the rooftop(included plant box type), the greening roof as a type of pergola, the greening surface of the middle floor rooftop(included plant box type). Elevation part : climbing type, downfall type, espalier, flower bed in balcony type, wall-installing type, water wall type, other design types. Ground level part : paving the whole surface with permeability, paving the gap with permeability, plant box type, ground plant type, waterside zone, wetland, fence greening type, terrace greening type, retaining wall greening type.

• Archives of Plastic Surgery
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• 제35권4호
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• pp.360-366
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• 2008

Purpose: Botulinum toxin type A(BoTA) can block the release of vasoconstriction cotransmitters as well as acetylcholine in nerve terminal. The authors observed that BoTA increases flap survival by preventing sympathetic collapse of peripheral vessels. Methods: 10 Sprague Dawley rats were divided into control(n=5), and BoTA group(n=5). $3{\times}10cm$ sized random pattern cutaneous flaps were elevated on the dorsal side in both groups. In BoTA group, BoTA was injected into the flap via intradermal to subdermal route, 7 days before the flap elevation. Flap survival rates (survival area/total area) were measured 7 days after the elevation. Cutaneous blood flow was measured in proximal, middle and distal compartments of the flap using laser Doppler flowmetry initially, preoperatively, at immediate postoperation, and 7 days after flap elevation, respectively. Histological examination was performed 7 days after the flap elevation. The number and shape of the vessels were evaluated under microscope. Results: Mean flap survival was $53.18{\pm}6.58%$ in control group and $93.79{\pm}6.06%$ in BoTA group, displaying statistically significant difference(p=0.0008, p<0.05). In the control group, blood flow to the middle and distal compartments of the flap decreased significantly immediately after flap elevation. In the BoTA group, blood flow to the middle compartment did not decrease(p=0.002) and slightly decreased in the distal compartment(p=0.001). Cutaneous blood flow was significantly higher in all compartments of the flap in BoTA group than in control group, 7 days after the flap elevation. In histopathologic examination, greater number of vessels were noted in the BoTA group than in the control group. Conclusion: Botulinum toxin A can increase the survival of the random pattern cutaneous flap in rats by preventing the sympathetic collapse of peripheral vessels.

• 한국유체기계학회 논문집
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• 제14권5호
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• pp.39-47
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• 2011

Flow control range of valve, which is installed on pipeline, varies according to valve type, pipe diameter, pipe length, roughness, and elevation difference of both ends of pipeline. A lot of computation efforts and knowledge are needed to estimate flow control range of valve, considering above many parameters. The table of flow control range of each valve type is presented for convenience of pipeline design engineers who must make decision of valve size and type in this study. Also the reason that butterfly valve is recommended for flow control, and gate valve is forbidden is presented via quantification and figures in this study.

• 한국태양에너지학회 논문집
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• 제23권1호
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• pp.9-16
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• 2003

For the study of an effect that fin thickness and shape of heat exchanger have on the elevation of heat transfer efficiency, we make models of plate fin type heat exchanger and louvered fin type heat exchanger which was given a transformation of fin thickness in plate f)n type heat exchanger and louvered fin type heat exchanger which are often used now. And the effect of fin thickness on pressure drop and characteristics of heat transfer was experimented and analysed when air velocity and temperature of plate heating was a variable. The results of experiment shows below. Pressure drop shows larger in louvered fin type exchanger than in plate fin type exchanger, size of pressure drop shows like this order that fin thickness is 0.3mm, 0.2mm, 0.1mm. Mean heat transfer coefficient shows higher in louvered fin type exchanger than in plate fin type exchanger, size of mean heat transfer coefficient by fin thickness shows same in both case in louvered fin type heat exchanger and plate fin type exchanger like this order that fin thickness is 0.1mm, 0.2mm, 0.3mm.

• 교육시설
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• 제10권3호
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• pp.5-13
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• 2003

This paper is a series of study for the development of rural elementary school facilities model applying to the regional characteristics. Therefore, main theme of this paper is to pile up and analysis of elementary school facilities data in Po Cheon through a series of actual survey and interview with teachers. The results are summarized as follows ; First of all, in case of Po Cheon, it needs to study for urban model type as well as rural elementary school facilities model type. Second, extension type of buildings has separated as three types-zigzag extension type, vertical & horizontal extension type, separate building type. But another characteristics, such as type of site plan, type of corridor and module of classroom unit, outdoor space and elevation design, are monotonous. Third. the results of this analysis show that it is desirable to locate houses for teachers within boundaries. Finally, the future paper needs to be studying more various module of classroom unit, extension type, space program, type of floor plan and site plan.