• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2004년도 학술발표회
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• pp.1335-1339
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• 2004

A hydro-geomorphologic change in a sand bed channel reach and vegetation expansion by changes in the How regime is analyzed in this study. Field and aerial photo surveys, basic hydrological analysis about flow regime change due to two dams, Andong Dam and Imha Dam, on the upstream river and computer modeling are conducted. Two Dams in the study reach have obviously affected downstream channel in many ways including the bed particle coarsening, vegetation expansion on the sandbars and following river channel braiding. The phenomenon of no vegetation on the large point bar in front of Hahwe Village seems due to disturbance of the sandbar surface probably due to the cross flow in the meander reach during the flood. Another reason for no vegetation is that the sandbar on this reach has lower subsurface water lovels, as compared with the others in the up- and downstream of the reach where vegetation expanded, which would hinder vegetation from germinating and growing on the sandbar.

• International Journal of Air-Conditioning and Refrigeration
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• 제15권1호
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• pp.1-9
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• 2007

This study concerns the characteristics of helical flow in a concentric and eccentric annulus with a diameter ratio of 0.52 and 0.9, whose outer cylinders are stationary and inner ones are rotating. Pressure losses and skin friction coefficients have been measured for fully developed flows of water and 0.2% aqueous of sodium carboxymethyl cellulose (CMC), respectively, when the inner cylinder rotates at the speed of 0-500 rpm. The effect of rotation on the skin friction is significantly dependent on the flow regime. In all flow regimes, the skin friction coefficient is increased by the inner cylinder rotation. The change of skin friction coefficient corresponding to the variation of rotating speed is large for the laminar flow regime, whereas it becomes smaller as Re increases for the transitional flow regime and, then, it gradually approach to zero for the turbulent flow regime.

• 한국에너지공학회:학술대회논문집
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• 한국에너지공학회 2003년도 추계 학술발표회 논문집
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• pp.153-158
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• 2003

This study concerns the characteristics of helical flow in a concentric annulus with a diameter ratio of 0.52 and 0.9, whose outer cylinders are stationary and inner ones are rotating. Pressure losses and skin friction coefficients have been measured for fully developed flows of water and 0.2％ aqueous of sodium carboxymethyl cellulose(CMC), respectively, when the inner cylinder rotates at the speed of 0∼500rpm. The effect of rotation on the skin friction is significantly dependent on the flow regime. In all flow regimes, the skin friction coefficient is increased by the inner cylinder rotation. The change of skin friction coefficient corresponding to the variation of rotating speed is large for the laminar flow regime, whereas it becomes smaller as Re increases for the transitional flow regime and, then, it gradually approach to zero for the turbulent flow regime.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2010년도 학술발표회
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• pp.933-937
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• 2010

This study aimed at the introduction of desktop method for assessment of environmental flows developed by IWMI(International Water Management Institute) recently and its application to Geum river basin. This scheme simulated the influence on aquatic ecosystem caused by watershed development and in turn the decrease of water quantity keeping the river's own flow regime. It was found to be as very effective method although it had simple structure. Flow duration curves for different environmental classes at Sutong and Gongjoo sites were estimated according to the natural conditional scenario of Geum river basin and the results were relatively compared well with the previous studies. The behaviors of monthly average runoff time series of both sites showed the level of A class. The results of this study would provide the fundamental data to establish the future plans of monitoring or management for aquatic ecosystem of Geum river basin.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2005년도 학술발표회(1)
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• pp.314-315
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• 2005

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 1994년도 수공학연구발표회논문집
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• pp.107-112
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• 1994

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2005년도 학술발표회(2)
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• pp.1020-1022
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• 2005

• 한국수자원학회논문집
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• 제37권1호
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• pp.55-66
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• 2004

황강 상류에 위치한 합천댐은 1988년 12월에 완공되었다. 완공 이후 댐의 저수량 부족으로 10여년간 수문을 통한 방류가 없었기 때문에, 댐 하류부에 새로운 생태계가 조성되었다. 이러한 현상은 국내 다른 지역에서 찾아보기 힘든 매우 특이한 사항이다. 본 연구에서는 댐 건설로 인한 유황변화에 따른 하천의 지형학적 변화와 식생 피복상태의 변화에 대한 분석을 수행하였다. 이를 위해 하상고 및 하천수로단면의 변화를 조사하였다. 또한 나이테 분석을 포함한 현지조사를 수행하였다. 또한 댐 건설 전ㆍ후 대상유역의 항공사진을 비교하여 댐 건설 후 식생피복이 증가한 것을 확인하였다.

• 한국해양공학회지
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• 제21권2호
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• pp.35-41
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• 2007

In general, coastal damage is mostly occurred by the action of complex factors, like severe water waves. If the maximum storm surge height combines with high tide, severe water waves will overflow coastal structures. Consequently, it can be the cause of lost lives and severe property damage. In this study, using the numerical model, the storm surge was simulated to examine its fluctuation characteristics at the coast in front of Noksan industrial complex, Korea. Moreover, the shallow water wave is estimated by applying wind field, design water level considering storm surge height for typhoon Maemi to SWAN model. Under the condition of shallow water wave, obtained by the SWAN model, the wave overtopping rate for the dike in front of Noksan industrial complex is calculated a hydraulic model test. Finally, based on the calculated wave-overtopping rate, the inundation regime for Noksan industrial complex was predicted. And, numerically predicted inundation regimes and depths are compared with results in a field survey, and the results agree fairly well. Therefore, the inundation modelthis study is a useful tool for predicting inundation regime, due to the coastal flood of severe water wave.

• 농업과학연구
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• 제11권2호
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• pp.207-217
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• 1984

상수리나무, 신갈나무 및 굴참나무의 근원경(根元徑)과 묘고(苗高)의 계절적(季節的)인 생육과정(生育過程)을 토양수분(土壤水分)${\times}$시비(施肥)로 구성(構成)되는 몇가지 처리(處理)를 한 후(後)에 10일(日) 또는 15일간격(日間隔)으로 조사(調査)하였다. 토양수분(土壤水分)과 시비처리(施肥處理)는 시간(時間)이 지나면서 서로 다르게 묘목(苗木)의 생육(生育)에 영향(影響)을 주었다. 그 생장(生長)은 수종별(樹種別)로 다른 시기(時期)에 수분처리간(水分處理間), 시비처리간(施肥處理間) 및 상호작용(相互作用)에서 고도(高度)의 유의적(有意的) 차이(差異)를 나타냈다. 토양수분(土壤水分)의 영향(影響)은 시비(施肥)에서 보다 늦게 나타났으며 N 또는 N+P+K 시비처리(施肥處理)에서 더욱 현저(顯著)한 차이(差異)를 보여 주었다. 생장(生長)에 크게 영향(影響)을 주는 토양수분(土壤水分) potential의 한계(限界)는 모든 수종(樹種)에서 -3~-6bar안에 있는 것으로 추정(推定)되었다. 모든 수종(樹種)에서 N 또는 N+P+K의 처리(處理)와 P, K 또는 무처리간(無處理間)에 유의적(有意的)인 생육차이(生育差異)를 보였으며 처리(處理)의 효과(效果)는 건조구(乾燥區)보다 습구(濕區)에서 더 큰 차이(差異)를 나타냈다. 토양수분(土壤水分)과 시비(施肥)의 상호작용(相互作用)은 모든 처리(處理)에서 시간이 지나면서 서서히 나타났다. 처리(處理)에 따른 근원경(根元徑)의 생육반응(生育反應)에 대(對)한 통계학적(統計學的)인 차이(差異)는 묘고(苗高)에 비(比)해서 조기(早期)에 보여줬다. 대상수종(對象樹種)의 생육반응(生育反應)을 비교(比較)할 때 굴참나무와 신갈나무는 상수리나무에 비(比)하여 보다 내건성(耐乾性)인 것으로 볼수 있었다.