• 한국농공학회논문집
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• 제62권4호
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• pp.1-12
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• 2020

The extreme 2017 spring drought affected a large portion of South Korea in the Southern Gyeonggi-do and Chungcheongnam-do districts. This drought event was one of the climatologically driest spring seasons over the 1961-2016 period of record. It was characterized by exceptionally low reservoir water levels, with the average water level being 36% lower over most of western South Korea. In this study, we consider drought response methods to alleviate the shortage of agricultural water in times of drought. It could be to store water from a stream into a reservoir. There is a cyclical method for reusing water supplied from a reservoir into streams through drainage. We intended to present a decision-making plan for water supply based on the calculation of the quantity of water supply and leakage. We compared the rainfall-runoff equation with the TANK model, which is a long-term run-off model. Estimations of reservoir inflow during non-irrigation seasons applied to the Madun, Daesa, and Pungjeon reservoirs. We applied the run-off flow to the last 30 years of rainfall data to estimate reservoir storage. We calculated the available water in the river during the non-irrigation season. The daily average inflow from 2003 to 2018 was calculated from October to April. Simulation results show that an average of 67,000 tons of water is obtained during the non-irrigation season. The report shows that about 53,000 tons of water are available except during the winter season from December to February. The Madun Reservoir began in early October with a 10 percent storage rate. In the starting ratio, a simulated rate of 4 K, 6 K, and 8 K tons is predicted to be 44%, 50%, and 60%. We can estimate the amount of water needed and the timing of water pump operations during the non-irrigation season that focuses on fresh water reservoirs and improve decision making for efficient water supplies.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2012년도 학술발표회
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• pp.36-36
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• 2012

Drainage water in lowland paddy fields is quantitatively influenced recycle and/or repeated irrigation by irrigation facilities, i.e. pumps, check gates, small reservoirs and so on. In those drainage channels, nutrients accumulation and increasing organic matters are considered to be occurred, and water quality would be degraded not only environmental aspect but irrigation purpose. In general, Total Nitrogen (T-N) is interested water quality index in irrigation water, because high nitrogen concentration sometimes caused decreasing rice production by excess growth and fallen or degrading quality of taste, then, farmers would like to clear water less than 1mg/L of T-N concentration. In drainage channel, it is known that the nitrogen concentration change is influenced by physical, chemical and biological properties, i.e, stream or river bed condition, water temperature, other water quality index, and plant cover condition. In this study, discharge data (velocity and level) in a drainage channel was monitored by an Acoustic Doppler system and water quality was sampled at same time in 2011. So those data was analyzed by multi regression model to realize hydrological and environmental factors to influence with nitrogen concentration. The results showed the difference tendency between irrigation and non-irrigation period, and those influenced factors would be considered in water quality model developing in future.

• 한국농공학회논문집
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• 제55권6호
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• pp.177-186
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• 2013

The purpose of this study was to analyze the temporal and spatial characteristics of the stream flow of small rural streams for investigating the status of stream depletion located downstream of irrigation reservoir. Bonghyun and Hai reservoirs and each downstream were selected for this study. Streamflow was measured for 8 stations downstream from two reservoirs from 2010 to 2012. The water quality samples were collected monthly from the 8 stream stations and 2 reservoir stations from 2011 to 2012. The stream depletion was found in most of the downstream of reservoirs for the non-irrigation period and even in the irrigation period when there were a lot of antecedent precipitation. We found that the stream segments where there were few streamflow, vegetation covers the stream and block the streamflow which makes the stream lost its original function as a stream. Water quality monitoring results of Bonghyun stream indicated that the concentration of SS, Turbidity, TOC, COD were decreased as the stream flows from the reservoir to downstream while the TN and TP were increased. The correlation analysis for water quality data indicated that the correlation between T-N and T-P was high for Bonghyeon and Sukji streams, respectively. Continuous monitoring for rural streams located in downstream of reservoirs are required to quantify the status of stream flow depletion and determine the amount of environmental flows.

• 한국수자원학회논문집
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• 제49권8호
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• pp.673-683
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• 2016

시 공간적 유량변화를 반영한 탄력적인 하천수 사용허가 기준유량 설정 방법을 개발하고 이를 금호강 유역에 적용하여 현재 관리방식과 비교 평가하였다. 홍수기/이수기, 관개기/비관개기를 고려하여 4개의 시기로 구분하고, SWAT모형의 10년간 일별 모의 자연유량을 활용하여 유역내 주요지점인 동촌과 성서 수위관측지점에서 각 기간별 안정적으로 흐르는 유량(기준갈수량, 저수량, 평수량, 평균갈수량)을 판단하였다. 금호강 19개 표준유역의 4개 시기별 안정적으로 흐르는 유량에서 하천유지유량을 제외한 값을 시기별 허가기준유량으로 설정하고 하천수 허가량과 회귀량을 고려하여 가용유량을 산정하였다. 현재 연중 일정하게 적용되는 하천수 사용허가 기준유량(기준갈수량에서 유지유량을 제외한 값)과 본 연구에서 제시한 탄력적 기준유량을 적용하였을 때를 비교한 결과, 추가적인 수자원 확보시설을 건설하지 않고도 10.6 백만$m^3$/년의 가용수량을 확보할 수 있을 것으로 나타났다. 그러므로 본 연구에서 개발된 시 공간적 유량변화를 고려한 탄력적 하천관리 기준유량 산정 방안은 효율적인 물이용을 위한 정책 개선에 활용할 수 있을 것이다.

• Imaging Science in Dentistry
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• 제52권1호
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• pp.61-66
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• 2022

Purpose: This study aimed to compare the therapeutic effects of corticosteroid irrigations and normal saline irrigations in the early inflammatory state of the salivary gland. Materials and Methods: Adult male Wistar rats were divided into experimental (n=6) and control (n=3) groups. Inflammation was induced in the experimental subjects on both sides of the submandibular gland with ligation. After 14 days, both sides of the glands were de-ligated and retroductal irrigation using saline (n=3) and a corticosteroid (n=3) was performed on the left sides only. The controls (n=3) were used to normalize the gland state for the effects of diet and aging. Magnetic resonance imaging was performed to confirm inflammation and post-irrigation gland recovery by measuring relative signal intensity (SI). The glands were excised for histological examination. Results: All experimental animals showed inflamed glands with increased SI and subsequent recovery of the gland with decreased SI to varying degrees. The SI of the controls showed no significant changes during the overall period. The mean SI change of the irrigated gland was higher than that of the non-irrigated side, without a significant difference. The corticosteroid-irrigated glands showed a greater change in SI than that of the saline-irrigated glands. Histology revealed that inflammation was not observed in most of the irrigated glands, while mild to moderate quantities inflammatory cells were found in non-irrigated glands. Conclusion: Corticosteroid irrigation mitigated the early stages of salivary gland inflammation more effectively than normal saline.

• 한국농공학회논문집
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• 제57권6호
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• pp.163-171
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• 2015

This study aimed to establish a field observation system for monitoring tempo-spatially precise changes of groundwater level and to analyze the impact of rainfall and irrigation practices on groundwater changes in paddy regions. The monitoring system comprising of all nine groundwater observation wells and four ponding depth sensors was installed in a part of paddy regions benefited from Gosam reservoir, Ansung-si. The result of grundwater level change during the irrigation period in 2002 was averagely 0.51 m higher than that during the non-irrigation period. In particular between March before puddling and June after transplanting, there was maximum 1.23 m rise in groundwater level. On the other hand, concerning the change in ponding depth, groundwater level changed similarly, and hourly rainfall was revealed to have better correlation with 24-hour delayed hourly groundwater level than with the corresponding groundwater level. Eventually, this study could be referenced for further studies to set up a more comprehensive and sustainable monitoring system of groundwater conditions.

• 한국관개배수논문집
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• 제18권1호
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• pp.4-17
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• 2011

The standard design methodology was suggested to construct wetland system for reducing non-point source pollution from Saemangeum reclaimed paddy land. To set for the design flow and concentrations, runoff and water quality survey were conducted during the irrigation period in 2008 at Gyehwa reclaimed paddy land located at near Saemangeum lake. It is rational that 1ha is the optimum constructed wetland size. To meet this size, the moderate drainage area of reclaimed paddy field was 50ha under the conditions that rainfall is 30mm, average runoff coefficient is 0.83, and runoff capture ratio is 0.6. At these condition, the runoff volume from 50ha was 10,520 $m^3/d$ including base flow during irrigation period. To select the optimum wetland system, several case studies were conducted by focusing on the tidal reclaimed land areas having wetland systems in Seokmun. Pond-Wetland system was selected as the standard model because of showing the highest reduction efficiency. Single variable regression equation were delivered to estimate effluent water concentrations from the designed wetland by using long-term monitoring data from the Seokmun experiment site. The effluent concentration from the designed wetland using these equation were showed moderately range.

• 대한간호학회지
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• 제35권1호
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• pp.125-134
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• 2005

Purpose: The purpose of this study was to identify the influencing factors on the development of pressure ulcers in patients undergoing surgery which lasted more than two hours. Method: One hundred nineteen surgical adult patients were included in the study. Data was measured on each participant from December 2003 to February 2004. It was collected using a structured researcher-administered sheet and analyzed by descriptive statistics, t-test, chi-square test and logistic regression analysis. Result: The prevalence of a perioperative pressure ulcer was 26.1%. The level of moisture, friction and shear, length of surgery, and perioperative irrigation were significantly higher in the pressure ulcer group than those in the non-pressure ulcer group. The level of activity and level of consciousness were significantly lower in the pressure ulcer group than those in the non-pressure ulcer group. Significant influencing factors on the development of pressure ulcer were 'moisture' and 'irrigation' and those variables explained 23.1% of varience in the development of a pressure ulcer during surgery. Conclusion: It is necessary to develop a strategy to prevent pressure ulcer by taking 'moisture' and 'irrigation' into account during the preoperative, perioperative and postoperative period.

• 한국환경복원기술학회지
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• 제7권6호
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• pp.75-83
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• 2004

본 연구는 경량형 옥상조경 소재로 도입가능성이 높은 자생식물을 중심으로 인공배합토에서 토심과 관수주기에 따른 식물의 생육반응을 검증함으로써 경량이면서 저관리형의 옥상조경을 실현하고 자생식물의 활용성을 높이고자 실시하였으며 그 결과는 다음과 같다. 1. 토심과 관수주기에 상관없이 생육이 양호하였던 수종은 애기기린초(Sedum middendorffianum Maxim)와 두메부추(Allium senescens L.)로 고사율 0%로 나타나 토심 5cm의 무관수의 조건에서도 생육이 가능한 저관리 경량형 옥상녹화에 적용 가능한 소재라 판단된다. 또한 두메부추는 토심 5cm에서 건물률이 높아 충실한 생장을 한 것으로 나타났으나 엽록소 측정을 통한 관상가치에서는 토심 10cm에서 양호한 것으로 나타나 관상가치를 고려한다면 토심 10cm 이상의 옥상녹화에 도입하는 것이 바람직한 것으로 판단된다. 2. 한라구절초(Chrysanthemum zawadskii Herb. Subsp. Coreanum (Nakai) Y. Lee Stat.)와 술패랭이(Diauthus superbus L. var. longicalycinus (Maxim) Williams)는 토심 5cm에서 고사율이 높았으며 생육이 저조하였다. 관수는 토심이 5cm인 경우 반드시 필요한 것으로 나타났으며 토심 10cm에서는 무관수에서도 양호한 생장을 하였다. 따라서 무관수의 저관리 경량형 옥상녹화를 조성하기 위해서는 최소 10cm 이상의 토심을 조성하여 식재하는 것이 바람직한 것으로 판단된다. 3. 목본류인 백리향(Thymus quinquecostatus Celak)은 토심 5cm에서 무관수이거나 3주간의 관수주기에서 90% 이상 고사하였으며 최소 1주간격으로 관수하였을 경우 생육상태가 양호하였다. 특히 토심 10cm에서는 무관수일 경우에도 생육이 우수한 것으로 나타났다. 따라서 토심 10cm에서 저관리 옥상녹화의 조성에 도입 가능한 수종으로 판단된다. 결론적으로, 본 연구에서 실험한 수종은 저관리 경량형 옥상녹화에 도입할 경우 최소 토심 10cm가 적정하며 5cm 이하의 토심에서는 최소 2주일에 1회 이상의 관수를 하는 것이 바람직한 것으로 나타났다. 특히 토심 5cm에서도 애기기린초(Sedium middendorffianum)나 두메부추(Allium senescens L.)와 같은 수종을 도입하였을 경우에는 초경량 저관리의 옥상녹화 조성이 가능한 것으로 나타났다. 본 연구는 자생초화류을 중심으로 토심과 관수와의 관계에 대한 기초적인 자료를 제시한데 그 의의가 있다고 하겠다. 이에 앞으로 다양한 토양과 수종에 대한 개발과 연구가 진행되어야 하며 특히 인공배지에서의 적정시비량과 저토심에서의 목본류에 대한 실험과 연구가 이루어져야 할 것이다.

• 한국농공학회논문집
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• 제53권1호
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• pp.17-28
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• 2011

This study was performed to ascertain the possibility of securing inflows to reservoir with low ratio of watershed to paddy field areas by outside diversion weir. The case of Maengdong reservoir and Samryong diversion weir was selected. Most of inflows to Maengdong reservoir with watershed area of $7.06\;km^2$ and total storage capacity of $1,269{\times}10^4\;m^3$ are filled with intake water from outside Samryong diversion weir. Only using water storage data in Maengdong reservoir from 1991 to 2009, the range of water intake in Samryong diversion weir to Maengdong reservoir was optimized to 0.135~30 mm/d, from which water intake to Maengdong reservoir was $1,672.9{\times}10^4\;m^3$ (70.1 %) and downstream outflow to Weonnam reservoir was $714.4{\times}10^4\;m^3$ (29.9 %). The parameters of DAWAST model for reservoir inflow were determined to UMAX of 313.8 mm, LMAX 20.3 mm, FC 136.8 mm, CP 0.018, and CE 0.007. Inflows to Maengdong reservoir were $427.1{\times}10^4\;m^3$ (20.3 %) from inside watershed, and $1,672.9{\times}10^4\;m^3$ (79.7 %) from outside. Paddy irrigation water requirements were estimated to $1,549{\times}10^4\;m^3$ on annual average. Operation rule curve was drawn by using daily inflow and irrigation requirement data. By securing the amount of inflow to Maengdong reservoir to about 80 % from outside Samryong diversion weir, water supply capacity for irrigation of $1,549{\times}10^4\;m^3/yr$ was analyzed to be enough. Additional water supplies for instream flow were analyzed to $1,412\;m^3/d$ in normal reservoir operation, $36,000\;m^3/d$ in withdrawal limit operation by operation rule curve from October to March of non irrigation period.