• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제25권3호
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• pp.132-148
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• 2021

The modified F-expansion method is used to construct analytical solutions of the foam drainage equation with time- and space-fractional derivatives. The conformable derivatives are considered as spacial and temporal ones. As a result, some analytical exact solutions including kink, bright-dark soliton, periodic and rational solutions are obtained.

• 한국작물학회지
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• 제50권spc1호
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• pp.85-87
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• 2005

본 연구는 남서해안 간척지에서 토양 염농도(저염; $0.1\%$, 중염; $0.3\~0.4\%$)별로 쌀 품질 향상을 위한 완전 낙수시기를 구명하기 위하여 시험한 결과를 요약하면 다음과 같다. 1. 저염토양에서의 완전낙수시기에따라 $m^2$당 립수가 비슷하여 쌀 수량은 유의차가 없었다. 중염토양에서는 완전낙수시기가 빠를수록 염피해를 받아 등숙비율이 낮아져, 쌀 수량은 출수후 30일까지는 감수하였고 35일 이상에서는 같았다. 2. 토양 염농도간의 쌀 수량은 중염 토양에서 저염 토양의 $64\%$ 수준으로 감소하였다. 3. 저염 토양에서 완전미 비율이 높았으나 현미품위는 처리농도간에 차이를 볼 수 없었다. 4. 2002년 기상은 완전낙수시기에 잦은 강우로, 2003년에는 생육기 저온으로 인하여 완전 낙수시기를 결정하기 어려웠지만 수량 및 도복 등을 고려해 볼 때 저염 토양에서는 출수 후 $20\~40$일에, 중염 토양에서는 출수 후 $35\~40$일에 완전낙수하는 것이 안전할 것으로 생각된다.

• 한국농공학회논문집
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• 제65권4호
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• pp.25-32
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• 2023

KDS (Korean Design Standard) for agricultural drainage is a planning standard that helps determine the appropriate capacity and type of drainage facilities. The objective of this study was to analyze the inundation of the agricultural basin considering the current design standard and the critical rainfall duration. This study used the rainfall durations of 1-48 hour, and the time distribution method with the Chicago and the modified Huff model. For the runoff model, the NRCS (Natural Resources Conservation Service) unit hydrograph method was applied, and the inundation depth and duration were analyzed using area-elevation data. From the inundation analysis using the modified Huff method with different rainfall durations, 4 hours showed the largest peak discharge, and 11 hours showed the largest inundation depth. From the comparison analysis with the current method (Chicago method with a duration of 48 hours) and the modified Huff method applying critical rainfall duration, the current method showed less peak discharge and lower inundation depth compared to the modified Huff method. From the simulation of changing values of drainage rate, the duration of 11 hours showed larger inundation depth and duration compared to the duration of 4 hours. Accordingly, the modified Huff method with the critical rainfall duration would likely be a safer design than the current method. Also, a process of choosing a design hydrograph considering the inundation depth and duration is needed to apply the critical rainfall duration. This study is expected to be helpful for the theoretical basis of the agricultural drainage design standards.

• 대한토목학회논문집
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• 제37권6호
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• pp.949-963
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• 2017

본 연구는 도시홍수 피해저감을 위한 비구조적 대책의 일환으로 배수펌프장의 효율적인 운영방안을 제시하고자 한다. 배수펌프장 내의 수위를 뉴로-퍼지모형을 통하여 예측하고 예측되는 내수위에 따라 유전자 알고리즘 기법을 적용하여 배수펌프장의 운영룰을 결정하고자 한다. 뉴로-퍼지모형 구축시 배수구역의 지형적 특성을 반영하기 위하여 공간적 매개변수를 고려한 GeoANFIS모형을 개발하였고 배수펌프장 내 최고수위를 저하시키면서 반복적인 정지와 운영이 발생하지 않도록 벌칙유형의 유전자 알고리즘을 적용하였다. 마포 배수구역 내 5개의 배수펌프장(마포, 합정, 상수, 봉인, 당인)에 대하여 개발 모형의 적용성을 검증하였다. 이러한 운영룰의 개발로 효과적으로 내배수 시설을 운영할 수 있을 것으로 판단된다.

• 한국농공학회지
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• 제37권5호
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• pp.53-61
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• 1995

Analyses of subsurface drainage effects of farmland with respect to pipe and envelop material are made by the laboratory experiments using soil box to give basic information for the subsurface drainage system planning and design. Three different diameter PVC perforated pipes and a mesh pipe are used with envelop materials such as sand, rice bran, and crushed stone. Steady state subsurface drainage flow rate increased as envelop material changed from sand to rice bran and crushed stone. This indicates that as the hydraulic conductivity of the envelop material increases, the drainage flow rate increases. On the other hand, for a given envelop material, the mesh pipe which has the largest openning area shows the largest flow rate while small diameter PVC pipes show small flow rates. This tells that as the openning area and pipe diameter increase, the flow rate increases, too. Therefore, selection of pipe and envelop material should be made in accordance with the design drainage flow rate. Unsteady state subsurface drainage flow rate with respect to time differs for different envelop material. In case the sand was used as an envelop material, the small diameter PVC pipes show larger flow rates than the large diameter PVC pipe and mesh pipe. When the rice bran was used, the mesh pipe shows the largest flow rate, while small diameter pipes show smaller flow rates. In case the crushed stone was used as an envelop material, the large diameter PVC pipe and mesh pipe show larger flow rates, while small diameter pipes show a little bit smaller flow rates. However, the variation of flow rates among different pipes is the smallest when the crushed stone is used. The flow rate curve with respect to the pipe changes little for the crushed stone envelop which has a large hydraulic conductivity, while that changes much for the sand and rice bran envelops. However, it is difficult to draw a consistent relationship between the drainage flow rate and pipe for all the envelop materials. Since the subsurface drainage experiments are made only under the restricted laboratory condition in this study, further study including field experiment is required.

• 물과 미래
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• 제9권2호
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• pp.67-75
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• 1976

With 9 existng reservoirs selected in the Sab-Gyo River Basin, the sedimentation of the reservoirs has been calculated by comparing the present capacity with the original value, which revealed its reduced reservoirs capacity. The reservoirs has a total drainage area of 6,792 ha, with a total capacity of 1,204.09 ha-m, and are short of water supply due to reduction of reservoirs capacity. Annual sedimention in the reservcire is relation to the drainage area, the mean of annual rain fall, and the slop of drainage area. The results of obtained from the investigation are summarized as follow; (1) A sediment deposition rate is very high, being about $9.19{m}^3/ha$ of drainage area, and resulting in the average decrease of reservoir capacity by 19.1%. This high rate of deposition could be mainly attributed to the serve denvdation of forests due to disor derly cuttings of tree. (2) An average unit storage of 415.8mm as the time of initial construation is decreesed to 315.59mm at present, as resultting, we could'nt supply water at 566.24ha. (3) A sediment deposition rate as a relation to the capacity of unit drainage area is as follow; $Qs=1.43 (c/a)^{0.531}$ (4) A sediment deposition rate as a relation to the mean of annval rainfall is as follow; $Qs=672.61 p^{0.024}$ (5) A sediment deposition rate as a relation to the mean slop of drainage area is follow; $Qs=267.21 S^{0.597}$

• 펄프종이기술
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• 제42권3호
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• pp.7-13
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• 2010

KOptimization and control of wet-end process provide a key solution to improve paper quality and production efficiency at the same time. Wet-end of paper machine is to determine three important influencing factors of papermaking i.e., retention, drainage and formation. Good formation of paper could be made at the cost of deteriorated retention or drainage. In the same manner increase of retention aid could cause the bad formation of paper. It is very important to find a proper retention chemical which may satisfy one of three factors without the sacrifice of other two. Laboratory scale analyzing or screening chemical additives of wet-end was reported in this study based on RDA sheet molding. Different from the conventional test method, simultaneous consideration of three important wet-end properties could be made by RDA and consequently more reliable prediction of actual paper machine wet-end could be expected.

• 한국관개배수논문집
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• 제17권2호
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• pp.105-114
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• 2010

Tidal land reclamation provided water resources and land for agriculture and contributed stable crop production. However, climate change by global warming disrupts the hydrologic circulatory system of the earth resulting in sea level rise and more frequent flood for reclaimed arable land. Recently, Suyu reclaimed paddy field in Jindo-gun experienced prolonged inundation after heavy rainfall and there is a growing risk of flood damage. Onsite survey and flood analysis using GATE_Pro model of Korea Rural Corporation were conducted to investigate causes of flooding. To perform the analysis, input data such as inflow hydrograph, the lowest elevation of paddy field, neap tide level, management level of Gunnae estuary lake at the time of the flood were collected. Flood analysis confirmed that current drainage facilities are not enough to prevent 20year return period flood. The result of analysis showed flooding more than 24hours. Therefore, flood mitigation alternatives such as sluice gate expansion, installation drainage pumping station, refill paddy land, and catch canal were studied. Replacing drainage culvert of Suyu dike to sluice gate and installing drainage pumping station at the Gunne lake were identified as an effective flood control measures. Furthermore, TM/TC (SCADA) system and expert for gate management are required for the better management of drainage for estuary dam and flood mitigation.

• 대한환경공학회지
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• 제32권2호
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• pp.121-130
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• 2010

산성광산배수(Acid Mine Drainage; AMD)는 낮은 pH조건에서 중금속 및 황산염이온 등이 다량 용존되어 환경오염 문제를 발생시킨다. 국내의 폐광산 일부에서는 산성광산배수를 처리하기 위해 정화시설이 운영되고 있으나 여전히 주변 하천에 영향을 미치고 있다. 본 연구는 산성광산배수 및 영향을 받는 하천에서 지표미생물의 특이적 유전자를 실시간 정량 중합효소 연쇄반응(Real-time quantitative Polymerase Chain Reaction; Real-time qPCR)을 이용하여 확인 및 정량함으로써 광산배수의 환경영향을 미생물학적으로 판단하고자 수행되었다. 지표 종으로 선정한 미생물은 16S rRNA 미생물 군집분석 결과 발견된 미생물 중 철환원균인 Rhodoferax ferrireducens T118, Acidiphilium cryptum JF-5이며 이 외에 기존에 광산에 존재하는 것으로 알려진 미생물 중 호산성 황환원균인 Desulfosporosinus orientus, 철산화균인 Leptosprillum ferrooxidans, 철 및 황산화균인 Acidothiobacillus ferrooxidans이었다. 최종적으로, 본 연구에서 각 광산의 광산배수가 하천에 미치는 영향을 정량적으로 판단하여 비교하기 위해 광산배수로 인한 하천에서의 미생물 변동 지수를 산정하였으며 연구 대상 4개 광산 중 광산배수 처리시설이 없는 삼탄의 광산배수의 경우 주변 방류 하천으로의 미생물학적 환경영향이 가장 큰것으로 나타났다

• 한국작물학회지
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• 제35권6호
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• pp.487-491
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• 1990

미질향상을 위한 재배기술을 구명하고자 재배시기, 수비 및 실비시용량, 출수후 락수시기 등을 달리하여 시험한 결과를 요약하면 다음과 같다. 1. 재배시기는 늦어질수록 완전립 비율이 떨어지고 청미와 사미의 비율이 증가되었으며, 아밀로스함량도 높아지는 경향이었다. 2. 수비 및 실비 시용량간에는 완전미비율에 큰 차이가 없었으나 무시용에서 약간 높았다. 아밀로스 함량과 단백질함량은 시비량이 증가함에 따라 약간씩 높아지는 경향이었다. 3. 출수후 조기낙수함에 따라 완전립비율은 낮아지고 청미와 사미는 증가하는 경향이었다. 단백질 함량은 낙수시기에 따라 큰 변화는 없으나 아밀로스 함량은 후기락수할수록 낮아졌다.