• 한국작물학회지
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• 제46권3호
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• pp.209-214
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• 2001

본 실험은 청수, 반탁수, 탁수에 따른 탁도처리와 관수시간에 따른 광합성, 엽록소형광, 증산량 및 회복능을 분석하여 관수스트레스에 대한 벼의 생리반응을 구명하고자 실시한 결과는 다음과 같다. 1. 광합성은 탁도가 높고, 관수 시간이 경과할수록 감소하였다. 특히 관수 36시간 전까지는 약 25%, 42시간이후에는 약 50%가 감소하였다. 증산량은 탁도 및 관수시간이 증가함에 따라 증가하였으며, 청수에서는 약 30%, 반탁수에서는 약 25%, 탁수에서는 약 20%가 증가하였다. Fv/Fm은 탁도 및 관수시간 증가에 따라 감소하였으며, 청수에서는 48시간이후에, 반탁수 및 탁수에서는 36시간이후 약 20%가 감소하였다. 전질소함량은 관수스트레스에 의해 감소하였고, 탁수처리 36시간이후부터 감소량이 켰다. 2. 관수스트레스에 따른 회복력을 나타내는 건물중은 탁도 리별 차이는 작았으나, 관수시간이 경과할수록 크게 감소하였다. 피해정도는 24시간안에는 약 25%, 42시간이후에는 각 처리구 모두에서 약 50%의 생장감소가 일어났다. 관수 48시간의 반탁수 및 탁수는 고사하였다. 광합성은 탁도에 따라서는 청수에서 약 15%, 반탁수, 탁수에서는 10%가 감소하였고, 특히 42시간이후에는 30-50% 감소하였다. 증산량은 탁도 및 관수시간에 처리간의 차이 없이 약 20%증가하였다. 3. 관수 24시간처리에서 관수처리 시 및 퇴수 후 회복기간에도 광합성과 증산량의 일시적인 감소가 일어났다

• 수산해양교육연구
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• 제28권6호
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• pp.1739-1750
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• 2016

This paper proposed a process for estimating the required capacity of emergency drainage system on a ship when the ship encounters a flooding accident. The process was established by selecting target vessel, making a scenario of flooding accident, considering static behavior of flooding water and the effect of ship motion due to ocean condition. In order to obtain the object of the research, MATLAB codes were developed for analyzing of static behavior of flooding water. Additionally, Ansys AQWA-NAUT was used to analyze the motion of the ship under an ocean condition and then the effect of ship motion was considered when the static behavior of flooding water was studied. The research exploited a trawler as a target vessel, and estimate the necessary capacity of the trawler's emergency drainage system by simulating a flooding water in the vessel.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2020년도 학술발표회
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• pp.95-95
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• 2020

Urban flooding occurs in the form of internal-water inundation on roads and lowlands due to heavy rainfall. Unlike in the case of rivers, inundation in urban areas there is lacking in research on predicting and warning through measurement data. In order to analyze urban flood patterns and prevent damage, it is necessary to analyze flooding measurement data for various rainfalls. In this study, the pattern of urban flooding caused by rainfall was analyzed by utilizing the urban flooding measuring sensor, which is being test-run in the flood prone zone for urban flooding management. For analysis, 2019 rainfall data, surface water depth data, and water level data of a street inlet (storm water pipeline) were used. The analysis showed that the amount of rainfall that causes flooding in the target area was identified, and the timing of inundation varies depending on the rainfall pattern. The results of the analysis can be used as verification data for the urban inundation limit rainfall under development. In addition, by using rainfall intensity and rainfall patterns that affect the flooding, it can be used as data for establishing rainfall criteria of urban flooding and predicting that may occur in the future.

• 대한기계학회논문집B
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• 제30권5호
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• pp.489-495
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• 2006

Proton exchange membrane (PEM) should be sufficiently hydrated with a careful consideration of heat and water management. Water management has been a critical operation issue for better understanding the operation and optimizing the performance of a PEM fuel cell. The flooding on cathode side resulting from excess water can limit the fuel cell performance. In this study, the visual cell was designed and fabricated fur the visualization of liquid water droplet dynamics related to cathode flooding in flow channels. The experiment was carried out to observe the formation, growth and removal of water droplets using CCD imaging system. Effects of operating conditions such as cell temperature, air flow rate and air relative humidity on cathode flooding characteristics were mainly investigated. Based on this study, we can get the basic insight into flooding phenomena and its two-phase flow nature. It is expected that data obtained can be effectively used fur the setup and validation of two-phase PEM fuel cell models considering cathode flooding.

• The Korean Journal of Ecology
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• 제20권3호
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• pp.175-179
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• 1997

To explanin allopatric distribution of Carpinus cordata and C. laxiflora in the field the effect of soil flooding on photosynthesis and water relations was tested with field grown saplings. Under the flooding condition stomatal conductance of C. laxiflora decreased markedly from day two after flooding treatment and remanined low throughout the experiment. In contrast, flooding had no effect on stomatal conductance of C. cordata throughout the exper iment. The rate of photosynthesis of C. laxiflora was significantly suppressed under flooding conditions, whereas that of C. cordata was not affected in the flooded condition. On day seven after flooding treatment xylem pressure potential of C. laxiflora significantly decreased. Flooding, however, did not have any effect on the xylem pressure potential of C. cordata throughout the experiment. From these findings it is concluded that there is a difference in resistance to flooding between C. cordata and C. laxiflora and that one of the the factors responsible for allopatric distribution in the two species is flooding.

• 한국물환경학회지
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• 제33권4호
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• pp.434-440
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• 2017

In order to understand the characteristics of phosphorus in the paddy field, this study analyzed $PO_4-P$ and T-P concentrations of irrigation water, flooding water, and runoff from 2008 to 2010. The variation of phosphorous form within hydrologic cycle around the rice paddy field was investigated using the ratio of $PO_4-P$ to TP. In addition, the correlation between pH, EC, and DO in flooding water was analyzed and the factors affecting phosphorus form in paddy field were investigated. The concentration of T-P in flooding water was high during the survey period, and the concentration of T-P in runoff was assumed to be decreased by dilution due to irrigation and rainfall. On the other hand, the ratio of $PO_4-P$ to T-P was lower in flooding water than those of irrigation water and runoff, which was interpreted to be due to the fact that the phosphorus fertilizer was applied in the paddy field but the adsorption was rapidly occurred to the paddy field by the soil. The similar proportions of $PO_4-P$ to T-P in flooding water and runoff suggest that the form of phosphorus outflowed from the paddy is influenced by the form of phosphorus in the flooding water of paddy field. In addition, DO concentration in flooding water showed negative correlation with the concentrations of $PO_4-P$ and T-P. The effort to survey frequent irrigation water quality data is required for the analysis of phosphorus behavior in the paddy water system since concentration of phosphorous and DO in irrigation water would influence rhe form of phosphorous in flooding water and subsequent runoff.

• 대한임베디드공학회논문지
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• 제18권3호
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• pp.133-139
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• 2023

This paper proposes a two-stage Water Shield Automation System (WSAS) to predict the possibility of river overflow and vehicle flooding due to sudden rainfall. The WSAS uses a two-stage Deep Neural Network (DNN) model. First, a river overflow prediction module is designed with LSTM to decide whether the river is flooded by predicting the river's water level rise. Second, a vehicle flooding prediction module predicts flooding of underground parking lots by detecting flooded tires with YOLOv5 from CCTV images. Finally, the WSAS automatically installs the water barrier whenever the river overflow and vehicle flooding events happen in the underground parking lots. The only constraint to implementing is that collecting training data for flooded vehicle tires is challenging. This paper exploits the Image C&S data augmentation technique to synthesize flooded tire images. Experimental results validate the superiority of WSAS by showing that the river overflow prediction module can reduce RMSE by three times compared with the previous method, and the vehicle flooding detection module can increase mAP by 20% compared with the naive detection method, respectively.

• 대한조선학회논문집
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• 제43권4호
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• pp.451-459
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• 2006

When a ship is damaged and flooded, the motion of the damaged ship is significantly influenced by the flooding water dynamics. The flooding water in the damaged ship has been treated as a lumped mass under the quasi-static assumption in most of previous researches. To calculate the motion of damaged ship rigorously, it is necessary to analyze the coupled dynamics of flooding water. In this study, a series of numerical and experimental studies is conducted for the damaged part of ITTC RORO passenger. FLOW3D is used for investigating the feasibility of the state of the art CFD technique. An applicability of the coupled motion analysis of damaged ships can be confirmed by agreement between the numerical results and the model experiments. A CFD technique is considered for the numerical modeling of the dynamics of flooding water.

• 한국물환경학회지
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• 제22권1호
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• pp.110-115
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• 2006

Flooding situation of Sutak basin was simulated and simulation seemed to be consistent with the real flooding situation in terms of high water levels and timings of flooding. The flood simulation model was used to evaluate alternatives to mitigate flooding problems in Sutak basin. From the evaluation of flood mitigation plans, it was found that combined operation of Sutak and Inchang pumping stations through partial diversion of inflow of Sutak pumping station to Inchang pumping station was the most effective one among the suggested mitigation plans. About 500 meter diversion channel will be needed to send 30% of Sutak pumping station inflow to Inchang pumping station. This will reduce overload of Sutak pumping station and the storage capacity of Inchang pumping station will be more efficiently utilized.

• 한국수소및신에너지학회논문집
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• 제23권5호
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• pp.476-483
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• 2012

Proper water management is crucial for the efficient operation of polymer electrolyte membrane (PEM) fuel cell. Especially, for automotive applications, A novel water management that can avoid both membrane dry-out and flooding is a very important task to achieve good performance and efficiency of PEM fuel cells. The aim of this study is to investigate the liquid water behavior on the gas diffusion layer (GDL) surface and in the cathode flow channel of a PEM unit fuel cell under flooding conditions. For this purpose, a transparent unit fuel cell is devised and fabricated by modifying the conventional PEM fuel cell design. The results of water droplet behavior under flooding conditions are mainly presented. The water distributions in the cathode flow channels with cell operating voltage are also compared and analyzed. Through this work, it is expected that the data obtained from this fundamental study can be effectively used to establish the basic water management strategy in terms of water removal from the flow channels in a PEM fuel cell stack.