• Journal of Wetlands Research
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• v.4 no.1
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• pp.51-61
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• 2002

The wetland is a biologically integrated system consisting of water, soil, bacteria, plants, and animals. The wetland helps sustain the ecosystem, control the micro-climate and flood, maintain the ground water level, and provide fishing grounds. From the environmental standpoint, the wetland plays a vital role in reducing water pollution by filtering out sand and other polluted matters, producing oxygen, absorbing chemicals and nutrients. For these reasons, interest in restoring the wetlands has been steadily increasing. Artificial wetland, which is also referred to as created wetland or constructed wetland, is an alternative to natural wetland. Like natural wetland, artificial wetland is environmentally friendly and can effectively lower pollutant levels. The Korea government is actively reviewing the construction of artificial wetlands in mining and water supply areas to decrease nonpoint pollutant sources. This paper attempts to develop a pollutant removal model for the water quality improvement function of artificial wetlands. Artificial wetland can improve the quality of the water; however, depending on the type of water inflow, vegetation and hydrology, its effect can be different.

• Proceedings of the Korea Water Resources Association Conference
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• 2018.05a
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• pp.258-258
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• 2018

In this study, a hydraulic flow model and an error correction model are combined to improve the flood simulation accuracy. First, the hydraulic flow model is calibrated by optimizing the Manning's roughness coefficient that considers spatial and temporal variability. Then, an error correction model were used to correct the systematic errors of the calibrated hydraulic model. The error correction model is developed using Artificial Neural Networks (ANNs) that can estimate the systematic simulation errors of the hydraulic model by considering some state variables as inputs. The input variables are selected using parital mutual information (PMI) technique. It was found that the calibrated hydraulic model can simulate flood water levels with good accuracy. Then, the accuracy of estimated flood levels is improved further by using the error correction model. The method proposed in this study can be used to the flood control and water resources management as it can provide accurate water level eatimation.

• Journal of The Korean Society of Agricultural Engineers
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• v.56 no.6
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• pp.103-111
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• 2014

This study was to develop the flood analysis module (FAM) for implementation of a web-based real-time agricultural flood management system. The FAM was developed to apply for an individual watershed, including agricultural reservoir. This module calculates the flood inflow hydrograph to the reservoir using effective rainfall by NRCS-CN method and unit hydrograph calculated by Clark, SCS, and Nakayasu synthetic unit hydrograph methods, and then perform the reservoir routing by modified Puls method. It was programmed to consider the automatic reservoir operation method (AutoROM) based on flood control water level of reservoir. For a $15.7km^2$ Gyeryong watershed including $472{\times}10^4m^3$ agricultural reservoir, rainfall loss, rainfall excess, peak inflow, total inflow, maximum discharge, and maximum water level for each duration time were compared between the FAM and HEC-HMS (applied SCS and Clark unit hydrograph methods). The FAM results showed entirely consistent for all components with simulated results by HEC-HMS. It means that the applied methods to the FAM were implemented properly.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 1998.10a
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• pp.311-317
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• 1998

Recently irrigation reservoir has been developed to perform multipurpose function. To get a maximum effect it requires to establish optimal management system for irrigation reservoir in drought and flood season. Especially we dealt with optimal flood control system for irrigation reservoir in this study. This system consists of real-time rainfall data via online system, real-time flood forecasted by SCS method in hourly basis, storage volume by water balance equation, optimal releasing discharge from the gate, the water level in right downstream, and calculation of innundated area, depth, and time using GIS, and amount of flood damages. If we consider the relation of these sub module reasonably, we can reach the optimal flood control to minimize flood damage

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2007.04a
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• pp.783-788
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• 2007

Many researches have been studied several vibration control device such as TMD and TLD to reduce the influence of wind or seismic waves for high-rise buildings. TLD provides some advantages such as easy installation and low maintenance cost. However, because of the difficulties in evaluating the characteristics of TLD, the dynamic characteristics of TLD must be investigated by experiment or analysis. In this study, the dynamic response analysis of structure with TLD was carried out to verify the vibration control ability of the proposed TLD for high-rise building. The parameter of interest was chosen by the height of the water level and the frequency of input seismic wave in the same shape of water tank.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.24 no.7
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• pp.967-975
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• 2000

Transient characteristics of a boiler and turbine system for a steam power plant are simulated. One-dimensional unsteady models are introduced for each component. An interaction between boiler and turbine and a control of the water level in the drum are taken into account. Transient responses of the system to the variations of main system variables such as fuel and air flow rate, cooling water injection rate at the attemperator, gas recirculation rate at the furnace and opening of the turbine control valve are examined. Effect of fluid inertia and tube wall thermal inertia on predicted dynamic behavior is investigated.

• The Korean Journal of Food And Nutrition
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• v.7 no.2
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• pp.108-113
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• 1994

This study was carried out to evaluate the effect of Cnidi rhizoma (CR) water extract on fat accumulation In fatted rats induced by the oral high fat administration for six weeks. To accomplish this evaluation, the serum and liver tissue have been examined for enzyme activity, cortisol and insulin level. The change of liver or tissue have been observed by the light microscope. GOT GPT and LDH activities were lower than the control group. Insulin and cortisol were higher than the control group, due to the fat accumulation. The liver of the control group observed by the tight microscope appeared to the fatty liver, but CR group showed some improvement of the fatty liver Based on the above results, it was shown that it is possible to improve fat accumulation induced by high fat dietary through using the oral administration of Cnidi rhizoma water extract.

• Journal of Marine Life Science
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• v.6 no.2
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• pp.117-123
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• 2021

Post-disturbance recovery pattern of subtidal soft corals-macroalgae mixed community and the role of water depth were investigated. The experiment was conducted in a subtidal rock wall of Munseom, Jeju Island, Korea for 2.5 years. Artificial disturbance was done at established treatment plots at depths of 10, 15 and 20 m and were then compared with undisturbed control plots. After disturbance, recovery of soft corals was very slow, whereas macroalgae quickly occupied the plots and reached a similar level as the control in 6 months, and this pattern was consistent at all water depths. This unbalanced speed of recovery caused higher macroalgae establishment than soft corals in treatment compared to control plots, indicating a possible phase shift in the community structure. This study provides an important implication for the necessity of monitoring the influence of disturbance at a larger scale, from a conservation perspective of soft corals in Jeju coast.

• Journal of Nutrition and Health
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• v.33 no.5
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• pp.497-501
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• 2000

We investigated the effect of tea fungus/kombucha(TF) beverage on serum and liver lipid metabolism in growing male rats. The rats(Sprague-Dawley) were divided into five groups; control(TF free water), 20 or 40% TF groups(20 or 40% TF in water) and 20 or 40% TFS groups(20 or 40% TF autoclaved in water) according to the level of TF supplementation. The rats were fed ad libitum each of the experimental beverage for 7 weeks. The body weight gain of all the TF and TFS groups were similar to that of the control group. The total lipid and triglyceride concentrations of serum in the 40% TF group were increased more than those in the control group, but those in the 20% TF and 20% TFS groups were similar to that of the control group. The total cholesterol, HDL-cholesterol concentrations, HDL-cholesterol / total cholesterol ratio and atherogenic index of serum in all the TF and TFS groups were similar to those of the control group. The LDL-cholesterol concentration of serum was significantly lower in the 20% TF group than that in the control group. The LDL-cholesterol concentration of serum was significantly lower in the 20% TF group than that in the control group, but those of the 40% TF, 20% TFS and 40% TFS groups were similar to that of the control group. The liver weights of all the TF and TFS groups were heavier than that of the control group. The concentrations of hepatic triglyceride in the 20% TF and 20% TFS groups were significantly decreased, compared with that in the control group. The concentrations of hepatic total cholesterol in all the TF and TFS groups were significantly more decreased than that in the control group. These results indicated that the liver weights of tea fungus/kombucha beverage feeding rats were increased, also the serum triglyceride and total cholesterol concentrations of 40% TF feeding rats were increased. but the serum LDL-cholesterol, hepatic triglyceride and cholesterol levels of 20% TF feeding rats were decreased.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.47 no.1
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• pp.48-53
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• 2002

To investigate the changes in the composition and pool size of carbohydrates under drought stress, white clover (Triforium repens L.) were exposed to -0.04 Mpa(well-watered, control) or to -0.12 Mpa (drought-stressed) of soil water potential during 28 days. Dry weight of leaves in drought-stressed plants was remarkably decreased by 45% within 14 days and 74% within 28 days compared to those of the control. Glucose concentration in drought-stressed plants was increased, while that of control was slightly decreased or remained at same level throughout experimental period. Fructose and sucrose concentrations in leaves were not significantly changed for drought-stressed plants, but those of the control were significantly decreased on plant after 14 days. Fructose and sucrose concentrations in stolon of control plants were sharply decreased, while that of drought-stressed plants was less varied. Those concentrations in roots were generally increased in drought-stressed plants. The concentration of total soluble sugars at 28 day was 438.0 and 632.6 mg $g^{-l}$ dwt. in control and drought stressed plants, respectively. Starch concentration of stolon and roots of control plants was significantly increased to 2.0 and 1.4 times of initial level, respectively, whereas those of drought stressed plants was nearly same level or slightly decreased compared to initial level.l.