• Journal of The Korean Society of Agricultural Engineers
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• v.62 no.3
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• pp.85-94
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• 2020

Since the salinity of irrigation water is a critical constraint to the production of certain vegetable crops, salinity was considered as one of the most important factors of irrigation water. The purpose of this study were to monitor and assess the effects of saline irrigation water on strawberry and red radish growth in protected cultivation. One control and three treatments, which were differentiated according to the level of salinity in irrigated water, were employed for each vegetable to assess the effects of the irrigation with saline water. Monitoring has shown that using irrigation water with salinity above a certain level causes excessive accumulation of sodium (Na⁺) in both strawberry and red radish. Increased Na+ content was analyzed to be able to decrease the sugar content in strawberry. In addition, the salinity higher than the threshold level of irrigation water was found to reduce the growth and yield of strawberry and red radish. This study could contribute to suggest criteria for safe use of saline water in protected cultivation, although long-term monitoring is needed to get more representative results.

• Journal of The Korean Society of Agricultural Engineers
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• v.54 no.1
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• pp.27-38
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• 2012

This study is to analyse the hydrological behavior of agricultural reservoir using CAT (Catchment hydrologic cycle Assessment Tool). The CAT is a water cycle analysis model in order to quantitatively assess the characteristics of the short/long-term changes in watershed. It supports the effective design of water cycle improvement facilities by supplementing the strengths and weaknesses of existing conceptual parameter-based lumped hydrologic models and physical parameter-based distributed hydrologic models. The CAT especially supports the analysis of runoff processes in paddy fields and reservoirs. To evaluate the impact of agricultural reservoir operation and irrigation water supply on long-term rainfall-runoff process, the CAT was applied to Idong experimental catchment, operated for research on the rural catchment characteristics and accumulated long term data by hydrological observation equipments since 2000. From the results of the main control points, Idong, Yongdeok and Misan reservoirs, the daily water levels of those points are consistent well with observed water levels, and the Nash-Sutcliffe model efficiencies were 0.32~0.89 (2001~2007) and correlation coefficients were 0.73~0.98.

• The Journal of Korean Medicine
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• v.16 no.2 s.30
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• pp.433-446
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• 1995

The present study was carried out to investigate the effect of water extract and 70% ethanol extract from Gastrodiae Rhizoma on cardiovascular activities and plasma levels of catecholamines in unanaesthetized spontaneously hypertensive rats. The depressor response in SHR was observed during three to six hour period after an oral administration of water extract from Gastrodiae Rhizoma(GR). There was a statistically significant correlation between the magnitude of the depressor response induced by an oral administration of water extract from GR and the initial control blood pressure level. The increase in blood pressure induced by norepinephrine was less in Wistar rat treated with GR water extract than those without GR extract. No significant change in heart rate was observed in SHR receiving either water extract or ethanol extract from GR. Associated with the depressor response, there was a concomitant reduction in plasma levels of norepinephrine in SHR at 4 hour after an oral administration of water extract from GR. Plasma levels of norepinephrine and epinephrine were decreased slightly at 2 hour after an oral administration of ethanol extract from GR. These results suggest that the depressor effect of water extract from GR may be due, in part, to a decreased sympathoadrenal activity.

• Journal of The Korean Society of Agricultural Engineers
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• v.58 no.6
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• pp.9-21
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• 2016

Agricultural reservoirs in Korea have been recognized as an emerging resource for recreational and cultural activities for residents. However, most of the reservoirs are eutrophic and showing high level of contamination with nuisance algal bloom and offensive odor during the summer. For better management and restoration of the reservoirs' water quality, scientific modeling approaches could be used to diagnose the problems and evaluate the efficacy of alternative control measures. The objectives of this study were to validate the performance of a three-dimensional (3D) hydrodynamic and water quality model (Environmental Fluid Dynamics Code, EFDC) for a eutrophic agricultural reservoir and assess the effect of bypassing of the effluent from a wastewater treatment plant on the reservoir water quality. The 3D model successfully simulated the temporal variations of water temperature, DO, TOC, nitrogen and phosphorus species and Chl-a observed in 2014 and also captured their spatial heterogeneity in the reservoir. The simulation results indicated that the point source bypassing may reduce the T-N and T-P concentrations of the reservoir by 6.6 ~ 8.2 %, and 1.7 ~ 16.8 %, respectively. The bypassing, however, showed a marginal effect on the control of TOC due to the increased algal biomass associated with the increased water retention time after bypassing as well as the lower TOC level of the effluent compared to the ambient reservoir water.

• Journal of the Korean Geotechnical Society
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• v.19 no.6
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• pp.61-70
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• 2003

The behaviour of an earth and rock-fill dam is complicated due to reservoir water and various materials in zoned dams. Different materials with a wide range of permeability and seasonal variation of reservoir water result in the time dependent post-constructional behaviour. In aged dams it is often required to control water level to keep the dams safe. In this case information on the post-constructional dam behaviour is important. However, present geotechnical knowledge does not fully support the occasion. In this study the post-constructional behaviour of a dam is investigated using coupled finite element models for series of idealized water reservoir cases: impoundment, draw down, seasonal fluctuation with different rising and falling speeds. Numerical results were analysed in respect of geotechnical parameters such as load transfer, hydraulic fracturing potential and stress paths. It is shown that the control of water level is an important factor while operating dams.

• Magazine of the Korean Society of Agricultural Engineers
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• v.41 no.5
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• pp.68-76
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• 1999

The purpose of the study was to investigated the change of hydraulic characteristics like water surface profile and rivered section in the down stream of Keum river after the construction of esturary dam. The effect of esturary dam on the flood control in the Keum river was recognized with the data of two flood events happened in July, 1987 before the construction and in August, 1995 after the construction of estuary dam. For example , duration time above the water level of the warning -flood was changed from 46.5 to 42.8 hours and duration time above the eater level of the danger-flood was changed from 24.7 to 19.8 hours at the Kyuam station. The time difference to reach the water level of the designated -flood between Kyuam and Kangkyung was changed from 3 hours in 1987 to 12 hours and 20 minutes in 1995. The water surface slope of river decreased 25.6% between estuary dam and Kangkyung and increased 16.5% between Kangkyung and Kyuam, and decreased 8.8% between Kyuam and Kongju. As the result, velocity was getting faster and river bed was scoured in the reach of Kangkyung and Kyuam, and velocity was getting slower and river bed was sedimented in the reach of Kangkyung and estury dam.

• Journal of Institute of Control, Robotics and Systems
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• v.20 no.9
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• pp.936-941
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• 2014

Walking mechanisms are very important for legged robots to ensure their stable locomotion. In this research, Klann-linkage is suggested as a walking mechanism for a water-running robot and is optimized using level average analysis. The structure of the Klann-linkage is introduced first and design variables for the Klann-linkage are identified considering the kinematic task of the walking mechanism. Next, the design problem is formulated as a path generation optimization problem. Specifically, the desired path for the foot-pad is defined and the objective function is defined as the structural error between the desired and the generated paths. A process for solving the optimization problem is suggested utilizing the sensitivity analysis of the design variables. As a result, optimized lengths of Klann-linkage are obtained and the optimum trajectory is obtained. It is found that the optimized trajectory improves the cost function by about 62% from the initial one. It is expected that the results from this research can be used as a good example for designing legged robots.

• Journal of the Semiconductor & Display Technology
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• v.18 no.4
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• pp.87-91
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• 2019

The diagnosis of the failure for the existing electrical facilities was based on regular preventive maintenance, but this preventive maintenance was limited in preventing a lot of cost loss and sudden system failure. To overcome these shortcomings, fault prediction and diagnostic techniques are critical to increasing system reliability by monitoring electrical installations in real time and detecting abnormal conditions in the facility early. As the performance and quality deterioration problem occurs frequently due to the increase in the number of users of the motor pump, the purpose is to build an intelligent control system that can control the motor pump to maximize the performance and to improve the quality and reliability. To this end, a vibration sensor, temperature sensor, pressure sensor, and low water level sensor are used to detect vibrations, temperatures, pressures, and low water levels that can occur in the motor pump, and to build a system that can identify and diagnose information to users in real time.

• Food Science of Animal Resources
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• v.33 no.2
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• pp.170-180
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• 2013

This study was conducted to evaluate the antioxidant activity of oven-dried ($60^{\circ}C$) tomato powder (TP) as affected by water solubility and to evaluate the effects of TP on the physico-chemical properties, and antioxidant and antimicrobial activities of emulsified pork sausages with two levels of TP (1% and 2 %). After fresh tomatoes were homogenized and dried at $60^{\circ}C$ oven, they were extracted by stirring with water. Then, the aqueous solution was filtered, and water soluble and insoluble tomato powders were obtained with freeze drying. In experiment I, total phenolic contents in oven-dried tomato powder, water soluble and insoluble powder were more than 2 g/100 g. The radical scavenging activity and iron-chelation ability of the water-insoluble extracts were higher than those of dried TP and water-soluble extracts. In experiment II, pH values and Hunter L values of pork sausages formulated with TP were reduced. However, hunter a and b values were higher than those of the control, and those effects were increased with increased levels of TP. 2-Thiobarbituric acid reactive substance values of pork sausages containing TP were lower than that of the control during refrigerated storage, regardless of the TP level. These results indicated that TP could be used as a natural color agent and antioxidant in meat products without defects.

• Journal of the Korean Society of Food Culture
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• v.30 no.6
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• pp.818-824
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• 2015

Makgeolli is a health beneficial food for diabetes compared to other alcoholic beverages. We examined the effect of Makgeolli on blood glucose level and survival rate in a streptozotocin (STZ)-induced diabetic mouse model. We force fed 30 male STZ-induced diabetic ICR mice Makgeolli consisting of 6% alcohol (DM-MAK), 6% ethanol (DM-EtOH), or distilled water (DM-DW) for 4 weeks. In the DM-MAK group, food intake and water intake were higher than those of other groups after 4 weeks. Body weight, however, was not different among the experimental groups. We also found no significant difference in blood glucose level among the experimental groups. In normal ICR mice fed Makgeolli for 1 week, the area of the blood glucose curve was higher than those of other groups fed 6% ethanol, 2% glucose, or distilled water. Survival rates of STZ-induced diabetic mice fed Makgeolli, 6% ethanol, or DW for 4 weeks were 100%, 25%, and 62.5%, respectively. In conclusion, Makgeolli had no beneficial effect on blood glucose in a STZ-induced diabetic mouse model, although their survival rate was high. These results show that Makgeolli has an effect on type 1 diabetes through other mechanisms than blood glucose control.