• Journal of Korean Society of Water and Wastewater
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• v.26 no.3
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• pp.361-372
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• 2012

In order to establish the methodology for estimating an emergency drinking water supply in Korea, overseas cases and accidents history of cutting off water supply were investigated, and questionnaire was conducted. Investigating accidents history of cutting off water supply in Korea, actual cutting off times of most cases were less than 13hours. Also, cases related with water quality and facility failure have been not enough to derive useful information for estimating an emergency water. From the results of questionnaire and cross-tabulation analysis, about 1,066 lpcd(liter per capita${\cdot}$day) as an emergency water and 14 days as tolerable outages time could be estimated. The results of water quality simulation could tell us that it might take 5-16 days for pollutant matter to travel from 15 contamination points to source water intake point in the selected reservoir(D-dam). This travel time was in good accordance with the estimated tolerable outage time, 14days.

• Journal of the Korean Society of Mechanical Technology
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• v.13 no.1
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• pp.113-118
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• 2011

To analyze and verify the effect of replacing thermal storage heater by a cascade cycle heat pump using midnight electricity was installed and tested at a customer's house in Wonju, Korea. The electric night storage heater is consist of 30kW electric heater and 2,700 liters of thermal storage water tank to supply hot water for warming house floor. The power for electric heater was cut off and hot water was only generated by cascade cycle heat pump. Current thermal storage water tank was not eliminated and electric heater wiring was modified. Some operation logic of the heat pump was also modified for proper operation. The required capacity of the heat pump and hot water temperature for given warming condition were estimated. The estimated capacity of heat pump was about 19kW and estimated hot water temperature for proper heating was at least $75^{\circ}C$.

• The Journal of Engineering Geology
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• v.28 no.2
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• pp.267-276
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• 2018

Volcanic ash from volcanic eruptions spreads to vast areas hundreds of kilometers away, and when volcanic ash flows into surface waters, it will be damaged by water supply. In case of water supply facilities, it provides to people drinking water and domestic water, be consumed by the people cause social disorder when water supply is cut off due to damage such as water pollution caused by harmful materials of volcanic ash. However, when we looked at the disaster management manual, the establishment of a water supply facility manual to deal with the damage of volcanic ash was found to be insufficient. Therefore, in this study, the existing volcanic and water pollution related manuals were analyzed and problems were derived. In order to make quick situation judgment and response activities, we have suggested the scope of the water supply facility manual, disaster type, major missions and system of related organizations, and scenario of crisis situation by disaster type.

• Journal of ILASS-Korea
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• v.2 no.2
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• pp.35-42
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• 1997

An innovating technique of atomizer has been proposed to supply and to atomise molten materials. Both of a simple geometry of nozzle and an improved nozzle have been fabricated in the present study. With these nozzles, characteristics of the suction and disintegration have been empirically investigated. The important conclusions are as follows; In the case of a simple nozzle: 1) Although the sucking up and supplying of molten materials are available, the applications of powder metallurgy are limited. 2) It is concluded that the more air flow rate, $W_A$ or the shorter the height of air nozzle from the surface of supplied water, $L_h$, the more the atomizing mass of liquids, $W_L$. In the case of an improved nozzle: 3) The stable liquids can be supplied due to cut off the passage of surrounding air entrainment by air jets. 4) The atomizing mass of liquids, $W_L$ has affected not so much on the height of nozzle from the surface of supplied water, $L_h$ as that from the orifice, hc.

• Korean Journal of Environment and Ecology
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• v.36 no.5
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• pp.468-480
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• 2022

Although the construction of the Nakdong River Estuary Barrage (NEB) improved the water supply in the region, it cut off the longitudinal connectivity of the estuary aquatic ecosystem. Thus, the social demands for opening the NEB have been continuously raised, and the efforts to restore the aquatic ecosystem of the Nakdong River estuary began in 2017. Many fish species have inhabited the Nakdong River estuary. Since their habitat and migration characteristics vary widely, the sluice gate operation considering them is essential for the restoration of the aquatic ecosystem. Therefore, in this study, we monitored the fish species living and migrating in the Nakdong River estuary and analyzed the possibility of smooth movement of for each fish species by calculating the average flow velocity according to the type and the height of the gate opening. Moreover, we selected the target fish species for each month and suggested the sluice gate operation according to the depth of the main habitat to present the measures that are ideal for optimal restoration of the aquatic ecosystem in the Nakdong River estuary area.

• Magazine of the Korean Society of Agricultural Engineers
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• v.15 no.1
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• pp.2913-2924
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• 1973

This study was to investigate the drying mechanism of stratified soil by investigating 'effects of the upper soil on moisture loss of the lower soil and vice versa' and at the same time by examining how the drying progressed in the stratified soils with bare surface and with vegetated surface respectively. There were six plots of the stratified soils with bare surface($A_1- A_6$ plot) and the same other six plots($B_1- B_5$ plot), with vegetated surface(white clover). These six plots were made by permutating two kinds of soils from three kinds of soils; clay loam(CL). Sandy loam(SL). Sand(s). Each layer was leveled by saturating sufficient water. Depth of each plot was 40cm by making each layer 20cm deep and its area. $90{\times}90(cm^2)$. The cell was put at the point of the central and mid-depth of the each layer in the each plot in order to measure the soil moisture by using OHMMETER. soil moisture tester, and movement of soil water from out sides was cut off by putting the vinyl on the four sides. The results obtained were as follow; 1. Drying progressed from the surface layer to the lower layer regardless of plots. There was a tendency thet drying of the upper soil was faster than that of the lower soil and drying of the plot with vegetated surface was also faster than that of the plot with bare surface. 2. Soil moisture was recovered at approximately the field capacity or moisture equivalent by infiltration in the course of drying, when there was a rainfall. 3. Effects of soil texture of the lower soil on dryness of the upper soil in the stratified soil were explained as follows; a) When the lower soil was S and the upper, CL or SL, dryness of the upper soils overlying the lower soil of S was much faster than that overlying the lower soil of SL or CL, because sandy soil, having the small field capacity value and playing a part of the layer cutting off to some extent capillary water supply. Drying of SL was remarkably faster than that of CL in the upper soil. b) When the lower soil was SL and the upper S or CL, drying of the upper soil was the slowest because of the lower SL, having a comparatively large field capacity value. Drying of CL tended to be faster than that of S in the upper soil. c) When the lower soil was CL and the upper S or SL, drying of the upper soil was relatively fast because of the lower CL, having the largest field capacity value but the slowest capillary conductivity. Drying of SL tended to be faster than that of S in the upper soil. 4. According to a change in soil moisture content of the upper soil and the lower soil during a day there was a tendency that soil moisture contents of CL and SL in the upper soil were decreased to its minimum value but that of S increased to its maximum value, during 3 hours between 12.00 and 15.00. There was another tendency that soil moisture contents of CL, SL and S in the lower soil were all slightly decreased by temperature rising and those in a cloudy day were smaller than those in a clear day. 5. The ratio of the accumulated soil moisture consumption to the accumulated guage evaporation in the plot with vegetated surface was generally larger than that in the plot with bare surface. The ratio tended to decrease in the course of time, and also there was a tendency that it mainly depended on the texture of the upper soil at the first period and the texture of the lower soil at the last period. 6. A change in the ratio of the accumulated soil moisture consumption was larger in the lower soil of SL than in the lower soil of S. when the upper soil was CL and the lower, SL and S. The ratio showed the biggest figure among any other plots, and the ratio in the lower soil plot of CL indicated sligtly bigger than that in the lower soil plot of S, when the upper soil was SL and the lower, CL and S. The ratio showed less figure than that of two cases above mentioned, when the upper soil was S and the lower CL and SL and that in the lower soil plot of CL indicated a less ratio than that in the lower soil plot of SL. As a result of this experiments, the various soil layers wero arranged in the following order with regard to the ratio of the accumulated soil moisture consumption: SL/CL>SL/S>CL/SL>CL/S$\fallingdotseq$S/SL>S/CL.