• Proceedings of the Korea Water Resources Association Conference
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• 2004.05b
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• pp.790-793
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• 2004

TM/TC system is composed of control center, reservoirs, pumping stations and twelve canal systems. For this system we developed water management program which includes flood forecast program, drought reduction program, irrigation scheduling program and database program. With these program we expect that operators improve the irrigation efficiencies of the irrigation systems due to the timely irrigation on a right place, in a proper quantity and refute tile cost of maintenance and reduce flood and drought damages. In agricultural engineering respect, the databases including water level, rainfall, the amount of flowing can be useful to the researcher who make a study of hydrology and hydraulics in . rural area. Water management program records all of the TM/TC data to MDB format file per 10 minutes.

• Journal of Soil and Groundwater Environment
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• v.20 no.7
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• pp.34-42
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• 2015

Feasibility tests for the hydraulic fracturing were conducted in order to secure additional saline groundwater for irrigating to the land-based aquaculture farm. Two boreholes were placed to the aquaculture farm A and B, respectively. A hydraulic fracturing using single packer was applied to major fracture zones within two boreholes. To identify effects of hydraulic fracturing on securing additional saline groundwater, some selective methods including well logging methods, pumping tests, and groundwater quality analysis were commonly applied to the boreholes before and after the hydraulic fracturing. Enlarging/creating fracture zones, increasing water contents in bedrock near boreholes, and increasing transmissivity were observed after the hydraulic fracturing. Even though the hydraulic fracturing could be an alternative to secure additional saline groundwater to the land-based aquaculture farm, salinity of the groundwater did not meet optimal thresholds for each fingerling in two farms: Fresh submarine groundwater discharge flowed the more into borehole of the farm A that resulted in decreasing a salinity value. Increased saline groundwater quantity in the borehole of the farm B rarely affect to the salinity. Although salinity problem of groundwater limited its direct use for the farms, the mixing with seawater could be effectively used for the fingerlings during the early stage. A horizontal radial collector well placed in the alluvial layer could be an alternative for the farms as well.

• Journal of the Korean Society of Groundwater Environment
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• v.2 no.1
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• pp.1-8
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• 1995

Wastes produce groundwater contamination, offensive odor, and hazardous gases. This study investigates the contamination of groundwater at the Seokdae waste landfill area and seeks the desirable ways to minimize the groundwater contamination. Groundwater levels, water chemistry and aquifer characteristics of wells were examined around the Seokdae waste landfill. The water chemistry of the Dong stream, the groundwater distribution and flow were also studied. The results of this research show that the estimated quantity of the percolation from the landfill base to the ground is 520 ㎥/day and the extent of groundwater contamination is about 1-1.5 km from the center of the waste landfill. The groundwater contains heavy metals and other toxic elements. The conservation and management of the groundwater of the waste landfill need several monitoring wells to check the quantity and quality of groundwater, pumping wells to extract the contaminated groundwater, and slurry walls to protect the movement of contaminated groundwater.

• Journal of Korea Water Resources Association
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• v.44 no.12
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• pp.1001-1013
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• 2011

Development of an optimal water supply system considering water quantity, quality, and economical efficiency is needed to decide optimal available area by combine water supply systems in overlapped area where are more than 2 water sources. The EPAnet and the KModSim were coupled to develop optimal network model. The developed network model was calibrated by measured data from water supply system in Geoje City, Korea in 2007 which have three water sources such as Sadeong booster pumping station, Guchun dam reservoir and Yoncho dam reservoir. The optimum network model was validated by operating results of 2011 to assess the economically optimized service area and optimal pump combination under the given hydraulic operating rules developed in this study. The developed model can be applied into designing water supply systems and operating rules for the conjunctive operation since the model can give the optimal solution satisfied with water quantity, economical efficiency and quality.

• Journal of Biosystems Engineering
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• v.29 no.6 s.107
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• pp.521-530
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• 2004

The solar powered water pump is very ideal equipment because solar power is more intensive when the water is more needed in summer and it is very helpful in the rural area, in which electrical power is not available. The average solar radiation power is $3.488\;kWh/(m^2{\cdot}day)$ in Korea. In this study, the experimental system of the water pump driven by the radiation energy were designed, assembled, tested and analyzed fur realizing the solar powered water pump. Energy conversion ken radiation energy to mechanical energy by using n-pentane as operating material was done and the water pumping cycles were able to be continued. The quantity of the water pumped per cycle ranged from 2 L to 10 L depending on the level of the valve open area far the vapour supply. The average quantity was about 4,366 cc. The thermal efficiency was about $0.018\%$. The pressure level of the n-pentane vapour in flash tank was about $110\~150\;kPa$ and that in the water tank was $93\~130\;kPa$. The pressure in the condenser during cycles was maintained as about 70 kPa. The condensation of the n-pentane vapour in the water tank was increased with the cycles even though the internal and external insulation were done. Air tank performance was better with increasing of the water piston displacement and the water could be pumped with the water piston displacement becoming higher than 6,500 cc.

• Journal of Soil and Groundwater Environment
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• v.6 no.4
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• pp.73-81
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• 2001

With the development of industry and standard of living, the quantity of groundwater consumption has been increasing. For the analysis of groundwater, to determine the hydraulic parameters of aquifer is very important. Various numerical methods have been developed to solve aquifer tests and eliminate the subjectivity of traditional graphical type curve methods. The slope-matching method, which matches the slope of the Theis type curve to the slope of the field data, can be used to numerically solve pump tests for both leaky and nonleaky aquifers. A FORTRAN program on based slope-matching method was developed to obtain the transmissivity, storage coefficient, and leaky factor from pumping test data automatically. Results derived from published data show that the improved slope-matching method gives parameters close to the ones derived by the slope-matching method.

• Journal of The Korean Society of Agricultural Engineers
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• v.48 no.2
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• pp.45-55
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• 2006

This study analyze the hydrologic conditions and the effects of selected runoff characteristics as an attempt to estimate the optimal dredge amount for Asan Lake in Korea. The runoff feature was calculated by utilizing the water balance simulation from DIROM (Daily Irrigation Reservoir Operation Model), which allowed changes in landuse to be quantified using remote sensing for 14 years. The distribution of prospective sediment deposits was been tallied based on the changes in landuse, and quantity of incoming sediment estimated. From these findings, we were then able to simulate the fluctuation of water level, gauging the pumping days not already in use, to determine the frequency of the distribution for around the. requirement annual water storage and the changing water level. The optimal dredge amount was calculated on the basis of the distribution of frequency, taking into account the design criteria for agricultural water with the 10-year frequency of resistant capacity.

• Tribology and Lubricants
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• v.29 no.2
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• pp.111-116
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• 2013

This paper describes the adherence phenomenon, including the tribological characteristics, of a low-pressure fuel pump in a diesel engine for an excavator. Most fuel pumps of a diesel-engine excavator are of the fixed-quantity-gear type and have low pressure. However, the developed pumps develop problems in the pumping system owing to performance instability. Cavitation, which is the main obstacle to stable driving in the pump, occurs between an idle gear and the housing to produce a serious adherence problem. The present study not only examined how to suppress cavitation in a pump but also developed a simple method to improve pump performance through the early creation of a lubrication film with a phosphoric acid coating on the surface of the idle gear. The results showed that the coating successfully prevents breakage of the idle gear due to adherence.

• Journal of Wetlands Research
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• v.20 no.3
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• pp.219-226
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• 2018

Interceptor sewer is installed underground near to the river side mostly ofstate-owned land and the management efficiency of public sewage disposal facilities is decreasing as too much infiltration/inflow(I/I) and river flow to interceptor sewer are caused by broken or deteriorated sewer. This also affects the sewer pipeline project and decreases its efficiency. Therefore, the aim of this study is to investigate interceptor sewer which has influence on the reduction of the project effect. The investigation were performed for three study areas. The study includes the investigation of current condition of interceptor sewer(sewer extension, pipe diameter, pipe type, installed year, installed locations, etc), investigation of inside of sewer by CCTV accompanied by pumping and dredging works where required, investigation of inside of manholes by eyes, calculation of pollutant load using the results of investigation of flow quantity and quality. Multipoint investigations were simultaneously performed for flow quantity at confluence area and other investigations were also performed for flow quantity and BOD for interceptor sewer and comparison of pollutant load, investigation of infiltration/inflow(I/I) caused by deterioration of interceptor sewer. As the result of the study, a main reason for reduced effect of sewer pipe improvement project was analyzed as the low-density sewage and I/I in public seweage treatment Facility due to deteriorated and unmanaged interceptor sewers.

• The Journal of Engineering Geology
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• v.28 no.1
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• pp.101-115
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• 2018

This study was carried out to evaluate the effects of various filter conditions on unconfined aquifer (alluvial aquifer). We made model test device which has filter layer, pumping well and observation well which consist of sand layer and gravel layer to test. Step drawdown test and long term pumping tests were carried out using the device. The permeability characteristics of each test group were confirmed and the optimal yield was calculated. As a result of comparing the optimal yield of double filter and single filter in sand, dual-filter SD-300 was valued at 216.8 % higher final optimal yield than single-filter SS-300. Comparing the dual filter SD-300 and the single filter SS-100 with a thin filter layer, dual-filter SD-300 was valued at 709.2% higher final optimal yield than single-filter SS-300. As a result of analysis of optimal yield change over time, It was confirmed that the ratio of optimal yield of single filter and dual filter increase over time. In order to evaluate the long-term change in water intake efficiency, we considered the point at which the initial optimal yield was reduced by 50%. The dual filter SD-300 is about 351.1% higher than SS-300, which is the same thickness filter, and about 579.0% higher than SS-100. From these results, Assuming that the point at which the initial quantity of water intake is reduced to 50% is the well life, double filters are expected to increase their lifespan by about 3.5 times over single filters of the same thickness and by about 5.8 times over typical single filter. These results can be used to design wells to river bank filtration or filtered seawater. In addition, it is possible to clarify the effect of the double filter through the comparison with the future field test results.