• Journal of Korean Society of Water and Wastewater
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• v.24 no.1
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• pp.25-32
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• 2010

Until now, we recognize that water supply is a public sector rather than business sector in Korea. In spite of the general recognition, water supply sector has an important role within the national economy as an industry. This study try to analyze the current status of water supply sector as a industry with input-output analysis. As we expected, water supply sector is still minor as an industry sector. However, this is not because water supply sector is not important as a industry, but because the price of water too low or free. With regard to the water price impacts, our results show that the 10% increasing water price has only increased 0.01% of the general price level, which is neglectable. To have a competitiveness as a industry, water sector should be reevaluated based on its socioeconomic value. Government policy for water supply sector should achieve two purposes; the one is for as a public service, the other is for the setting new paradigm as an industry.

• Transactions of the Korean Society of Automotive Engineers
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• v.6 no.1
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• pp.205-212
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• 1998

In this study, the effects of water vapor in inlet air on combustion efficiency, general performance, knock characteristics and emission gas concentration were investig- ated through the experiments of combustion and vibration analyses, emission gas analysis by changing water vapor quantity in inlet air with temperature and humidity auto control unit. With partial vapor pressure increase, the brake torque at wide open throttle status decreased and the average ignition delay angle increased, IMEP (indicated mean effective pressured using the integral and 3rd derivatives of filtered cylinder pressure as knock intensity, which matched well with the method of frequency power spectrum of block vibration signal. Water vapor in intake air had influence on the spark knock sensitivity. With the increase of water vapor content in intake air NOx emission was decreased and HC emission was increased.

• Magazine of the Korean Society of Agricultural Engineers
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• v.42
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• pp.1-8
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• 2000

To examine the irrigation water uses in Sunjin river basin, existing status and operation records of headworks facilities including reservoirs, pumping stations, tube wells, and diversion dams were surveyed and analyzed for the period of 1994∼1998. Daily irrigation demand and water use were estimated for the irrigated paddy field using penman equation, Thank model, reservoir water balance model and daily pumping rate of pumping stations. Irrigation water use from multi-purpose dams in the basin was not included in this study.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.1194-1196
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• 2003

Variations in soil physical and chemical properties can affect agricultural productivity and the environmental implications of crop production. These variations are present and may be important at regional, field, and sub-field (precision agriculture) scales. Because traditional measurements are time-consuming and expensive, reflectance-based estimates of soil properties such as texture, organic matter content, water content, and nutrient status are attractive. Soil properties have been related to reflectance measured with laboratory, in-field, airborne, and satellite sensors. Both multispectral and hyperspectral instruments have been used, with both natural and artificial illumination. Varying levels of accuracy have been obtained, with the best results (r > 0.95) using hyperspectral reflectance data to estimate soil organic matter and water content.

• Journal of Environmental Impact Assessment
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• v.20 no.1
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• pp.89-96
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• 2011

This study was carried out to assess the variations of water quality caused by the dam construction on the river. Six dams-Yongdam, Miryang, Hoengseong, Boryeong, Jangheung and Buan- constructed recently in Korea were selected for the study. Chemical oxygen demand(COD) was increased in the initial stage of water storage at dams compared to the lotic(river) environment, but after 3 years it was maintained lower and stabilized concentrations. Five dams except for Jangheung Dam were maintained Ia~Ib grade conditions under the water quality criteria of Korea. The concentrations of total nitrogen(T-N) were decreased under the lentic(reservoir) environment compared to the river status. Total phosphorus(T-P) was decreased 13~63% at the reservoir condition. We concluded that increase of COD concentration was due to the debris organic materials of the land, but temporary phenomenon. T-N and T-P concentrations were decreased at the lentic condition compared to the lotic.

• Hwankyungkyoyuk
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• v.24 no.4
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• pp.78-93
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• 2011

Clean and safe water is the fundamental element for the good life of people. However, expanding the distrust on the tap water increased the anxiety on drinking water and accelerated the growth of the natural and purified water market. In this respect, this study was made to find an opportunity to invigorate the use of the Seoul tap water for drinking by means of assessing the awareness of the citizen and the current condition on the tap water in Seoul. The findings were that the direct use of the tap water for drinking was very low and 'use after boiling' was also lower relative to 'use of purified water'. Also, the education on the environment should include the importance of the use of the tap water to improve the awareness of the citizen on the tap water and the administrative role, typically for educational institutes and schools, might be required to increase the use of the tab water for drinking.

• Journal of Korean Society on Water Environment
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• v.21 no.5
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• pp.470-476
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• 2005

The Korean Water Quality Index (K-WQI) was applied to the rivers located in the watershed of Daecheong Lake to assess the status of river water quality, and propose potential target constituents for better water quality management in the watershed. The estimated K-WQI value for each river was varied from 70 to 90, and Youngdongcheon showed the worst score while Mujunamdeachen showed the best score. The total nitrogen (TN) and total coliform bacteria were identified as the most significant constituents that degrade the K-WQI values in the rivers. The correlation coefficients (r) were determined between K-WQI and the delivered specific load ($kg/km^2/yr$) of BOD, TN, and TP to justify potential target constituents that have a great influence on the improvement of K-WQI values. The results showed that TN (r=-0.86) and TP (r=-0.85) have a strong negative relationships with K-WQI, but BOD have almost no effect. This implies that BOD, the surrogate parameter for organic pollutants, is no more a feasible water quality variable for the water quality management in the study site.

• Journal of Korean Society on Water Environment
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• v.33 no.6
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• pp.640-649
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• 2017

The purpose of this study is the analysis of the water quality spatial characteristics for the main stream of Nakdong River in consideration of the tributary inflow. The flow and water quality (BOD, TOC, TP) data for 32 monitoring stations located in the main stream and the tributaries of Nakdong River were collected from 2003 to 2016. From the results of the flow and water quality analyses for each site, a status map of the flow and the water quality for Nakdong River was produced. The water quality of each river section was classified according to seven river-environment standards. The water quality changes in the main stream before and after the confluence were analyzed spatially. As a result, the water quality of Kumho River, in particular the Kumho B to Kumho C section, is the worst among the tributaries. In addition, the water quality grades of the lower streams such as Nam River and Miryang are worse than that of the upper streams of the Nakdong River. In the case of the main stream, the water quality grades of the sections between the Wicheon and Nam River confluences and the section from Nakbon L to Nakbon N are relatively poor.

• Journal of Korean Society of Water and Wastewater
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• v.31 no.3
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• pp.205-217
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• 2017

This paper tries to show the efficiency of water financing between central and local governments. From the year of 2017, the operation and maintenance costs for change water pipes has been provided by central government as block grants system(RDSA: Regional Development Special Account). Even though the water financing is responsible for local government, water drought and high production cost in poor area affects the quality of life nowadays. Then, fiscal transfer through block grant for water financing has been decided to invest regional SOC. The purpose of the paper sheds light on the function of the block grant for public provision by water financing. The firstly tried empirical results are based on the survey from local governments and ministry of environments. The point of the empirical analysis shows that the local governments does not have proper measurement for unexpected water leakage and termination until now. In a policy manner, the paper raises the issues about benefit principle for water users by the increase of tariffs. In order to do so, the paper investigates the relationship between the water provision and fiscal status of each local governments.

• Journal of Korea Water Resources Association
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• v.55 no.2
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• pp.171-176
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• 2022

Citizen perception is increasingly emphasized as one of the critical factors in establishing public policies including river management. Our results show that citizens expect integrated river management by specialized river management organization. We found that the river condition was perceived more negatively than the actual status of water quality and river ecosystem by citizens. The gap in perception implies that it is important to restore the reliability of river management. Therefore, it is necessary to encourage organizations with public trust to participate in river management. and credible river management policies should be established and implemented.