• Journal of Korean Society on Water Environment
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• v.30 no.2
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• pp.128-137
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• 2014

The land use of the unit watersheds should be maintained appropriately in order to keep the load allotment stable for the management of Total Maximum Daily Loads (TMDLs). This study classified the land area in four types and analyzed the use of each land type and its changing pattern by calculating the occupation and conversion ratios for the unit watersheds in three river basins. The forest land showed the greatest occupation ratio with 63.0%, followed by the farm land with 23%, the other area with 8.0% and the site area with 6.0% in 2003. The occupation ratio of the site and the other area increased by 0.4% and 0.2% respectively, and that of the farm and the forest land decreased by 0.4% and 0.2% respectively in 2007. The conversion ratio for the site area ranged from 1.65% to 1.97%, for the farm land from -0.47% to -0.33%, for the forest land from -0.10% to -0.04% and for the other area from 0.17% to 1.97%. It can be inferred that the decrease in the farm and the forest land contributed to the increase in the site area and that the increase in the other area was mainly made by the decrease in the forest land. It could be more effective to take into account the changes in the site area and in the forest land in the process of developing the TMDL plans.

• Journal of the Korean Society of School Health
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• v.8 no.2
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• pp.305-314
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• 1995

A comparative study on the effects of the water fluoridation program and fluoride mouth rinsing program in the elementary school children. This study was performed to compare the oral health status of permanent teeth for children of the caries prevention effects by using methods of fluoride 309 children for water fluoridated program, 240 for fluoride mouth rinsing program and 248 for control group. The DMFS rate, DMFT index, soft and hard deposite rate were analysed from the oral examination. And 300 questionares from the parents who lived in Cheong ju city were evaluated to see the situations of using the tap water. The results were as follows; 1. Caries experience rate in permanent dentition was the lowest in fluoride mouth rinsing group. 2. It was estimated that soft deposite rate was comparatively low in the fluoride mouth rinsing group but calculus deposite rate was no significant difference in each other groups. 3. The 72.0 percentage of parents who lived in non fluoridated water area were misunderstood that they lived in water fluoridated area. 4. The 66.8 percentage of residents used the piped water as drinking water. 5. It was recommended that fluoride mouth rinsing program was suggested in rural area, on the other hands, toothbrusing program in urban area with water fluoridation to prevent the dental caries for school children.

• Journal of Environmental Health Sciences
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• v.42 no.4
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• pp.274-279
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• 2016

Objectives: We investigated bacterial diversity in the Han River water resource protection area in order to provide basic microbiological information on the drinking water safety of the Seoul metropolitan region. Methods: Samples were collected in the spring and winter, but not during the rainy season. Pyrosequencing, gene amplification, and extraction of nucleic acids were employed in this study. Results: In total, 57 and 48 operational taxonomic units were respectively analyzed in samples collected during spring and winter. Proteobacteria were predominant in all samples. The samples contained phylogenetically diverse bacterial communities, with eleven major phyla and 36 genera. Cyanobacteria were predominant in the spring samples, but not in the winter samples. The predominant species in the samples collected during both seasons belonged to the genus Aquamicrobium and Bradyrhizobium. Moreover, no pathogenic bacteria were detected in the samples. Conclusion: Proteobacteria were predominant in the samples from the Han River water source protection area. Cyanobacteria were more predominant in the spring samples than in the winter samples, but Aquamicrobium and Bradyrhizobium were predominant in both sampling seasons.

• Journal of environmental and Sanitary engineering
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• v.7 no.2
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• pp.111-128
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• 1992

According to the increase of population and industrialization, the quality of our drinking water are becoming worse by the contamination of resources, production of THM and other halogenated hydrocarbons during the purifying process, the problem of corroded water supplying pipeline, and the water reservoir tanks, Many people choose groundwater to drink instead of city tap water, but sometimes we get report about groundwater contamination by wastes, swage, septic tank, etc. It is reported that in U. S. over 20% of population are drinking groundwater, but U. S EPA reported the groundwater contamination by pesticides, herbicides, fungicides, fertilizer, and various chemical substances. Craun, et at announced the groundwater contamination by bacteria which are related with poor installation of septic tank. Johnson and Kross mentioned aboutmethemoglobinemia by NO3-N originated from human and animal feces, organic chemicals, and fertilizer, and as the results the infant mortality could be risen. Some scientist also reported the high concentration of metals in groundwaters and some cation and anions, and volatile organic compou nds. Authors investigated 80 groundwaters in urban, agricultural, and industrial area during last 3 month(June - August) to check any drinking water quality parameters are exceeding the standards. The results were as follow. 1, The average value of ammonia nitrate were within the standard, but 11.76% of urban area were exceeded the 10 rpm standard, in agricultural area 42.3175 were exceeded, and in industrial area 20.2% were exceeded the drinking water standard of 10 ppm. the highest concentration was 29.37 ppd in industrial area. 2. The mean value of metals is not exceeded the standard, but there were some groundwater whose Mn value was 0.424 ppm(standard is 0,3 ppm) in urban area, 0.737 rpm in agricultural area, and 5.188 ppm in industrial area. The highest Zn value was 1.221 ppm (standard is 1.0 ppm)was found in industrial area. 3. The percentage of contamination by general bacteria was 8.82% in urban area, 15.38% in agricultural area, and 15.00% in industrial area. Escherichia coil group was also contaminated by 35.29% in urban area, 30.76% in agricultural area, and 30.00% in industrial area. 4, The pH value was within the standard which means there was no influence by acid or alkali chemicals, nor acid rain Through the above results, all the groundwater should be tested to check the safety for drinking water and should make some alternative methods suitable for drink.

• Journal of Korea Water Resources Association
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• v.42 no.3
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• pp.177-190
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• 2009

Rehabilitation projects for old water mains typically require considerable capital investments. One of the economical ways of pursuing the rehabilitation projects is to focus on a specific area within the entire region under management. In this paper the hierarchical clustering methods that analyze spatial inter-relationship of location data are applied to about 8,000 water leak location data recorded in a case study area from 1992 to 1997. Among the hierarchical clustering methods Single, Complete, and Average Linkage Methods are used to identify clusters of the water leak locations and to divide the area according to the defined clusters. By comparing the clusters identified by the clustering methods, the best clustering method for the case study area is suggested. Prioritization of the area for maintenance is obtained based on the water leak incident intensity for the clustered area using the suggested best clustering method.

• Journal of The Korean Digital Architecture Interior Association
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• v.12 no.1
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• pp.53-59
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• 2012

This research studied the characteristics of the customer circulation in four department store food court restaurants located in Seoul. The characteristics of the customer circulation are the following: Before customers leave the dining space where they eat food, they come and go to spaces such as the water purifier space, the napkin storage, and the cup storage. On the other hand, they do not come and go from the dining space to the waste area or the area where used cups are returned. Therefore the spaces, that need to be located very near the dining space, are the water purifier space, the cup storage, and the napkin storage. The waste area does not have to be placed very near the dining area and the area where used cups are returned is not needed. A minority of customers drink water and use napkins after going to the waste area and the area where dirty dishes are kept. To prevent these customers from going against the circulation of the majority of customers, a water purifier space, a cup storage, and a napkin storage should be placed additionally connecting to the waste area and the area where dirty dishes are kept. For effective circulation plan and spatial composition of food court restaurants, these characteristics of customer circulation should be considered. It is not recommended to place the water purifier space, the napkin storage, and the cup storage, the waste area or the area where used cups are returned, and the hand cleansing facility in the same location just for the convenience of workers.

• Journal of the Speleological Society of Korea
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• no.67
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• pp.43-51
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• 2005

This study on Gobongdond Wetlands have hydrogeomorpholosic charateristics in the southern-west of Gogongsan. This study area have been dissected and deep weathered. in geology, this area show banded gneiss consisting of alternated felsis and mafic layers. in geomorphology this area have 3 slope that surplyed the surface water and ground water, but have a little water source by surface water. The most of Gobongdong wetland's water sources are aquifer or confined aquifer, so this wetlands have many seepages or discharges. The characteristics of Soil have retained the wetland's water. Deep weathering made the parents soil into clay minerals.(siallitization) This clay minerals have a high water table.

• International journal of advanced smart convergence
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• v.8 no.2
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• pp.218-226
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• 2019

The use of Information and Communication Technologies (ICT) is the key to operate a change from the traditional manual reading of water meters and sensors to an automated system where high frequency data is remotely collected and analyzed in real time, one of the main components of a Smart Water Grid. The recent boom of ICT offers a wide range of both wired and wireless technologies to achieve this objective. We review and present in this article the most widely recognized technologies and protocols along with their respective advantages, drawbacks and applicability range which can be Home Area Network (HAN), Building Area Network (BAN) or Local/Neighborhood Area Network (LAN/NAN). We also present our findings and we give recommendations on the application of ICT in Smart Water Grids and future work needed.

• Journal of Science Education
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• v.32 no.1
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• pp.73-84
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• 2008

The purpose of this study was to elucidate the perception of drinking water and water environment held by housewives in Gumi city area. The subject of this study were 20 housewives and surveyed with a questionnaire on a self-reporting basis. Results are as follows: 1. Housewives were concerned about drinking water and water environment as natural resource affecting Gumi city area. The percentage og the housewives who had used the purified tap water and the boiled water as drinking water was 35% and 30%, respectively. Also, The percentage of the safety of tap water was 75%. However, their perceived level about the safety of drinking water was relatively low. 2. Housewives suggests that a drinking water conservation campaign and active participation may be more effective if it is linked to local community. Furthermore, continuous education about drinking water and water environment promoting perception of tap water as drinking water.

• Journal of the Korean Solar Energy Society
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• v.29 no.2
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• pp.31-38
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• 2009

This study was conducted to forecast inner water temperature strata change by extracting deep water from a dam. For the methodology, the scope wherein the balance between the volume of low-temperature water intake through the virtual water intake opening as installed within the stored water area and the volume of water intake from the surrounding area is not destroyed was calculated through the CFD simulation technique using the computational fluid dynamics(CFD) interpretation method. This study suggested a supplementary method(diffuser) to avoid destroying the water temperature strata, and the effect was reviewed. In case of intake of the same volume, when the velocity of flow of water intake is reduced by increasing the pipe diameter, the destruction of water temperature strata can be minimized. When the area(height) where the intake of water is possible is low, a diffuser for interrupting the vertical direction inflow should be installed to secure favorable water intake conditions in case of water intake on the upper part. This study showed that there was no problem if the intake-enabled, low-temperature area was secured approximately 10m from the bottom when the scope that does not destroy the water temperature strata in case of water intake was forecast using the regression formula.