• Journal of Korean Port Research
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• v.13 no.1
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• pp.133-146
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• 1999

Mokpo coastal area is connected to the adjacent a long river and two large basins. It is essential for port planning coastal zone management and environmental impact study to analyze the data related to the ship operation and variation of current and water quality due to the development of water area including dredging reclamation and estuary barrage. The Yongsan river estuary weir and Yongam-Kumho basins discharge much of water through water gates for the purpose of flood control and prohibit salt intrusion at the inland fresh water area. To meet this purpose discharge through the gates have been done at the period of maximum water level difference between inner river and sea level. This discharged water may cause the changes of current pattern and other environmental influences in the vicinity and inner area of semi-closed Mokpo harbor. In this study ADI method is applied to the governing equation for the analysis of the changes on current pattern due to discharged water. As the results of this study it is known that the discharging operation causes many changes including the increase of current velocity at the front water area at piers approaching passage and anchorages. Discussion made on the point of problems such as restricted maneuverability and the safety of morred vessels at pier and anchorage. To minimize this influence the linked gate operation discharging warning system and laternative mooring system are recommended.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.21 no.2
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• pp.94-100
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• 2022

A study was conducted to significantly increase the heat transfer area by simultaneously burying the excel pipe in the floor and wall of a container house, thereby greatly reducing the initial heating time. In addition, a small hot water boiler suitable for the heating load of a small container house with a maximum area of 6 m² was studied. A wall-mounted hot water boiler was developed as a result of the study. When a hot water boiler is installed outdoors for heating, heat radiation energy is lost in winter from the hot water boiler and hot water pipe due to the low temperature. We propose an approach through which the energy loss was greatly reduced and the temperature of hot water increased in proportion to the operating time. Moreover, as the mass flow rate of the hot water flowing inside the excel pipe increased, the temperature of the hot water decreased. The temperature of the wall and floor surfaces of the container house increased in proportion to the increase in the mass flow rate of hot water flowing inside the excel tube. Natural convection heat transfer was realized from the wall and floor surfaces of the container house, and the heat transfer area was increased by a factor of 3 with respect to heat transfer area limited to the floor by the existing hot water panel. As a result, the initial temperature increase rate was much higher because of the larger heat transfer area.

• Journal of Fisheries and Marine Sciences Education
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• v.27 no.4
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• pp.1021-1030
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• 2015

For the water quality improvement in the ocean outfall area of sewage treatment plant, this study tried to control the water quality of outfall area using the biofilter method through seaweeds, a way of ecological engineering treatment that is applicable in the marine ecosystem. Therefore, this research made an attempt the main factors necessary for creating seaweed bed to improve water quality in the outfall area of sewage treatment plant, and the results are as follows. In the case of making the seaweed bed in the ocean outfall area of sewage treatment plant, Habitat Suitability Index of Ecklonia cava per all survey points, considered physical and physico-chemical factors in 5~10 meters below sea level, was 50~93% (average 80%), so this seaweed, Ecklonia cava, was suitable for making the seaweed bed.

• Journal of Korean Society of Water and Wastewater
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• v.19 no.5
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• pp.547-556
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• 2005

The objective of this study is to obtain adequate intercepting flow during wet weather conditions in combined sewer system. Two study sites are selected under considering different population density, one is developed area with heavy urbanization. Another is recently developing area. In the analysis of field investigation, SS was most significant in initial flushing effects compared with other factors and showed the result with the order of COD, TP, TN. As compared with event mean concentration(EMC) of runoff, BOD, TN and TP showed high concentrations in wide area with relatively large population density. It is by the reason that much pollution load was discharged to receiving water from urbanized area during wet period. According to results of storm-water modeling, 53% of total COD and 52% of total SS pollution load were discharged to receiving water by overflow than intercepting capacity in middle population density site. Also, in the urbanized area, pollution load was discharged to receiving water by 49% of total COD and 77% of total SS. These results can be applied to setup for pollution load flow(budget) generation, collection, treatment and discharging in order to obtain adequate intercepting flow.

• Journal of environmental and Sanitary engineering
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• v.9 no.1
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• pp.17-28
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• 1994

There are many possibilities that may lead to low quality of drinking water Recently, some unknown deposits in tap water raised a lot of public concern regarding the safety of drinking water in Seoul. We analyzed the quality of tap water from several areas of Seoul, including the area where public complaints about tap water were high. The results shows that the quality of tap water in Seoul was good, well below the environmental standards. Only the tap water from the area with high public complaints showed turbidity higher than that of other area. Also, result shows that component of deposit in tap water was Al, Fe, Mn, and Zn. Based on the research result we propose several measures that might help to reduce the amount of deposit in tap water as follows : 1 Using coagulant aid when coagulating or adjusting pH when filtering. 2. Replacing old water pipeline with new corrosive- resistant one. 3. Increasing water treatment efficiency by enhancing water treatment system such as automation of water treatment system adjusting production capacity, and improving operational condition of filler basin. 4. Chlorine disinfection at the distribution reservoir would help maintaining the same pH level and chlorine concentration throughout the water pipeline and reduce corrosion of pipe.

• Journal of The Korean Society of Agricultural Engineers
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• v.58 no.5
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• pp.19-28
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• 2016

This study was to design the optimal locations of the water level monitoring to quantify the agricultural water use in irrigation area supplied from an agricultural reservoir. In most of agricultural areas without TM/TC (Tele-Monitoring and Tele-Control) or monitoring network, irrigation water have been supplied on conventional experience and agricultural reservoir have been operated based on the operating simulation results by HOMWRS (Hydrological Operation Model for Water Resources System). Therefore, this study quantified the amount of agricultural water use in an irrigation area (Musu Reservoir, Jincheon-gun) by establishing water level monitoring network and analyzed the agricultural water saving effect. According to the evaluation of the economic values for water saving effect, the saving agricultural water of 1.7 million ton was analyzed to have economic values of 0.85 million won as water for living, and 1.78 million won as water for industrial use. It is identified to secure economic feasibility of the new water monitoring network by establishing one monitoring point in the entrance, irrigation area and endpoint through the economic analysis.

• Journal of environmental and Sanitary engineering
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• v.5 no.2
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• pp.15-21
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• 1990

Current analyses of tap water in Seoul metropolitan area prove the water is still safe, despite the Pollution of raw water source. However, it also significantly suggests that a feasibility study of apply, additional advanced technology to existing water treatment processes is needed in order to cope with future pollution. Also, the monitoring of water quality within private, multi-household buildings is important as the monitoring of public water distribution system.

• The Journal of Korean Society for School & Community Health Education
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• v.1 no.2
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• pp.87-104
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• 2000

The purpose of this study was to obtain the basic data as a improvement method through the fact-revealing concerning the drinking water management of school and utilization of student. The problems of the research are as follows: First, to investigate status of management of drinking water by area and school. Second, to investigate student's utilization of drinking water by area and school. 1,400 students was selected at 45 elementary and middle-high schools located in Kang-won province, and this study was constituted of two questionnaires(for school's questionnaire and student's questionnaire). The results was analyse through the frequency analysis, $x^2$-test on the basis of the above research problem by SPSS program. The findings of this research are as follows; 1) The Management of School Drinking Water First, the source of school drinking water was mostly piped water. Inspection of water quality has been fulfilled under four times a year, in the other hands, from the result inspection, the schools which was given inadequate determination was 22.2%. Second, reservoir cleaning and hygiene inspection failed far short of the regulations. Especially, reservoir cleaning was managed by exterior consignment industry not low-level officials. Third, school water drinking was the most supplied through the type of water purifier. Water purifier has been distributed to city-located and middle-high school highly, factually the water from water purifier was served with water cup. Fourth, the selection standard of water drinking manager showed slightly differently by school, accordingly there need to develope integrated system with the respective to its effective systematic management. Fifth, water cup was mostly treated by only water clear, which is to vindicate the problems concerning hygiene management. 2) Utilization of school student on Drinking Water First, Disbelief on drinking water of school student was very high. Especially, proportion of middle-high school student's disbelief of drinking water was higher than elementary school student, also girls higher than boys. Many of student have heard to don't drink water from around people. And there were showed meaningful differences by area and school. Second, It was showed many student recognize had to utilize water purifier, boiled water. However, they have still drunken the tap water or portable water from their home. Third, Many of student showed negative response with the respective to the management conditions of drinking water in classroom, There were showed meaningful differences by area and school. From the fact-revealing of water cup management, Students mostly answered to 'only water clear' and the answer of 'None use' or 'With personal cup' was higher. Fourth, In bad experience of Drinking Water, student mostly answered to 'occasionally' and there were showed meaningful differences by school. student's disease experience with school drinking water was few and there were showed meaningful differences by area and gender.

• Proceedings of the Korea Water Resources Association Conference
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• 2005.05b
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• pp.138-142
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• 2005

The change of precipitation and temperature due to the global. warming eventually caused the variation of water availability in terms of potential evapotranspiration, soil moisture, and runoff. In this reason national long-term water resource planning should be considered the effect of climate change. Study of AOGCM-based scenario to proposed the plausible future states of the climate system has become increasingly important for hydrological impact assessment. Future climate changes over East Asia are projected from the coupled atmosphere-ocean general circulation model (AOGCM) simulations based on Intergovernmental Panel on Climate Change (IPCC) Special Report on Emissions Scenarios (SRES) A2 and B2 scenarios using multi-model ensembles (MMEs) method (Min et al. 2004). MME method is used to reduce the uncertainty of individual models. However, the uncertainty increases are larger over the small area than the large area. It is demonstrated that the temperature increases is larger over continental area than oceanic area in the 21st century.

• Journal of The Korean Society of Agricultural Engineers
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• v.53 no.6
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• pp.51-58
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• 2011

The objective of this study is to identify whether or not the ground water level is decreasing. We suggest a method of estimating the change in groundwater level using newly developed groundwater pumping station data. The Goseong area located in Gyeongnam province was selected considering three factors. First, this area demands relatively large amount of irrigation water because most of the land is used as a paddy field and the proportion of the paddy field within total arable land is increasing. Second, groundwater level data in nearby area are available since these are monitored by Water Management Information System (WAMIS). Third, many groundwater pumping stations have been developed in this area in order to overcome droughts thus detail information for pumping stations are available. Regression results indicate groundwater level has been decreased for over 20 years. This decreasing trend is due to the shortage of surface irrigation water which was caused by the decrease in rainfall.