• Journal of The Korean Society of Agricultural Engineers
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• v.63 no.4
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• pp.97-104
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• 2021

Despite the practical limitations of calculating the amount of inflow and supply related to the operation of agricultural reservoirs, the role of agricultural reservoirs is gradually being emphasized. In particular, as interest in disaster safety has increased, the demand for preliminary measures to prepare for disasters has been rising, for instance, pre-discharging agricultural reservoirs for flood control. The aim of this study is to analyze the plans for the flood season reservoir operation considering pre-discharge period and water level limit. Accordingly, we optimized the simulation of daily storage using the ratio correction factor (RCFs) and analyzed the amount of inflow and supply using K-HAS. In addition we developed the drought determination coefficient (k) as a indicator of water availability and applied it for supplementing the risk level criteria in the Drought Crisis Response Manual. The results showed that it would be difficult to set the water level limit during the flood period in the situation of little water supply for flood control in agricultural reservoirs. Therefore, it is necessary to operate the reservoir management regulations after measures such as securing additional storage water are established in the future.

• Journal of Korean society of Dental Hygiene
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• v.8 no.3
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• pp.85-98
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• 2008

This study is to enforce to ready basic data of effective dental education program and no smoking and no drinking program for high school students who do smoking and drinking, executed investigation by own recording way using smoking and questionnaire consisted of actual conditions and caries prevention awareness and dental health knowledge degree of drinking to some man high school. Analyzes result that total 487 people respond in SPSS WIN 13.0 programs and got following sequence. Result of this study is as following. 1. Mans high school students had more students who do not than a drinking student and main current received most soju. Third-year student appeared by thing which receive a lot of soju than 1 or 2 class student but different other difference was not seen by class. 2. Mans high school students had more students who do not than a smoking student and a student who smoke more than 3 years was the most. I can know was old since third-year student smokes than 1 or 2 class student. 3. It was not difference that keep in mind by drinking, smoking availability although there were many students who recognize that all of the on-time dental medical examination, sugar intake limitation, fluorine inclusion toothpaste, teeth fluorine application are seldom effective on caries prevention. 4. Recognized that right brushing is effective relatively on caries prevention. I was shown difference that recognized that righter brushing is effective on bad tooth courtesy call than a student who a student who do not smoke does, and keeps in mind according to smoking availability ($x^2$=6.78, p<0.05). 5. I knew best about question of 'A caries may not treat if is painless' among that question ask knowledge for a caries, and appeared by thing which do not know best about question of 'Know that method that supply fluorine in water'. 6. A student who do not drink general dental know-how for a caries was high knowledge degree for a caries than a drunk student but it was no difference that keep in mind by drinking availability. Also, a student who do not smoke by smoking availability was high knowledge degree for a caries than a done student but difference that keep in mind statistically was not seen. 7. It was no difference that keep in mind by drinking availability, but a student who do not smoke by smoking availability was high relation knowledge degree with food and a caries than a smoked student, and I was shown difference that keep in mind according to smoking availability(t=-2.03, p<0.05). 8. Awareness and synthetic estimation degree of knowledge degree a student who do not smoke than a smoked student mouth knowledge degree high, and I was shown difference that keep in mind according to smoking availability(t=-2.03, p<0.05). When see as result such as singularity, family, school, all social institutions may have to help by national business coming and try so that can become national business based on special know-how for development of effective and epoch-making education program as quickly as possible.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.297-298
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• 2006

Water leak for the water-cooled generator stator windings affects seriously the availability and the reliability of power plants. Generally, water absorption test is conducted in the power plant during outage in order to confirm if leak part is in the bars or not. In this paper, it is described that the capacitance of winding bars is measured by using the developed water absorption instrument system and the water absorption of winding bars is evaluated by using the stochastic methods. The good results by proposed diagnosis technique can be got. It is expected that the reliability of diagnosis for water absorption is increased if the proposed methods are applied to evaluate the water absorption of stator winding bars.

• Journal of Environmental Impact Assessment
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• v.27 no.3
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• pp.267-278
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• 2018

With climate change and population growth, there are significant increases in water scarcity. There have been water security assessments to abate the gap between water demand and availability to support water resource management. However, most of the assessments are focusing on the water that flows through either on or below the land surface, failing to consider water that infiltrates and can be used by vegetation. This study presents water scarcity assessment accounting for Blue and Green water concept, and applied the method to Boryung region. Monthly streamflow, evapotranspiration, and soil moisture were estimated by SWAT modeling, and each of them was used to analyze Blue and Green water scarcity. Blue and Green water scarcity had different aspect, and the result indicated the time when water scarcity is more likely to happen. The water scarcity assessment framework presented in this paper provides novel assessment method integrating hydrologic and ecosystem aspects, thereby improving the understanding of how water resources should be managed.

• Journal of Korean Society of Water and Wastewater
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• v.8 no.1
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• pp.9-17
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• 1994

The study of lake pollution problems is often related to the dynamic behavior of phosphorus. Several phosphorus models are available that may be suitable to study these problems. Depending on the the management objectives and data availability, some models may be more appropriate than others. Criteria are defined to help modelers choose the most appropriate total phosphorus models for different lakes. These criteria consider in-lake processes such as sediment feedback, stratification, and algal uptake and recycle.

• Journal of the Korean Solar Energy Society
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• v.34 no.5
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• pp.73-80
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• 2014

This study introduces and analyzes the geothermal energy availability in Non-active volcanic region. Jeju island in Korea is situated in non-active volcanic region. The island is composed of rock with high pore and clinker, scoria geological layer formed by volcanic activity about two million ago. Volcanic geological layers with porous characteristics have air, vapor, water and a underground structure through which air or water can move easily. For this reason, it is probable that the mechanism of energy acquisition is by convective heat transfer. For this presumption, the availability of underground air as energy source has been studied here through theoretical analysis and experimental data. The energy output of our system ranged from 2,485,076 kJ/day to 4,060,978 kJ/day monitored using variable velocity air flow controller. Our system has capability to be a reliable energy source irrespective of environmental changes. Consequently, underground air can be utilized for energy source and provide the optimal design of heating/cooling system.

• Fisheries and Aquatic Sciences
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• v.12 no.2
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• pp.118-129
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• 2009

To develop a sustainable management model for oyster farming in Pukman Bay, Korea, we estimated the carrying capacity for oyster farming using food availability data. Optimal culture densities were calculated to be 124-133 individuals per unit flux area ($m^2$) and 310-330 individuals per string. The present annual production is approximately 1,038 tons/year, which is 87% of the estimated maximum yield of 1,193 tons/year. Therefore, considering annual fluctuations and a critical buffer to reduce ecological impacts, the current level is within optimal conditions. During periods of increased water temperature, energy demand was largely met by high primary production. The food supply significantly decreased as the harvest season approached, and 10 out of 21 oyster farms had a deficient food supply for at least 1 month. Therefore, these farms (39% of the farms within the bay) exceeded optimal densities.

• Proceedings of the KSRS Conference
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• v.2
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• pp.1019-1022
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• 2006

Satellite sea ice data from 1978 to the present reveal that the perennial ice (or ice that survives the summer) has been rapidly declining at almost 10% per decade. Warming due to increases in greenhouse gases in the atmosphere is now also being reflected in winter with drastic reductions in the maximum extent observed in 2005 and 2006. The retreat of the perennial ice also exposes more open water and has revealed an asymmetric distribution of chlorophyll a pigment concentration in the Arctic basin. Phytoplankton blooms are most dominant at high latitudes, partly on account of sea ice, but in the Arctic basin, it appears that pigment concentrations in the Eastern (Laptev Sea) Region are on the average three times higher than those in the Western (Beaufort Sea) Region. Such asymmetry suggests that despite favorable conditions provided by the melt of sea ice, there are other factors that affects the productivity of the region. The asymmetry is likely associated with much wider shelf areas in the East than in the West, with sea ice processes that inhibits the availability of nutrients near the surface in deep water regions, and river run-off that affects nutrient availability. The primary productivity in the pan-Arctic region have been estimated using the pigment concentrations and PAR derived from SeaWiFS data and the results show large seasonal as well as interannual variability during the 1998 to 2005 period. The data points towards increasing productivity for later years but with only 9 years of data it is too early to tell the overall effect of the sea ice retreat.

• Journal of The Korean Society of Agricultural Engineers
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• v.55 no.4
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• pp.45-53
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• 2013

Efficient water operation and management of an irrigation system plays an important element in the sustainability of irrigated agriculture. An agricultural water is delivered in many open canals of irrigation delivery system by reservoirs. The poor water distribution and management in an irrigation system is a major factor leading to low water efficiency. It is necessary to compare the estimated irrigation demands with the actual water supplies for decision making to maintain the water supply according to demand strategy. Smarter water management, new technologies and improvement of water management system, is essential to solve the problem of water efficiency and availability. In this paper, the irrigation efficiencies according to water delivery performance indicator were measured with automatic water gauge at irrigation canals, and calculated from spatial and temporal distribution of water supply for the lack of planning in water delivery. The analysis of results are obtain an insight into possible improvement methods to develop canal water management policies that enable irrigation planners to optimally manage scarce available water resources.

• Journal of Korean Society of Water and Wastewater
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• v.20 no.4
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• pp.509-518
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• 2006

Although final water of domestic water treatment plants almost contains highly corrosive characteristics, the countermeasures for eliminating internal corrosion of pipeline system have not been conducted yet by controlling water quality in plants. The technologies of internal corrosion control are to control water quality parameters(pH, Alkalinity, and Calcium Hardness etc.) and to use corrosion inhibitor. Under the conditions of domestic water treatment, first of all, the technologies of adjusting water quality parameters has to be considered. Otherwise, The technology of using corrosion inhibitor is favorably thought to be applied with the technology of adjusting water quality parameters in accordance with the result of availability for water treatment process. Since the technology of adjusting water quality parameter influences on other water treatment processes, the guideline of water quality management to be apt for water quality characteristic is required to be estabilished. While the selection of proper chemicals and technologies is dependent upon the raw water characteristics and water treatment process, typically, the technology of $Ca(OH)_2$ & $CO_2$ additions is considered more effective than other technologies in order to adjust pH and Alkalinity, increase $Ca^{2+}$ and form $CaCO_3$ film