• Journal of Korean Society of Water and Wastewater
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• v.27 no.5
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• pp.611-619
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• 2013

In this study, Back Tracing Calculation Method was developed to determine the leakage location and leakage amount. Previously developed determination method of monitoring location and newly developed Back Tracing Calculation Method were applied to the sample pipe network and real size pilot plant. After leakage was assumed in the pilot plant, leakage location and leakage amount could be traced by Back Tracing Calculation Method. From the results, it was found that Back Tracing Calculation Method can be applied for the leakage detection in water distribution system. Furthermore, this method can be applied for the pressure management or leakage detection as a pressure control method in water distribution system.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2000.11c
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• pp.639-646
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• 2000

Hot air heater with light oil combustion is the most common heater for greenhouse heating in the winter season in Korea. However, since the heat efficiency of the heater is about 80%, considerable unused heat in the form of exhaust gas heat discharges to atmosphere. In order to capture this exhaust gas heat a heat recovery system for plant bed heating in the greenhouse was built and tested in the hot air heating system of greenhouse. The system consists of a heat exchanger made of copper pipes, ${\phi}\;12.7{\times}0.7t$ located inside the rectangular column of $330{\times}330{\times}900mm$, a water circulation pump, circulation plastic pipe and a water tame The total heat exchanger area is $1.5m^2$, calculated considering the heat exchange amount between flue gas and water circulated in the copper pipes. The system was attached to the exhaust gas path. The heat recovery system was designed as to even recapture the latent heat of flue gas when exposing to low temperature water in the heat exchanger. According to performance test it can recover 45,200 to 51,000kJ/hr depending on the water circulation rates of 330 to $690{\ell}$/hr from the waste heat discharged. The exhaust gas temperature left from the heat exchanger dropped to $100^{circ}C$ from $270^{circ}C$ by the heat exchange between the water and the flue gas, while water gained the difference and temperature increased to $38^{circ}C$ from $21^{circ}C$ at the water flow rate of $690{\ell}$/hr. And, the condensed water amount varies from 16 to $43m{\ell}$ at the same water circulation rates. This condensing heat recovery system can reduce boiler fuel consumption amount in a day by 34% according to the feasibility study of the actual mimitomato greenhouse. No combustion load was observed in the hot air heater.

• Journal of People, Plants, and Environment
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• v.23 no.1
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• pp.15-21
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• 2020

In this study, we compared efficiency of different aquatic plants in removing indoor pollutants and examined their potential to purify indoor air. Two liter of water in chamber was used as the control, while the other chambers containing water lettuce (Pistia stratiotes), water hyacinth (Eichhornia crassipes), and water coin (Hydrocotyle umbellata) were used as treatment groups. Temperatures inside all the chambers were maintained between 20 ℃ and 23 ℃. Humidity in the chambers with aquatic plants increased by 30% and 50% control respectively. The removal of formaldehyde per unit leaf area was examined in each aquatic plant. It turned out that water hyacinth removed the highest amount of formaldehyde, followed by water lettuce and water coin. Both water hyacinth and water lettuce increased the amount of removal of formaldehyde until the end of the experiment. In the case of airborne dust (PM 10) and fine dust (PM 2.5), water coin, which had the highest number of leaves, removed more PM 10 and PM 2.5 than the other aquatic plants, with statistically significant difference. In addition, both water coin and water hyacinth smoothly opened and closed stomata before and after the experiment. Consequently, as the aquatic plants were effective in controlling humidity and removing pollutants, they can be used as air purifying plants.

• Journal of Veterinary Clinics
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• v.18 no.2
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• pp.105-110
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• 2001

The water celery, Oenanthe Javanica DC., is a perennial herb which mostly grows on a damp ground or a streamside. The water celery is widely distributed in Korea, Japan, china, Taiwan, Indonesia, Malaysia and the other countries. From ancient times, the water celery has widely been used for food or medicine. In herbal medicine, the water celery has a medical actions which are defervescence, diuresis, jaundice, edema, hypotensor, haematic, angiostasis, sthenia, appetizer. Recently, studies on the water celery are briskly being conducted. For example, studies on the morphologic property and classifications of origin of the water celery, studies on the chemical constituents of the water celery which contains vitamins, proteins and amino acids, studies on the bio activities of the water celery which contains flavonoids. However, there is not studies of hematological changes in dogs administrated the water celery until now. Consicontly, this study was conducted to observed the hematological changes in dogs administrated excessive amount of the water celery crude juice for a long period. In this studies, all dogs showed significantly decrease of the PCV and Hb, and increase of the WBC, GSH and reticulocytes, but did not significantly change in the RBC, MCV, MCHC and Met-Hb.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.2 no.3
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• pp.54-63
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• 1999

Quantifications of fish farm influences on stream water quality may provide basic informations on watershed management to reduce environmental impact due to fish farm development and to conserve stream water quality in forested watershed area. In this research stream water qualities around (Mt.) Paekun area were monitored by seasons and the following results were obtained. Due to the increase of pH in effluent water from the fish farm it was believed that alkalization of stream water can be accelerated by large scale development of fish farms in the forested watershed area. Negative effects on stream water quality was also observed by indications of increase in electrical conductivity and temperature of effluent water from the fish farm. Decreases of physicochemical indexes such as the amount of dissolved oxygen, percentage of dissolved oxygen and total amount of ion in effluent water from the fish farm were also negative aspects in downstream ecology. It is recommended that water purification system as well as eco-friendly fish farm design be incorporated to large scale fish farm development plan in forested watershed area.

• Journal of Environmental Policy
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• v.8 no.4
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• pp.37-49
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• 2009

While water management policies in Korea have focused on industrial water demand during the last decade, the amount of industrial water usage has decreased significantly. This paper estimates the technical efficiency of industrial water in order to test whether the reduction of industrial water usage is a result of improving the level of technical efficiency of industrial water. This paper shows that the technical efficiency of industrial water use slightly decreased from 0.5183 in 1998 to 0.4853 in 2003. In addition, these estimates are much less than those of other inputs and so, there is still much room for reducing the amount of industrial water use through improving technical efficiency even though the average productivity of industrial water has improved during this period.

• Journal of Korean Society of Water and Wastewater
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• v.25 no.3
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• pp.293-305
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• 2011

A special concern is paid to the risks with which small-sized water resources systems are confronted in supplying water in the far future. Taking the Gwangdong dam reservoir as a case study, the authors seek to understand demand-side and supply-side disturbances of a reservoir, which, respectively, corresponds to effects of water demand changes on the intake amount and those of climate changes on the inflow amount. In result, it is demonstrated that both disturbances in the next 50 years are almost unpredictable. Yet the projection ranges, thought of as relatively reliable information that models offer, reveal that severity and period of water shortage is very likely to change. It is therefore concluded that water resources management requires more rigorous approaches to overcoming high uncertainties. The methods and models for projecting those disturbances are selected, based on practicality and applicability. Nevertheless, they show a large usefulness, especially in dealing with data shortage and reducing the needs for expensive modeling resources.

• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.465-470
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• 2009

This study investigated the water saving technology for the toilet stool system in a water closet. Since in 21st century water would be the prospected factor to measure the wealth of a country instead of the oil, water saving technologies in the toilet stool in a closet system is getting more important than the cleaning stool and the reducing noise performances. According to the statistics in Korea the percentage of using water in toilet is about 27% to the total amount of water used. Therefore, this study theoretically approached the possible amount of water saving and suggested the new variable position straight trap device in the toilet stool system.

• Journal of Pharmaceutical Investigation
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• v.37 no.5
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• pp.269-273
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• 2007

Poorly water-soluble ibuprofen and ethanol can be encapsulated in gelatin microcapsule by spray drying technique. To select an optimal formula of ibuprofen-loaded gelatin microcapsule which increased the ethanol content and ibuprofen solubility with the decreased amount of gelatin in the microcapsules, in this study, the effect of gelatin, ibuprofen and sodium lauryl sulfate on the ibuprofen solubility and the amount of ethanol and ibuprofen encapsulated in the gelatin microcapsule were investigated. Ibuprofen solubility and the amount of ethanol encapsulated increased as gelatin and sodium lauryl sulfate increased, reached maximum at 4% and 0.6%, respectively and then followed a rapid decrease. Furthermore, the ibuprofen solubility and the encapsulated ibuprofen content increased as the amount of ibuprofen increased, reaching maximum at 0.5% and beyond that, there was no change in the solubility and ibuprofen content. However, the encapsulated ethanol content remained same irrespective of the amount of ibuprofen. On the basis of increased ibuprofen solubility, our results showed that the formula of ibuprofen-loaded gelatin microcapsule at the ratio of gelatin/ibuprofen/sodium lauryl sulfate/water/ethanol of 4/0.5/0.6/30/70 with ibuprofen solubility of about $290\;{\mu}g/mL$ and ethanol content of about $160\;{\mu}g/mg$ could be a potential oral delivery system for poorly water-soluble ibuprofen.

• Journal of Korea Water Resources Association
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• v.52 no.12
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• pp.1075-1086
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• 2019

Recently, as the incidence of climate warming and abnormal climate increases, the forecasting of hydrological factors such as precipitation and river flow is getting more complicated, and the risk of water shortage is also increasing. Therefore, this study aims to develop a model for predicting the amount of water intake in mid-term. To this end, the correlation between water intake and meteorological factors, including temperature and precipitation, was used to select input factors. In addition, the amount of water intake increased with time series and seasonal characteristics were clearly shown. Thus, the preprocessing process was performed using the time series decomposition method, and the support vector machine (SVM) was applied to the residual to develop the river intake prediction model. This model has an error of 4.1% on average, which is higher accuracy than the SVM model without preprocessing. In particular, this model has an advantage in mid-term prediction for one to two months. It is expected that the water intake forecasting model developed in this study is useful to be applied for water allocation computation in the permission of river water use, water quality management, and drought measurement for sustainable and efficient management of water resources.