• 전자공학회논문지 IE
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• v.46 no.4
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• pp.25-30
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• 2009

The cooling water circulation pipes had been used to drop the temperature of refractory outside shell of blast furnace by cooling plate or stave type. They were attacked by surrounding CO gas and it was the cause that they were corroded and the water inflow in the refractory due to leakage of water. So, the life of refractory material was shorten and changed for the worse the conditions of blast furnace. The automatic sensing device for water leakage of cooling pipe was developed to check the position of trouble by use the micro-process system when cooling water leak and then CO gas will be inflowed into the cooling pipe at the leakage position. The inflowed CO gas will be detected in the micro-process system and delivered the detected position of cooling plate or stave to main control room through the wireless-radio relay station. This system can be possible to detect the position of cooling plate or stave the water leakage part immediately and then deliver the signal to main control room by use the micro-process system and wireless-radio relay station. This system will develop the working condition from manual system to unmanned auto alarm system.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.9
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• pp.1217-1225
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• 2010

The possibility of a sodium-water reaction occurring in a conventional single-wall-tube steam generator in an SFR is a major problem. To improve the reliability of a steam generator, a double-wall-tube steam generator that can reduce the possibility of the occurrence of a sodium-water reaction is being developed. Current developments are focusing on improving the heat-transfer capability of a double-wall tube; further, the development of a leak-detection method to detect the occurrence of a sodium-water reaction during the reactor operation is also underway. In this study, new concepts, which will solve the above-mentioned problems, have been developed. Accordingly, a double-wall tube has been designed, fabricated, and mechanically tested for the purpose.

• Tunnel and Underground Space
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• v.32 no.5
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• pp.285-297
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• 2022

We report results of Extended Leak-Off Test (XLOT) conducted in a large diameter borehole, which is drilled for installation of deep borehole geophysical monitoring system to monitor micro-earthquakes and fault behavior of major fault zones in the southeastern Korean Peninsula. The borehole was planned to secure a final diameter of 200 mm (or more) at a depth of ~1 km, with 12" diameter wellbore to intermediate depths, and 7-7/8" (~200 mm) to the bottom hole depth. We drilled first the 12" borehole to approximately 504 m deep and installed American Petroleum Institute standard 8-5/8" casing, then annulus between the casing and bedrock was fully cemented. XLOT was carried out for several purposes such as confirming casing and cementing integrity, measuring rock stress states. To that end, we drilled additional 4 m long open hole interval to directly inject water and pressurize into the rock mass using the upper API casings. During the XLOT, flow rates and interval pressures were recorded in real time. Based on the logs we tried to analyze hydraulic conductivity of the test interval.

• Journal of the Korean Institute of Gas
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• v.23 no.4
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• pp.1-9
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• 2019

Large-scale industrial boilers operating at high temperature and high pressure, have a large amount of water, and a large amount of energy is released at the time of explosion. Currently, most industrial boilers use gas fuel such as LNG and LPG, etc. and fuel exists in the same space as equipment, so there is a high possibility of secondary damage such as fire or explosion in the event of a boiler accident. Both special care and management are required to operate the very dangerous equipment that causes casualty 2.51 per accident. For boilers of a certain size or more, the Korea Energy Agency conducts inspections in accordance with the Energy Usage Rationalization Act, KS, and public notice of the Ministry of Industry, Trade and Resources. In this research, based on the results of the inspection, the hazard factorss are configured, and a questionnaire is conducted to the inspector, the equipment manager, the maintenance person, and the person in charge of the manufacturer. We analyzed the results by using AHP (Analytic Hierarchy Process). As a result of analysis, generally recognized hazard factorss are not good management, measurement failure, specification failure, water leak, leak analysis, but connection, welding, scale, and corrosion, etc. are relatively less important. It is judged that the adverse factors that are recognized to be highly important among all groups and careers are already well managed, but less important and adverse factors should be well managed to ensure that the safe usage of the boiler.

• Ocean Systems Engineering
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• v.2 no.1
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• pp.33-47
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• 2012

This study revealed the behavior of droplets formed through leak process in deep water. There was a threshold depth named the universal attraction depth (UAD). Droplets rose upward in the zone below the UAD called the rising zone, and settled down in the zone above the UAD called the settling zone. Three mass loss modes were identified and formulated: dissolution induced by mass transfer, condensation by heat transfer and phase separation by pressure decrease. The first two were active for the settling zone, and all the three were effective for the rising zone. In consequence, the life time of the droplets in the rising zone was far shorter than that of the droplets in the settling zone.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2022.04a
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• pp.55-56
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• 2022

Recently, water leak is increasing due to poor compaction or segregation of concrete on external wall. In addition, the flatness quality of the slab is lowered due to the deterioration of the workability of concrete. In this study, the performance of high fluidity concrete of 21MPa using a polycarboxylate-based superplasticizer was evaluated to improve the compaction and quality of the concrete wall.

• Journal of the Korean Society of Marine Environment & Safety
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• v.18 no.2
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• pp.161-165
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• 2012

It is one of the most important to protect the battery over charging for stable use and to extend the life of battery which occurs with repeated charging and discharging. Various research have been studied to know the state of health, and in this paper the terminal voltage of battery is measured to calculate the state of charge simply. The circuit used comparator is designed and built not to fall under the specific voltage of battery. The designed circuit board is attached to the automatic water sanitizer device with a solar power system. The system is located in the water tank where there is not water and electric service, and confirmed that the state of working is good.

• Korean Journal of Medicinal Crop Science
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• v.21 no.2
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• pp.118-123
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• 2013

This study was carried out to select optimal shade materials among four-layered polyethylene (PE) net (FLPN), aluminium-coated PE sheet (APSS), and blue PE sheet (BPSS) in condition of paddy field cultivated 6-year-old ginseng. The order of light-penetrated ratio and air temperature by shade materials was BPSS > APSS > FLPN. Light-penetrated ratio of BPSS before two fold shade was more 3 times and 2 times than that of FLPN and APSS, respectively. Air temperature of BPSS was also higher $1.6^{\circ}C$ and $1.4^{\circ}C$ than that of FLPN and APSS, respectively. BPSS showed good cultural environment because all of light-penetrated ratio and air temperature were become higher in spring and fall season but lower in summer season by additional shade with two-layered PE net. Survived-leaf ratio was highest in BPSS and lowest in FLPN causing a little water leak on a rainy day. Rusty-root ratio was also highest in FLPN because soil moisture content was increased by water leak. The order of root yield was BPSS > APSS > FLPN, and the cause of highest yield in BPSS was higher light-penetrated ratio during spring and fall season, higher survived-leaf ratio, and lower rusty-root ratio than that of APSS and FLPN. BPSS showed highest total ginsenoside content because of high light-penetrated ratio, blue light effect, and the difference in dry matter partitioning ratio such as low taproot ratio, and high lateral root ratio.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.11
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• pp.230-236
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• 2018

Earthquakes over 5.0 on the Richter scale have recently occurred in Korea, which has led to interest in the seismic safety of structures. If a water storage facility is damaged by an earthquake, the water could leak, and the insufficient water would make fire suppression difficult. Therefore, a water storage facility should satisfy safety requirements for earthquakes. In this study, the seismic performance of a water tank was improved by installing a lead rubber bearing between the foundation and the tank. It designed the lead rubber bearing available to the existed concrete foundation. ANSYS was used for modeling to consider the interaction between the fluid and structure of the tank and the hydrostatic and hydrodynamic pressure using four seismic waves. In the case of hydrostatic pressure at 2.5 water level, full level, the same stress appeared irrespective of whether the seismic isolation was installed. When hydrostatic pressure and hydrodynamic pressures are applied at the same time, the seismic-isolated water tank showed less seismic force, and the damping ratio was lower than that of general seismic isolation. This occurred because the weight of the water tank is much smaller than the stiffness of the seismic isolation. The result is expected to be used for further research on seismic capacity evaluation for water tanks.

• Nuclear Engineering and Technology
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• v.23 no.3
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• pp.299-305
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• 1991

Corrosive environment may be generated within steam generators from condenser cooling water in-leakage. Theoretical analysis of the accumulation of chloride as a sea water impurity is being carried out for the condenser cooling water used at YGN-1,2 nuclear power stations. Calculations have shown that highly concentrated chloride solution would be produced within the steam generators in the case of sea water in-leakage. Maximum allowable design condenser leak rate(0.5 gpm) leads chloride concentration of 2.3 ppm at steam generetor and 0.6 ppm at hotwell with the maximum blowdown rate and condensate purification. Concentration factor at steam generator is dependent only on both blowdoum rate and condensate purification efficiency as follows, Concentration Factor（equation omitted）(B$\neq$O) Blowdown and condensate purification are evaluated as the only effective measures to remove impurities from the secondary systems.