• Journal of Energy Engineering
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• v.18 no.1
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• pp.17-21
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• 2009

By using the heat recovery of water-cooled chillers, it is possible to reduce the energy operating costs positively and at the same time it could fulfill the heating re-heat air conditioning system as well as the hot water requirements. Basically templifiers are designed to economically to turn the waste heat into useful heat. Waste heat is extracted from a fluid stream by cooling it in the evaporator, the compressor amplifies the temperature of the heat and the condenser delivers the heat to heating loads such as space heating, kitchens and domestic hot water. Design of higher water temperature requirements and split condenser heat recovery chiller system (using of templifiers) produced hotter condenser water approximately up to $60^{\circ}C$ and control the entire heat recovery system.

• Journal of The Korean Society of Agricultural Engineers
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• v.48 no.2
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• pp.27-35
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• 2006

Large dams are managed with operation standard and flood forecasting systems, while small dams do not have management method generally. Shortage of water resources and natural disasters due to drought and flood raised public concerns for management of small dams. Most of small dams are irrigation dams, which need diversified water uses. However, the lack of systematic management of small dams have caused serious water wastage and increased natural disasters. Storage management method and system were developed to solve these problems in small dams. The system was applied to Seongju dam for effective management. The storage management method was established considering hydrology simulation and statistical analysis using the system. This method can bring additional available water, even in the same conditions of the water demand and the supply conditions of watershed. It can improve the flood control capacity and water utilization efficiency by' the flexible operation of storage space.

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.20 no.2
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• pp.125-133
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• 1991

This paper presents some design guidelines for using cold air/water distribution to cool commercial and industrial buildings. Cold air /water distribution systems provide primary air/water for space conditioning at nominal temperature between $3^{\circ}C$ and $10^{\circ}C$ ($4{\sim}5^{\circ}C$ might be recommendable for better selection). By using lower temperature primary air/water equipment could be downsized, means lower first costs, and often reduce annual energy costs up to 50% less than that of the conventional ($13^{\circ}C$) system. This concept takes full advantages of the $2{\sim}4^{\circ}C$ chilled water (brine) available with ice storate systems.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.50 no.3
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• pp.109-116
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• 2001

In this paper, we adapted BLDC motor to PV water pumping systems to maintain high efficiency in the wide speed area. Also, to design confidence we adapted the vector control that drive the maximum torque at each speed limit. We designed optimal gain value of current, speed and pressure PI controller. Inverter gate pulse used Space Vector PWM to reduce torque pulsation of BLDC motor. According to, it was improve general matters of high water storage tank method by direct water supply pumping method.

• Geomechanics and Engineering
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• v.20 no.3
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• pp.267-273
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• 2020

Solutions of the water pressure and groundwater inflow distribution along the tunnel perimeter in a half-infinite aquifer were investigated considering the conditions of the constant head and constant water pressure. It is assumed that the circular tunnel is buried in a fully saturated, homogeneous, isotropic and half-infinite space. Coordinate transformation technique was adopted, the problem of solving the control equations of water pressure in the Cartesian coordinate was transformed to that in the bipolar coordinate system, which can significantly simplify the derivation procedure of the water pressure and inflow distribution. The validation results show the accuracy and advantage of the proposed approach.

• Proceedings of the KSRS Conference
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• 2002.10a
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• pp.728-733
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• 2002

The measurement of river discharge is among the most fundamental observations and is necessary for understanding many water-related issues, such as flooding hazards, sediment transportation, and nutrient movement. Traditionally river discharge is estimated by measuring the water stage and converting the measurement to discharge using a stage-discharge rating curve. The possibility of monitoring river discharge from satellites has been largely ignored, because it is difficult to measure water surface information from space with sufficient precision. In this paper, an efficient approach to discharge estimation using mainly satellite data is developed and described. The proposed method, which focuses on the measurement of water-surface width coupled with river width-stage and stage-discharge relationships, is applied to the Yangtze River with good results.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.1036-1038
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• 2003

Diurnal variations in the atmospheric vapor at Banchiao of Taiwan are studied by analyzing 30 min-averaged data in the summer of 1998. The surface meteorological measurements were mainly obtained from the Central Weather Bureau (CWB) of Taiwan. It is found that precipitable water (PW) is increased in the afternoon. The maximum of precipitable water appears at around 0900 LST. The diurnal range of precipitable water is larger on the days with than without rainfall events. Rainfall events often occur in the afternoon and early morning. We also examine the difference in the characteristics of the PW signatures with and without rainfall according to the occurrence of the times for the rainfall peak and the onset of rainfall.

• Journal of the Korean Society of Visualization
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• v.21 no.3
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• pp.23-32
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• 2023

This study aims to explore the heat transfer and flow phenomena inside an instant water heater and the influence of the design parameters of the water heater on the heating performance was investigated by 3-D numerical simulations considering heat convection. The design parameters are the heating ceramic dimension, the power of the heating device, and the water flow rate. The results show that a reasonable space for the heating device is required to optimize the heating performance. It is desirable to design higher heating device as possible for a given electric power. There exists a critical water flow rate that best meets the heating performance. The change in electric power has no impact on the flow phenomena and heating performance.

• Journal of the Korean Regional Science Association
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• v.34 no.4
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• pp.49-60
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• 2018

To restore urban water cycle, it is necessary to improve domestic laws and regulations related to LID(Low Impact Development), which has been successfully applied to foreign countries. Thus, this study has intended to evaluate domestic legal systems related to space and environmental planning and to suggest directions to improve laws and regulations related to space and environmental planning toward extended application of LID in Korea. To reach this goal, this study has analyze the legal and institutional status of the foreign countries where LID has currently been applied, to derive the factors that laws and institutions are required to support LID based on the above analysis, to evaluate domestic laws and regulations related to space and environmental planning, and to suggest directions to improve the laws and regulations. After the evaluation, this study has found the following results. First, it was found that the concept and basic principles of LID and LID planning and associated methods were no longer mirrored in the space planning-related laws and regulations. However, these problems are not confined to LID, and result from thefailurein applying environmental planning to space planning overall. Second, it was revealed that the environmental planning-related laws and regulations defined the terminologies and targets of LID and suggested different measures to improve LID-related policies differently depending on the backgrounds ofenforcing thelaws and regulations and on environmental properties. Finally, this study has suggested the directions to improve laws and regulations related to space and environmental planning as follows. First, it is necessary to enact a law to support the extended application of LID. Second, the law to be enacted should be connected to laws, enforcement ordinances and regulations, and guidelines related to space planning. Third, environmental benefits provided by both structural and non-structural techniques of LID should be quantitatively measured.

• The Bulletin of The Korean Astronomical Society
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• v.32 no.1
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• pp.94.1-94.1
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• 2007