• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.10
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• pp.1718-1726
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• 2010

Utilization of renewable energy is becoming increaingly important from the viewpoints of environmental protection and conservation of fossil fuel. However, the generating power of renewable energy is always fluctuating due to the environmental status. This paper presents a scheme for supervisory control of wind generation system with the energy storage and STATCOM to reduce the power variation. In this paper, we especially concentrate on constant power output control of wind generation system. In order to achieve this purpose, the coordinated control strategy between different types of energy storage system and reactive power compensation device. The proposed control scheme has been validated by PSCAD/EMTDC simulation. As a result, the proposed scheme can handle the power output of wind generation system with a constant value.

• Proceedings of the KIEE Conference
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• 2001.07a
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• pp.521-523
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• 2001

The electric demand increase, financial need for new power plant constructions and environmental problem have led to search for more efficient energy production and energy conservation technology. To minimize the construction of power plants and reduce total power consumption include installation of inverters to motors used for pumps and fans. However, the high price of Inverters is the biggest obstacle to their wide use. Accordingly, to maximize the effect of energy saving by the expanded use of inverters, governmental economic support as well as the analysis of energy saving effect. This paper presents the cost-effectiveness analysis for DSM program evaluation and case study to analyze inverter DSM program.

• Journal of Conservation Science
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• v.34 no.6
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• pp.569-580
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• 2018

The possibility of applying poulticing was studied for removing Paraloid B72, a resin used for fixing an earthen mural painting. Five types of poultices were selected from clay and gel types, and acetone, ethanol, and methyl ethyl ketone(MEK) were used as mixed solvents. The possibility of mixing between the poultice and solvent was investigated, and then the spreadability, fluidity, acidity, drying properties, and solubility of the poultices were examined to confirm the characteristics. A poultice agent, which is suitable for applying to a mural painting, was selected and applied to a painting layer sample coated with Paraloid B72. As a result, all painting layers were good condition at under 50% of the solvent. The removal efficiency of Paraloid B72 was more effective when most of the solvents were used at 50%, rather than at 25%. However, it is difficult to mix 50% of MEK and ethanol with the gel-type poultices. When used at 25%, the removal performance was poorer than that at 50%, but the mixing with all the poultices was successful. In addition, the adsorption and removal power of the gel-type poultice were better than those of the clay-type, but the latter was expected to be more suitable in short-time cases due to its high drying speed. The results of this study show that the dissolution performance varies depending on the poultices and solvents. Hence, the poultice and solvent should be selectively applied, considering the fixative of the mural to be removed.

• Journal of the Korean Professional Engineers Association
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• v.27 no.4
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• pp.46-55
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• 1994

Demand Side Management(DSM) is a system to reduce the investment cost for new power plant construction and expansion of supply facilities, power through the investment for the energy conservation and load management. In this study, the trend of the energy environment, the necessity and feasibility of DSM shall be investigated and analysed, so that this study will give a help to select and develope a proper DSM technologies for actual use.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2000.11a
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• pp.235-240
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• 2000

This paper presents the reasonable method for electric power management through efficient use of electricity. With a rapid of national economics and living standard, electrical energy consumption markedly increased. Especially it is increased electrical energy consumption in commercial buildings and thus an energy conservation through efficient use of electricity became more important.

• Journal of the Korean Home Economics Association
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• v.25 no.1
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• pp.121-127
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• 1987

The purpose of this study was to investigate the importance of mental capacity and to see whether it can be a barometer to predict childrne's cognitive development. The instruments used were Pictoral Test of Intelligence to select homogeneous samples, Cucui Scale for their M-power and Conservation Test. The results showed that M-power develops as age increases, and it can be a strong variable to predict their cognitive development. It has been demonstrated that capacity increases developmentally but whether this reflects changes in capacity perse, or in the efficient use of that capacity is a debatable issue. More study needs to be repeated for this matter.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2011.04a
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• pp.63-64
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• 2011

• Journal of the Korean Professional Engineers Association
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• v.37 no.1
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• pp.38-42
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• 2004

The term of ‘the Basic Engineering-Doctrine’implies that “doing more with less”, which had been resulted in a proliferation of “technical slaves”capable of substituting for human labor or animal power during the 1760’s Industrial Revolution, Recently with the downsizing this has been also used to be as a basic concept of every company in Korea. Basically the word is based on a conception of energy conservation for human activities.

• The Transactions of the Korean Institute of Power Electronics
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• v.24 no.3
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• pp.147-152
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• 2019

With the recent emphasis on the importance of energy conservation, studies on high-efficiency elevator systems are being continuously conducted. Therefore, pulse width modulation converters are commonly used in traction drives on elevator systems. Wide bandgap devices have been increasingly commercialized, and their application to power conversion systems, such as renewable and energy storage system, has been gradually increasing. In this study, a SiC inverter for an elevator traction drive is investigated. In particular, an inverter is designed to minimize stray and parasitic inductance. Input and output filters are designed by considering switching frequency. The designed SiC inverter reduces volume by approximately 32% compared with that of a Si inverter, and power converter efficiency is over 98.8%.

• Journal of international Conference on Electrical Machines and Systems
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• v.1 no.4
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• pp.477-482
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• 2012

This paper describes a new rotor position sensorless control method for SRM drives based on an improved simplified flux linkage method. In the traditional simplified flux linkage method, every phases take turns conduction and current chopping control method is used. Every phases take turns conduction means turning on the incoming working phase while turning off the working phase. This conduction mode causes coupling between turn-on and turn-off angles, which goes against optimal efficiency or torque ripple minimization with sensorless speed control. In the improved simplified flux linkage method, turn-off angle is calculated by flux loop, the turn-on angle can be given arbitrarily and has no relations with the turn-off angle, and the current chopping control method is used. The speed and rotor position can be estimated then. Finally, a sensorless SRM speed control system and an experiment platform with DSP are built and validity of this method is confirmed.