• 한국사회복지학
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• 제43권
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• pp.328-357
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• 2000

From Foucault's Perspective of power, this study is trying to illuminate the characteristics and limitations of 'empowerment' which is widely accepted as a central value and practice skill of social work. Notwithstanding the superficial consensus on the empowerment, the author shows that it is a confusing concept with contrasting expectations and conflicting methodologies or only a wishful rhetorical jargon. Furthermore, he argues that the empowerment is not just a value-free intervention skill working outside the ruling power but a ruling-discourse or power-mechanism of a liberal society which makes citizens responsible voluntarily. For a theoretical background for these arguments, the 2nd chapter reviews Foucault's theory of power. The 1st part of the 3rd chapter summarizes the historical background of empowerment practice and its methodological characteristics and meanings, the 2nd part reviews the existing critics on the conceptual and practical limitations of empowerment, and the last part reveals, based upon Foucault's theory of power, that the empowerment is a typical mode of ruling power in liberal societies. The author expects that this study may warn the moral and intellectual superiority complex of social work discourse and help stimulate the ethical sensibility and responsibility in social work practice.

• 한국가스학회지
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• 제11권1호
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• pp.18-22
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• 2007

전력선에 지락고장이 발생할 경우 대지로 유입된 고장전류에 의하여 인접한 배관에 아크 용융이 발생하면 가스폭발이나 기름유출과 같은 대형사고를 발생시킬 수 있으며, 배관의 유지 및 보수를 담당하는 작업자의 안전에도 위험을 초래할 수 있다. 본 논문에서는 대지를 통한 철탑과 배관 사이의 아크 발생에 대하여 알아보고, 국내외에서 사용되고 있는 철탑 인근에 매설된 배관의 이격거리 기준을 조사하였다.

• KEPCO Journal on Electric Power and Energy
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• 제8권2호
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• pp.111-118
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• 2022

SF₆ is used as an insulating gas because of its excellent electrical insulation properties, non-toxicity, and non-inflammability. On the other hand, the global warming potential of SF₆ is 23,900 times higher than that of CO₂. The Korea electric power cooperation (KEPCO) is responsible for 80% of the domestic SF₆ usage, and approximately 6,000 tons are currently charged in electrical and power facilities. KEPCO will gradually replace the insulating gas with SF₆-free gas from 2023. SF₆ decomposition facilities are required because more than 60 tons of SF₆ will need to be disposed of annually from existing equipment. This study developed a novel decomposition and pollution control system that can process 60 tons of SF₆ per year. This facility can decompose more than 97.7% of SF₆, with the emissions of hazardous and toxic materials below the legal limit.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• 제5B권2호
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• pp.111-117
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• 2005

Several of the conventional hydraulic systems in an automobile are now being replaced by more reliable and energy efficient electromechanical systems. Developments in the brushless permanent magnet machine and in the power and control electronics are the key factors responsible for this transformation. These applications brought out some performance challenges associated with the brushless machines. This paper will focus on these challenges to be able to use these machines in such applications. In terms of replacing hydraulic systems with electromechanical systems, steering system is leading the way in automobiles. Currently, steering systems using Electro-hydraulically assisted systems and Electrically assisted (Electromechanical) systems are in the market. Though the Electrically assisted power steering has several advantages over other systems, certain performance and cost challenges delayed the penetration of such systems in to the market.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2002년도 전력전자학술대회 논문집
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• pp.515-518
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• 2002

A synchronous generator is equipped with an automatic voltage regulator(AVR), which is responsible for keeping the output voltage constant under normal operating conditions at various levels. The output voltage of Synchronous Generator is regulated constantly by field voltage control in excitation system. High frequency PWM converter (Buck converter) type excitation system for synchronous generator that can sustain prefer output voltage level even at the fault condition happened. The proper operation of the proposed excitation system was verified through the simulations and the experiments.

• 한국태양광발전학회지
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• 제3권3호
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• pp.56-61
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• 2017

With the appearance of the climate change concerns, energy transition to renewable energy is accelerating over the world. Korea, a latecomer to the renewable energy sector, has also been unable to avoid energy transition. The government is promoting strong goals for expansion of renewable energy. However, switching from stable and controllable conventional generation to intermittent and uncontrollable renewable generation will be a big challenge for the electric power industry. Korea Power Exchange(KPX), which is responsible for the planning and operation of the electric power industry in Korea, is trying to improve measures in various fields such as the implementation of real-time unit commitment and additional real-time markets in order to cope with the volatility and intermittency of renewable energy.

• Journal of Power Electronics
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• 제18권2호
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• pp.573-587
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• 2018

Recently evolved power electronics' based domestic/residential appliances have begun to behave as single phase non-linear loads. Performing as voltage/current harmonic sources, those loads when connected to a three phase distribution network contaminate the line current with harmonics in addition to creating a neutral wire current increase. In this paper, an enhanced performance three phase four leg shunt active power filter (SAPF) controller is presented as a solution for this problem. The presented control strategy incorporates a hybrid predictive fuzzy-logic based technique. The predictive part is responsible for the SAPF compensating current generation while the DC-link voltage control is performed by a fuzzy logic technique. Simulations at various loading conditions are carried out to validate the effectiveness of the proposed technique. In addition, an experimental test rig is implemented for practical validation of the of the enhanced performance of the proposed technique.

• Advances in Energy Research
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• 제7권2호
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• pp.101-121
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• 2020

Coal has made a wonderful contribution to the production of cheap electricity. Coal based power plants have been the backbone of world's electricity for a long time now. Coal while being cheap and easily available is also a source of various solid, liquid and gaseous effluents which are responsible for the environmental degradation. Environmental issues caused by coal need to be studied and analyzed, then a common global consensus must be formed. Efficient action must be taken against each and every type of pollutant that is produced by this particular industry. The research aims to provide a brief overlook of the environmental impact of India's coal-based power plants. The aim of this study is to introduce a novel environmentally feasible energy scenario for the future of Indian power sector which has been named as "OPES". OPES is mathematically simulated using the combination of GAMS and LEAP. OPES is simple to comprehend and can be reproduced easily for other case studies as well. Results show that OPES can help the Indian power sector to minimize its environmental impact without causing any problems in the energy supply.

• 한국재료학회지
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• 제24권11호
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• pp.604-609
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• 2014

The thermoelectric power and dc conductivity of $La_{2/3+x}TiO_{3-{\delta}}$ (x = 0, 0.13) were investigated. The thermoelectric power was negative between 80K and 300K. The measured thermoelectric power of x = 0.13 increased linearly with increased temperatures and was represented by $S_0+BT$. The x = 0 sample exhibited insulating behavior, while the x = 0.13 sample showed metallic behavior. The electric resistivity of x = 0.13 had a linear temperature dependence at high temperatures and a T3/2 dependence below about 100K. On the other hand, the electric resistivity of x = 0 has a linear relation between $ln{\rho}/T$ and 1/T in the range of 200 to 300K, and the activation energy for small polaron hopping was 0.23 eV. The temperature dependence of thermoelectric power and the resistivity of x = 0 suggests that the charge carriers responsible for conduction are strongly localized. This temperature dependence indicates that the charge carrier (x = 0) is an adiabatic small polaron. These experimental results are interpreted in terms of spin (x = 0.13) and small polaron (x = 0) hopping of almost localized Ti 3d electrons.

• 전력전자학회논문지
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• 제17권2호
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• pp.150-157
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• 2012

This paper presents CAN-based parallel-operation and load-sharing techniques for the communication server power supply. With the load information obtained through CAN communication, each modules performs its current control independently and the power unbalance caused by impedance differences of converter modules can be reduced. In conventional method, slave modules are controlled by master module. On the other hand, the proposed load share algorithm uses the Multi-Master method. Therefore, accurate load sharing can be accomplished by the reference structure of each module's average current. Each converter has two stages and it is separated into PFC, which is responsible for harmonic regulation, and LLC resonant converter, which controls output voltage. To verified the performance of the proposed method, two 2KW prototypes has been implemented and experimented.