• JSTS:Journal of Semiconductor Technology and Science
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• v.9 no.2
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• pp.110-116
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• 2009

The prominent advantages of Dual Material Surrounding Gate (DMSG) MOSFETs are higher speed, higher current drive, lower power consumption, enhanced short channel immunity and increased packing density, thus promising new opportunities for scaling and advanced design. In this Paper, we present Transconductance-to-drain current ratio and electric field distribution model for dual material surrounding gate (DMSGTs) MOSFETs. Transconductance-to-drain current ratio is a better criterion to access the performance of a device than the transconductance. This proposed model offers the basic designing guidance for dual material surrounding gate MOSFETs.

• The Transactions of the Korean Institute of Power Electronics
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• v.21 no.2
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• pp.182-189
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• 2016

A modeling method of electric power network inside a fishing boat less than 5 tons is proposed for its high-energy efficiency with renewable energy sources. The power network inside the fishing boat consists of a diesel engine, a starter motor, an alternator, battery packs, and electric loads, which are connected in parallel. To obtain proper power network model, the voltage -current characteristics of the electric components are considered to develop elaborate electrical models under several load conditions. Measured data of the battery and alternator current include noise. By using an average method, the AC components from the power network of the fishing boat can be reduced, which is verified by KCL rule. Using the proposed power network model, the power generation of the alternator and the reduction of diesel consumption in the boat's engine are predictable under various operating conditions. The validity of the proposed methodology is verified by comparing simulation results with experimental measurements using statistical inferences.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.18 no.5
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• pp.118-125
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• 2004

The use of electric arc furnace has been increasing as the steel consumption is increasing and the operation technique of electric arc furnace are developing. But as the use of electric arc furnace is increased, the furnace have produced the adverse effects of power quality: voltage and current harmonics, voltage and current imbalances, low power factor, and voltage flicker. One of the power quality problems, the harmonic have the characteristics of the time-varying and non-linear. This paper analyzed the harmonics for the various operation conditions of electric arc furnace. The power system model with electric arc furnace have been made, and the harmonic's effects on the power system has been analyzed according to the various operating conditions, first melting, second melting, so on. Also, the filter reducing the harmonic components have been designed and its effects on the power system have been examined.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.9
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• pp.1799-1807
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• 2016

In this paper, we propose the automatic demand response systems which reduce the electric power consumption for the period automatically distinct from the existing passive demand response that a subscriber directly controls the energy consumption. The proposed systems are based on SEP 2.0 and consist of the demand response management program, the demand response server, and the demand response client. The demand response program shows the current status of the electric power use to a subscriber and supports the function which the administrator enables to creates or cancels a demand response event. The demand response server transmits the demand response event received from the demand response management program to the demand response client through SEP 2.0 protocol, and it stores the metering data from the demand response client in a database. After extracting the data, such as the demand response the start time, the duration, the reduction level, the demand response client reduces the electric power consumption for the period.

• Journal of the Korean Society for Railway
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• v.20 no.1
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• pp.31-42
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• 2017

Many studies have been performed to reduce electric consumption in railway systems. Due to its low conduction loss and high regenerative braking efficiency characteristics, the ESS powered railway system is chosen as a promising candidate for future railway systems. This paper introduces the ESS powered railway system and analyzes current power charge calculation methods that have been set up by KEPCO (Korea Electric Power Corporation). Based on the analysis, this paper proposes two different power charge reduction methods for the railway system. One is to smooth the peaks of traction energy consumption by supplying additional energy to the grid. The other is to save electric charge by reducing electric energy consumed by the railway during the energy peak time, 2 p.m.~5 p.m., which has highest 'Won/kWh' rates. To verify the effectiveness of the proposed method, the power charge of Seoul Metro Line 2 is recalculated using the method.

• Journal of Power System Engineering
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• v.19 no.6
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• pp.39-46
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• 2015

With rising fuel costs and the depletion of fossil fuels, electric vehicles of high efficiency has been increasing interest. although high-performance battery continually is developing, Electric vehicles is not satisfied with the characteristics of the environment. In this study, By using the current fuel economy testing methods(5-cycle test), until the fully discharged battery electric vehicles is evaluated for a variety of environmental and operating conditions. As a result, Electric vehicles showed a low energy consumption efficiency in low temperature and rapid acceleration, deceleration in the operating environment compared with normal temperature.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.11
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• pp.1913-1918
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• 2016

In order to analyze the power consumption pattern of the DC urban rail system, the method to obtain a solution establishing the current equation according to fixed position of the substation and varying position of the train is used. The proposed analysis method using the network analysis is to model the transfer function of the component constituting a direct current power supply system (dc substation, train, catenary) to the voltage and current. By multiplying the model formula consecutive, it can calculate the voltage and current of each element of power supply circuit and shows a simple case analysis.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.05a
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• pp.904-907
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• 2013

Demand Controller is a control device that if current electric power consumption seems to exceed the targeted amount of electric power, block the connected load devices. When this ON/OFF way is applied to electric power management of electric furnace, start and stop operation of inverter and an electric heater which supplying electric power is being performed repeatedly. This has a problem of life-shortening of inverter and an electric heater by electrical damage. In addition, when electric power supplying is blocked, attemperation is not allowed until return to normal operation condition. In this paper, we develop power management system for electric furnace using the electric furnace remote controller. This system provides the automatic control for approved electric power to electric furnace organically and prevent electric damage of inverter and an electric heater through continuous electric power supply within the targeted amount of electric power.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.11
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• pp.1752-1757
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• 2012

With the development in industry, power demand has increased rapidly. As consumption of power has increased, Demand for new power line and electric capacity has risen. However, in the event of fault, problems occur in extending the range of fault coverage and increasing fault current. In these reasons, protection devise is recognized as the prevention of an accident and fault current. This paper dealt with minimizing fault propagation and limiting fault current by adjusting fault current limiter (FCL) with fast interrupter. At this point, we compared and analyzed characteristics between non-inductive resistance and fault current which is limited by superconducting units. In normal state of the power system, power was supplied to the load, but when fault occurred, the interrupter was operated as CT which detected the over-current. Its operation made the limitation of fault current through a FCL. We concluded that the limiter using superconducting units was more efficient with the increase of power voltage. Superconducting fault current limiter with the fast interrupter prevented the spread of a fault, and improved reliability of power system.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.1274-1275
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• 2011

This paper study effects that measured hamony occurence and changes of current and voltage according to variation of temperature of Far Infrared Ray Radiant Oven's room affect power quality.