• Journal of the Korean Professional Engineers Association
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• v.44 no.2
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• pp.29-33
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• 2011

In recent years, maximum electric power demand has been increasing steadily. But, Electric Power Supply & Demand problem is occurring due to lack of electric power reserve ratio caused by electric power peak. For this reason, I investigated the current status of the Electric Power Supply & Demand and established Electric Power Supply & Demand and established Electric Power Supply & Demand measures. I will expect that this paper will be contributed balanced and stable Electric Power Supply & Demand management.

• Proceedings of the KIEE Conference
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• 1987.11a
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• pp.539-542
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• 1987

This paper presents driving circuits technology to enable high speed drive of MOSFET, IGBT(Insulated Gate Bipolar Transistor) and SIT(Static Induction Transistor). In addition to, it demonstrates application circuits(high frequency resonant type inverters, ultrasonic power supply etc.) using the, developing drive circuits.

• Journal of electromagnetic engineering and science
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• v.10 no.4
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• pp.224-230
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• 2010

Wireless power transmission (WPT) is useful technology in near future. There are some kinds of the WPT technologies, WPT via radio waves, resonance coupling, and inductive. Especially the WPT via radio waves is used for multi-purposes from short range to long range application. However, unfortunately it is misunderstood that it is low efficiency and low power. In this paper, I show the theory of beam efficiency between transmitting antennas and receiving antennas and also show some high efficient applications of the WPT via radio waves. Especially, I pick up a wireless power charging system of an electric vehicle and show the experimental results. I show difference between the theory of beam efficiency and the experimental results of short range WPT. I indicate that reasons of poor beam efficiency in the experiment are (1) change of impedance caused by mutual coupling between transmitting antennas and receiving antennas, (2) oblique direction of microwave power to receiving antennas caused by short distance.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1597-1598
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• 2007

전력산업에 IT 기술의 적용으로 인해 I&C 시스템의 첨단화 및 다양화되고 있으며, I&C 시스템은 전력설비의 중추적 역할을 담당하여 높은 신뢰성을 요구되고 있다. 전력설비에서의 I&C 시스템의 중요성 증대되고 I&C 시스템의 국산화 개발 증가 및 필요성이 증대하여 제어시스템 연구 및 시험설비의 인프라 구축이 매우 필요하여 그 구성 방안에 대하여 검토하였다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.1A
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• pp.9-12
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• 2007

In this paper, we propose and analyze a scheme for wireless channels, which is a combination of a type I hybrid-automatic repeat request (H-ARQ) scheme and a power ramping. The power ramping is considered for more reliable downlink data transmission, in which the transmission power is gradually changed from a small level to a large level when the number of retransmissions increases. The simulation results demonstrate that, when the power ramping step size is 0.5dB, the average throughput gain may be as high as 2% to 5% with properly selected parameters.

• Proceedings of the KIEE Conference
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• 2003.07d
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• pp.2271-2273
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• 2003

Control Rod Control System(CRCS) is to control nuclear reaction of reactor by moving Control Rod Drive Mechanism(CRDM) with speed and direction signal from Reactor Regulating System(RRS). CRCS is made up of two parts : control cabinet and power cabinet. And this paper presents mainly power cabinet design for system reliability. To increase reliability of power cabinet, controller, power supply and communication line arc doubly designed and supervision and diagnosis function are applied.

• Proceedings of the KIPE Conference
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• 2018.11a
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• pp.217-218
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• 2018

Droop control method is the conventional controller to solve the problem of current sharing error and voltage deviation that can occur in parallel connection of DC-DC converter. This paper compared V-I droop control with I-V droop control, which based on communication and confirmed the results through experiments.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.58 no.4
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• pp.432-436
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• 2009

This paper is described that advanced study on network design of remote diagnosis system for power facilities of electric railway. In the field, it is very difficult for worker to diagnosis power facilities including catenary because workers should be maintenance on AC power supply. Therefore, to properly design on remote diagnosis system, we have searched the inside and outside of the country-related technology trends. Also we confirmed that required technologies to design interface technology required for the development of sensor devices and the USN network was designed in accordance with required skills. Throughout variety of requirements, we have development iRFS based ZA sensors and iRFM to receive data of sensor. Also CC2420 is applied as single-chip which used 2.4GHz IEEE802.15.4 compliant RF tranciver designed for low-power and low-voltage wireless applications for ZigBee communication.

• Proceedings of the KIEE Conference
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• 2004.07d
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• pp.2370-2373
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• 2004

In this paper we describe the design of a Dual-Redundant Power Controller(DRPC) for Control Rod Control System(CRCS). The CRCS also provides information regarding rod motion, rod position, and status of the Rod Control System. It has Hot/Stand-by type, and also has the function of fault detection for controller itself and power modules. We have implemented the various functions with the dual-redundant Power Controller. Due to the developed DRPC, we are assured that the commmecial use by this controller be made before long.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.16 no.1
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• pp.253-262
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• 2016

This paper proposes a balance-swap method for the dynamic economic load dispatch problem. Based on the premise that all generators shall be operated at valve-points, the proposed algorithm initially sets the maximum generation power at $P_i{\leftarrow}P_i^{max}$. As for generator i with $_{max}c_i$, which is the maximum operating cost $c_i=\frac{F(P_i)-F(P_{iv_k})}{(P_i-P_{iv_k})}$ produced when the generation power of each generator is reduced to the valve-point $v_k$, the algorithm reduces i's generation power down to $P_{iv_k}$, the valve-point operating cost. When ${\Sigma}P_i-P_d$ > 0, it reduces the generation power of a generator with $_{max}c_i$ of $c_i=F(P_i)-F(P_i-1)$ to $P_i{\leftarrow}P_i-1$ so as to restore the equilibrium ${\Sigma}P_i=P_d$. The algorithm subsequently optimizes by employing an adult-step method in which power in the range of $_{min}\{_{max}(P_i-P_i^{min}),\;_{max}(P_i^{max}-P_i)\}$>${\alpha}{\geq}10$ is reduced by 10; a baby step method in which power in the range of 10>${\alpha}{\geq}1$ is reduced by 1; and a swap method for $_{max}[F(P_i)-F(P_i-{\alpha})]$>$_{min}[F(P_j+{\alpha})-F(P_j)]$, $i{\neq}j$ of $P_i=P_i{\pm}{\alpha}$, in which power is swapped to $P_i=P_i-{\alpha}$, $P_j=P_j+{\alpha}$. It finally executes minute swap process for ${\alpha}=\text{0.1, 0.01, 0.001, 0.0001}$. When applied to various experimental cases of the dynamic economic load dispatch problems, the proposed algorithm has proved to maximize economic benefits by significantly reducing the optimal operating cost of the extant Heuristic algorithm.