• The Transactions of the Korean Institute of Electrical Engineers B
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• 제52권7호
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• pp.335-342
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• 2003

This paper presents a forward type high voltage pulse power supply for high voltage small current, which can be designed as a simple circuit configuration and managed easily using Power-MOSFET in the view of commercialization. According to the switching frequency, coupling factor(k) and duty ratio(D), the Principle of basic operation and the characteristics of the proposed pulse power supply are estimated. Simulation results have demonstrated the feasibility of the proposed pulse power supply. Also experimental results are presented to verify theoretical discussion with a lamp type ozonizer as a load. For studying the application at the part of environment of water, When ozonizer gas reacts with a colon bacillus, the sterilization characteristics of a colon bacillus according to the ozone concentration and response time have been investigated. This proposed pulse power supply will be able to be practically used as a pulse power supply in various environment improvement facilities like sterilization of colon bacillus, deodorization, and Nox gas elimination.

• Journal of Korean Society for Quality Management
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• 제46권2호
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• pp.351-374
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• 2018

Purpose: The collective civil complaint problem is considered as important obstructive factor of the nuclear power plant construction project's success and quality. Therefore, this study demonstrate the factors which can affect the settling collective civil complaints, and also suggest the improvement of the resolution. Methods: This study collected the data of Kori Nuclear Power Division staff, local residents and Hanul Nuclear Power Division staff, local residents, and use them for analysis. Results: The results are twofold in the study: First, the 'Situation Recognition' and 'Mutual Cooperation' which are independent variables for solving collective civil complaints have proved to give positive influence on both the nuclear staff and the local residents about the complaint resolution outcome of the dependent variable. Second, the moderation variable 'Expected Benefit' on the influential relationship between the collective civil complaint resolution factor and the civil complaints resolution outcome proved to have a moderating effect only on the nuclear staff. On the other hand, moderation variables 'Time of SOC Business Implementation' and 'Time of Compensation' proved to have a moderating effect only for the local residents. Conclusion: According to the results, the staff have a positive opinion on the benefits of the nuclear power plant construction, while residents feel strongly that they do not get any benefit from the construction despite of tremendous investment and expected benefit in local area. As this results, policy implementation which is superable different understanding is required.

• Journal of Electrical Engineering and Technology
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• 제7권1호
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• pp.1-8
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• 2012

The current paper presents a novel control strategy of a three-phase, four-wire Unified Power Quality (UPQC) to improve power quality. The UPQC is realized by the integration of series and shunt active power filters (APF) sharing a common dc bus capacitor. The realization of shunt APF is carried out using a three-phase, four-leg Voltage Source Inverter (VSI), and the series APF is realized using a three-phase, three-leg VSI. To extract the fundamental source voltages as reference signals for series APF, a zero-crossing detector and sample-and-hold circuits are used. For the control of shunt APF, a simple scheme based on the real component of fundamental load current (I $Cos{\Phi}$) with reduced numbers of current sensors is applied. The performance of the applied control algorithm is evaluated in terms of power-factor correction, source neutral current mitigation, load balancing, and mitigation of voltage and current harmonics in a three-phase, four-wire distribution system for different combinations of linear and non-linear loads. The reference signals and sensed signals are used in a hysteresis controller to generate switching signals for shunt and series APFs. In this proposed UPQC control scheme, the current/voltage control is applied to the fundamental supply currents/voltages instead of fast-changing APF currents/voltages, thus reducing the computational delay and the required sensors. MATLAB/Simulink-based simulations that support the functionality of the UPQC are obtained.

• Journal of Electrical Engineering and Technology
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• 제9권1호
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• pp.45-51
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• 2014

Distribution system is a critical link between customer and utility. The control of power loss is the main factor which decides the performance of the distribution system. There are two methods such as (i) distribution system reconfiguration and (ii) inclusion of capacitor banks, used for controlling the real power loss. Considering the improvement in voltage profile with the power loss reduction, later method produces better performance than former method. This paper presents an advanced evolutionary algorithm for capacitor inclusion for loss reduction. The conventional sensitivity analysis is used to find the optimal location for the capacitors. In order to achieve a better approximation for the current candidate solution, Opposition based Differential Evolution (ODE) is introduced. The effectiveness of the proposed technique is validated through 10, 33, 34 and85-bus radial distribution systems.

• Proceedings of the KIPE Conference
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• 전력전자학회 2001년도 전력전자학술대회 논문집
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• pp.525-529
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• 2001

A pulse frequency control(PFM) method for single-phase SEPIC-type rectifier is described in this paper. In the SEPIC rectifier, a relationship between the output power and the respective switching frequency is investigated to establish the control scheme of PFM. The propsed control method is provided with a feed-forward control loop of the output load as well as a feed-back control loop of the output voltage. The simulation results show good dynamic responses and unity power-factor operation.

• Journal of international Conference on Electrical Machines and Systems
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• 제3권3호
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• pp.354-361
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• 2014

The Unified Power Flow Controller (UPFC) can flexibly manage power flow and maintain line voltage. The UPFC consists of two inverters in parallel side and series side. In parallel side, the reactive power can be compensated to improve the power factor. In series side, the voltage drop can be compensated to maintain proper line voltage. It is necessary for the operation in both sides to output the current and the voltage quickly and accurately. As the method for the UPFC control, the deadbeat control with state observer is applied. The deadbeat control is able to realize a quick response of the current and voltage control for only a sampling period compared with the general PI control. A principle and simulation results are presented in this paper.

• Proceedings of the KIEE Conference
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• 대한전기학회 1997년도 하계학술대회 논문집 F
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• pp.2152-2154
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• 1997

본 논문은 복잡한 스위칭 변조없이 입력역률과 입력 전류파형을 향상시키는 우수한 정현 컨버터를 제안하고자 한다. 그 구성과 제어방법은 비교적 단순하지만 정현컨버터는 입력 선전류에 포함된 무효전력과 고조파를 효과적으로 감소시킴으로서 우수한 동작 특성을 이론적 분석과 Pspice 시뮬레이션을 통하여 입증하고자 한다.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 한국정밀공학회 1993년도 추계학술대회 논문집
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• pp.286-292
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• 1993

The classical way to improve the control performance is studied on the aspects of gun/turret deive systens. Two ways are discussed comparadively ; electrical case and electro-hydraulic case. System parameters are analytically studied in terms of resonance frequencies, and damping and gear train ratio effects are checked in relation to resonance frequency increase. Benefit of the feedback is discussed to increase the damping of the natural frequency lending to bandwidth increase.

• Proceedings of the KIEE Conference
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• 대한전기학회 2011년도 제42회 하계학술대회
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• pp.862-863
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• 2011

수도사업장 고압기동반 설비에 대한 연구를 통하여 표준화 기준제정 및 설비사고 예방을 위한 최적운영방안을 제시하고자 한다.

• Proceedings of the KSR Conference
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• 한국철도학회 2003년도 춘계학술대회 논문집
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• pp.480-486
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• 2003

This paper proposes the connection without cables among display devices in a train using piconet of the Bluetooth. Nowadays, each train has a number of the display devices that are connected with many cables to lead the passengers, so it has the waste of resource and factor of fault. This paper proposes the improvement schemes of those problems in a train using piconet of the bluetooth with low cost, low power, and high security.