• 설비공학논문집
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• 제25권4호
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• pp.187-193
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• 2013

Thanks to the characteristic of high-rise buildings, the increase of wind speed according to the height of a building makes it possible to use high wind power resources, many countries led by some advanced nations are recently making steady and persistent effort in introducing small wind turbine systems as a step to lower electric power load in high-rise buildings. The aim of this research is to propose an optimum application process of a small wind turbine system in high-rise buildings. To achieve this goal, the case studies on the applications of high-rise and tall buildings were conducted and the best application among them was selected. On the basis of the case studies, an application process was proposed.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.147-150
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• 2002

HPSL(High Pressure Sodium lamp)have attracted much attention in recent years, because they offer high luminous efficiency and very long life. Recently, AC-DC converters have been widely as power factor improvement circuits in the power conversion equipment An application of the ZVT-PWM(Zero Voltage Transition Pulse Width Modulation) boost converter, which has great advantage on miniaturization and high power density, to the power factor improvement circuit of the HPSL inverter are described to identify the power factor correction characteristics of the inverter. In this paper the series-parallel resonant inverter(electronic ballast) for driving a HPS lamp is discussed. Finally, a power factor corrector is cascaded in front of the electronic ballast. Consequently, a high power factor above 0.99 and low THD on the line current can be achieved.

• 전력전자학회:학술대회논문집
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• 전력전자학회 1998년도 전력전자학술대회 논문집
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• pp.171-174
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• 1998

The development of the high-frequency induction-heating for 2700kW power range intend to make localization at forging and rolling mill part by technical innovation. And, the development makes to increase our's competitive power at technique, quality and cost. This paper describes the heart of high-frequency induction-heating technique, switching technique, a few problem in common using as an unsatisfied technique, load adjustment technique, system control, diagnostic system, and auto-interface etc.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 C
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• pp.1550-1551
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• 2006

An L-band linear accelerator system for e-beam sterilization is under design for bio-technology application. The klystron-modulator system as RF microwave source has an important role as major components to offer the system reliability for long time steady state operation. A PFN line type pulse generator with a peak power of 71.5-MW, $7{\mu}s$, 285 pps is required to drive a high-power klystron. The high power pulse transformer has a function of transferring pulse energy from a pulsed power source to a high power load. The pulse transformer producing a pulse with a peak voltage of 275 kV is required to produce 30-MW peak and 60 kW average RF output power at the frequency of 1.3-GHz. We have designed the high power pulse transformer with 1:13 step-up ratio. The peak and average power capability is 71.5-MW (275 kV, 260 A at load side with $7{\mu}s$ pulse width) and 130 kW, respectively. In this paper, we present a system overview and initial design results of the high power pulse transformer.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2004년도 Asia Display / IMID 04
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• pp.135-138
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• 2004

This paper describes the architecture, the basic operation principle and detailed experimental results of digitally programmable high-voltage generators that can be used in monolithic low-power high-voltage bistable LCD drivers. Two different design approaches, depending on whether the application allows the use of external passive components or not, are analyzed.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2002년도 전력전자학술대회 논문집
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• pp.138-141
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• 2002

BLDCM(Brushless D.C. Motor) is widely used for industrial application because of high efficiency and high power density Especially, in servo system and home appliance, BLBCM is very useful due to high control performance and low acoustic noise. In this paper, 2.5HP rated BLDCM controller and drive was developed for tread mill application. The prototype BLDCM has 4 poles rotor and 24 slots stator. Ferrite was used as a rotor magnet due to the cost and temperature characteristic. For the stable operation of tread mill, over current and high temperature can be detected by the DSP controller. For the commutation signal, switching patterns from the sensorless circuit and hall sensor signal are used in the DSP controller.

• Nuclear Engineering and Technology
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• 제45권3호
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• pp.401-414
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• 2013

HTR50S is a small modular reactor system based on HTGR. It is designed for a triad of applications to be implemented in successive stages. In the first stage, a base plant for heat and power is constructed of the fuel proven in JAEA's $950^{\circ}C$, 30MWt test reactor HTTR and a conventional steam turbine to minimize development risk. While the outlet temperature is lowered to $750^{\circ}C$ for the steam turbine, thermal power is raised to 50MWt by enabling 40% greater power density in 20% taller core than the HTTR. However the fuel temperature limit and reactor pressure vessel diameter are kept. In second stage, a new fuel that is currently under development at JAEA will allow the core outlet temperature to be raised to $900^{\circ}C$ for the purpose of demonstrating more efficient gas turbine power generation and high temperature heat supply. The third stage adds a demonstration of nuclear-heated hydrogen production by a thermochemical process. A licensing approach to coupling high temperature industrial process to nuclear reactor will be developed. The low initial risk and the high longer-term potential for performance expansion attract development of the HTR50S as a multipurpose industrial or distributed energy source.

• Nuclear Engineering and Technology
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• 제53권3호
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• pp.1004-1012
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• 2021

High density polyethylene (HDPE) pipe has many advantages over metallic pipe, and has been used in non-safety related application for years in some nuclear power plants (NPPs). Recently, HDPE pipe was introduced into safety related applications. The main difference between safety-related and non-safety-related pipes in NPPs is the design method of extra loadings such as gravity, temperature, and earthquake. In this paper, the mechanical behavior of HDPE pipe under various loads in pipe gallery was studied by finite element analysis (FEA). Stress concentrations were found at the fusion regions on inner surface of mitered elbows of HDPE pipe system. The effects of various factors were analyzed, and the influence of various loads on the damage of HDPE pipe system were evaluated. The results of this paper provide a reference for the design of nuclear safety-related Class 3 HDPE pipe. In addition, as the HDPE pipes analyzed in this paper were suspended in pipe gallery, it can also serve as a supplementary reference for current ASME standard on Class 3 HDPE pipe, which only covers the application for buried pipe application.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 1992년도 특별강연 및 추계학술발표 개요집
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• pp.21-31
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• 1992

CO2 laser had enabled accurate and effective cutting. But its application has been limited to thin and small parts. Development of a high power oscillator and oscillator built-in cutting machine have realized cutting of thick and large steel parts. This machine brings also possibility of fully automated cutting systems to practical steel parts such as for construction machinery.

• 한국전자통신학회논문지
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• 제10권8호
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• pp.945-952
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• 2015

GaN 전력증폭소자를 이용한 전력증폭기의 고효율 특성을 구현하기 위하여 $50{\Omega}$으로 정합된 전력증폭소자는 적용 주파수 대역, 출력전력, 효율 특성 선정의 한계가 있으므로 본 연구에서는 source/load-pull 시험을 통한 측정 데이터를 기반으로 고출력, 고효율 특성의 설계 목적에 맞는 정량적 입력 및 출력 임피던스를 추출하여 고효율 전력증폭기를 구현하였다. 구현된 전력증폭기는 2.7-3.1GHz의 주파수 대역에서 25watt(44dBm), 66-76%의 PAE특성 나타낸다.