• 한국전자통신학회논문지
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• 제10권2호
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• pp.261-266
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• 2015

신재생에너지용 발전 시스템은 모듈, 직류 전력을 교류 전력으로 변환시키는 전력 역변환장치, 전력흐름을 제어하고 계통 연계를 담당하는 제어장치로 구성된다. 이러한 시스템은 일사량이 많은 여름철 및 낮 시간에 가장 많은 직류전력을 생산하지만 계통의 연계를 위해 필수적인 전력 역변환장치는 특정 온도 이상으로 상승하면 효율이 급격히 감소하게 된다. 따라서 열전소자를 부착한 열 저감 시스템을 제안하고 가장 발열이 심한 구간을 선정하여 사용개수 및 위치에 따른 온도 특성 해석을 통해 최적 모델을 도출하고자 한다.

• KEPCO Journal on Electric Power and Energy
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• 제3권1호
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• pp.35-39
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• 2017

Recently, the public opinion is growing that the main cause of greenhouse gas, fine dust and nitrogen oxide, sulfuric acid emission is coal-fired power plant, and now the decommission or conversion to other clean fuel is being demanded. However, it is a huge national loss to decommission coal-fired power plant with remaining life, and also simple fuel converting to natural gas will lead to drastic rise on power generating cost. Therefore, this study aims to provide the analysis result about the reduction effect of $CO_2$, environment emission, and to influence to power plant performance and facilities when repowering with adding gas turbine is applied to domestic aged coal-fired power plant.

• 정보처리학회논문지:컴퓨터 및 통신 시스템
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• 제3권9호
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• pp.273-278
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• 2014

최근 전력의 수요공급 불균형으로 전력사용 피크시간대의 전력사용 강제 제한이 불가피하다. 따라서, 본 논문에서는, 피크전력이 발생하지 않는 시간대의 전기를 저장하고 전력부족이 예상되는 피크전력 시간대에는 저장전력을 공급하는 병렬운전 기기의 회로를 설계하는데 있다. 이 회로설계를 통하여, PRS의 핵심기능인 상용전원과 인버터 발생전원의 병렬연결 운용으로, 상용전원의 피크치 전력을 조절할 수 있었다. 또한 효율을 높이기 위하여 Transless Power Circuit DC-AC 인버터를 개발하였다. 더 나아가, 가변임피던스 제어를 적용하여 무정전 전원장치의 저장전력을 상용전원과 연계함으로써, 기존의 무정전 전원장치에서 구현을 못하고 있는 저장전력 사용시간을 획기적으로 늘릴 수 있는 기술구현 가능성을 입증하였다.

• 한국전자파학회논문지
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• 제17권11호
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• pp.1132-1142
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• 2006

본 연구는 송전 선로 여러 가지 유형의 극저주파 자기장 저감 적용 모델을 조사하고 그 효과를 분석하였다. 본 연구에서는 154 kV 수평 배열 송전 선로를 기본으로 하여 적용 가능한 다양한 자기장 저감 모델에 대하여 적용시 얻게 되는 자기장 저감지수(Field Reduction Factor)를 검토하였다. 그 결과 compact 모델 채용시에는 상간거리 compact화 비율과 자기장 저감지수가 거의 비례하였으며, diamond 모델 및 transposed 선로 배치의 경우는 50 %에 근접한 자기장 저감이 가능하였다. 배전 선로에 적용이 가능한 삼각형 배열은 33 % 정도, 2회선 split는 50 % 정도 저감 효과가 나타나는 것으로 분석되었으며 수평 multi split 모델의 경우는 80 %까지 자기장 저감을 얻을 수 있었다.

• 한국통신학회논문지
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• 제25권7B호
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• pp.1320-1325
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• 2000

A very simple and effective peak power reduction scheme for a downlink OFDM-CDMA system is proposed using the relationship between peak-to-average power ratio (PAPR) and out-of-phase autocorrelation. Since power spectrum and autocorrelation function are Fourier transform pair, the PAPR property of the sequences can be estimated by the out-of-phase autocorrelation function of the spreading sequences. Thus, by scrambling the spread data in the frequency domain, we can reduce the sidelobe energy of autocorrelation, and at last, suppress PAPR in the proposed OFDM-CDMA system.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 하계종합학술대회 논문집(5)
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• pp.67-70
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• 2002

In this paper, we have researched a Automatic Power Factor Correction and THD reduction System for the multiple connection of CFL. Also in this paper, the power factor has been researched for the design of CFL, found the reason why the power factor is low and THD is too high. This paper has designed the PFC System for the multiple connection of CFL, and then we have increased the power factor and reduced the total harmonic distortion, by implementing them.

• Journal of electromagnetic engineering and science
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• 제6권4호
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• pp.197-202
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• 2006

This paper presents a study on the differential signaling for the rectangular power-bus structure. The full-wave modal analysis method analyzes how the differential-signaling can lower the power-bus resonance noise levels. The methodology is validated by the use of the FDTD method and reference measurements.

• Nuclear Engineering and Technology
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• 제39권5호
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• pp.655-662
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• 2007

Most decision makers in the electricity industry plan their electric power expansion program by considering only a least cost operation, even when circumstances change with differing complexities. It is necessary, however, to analyze a long-term power expansion plan from various points of view, such as environmental friendliness, benefit of a carbon reduction, and system reliability, as well as least cost operation. The objective and approach of this study is to analyze the proper role of nuclear power in a long-term expansion plan by comparing different scenarios in terms of the system cost changes, $CO_2$ emission reduction, and system reliability in relation to the Business-As-Usual (BAU). The conclusion of this paper makes it clear that the Korean government cannot but expand the nationwide nuclear power program, because an increased energy demand is inevitable and other energy resources will not provide an adequate solution from an economic and sustainability point of view. The results of this analysis will help the Korean government in its long-term resource planning of what kinds of role each electric resource can play in terms of a triangular dilemma involving economics, environmental friendliness, and a stable supply of electricity.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2009년도 춘계학술대회 논문집
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• pp.274-279
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• 2009

Reduction Gear Box where from productive site uses the gear with power delivery with high mechanical efficiency of power a deceleration and as the mechanical element union product which has the velocity ratio which is various together is produced with the power occurrence motor and leads gets a high driving force is plentifully used. The above occurs from gear drive issue sound Whine, Noise and Vibration as occurring from the rim process which the gear will bite mainly is delivered with the case etc. gear drive whole which leads the axis and the bearing. The productivity falls with the going straight rate decrease which with like this problem point is caused by with rework the problem point where the cost of production rises under improving boil many kinds analyzed the plan and investigates the resultant acceleration sensor which and a frequency analysis system and was made to apply.

• 대한인간공학회지
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• 제36권5호
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• pp.559-568
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• 2017

Objective: The aim of this study is to investigate the effective managerial factors influencing dose reduction of the nozzle dam installation and removal tasks ranking within top 3 in viewpoint of average collective dose of nuclear power plant maintenance job. Background: International Commission on Radiation Protection (ICRP) recommended to reduce unnecessary dose and to minimize the necessary dose on the participants of maintenance job in radiation fields. Method: Seven sessions of nozzle dam installation and removal task logs yielded a multiple regression model with collective dose as a dependent variable and work time, number of participants, space doses before and after shield as independent variables. From the sessions in which a significant reduction in collective dose occurred, the effective managerial factors were elicited. Results: Work time was the most important factor contributing to collective dose reduction of nozzle dam installation and removal task. Introduction of new technology in nozzle dam design or maintenance job is the most important factor for work time reduction. Conclusion: With extended task logs and big data processing technique, the more accurate prediction model illustrating the relationship between collective dose reduction and effective managerial factors would be developed. Application: The effective managerial factors will be useful to reduce collective dose of decommissioning tasks as well as regular preventive maintenance tasks for a nuclear power plant.