• Title/Summary/Keyword: Power Reduction

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Economic Effects of the Post-2020 Climate Change Mitigation Commitments: From the Generation Industry's Perspective (Post-2020 신기후체제의 발전부문 대응에 따른 경제적 파급효과 분석)

  • Yun, Taesik;Lee, Bongyong;Noh, Jaeyup
    • Journal of Energy Engineering
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    • v.25 no.3
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    • pp.136-148
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    • 2016
  • We analyze economic effects of GHG reduction measures of the generation industry to meet 2030 GHG reduction target using the scenario based approach. We estimate the GHG emission of the Korean power industry in 2030 based on both the $7^{th}$ Electricity Supply & Demand Plan and the GHG emission coefficients issued by IAEA. We set up three scenarios for reduction measures by replacing the coal fired plants with nuclear power, renewable energy and carbon capture and storage. Once and for all, the nuclear power scenario dominates the other energy technologies in terms of GHG reduction quantities and economic effects.

An Analysis on Korean Nuclear Power's Contribution to the GHG Emission Reduction and the Economic Effect (한국 원자력발전의 온실가스 저감 기여도 및 경제적 효과 분석)

  • Cho, Byung-Oke;Kim, Shin-Jong;Kim, Jum-Su
    • Journal of Energy Engineering
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    • v.19 no.4
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    • pp.203-214
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    • 2010
  • This study is to assess the reduction of greenhouse gas emission and economic contribution by operating nuclear power plants in Korea. According to the results of applying greenhouse gas emission coefficients to the current nuclear power generation and the estimated nuclear power generation of national energy master plan, it is confirmed quantitatively that nuclear power contributes to reducing greenhouse gas emission, controlling inflation, and substituting import of fossil energies. For the reliable and cost-effective supply of energy and the active respondency to climate change, a continuous expansion of nuclear power is implied to be necessary.

The Study on Miniaturization and Weight Reduction of Auxiliary Power Unit in Magnetic Levitation Train

  • Lee, Na Ri;Shin, Hee Keun;Choi, Sung Ho;Kim, Ju Bum;Lim, Jae Won;Park, Doh Young;Mok, Hyung Soo
    • International Journal of Railway
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    • v.8 no.1
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    • pp.10-14
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    • 2015
  • Due to the characteristics of the vehicle structure, the magnetic levitation train has a confined bottom space thus a study on miniaturization and weight reduction of auxiliary power unit is essential. This auxiliary power unit is an essential device used for illumination, air conditioning, heating and air brake equipment excluding the motor. The previous auxiliary power unit for magnetic levitation train has used the hard switching having a high switching frequency with heavy loss in order to reduce the size of filter reactor and transformer but the reduction in volume was not significant. In this paper, by reducing the loss, reducing the size of the cooling unit and by increasing the switching frequency using the soft switching of resonant converter, it has miniaturized and reduced the weight of filter reactor and transformer which occupy significant space in the auxiliary power unit. This study has verified the performance of 50KVA grade prototype through simulated interpretation and analysis, and compared the size and weight of auxiliary power unit of the previous magnetic levitation train.

A Study on Optimization of Noise Reduction of Auxiliary Power Unit for Military Tracked Vehicle (군용 궤도장비 보조동력장치의 소음저감 최적화 연구)

  • Lee, Ju-Seung;Kim, Byeong-Ho;Kim, Byung-Hyun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.8
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    • pp.336-342
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    • 2018
  • Noise reduction is an important issue in auxiliary power unit(APU) of tracking equipments for using military. In this study, we designed and tested reduction methods of structure borne noise and airborne source noise at the auxiliary power unit. From the bench test results, it is found that the effect of noise reduction is about 22 dB(A) if the silencer is redesigned, which is the rescue structure. However, the influence of noise reduction by air is insufficient. In addition, it is confirmed that the effect of noise reduction is excellent when structure borne noise reduction is applied to the vehicle. We expected that the test results of this study are used as basic data to reduce the noise of other tracking equipment developed later.

Reduction of Structural and Computational Complexity in IMD Reduction Method of the PTS-based OFDM Communication System (PTS 방식의 OFDM 통신 시스템에서 IMD 저감 기법의 복잡도와 계산량 저감)

  • Kim, Seon-Ae;Lee, Il-Jin;Baek, Gwang-Hoon;Ryu, Heung-Gyoon
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.34 no.8A
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    • pp.583-591
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    • 2009
  • OFDM(orthogonal frequency division multiplexing) signal with high PAPR(peak to average power ratio) produces the nonlinear distortion and/or decreases down the power efficiency of HPA(high power amplifier). So, the IMD(inter-modulation distortion) reduction method was proposed to reduce the nonlinear distortion, which shows better BER(bit error rate) performance than the PAPR reduction methods. However, IMD reduction method has inherent problem which system complexity and processing time increases because the FFT(fast Fourier transform) processor is added in transmitter and decision criterion of IMD reduction method is computed in frequency domain,. In this paper, therefore, we propose a new IMD reduction method to reduce the computational complexity and structure of IMD computation. And we apply this proposed method into OFDM system using PTS(partial transmit sequence) scheme and compare the computational complexity between conventional and proposed IMD reduction method. This method can reduce the system size and computational complexity. Also, the proposed has almost same BER performance with the conventional IMD reduction method.

A Study on Friction Reduction Related with the Piston Ring Pack with Thinner Width Ring and Lower Tension Ring (박폭 저장력 피스톤 링 팩에 대한 마찰저감 연구)

  • Chun, Sang-Myung
    • Tribology and Lubricants
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    • v.25 no.5
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    • pp.348-358
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    • 2009
  • To satisfy the more severe emission regulation and the demand of higher fuel economy in near future, the combustion pressure and power output of engines is going to be higher. In order to get the reduction of engine emission and the higher power, it is needed the reduction of the tension and width of ring pack. The lower tension ring and the manufacturing technology of cast iron thinner width ring can bring the friction reduction between the ring and liner during engine running. Therfore, the fuel economy can be achieved. Thereafter the engine emission can be reduced. In this study, by using a developed basic computer program that predicts the inter-ring pressure, the motion of ring and the inter-ring pressure through a crevice volume model between adjacent rings, and the oil film thickness and the friction computed by lubrication theories, it is to be examined the effect of friction reduction from piston ring pack equipped with thinner width ring and lower tension ring.

Analysis on Magnetic Field Reduction Factor of Transmission Lines (송전선로 전자계 저감 Field Reduction Factor 분석)

  • Myung, S.H.;Cho, Y.G.;Jung, Y.H.;Lee, D.I.;Sin, G.Y.;Yoo, Y.P.
    • Proceedings of the KIEE Conference
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    • 2003.10a
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    • pp.12-14
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    • 2003
  • 본 연구에서는 우리나라의 송전선로에 주로 적용하고 있는 역상수직 2회선 배열을 기본 모델로 하여 다양한 저감 설계기술 적용시의 FRF(Field Reduction Factor)를 구하는데 중점을 두었다. 검토한 결과로는 신규선로 저감기술로서는 송전선로의 경우 지상고 증가, Compact Tower개발, Diamond Tower의 채용, 일부 구간의 Transposed 선로배치 등이 우리나라에서 적용 가능한 후보군으로 분석되었다.

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Developement of planetary differential type traction drive (차동유성형 마찰드라이브의 개발)

  • 이종원;오세훈;최동엽;이대길;전한수
    • Journal of the Korean Society for Precision Engineering
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    • v.14 no.3
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    • pp.35-40
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    • 1997
  • The traction drive has advantages of having high efficiency and transmitting the power without blacklash. However, when high ratio of speed reduction is desired, excessively large size is required. In this study, a new type of traction drive is invented, designed and manufactured so that stable speed reduction mech- anisms are available by adopting a cross roller type drive. It has a simple structure, but produces high speed reduction ratio. Power loss is observed, and also, driving torque and torque transfer efficiency are calculated. Pre-loads are needed in order that the traction drive transfers power without slipping, and the spacer is enlarged due to the pre-loading. After all, the key point of pre-load mechanism is that the spacer's diameter becomes larger as pre-loads are applied.

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New PAPR Reduction Method for Spatial Modulation (공간변조 기법을 위한 새로운 PAPR 감쇄 방법)

  • Shang, Yulong;Kim, Hojun;Kim, Hongjoong;Jung, Taejin
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.39A no.1
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    • pp.12-18
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    • 2014
  • In this paper, a new peak-to-average power ratio (PAPR) reduction method for spatial modulation(SM) is presented. By using the matrix with all non-zero elements to precode the signals before transmitting, the transmit power is scattered over all transmit antennas for achieving the goal of PAPR reduction. If this matrix is also an unitary matrix, the distribution of transmit power over transmit antennas will be uniform and it also could retain the characteristic of avoiding inter channel interference (ICI) due to the orthogonality of unitary matrix. In case of a non-ideal amplifier, the proposed method can produce a considerable improvement that increases with a number of transmit antennas in performance. Furthermore, the new scheme achieves an identical performance with conventional one in the case of ideal amplifier.

INSTORE : A PC-Based Database Program for Occupational Radiation Exposure of a Nuclear Power Plant

  • Cho, Yeong-Ho;Kang, Chang-Sun;Mun, Ju-Hyung;Kim, Hak-Su
    • Nuclear Engineering and Technology
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    • v.30 no.4
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    • pp.308-317
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    • 1998
  • Ensuring occupational radiation exposure(ORE) as low as is reasonably achievable(ALARA) has been one of very important requirements in a nuclear power plant. It is well known that about 70 percent of occupational dose has incurred from maintenance jobs in the outage period. To reduce occupational dose effectively, the high-dose jobs in the outage period should be identified with their dose reduction potentials and methods. In this study, a PC-based ORE database program, INSTORE, is developed to evaluate ORE doses in individual jobs, and the ORE data of Kori Units 3 and 4 are assembled to the database. Based on customary job classification, radiation work is classified into 26 main jobs which comprise 61 detailed jobs, and occupational doses are assessed according to each detailed job. As a result, high-dose jobs are identified with dose reduction priority in terms of collective ORE dose. It is recommended that adeqaute dose reduction methods for these jobs should be prepared to improve their working conditions and procedures.

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