• 제목/요약/키워드: Small Field

검색결과 4,537건 처리시간 0.033초

해양소수력발전소 튜블러 수차 성능평가를 위한 현장시험 (Field Test for Performance Evaluation of a Tubular Turbine in Marine Small Hydro Power Plant)

  • 황영호;이영호;최영도
    • Journal of Advanced Marine Engineering and Technology
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    • 제35권8호
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    • pp.1070-1077
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    • 2011
  • 본 연구는 해양소수력발전소에서의 튜블러 수차의 성능평가를 위한 현장시험 및 그 결과에 대한 내용을 포함하고 있다. 현장시험용 수차의 발전기 최소출력은 측정된 유효낙차, 출력 그리고 효율을 이용하여 검토되었다. 정격 및 최대 출력시험은 수차 설치현장의 조수간만의 차에 의한 영으로 인하여 동일한 실험조건을 확보할 수 없었기 때문에 모델시험에 의한 성능 데이터를 이용하여 환산된 값을 사용하였다. 현장시험에 의한 수차의 성능은 최소출력, 정격출력, 최대출력 운전점에서 보증출력 및 보증효율을 만족시키는 결과를 나타냄을 확인하였다.

Construction of Structured q-ary LDPC Codes over Small Fields Using Sliding-Window Method

  • Chen, Haiqiang;Liu, Yunyi;Qin, Tuanfa;Yao, Haitao;Tang, Qiuling
    • Journal of Communications and Networks
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    • 제16권5호
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    • pp.479-484
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    • 2014
  • In this paper, we consider the construction of cyclic and quasi-cyclic structured q-ary low-density parity-check (LDPC) codes over a designated small field. The construction is performed with a pre-defined sliding-window, which actually executes the regular mapping from original field to the targeted field under certain parameters. Compared to the original codes, the new constructed codes can provide better flexibility in choice of code rate, code length and size of field. The constructed codes over small fields with code length from tenths to hundreds perform well with q-ary sum-product decoding algorithm (QSPA) over the additive white Gaussian noise channel and are comparable to the improved spherepacking bound. These codes may found applications in wireless sensor networks (WSN), where the delay and energy are extremely constrained.

복합모드형 소형 MR감쇠장치 성능에 관한 실험적 연구 (An Experimental Study on the Performance of a Mixed Mode Type Small Scale MR Damper)

  • 이상현;민경원;이명규;박은천
    • 한국지진공학회:학술대회논문집
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    • 한국지진공학회 2005년도 학술발표회 논문집
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    • pp.461-468
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    • 2005
  • In this paper, mixed mode magneto-rheological (MR) damper, which is applicable for vibration control of a small scale multi-story structure, is devised. First, the schematic configurations of the shear, flow, and mixed mode MR dampers are described with design constraints and then the analytical models to predict the field-dependent damping forces are derived for each type. Second, an appropriate size of the mixed mode MR damper is manufactured and its field-dependent damping characteristics are evaluated in time domain. Finally, the performance of the manufactured MR damper which is semi-actively applied to a small scale building excited by earthquake load, is numerically evaluated.

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$SF_6$ 가스차단기의 소전류 차단성능 해석 (Analysis of Small Current Interruption Performance for $SF_6$ Gas Circuit Breaker)

  • 김홍규;송기동;정진교;오연호;박경엽
    • 대한전기학회논문지:전기기기및에너지변환시스템부문B
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    • 제55권10호
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    • pp.528-533
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    • 2006
  • To analyze the small current interruption performance for the gas circuit breakers, the gas density and electric field intensity should be calculated. In this paper, the FVFLIC method is used for the gas flow analysis and the FEM for the electric field analysis. Then, the dielectric withstanding voltage is evaluated by the empirical formulation or Streamer theory. By comparing the calculated dielectric strength with the test result, it is found that both methods show good prediction capability for the small current interruption performance. Especially, when both methods predict the same interrupting performance, the prediction is in accordance with the experimental result.

Basis Set Requirement for Small Components Besides Kinetic Balance in Relativistic Self-Consistent-Field Calculations of Many Electron Systems

  • Lee, Yoon-Sup;Baeck, Kyoung-Koo
    • Bulletin of the Korean Chemical Society
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    • 제7권6호
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    • pp.428-433
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    • 1986
  • It is demonstrated by using a highly positive uranium ion as a test case that the exact relation between the small and the large components of a Dirac spinor in relativistic self-consistent-field (RSCF) calculations is not fully satisfied by the kinetic balance condition only even for two electron systems. For a fixed number of large component basis functions, total energies are sensitive to the change of the size of the small component basis sets even after the kinetic balance condition is fully satisfied. However, the kinetic balance condition appears to be a reasonable guideline in generating reliable and practical basis sets for most applications of RSCF calculations. With a complete small component basis set, energies from RSCF calculations exhibit a variational behavior, implying the stability of the present RSCF procedure.

소유역의 토지이용이 유출특성에 미치는 영향 (II) (The Influence on the Runoff Charateristics by the Land Use in Small Watersheds (II))

  • 최예환;최중대
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2005년도 학술발표회 논문집
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    • pp.178-182
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    • 2005
  • In the forthcoming 21C, the development of cultural lives depends on that the water demand will increase or not. On the opposite site of that circumstance, many factors of the small watersheds will influence directly on how to cover the surface of watersheds with land use, no planning developing watersheds, and the rearrangement of small rivers. Especially as the extraordinary climatic Phenomena, exhaust of $CO_2$ and destruction of 03 layer, water resource and water foresting content of the small watersheds will be decreased by confusing on the malting a plan of water resources. For example, those are Typhoon Rusa in 2002, Typhoon Maemi in 2003 and heavy storms in 2004. This study area has three group and one of them having three small watersheds, total five small watersheds. That is, Sabukmyeon small watersheds in Chuncheon, Three small watersheds in Wonju(Jeoncheon, Jupocheon and Hasunamcheon), and Suipcheon in Yanggu-Gun which are located far away each other three group and different precipitation data. According to the land use such as dry field(or farm), rice field, forest land. building site and others in small watersheds, the amount of runoff will be impacted by monthly precipitation. The comparison between the runoff was getting from Kajiyama Formula and calculated runoff from multi-linear regressed equations by land use Percentage was performed with different precipitation data and different small watersheds. Its correlations which are estimated by coefficient of correlation will be accepted or not, as approached 1.0000 values. As the monthly water resources amount is estimated by multi-linear regressed equations with different precipitation data and different small watersheds having no gauging station, we make a plan in order to demand and supply the water quantity from small river watersheds during return periods.

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절제 불가능한 비소세포 폐암의 다분할조사 방사선 치료 (Hyperfractionated Radiotherapy with Concomitant Boost Technique for Unresectable Non-Small Cell Carcinoma of the Lung)

  • 전하정;이명자
    • Radiation Oncology Journal
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    • 제9권2호
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    • pp.221-225
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    • 1991
  • 25예의 절제 불가능한 비소세포폐암 환자를 다불할조사 방사선 치료 및 추가 조사 기술로 치료하였다. 전에 수술이나 항암제 치료를 받았거나 늑막삼출 및 심 한 체중 감소(체중의 $10\%$이상)가 있는 환자는 이 연구에서 제외했다. 처음 3주에 걸쳐 27Gy를 15번에 나누어 large field에 조사하였다. 그 후에 large field에 1.8Gy를 준 후 cone down boost field에 1.4Gy를 하루에 두번 주어 총 49.4 Gy를 주었다. 49.4 Gy를 준 후 추가조사 영 역에 하루에 두번 1.8 Gy와 1.4 Gy를 주었다. 총 조사량은 12명의 환자에서는 62.2Gy, 13명의 환자에서는 65.4Gy였다. 추적관찰 기간은 6개월에서 24개월 사이였다. 실질적인 생존율은 6, 12, 18개월에 각각 $88\%,\;62\%,\;38\%$였다. 무병 생존율은 $88\%,\;41\%,\;21\%$였다. 집합적 국소 재발율은 9, 12, 15개월에 각각 $36\%,\;43\%,\;59\%$이었다. 24개월간 추적관찰한 결과 급성 합병증이나 후기 합병증의 증가는 없었다. 더 긴 기간의 추적관찰이 필요하지만, 절제 불가능한 비소세포 폐암의 다분할조사 방사선 치료 및 추가 조사기술의 효과를 판정하는데는 무작위 추출법을 사용하여 prospective 연구를 시행함이 필요하리라 생각된다.

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Small Nuclear Units에 의한 분산전원 및 계통연계(2) (Small Nuclear Units and Distributed Resource interconnection(2))

  • 이상성
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2005년도 제36회 하계학술대회 논문집 A
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    • pp.420-422
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    • 2005
  • This paper introduces a new paradigm for energy supply system in near future which produces electric and district heat cogeneration with dispersed power grid with small nuclear power units. Recently, in nuclear field, a lot of effort has been done in nuclear major countries to develop small and medium reactor for enhancement of nuclear peaceful use as like in district heating, electric power generation, seawater desalination or hydrogen generation.

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소형루프 전자탐사법에 의한 지하 영상화 (Subsurface Imaging by a Small-loop EM Survey)

  • 임진택;조인기
    • 지구물리와물리탐사
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    • 제6권4호
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    • pp.187-194
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    • 2003
  • 다중 주파수 소형루프 전자탐사법은 가탐심도의 한계에도 불구하고 조사가 신속하고 비용이 저렴하다는 장점을 가지고 있다. 따라서 이 방법은 각종 지반조사 및 환경문제의 해결을 위하여 널리 사용되고 있다. 본 논문에서는 소형루프 전자탐사 자료를 이용하여 지하의 2차원 영상화 기법을 개발하였다. 지하의 전기비저항 분포를 영상화하기 위하여 주파수 수직탐사 자료에 대한 1차원 역산법을 사용하였다. 이론 자료에 대한 역산결과 지하의 전기비저항 구조에 대한 양호한 영상을 구현할 수 있었다. 또한 강원도 춘천에 위치한 농장에서 획득한 현장자료를 사용하여 전기비저항 2차원 단면을 작성하고, 이를 쌍극자 배열 전기비저항 탐사 결과와 비교, 검토하였다.