• 제목/요약/키워드: Virtue

검색결과 826건 처리시간 0.027초

주파수 효율 향상을 위한 무선 중계장치의 직교편파 간섭제거기에 관한 연구 (A Study on the Cross-Polarization Interference Canceller of Radio Relay System for Spectral Efficiency Enhancement)

  • 서경환
    • 한국전자파학회:학술대회논문집
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    • 한국전자파학회 2001년도 종합학술발표회 논문집 Vol.11 No.1
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    • pp.25-28
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    • 2001
  • In this paper. to eliminate a cross-polarization interference caused by co-channel dual polarization technique of digital radio relay system(DRRS), a cross-polarization interference canceller(XPIC) is analysed in terms of the analytical modeling, digital design, and its performance. By virtue of a 13-tap adaptive equalizer and XPIC, about 23dB in XPIC improvement can be obtained by computer simulation. To show the operation of designed XPIC, some simulated results are reviewed under 64-QAM DRRS with co -channel dual Polarization.

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국내.외 과학기술 동향정보 제공 서비스 실태 조사 (Survey on S&T Trend Information Service in Korea and Abroad)

  • 최성배;오규연;한선화
    • 한국콘텐츠학회:학술대회논문집
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    • 한국콘텐츠학회 2004년도 춘계 종합학술대회 논문집
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    • pp.503-512
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    • 2004
  • The most important virtue that S&T information should possess is the promptness. In the era of global competition, it is very important to catch the technical trends and R&D policy of advanced countries in time. In this paper, we surveyed S&T trends information service in advanced and competing countries including USA, Japan, European countries, and china. Based on the survey result, we show that the "Overseas S&T Trends Information Service" provided by KISTI is dominant to those of other countries

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CONVERGENCE RATES FOR THE MOMENTS OF EXTREMES

  • Peng, Zuoxiang;Nadarajah, Saralees
    • 대한수학회보
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    • 제49권3호
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    • pp.495-510
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    • 2012
  • Let $X_1$, $X_2$,${\ldots}$, $X_n$ be a sequence of independent and identically distributed random variables with common distribution function $F$. Convergence rates for the moments of extremes are studied by virtue of second order regularly conditions. A unified treatment is also considered under second order von Mises conditions. Some examples are given to illustrate the results.

제로터 유압 모터의 치 접촉 응력 해석 (Analysis of Tooth Contact Stress of Gerotor Hydraulic Motors)

  • 김충현;김두인;안효석;정태형
    • Tribology and Lubricants
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    • 제15권2호
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    • pp.164-170
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    • 1999
  • Gerotor is widely used as a hydraulic pump or motor, by virtue of its volume changing ability. Performance deterioration of a gerotor hydraulic motor mainly due to the wear come from the contact between inner rotor with trochoidal curve and outer rotor with circular arc profile. This research covers the basic investigation about the contact forces of a gerotor hydraulic motor using analytic method. The influence of the eccentricity and the radius of circular arc teeth on the contact stress was evaluated.

Polychlorinated Biphenyls (PCBs) in the Bio-geochemistry of Oceans

  • Kannan, Narayanan
    • 한국해양바이오학회지
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    • 제2권4호
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    • pp.201-208
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    • 2007
  • Polychlorinated biphenyls (PCBs) are anthropogenic contaminants found globally in water, ice, soil, air and sediment. Modern analytical techniques allow us to determine these chemicals in environmental matrices at parts per trillion levels or lower. Environmental forensic on PCBs opens up new avenues of investigation such as transport and fate of water masses in oceans, sedimentation, onset of primary production, migration of marine mammals, their population distribution and pharmacokinetics of drugs inside organisms. By virtue of persistence, bioaccumulation, bioconcentration and structure-activity relationship PCBs emerge as unconventional chemical tracers of new sort.

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모형실험에 의한 강성포장체 가로줄눈에 다우웰바가 미치는 영향 (Effect of Dowel Bar on the transverse joint at the cement concrete pavement by model test)

  • 배주성;고영주;김평수
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 1998년도 가을 학술발표대회 논문집(III)
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    • pp.633-636
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    • 1998
  • The use of concrete pavements is increasing by virtue of durability and excellent load resisting capacity. But cracks and demage in concrete pavements may be occurred by continuous reciclic load, as time goes by. Therefore, transverser contraction joints are constructed in concrete pavements to relieve tensile stresses, and when properly spaced they control the location of transverse cracks.

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병렬 유전 알고리즘 기반 meta-유전 알고리즘을 이용한 교차율과 돌연변이율의 최적화 (Optimization of Crossover and Mutation Rate Using PGA-Based meta-GA)

  • 김문환;박진배;이연우;주영훈
    • 한국지능시스템학회:학술대회논문집
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    • 한국퍼지및지능시스템학회 2002년도 추계학술대회 및 정기총회
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    • pp.375-378
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    • 2002
  • In this paper we propose parallel GA to optimize mutation rate and crossover rate using server-client model. The performance of GA depend on the good choice of crossover and mutation rates. Although many researcher has been study about the good choice, it is still unsolved problem. proposed GA optimize crossover and mutation rates trough evolving subpopulation. In virtue of the server-client model, these parameters can be evolved rapidly with relatively low-grade

Reactions of 〔(2-N, N-Dimethylaminomethyl)phenyl〕methylvinychlorosilane with t-BuLi: Synthesis and Characterization of Five Isomeric 1,3-Disilacyclobutanes.

  • 이명유;조현모;이수흥;김장환
    • Bulletin of the Korean Chemical Society
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    • 제22권6호
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    • pp.593-596
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    • 2001
  • The reaction of [(2-N,N-dimethylaminomethyl) pheny] methylvinychlorosiane with t-BuLi in hexane solvent gave dimers, five isomeric 1,3-disilacyslobutanes which were weparated and charaterized. In trapping experiments with various trapping agents, no corresponding silene-trapping aduct was observed. We suggest that more important species for the formation of five isomeric dimers might be the zwitterionic species generated by virtue of intramolecular donor atom rather than the silene.

Ab initio Study on Structures, Energies and Vibrations of Methylammonium-(water)$_n$ (n=1-3) Complexes

  • 김광연;조융인;부두완
    • Bulletin of the Korean Chemical Society
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    • 제22권6호
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    • pp.597-604
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    • 2001
  • The reaction of [(2-N,N-dimethylaminomethyl) pheny] methylvinychlorosiane with t-BuLi in hexane solvent gave dimers, five isomeric 1,3-disilacyslobutanes which were weparated and charaterized. In trapping experiments with various trapping agents, no corresponding silene-trapping aduct was observed. We suggest that more important species for the formation of five isomeric dimers might be the zwitterionic species generated by virtue of intramolecular donor atom rather than the silene.

SIMPLIFYING AND FINDING ORDINARY DIFFERENTIAL EQUATIONS IN TERMS OF THE STIRLING NUMBERS

  • Qi, Feng;Wang, Jing-Lin;Guo, Bai-Ni
    • Korean Journal of Mathematics
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    • 제26권4호
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    • pp.675-681
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    • 2018
  • In the paper, by virtue of techniques in combinatorial analysis, the authors simplify three families of nonlinear ordinary differential equations in terms of the Stirling numbers of the first kind and establish a new family of nonlinear ordinary differential equations in terms of the Stirling numbers of the second kind.