• Title/Summary/Keyword: RE S/W

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Conjugate Heat Transfer in Cylindrical Annulus for an Insulated Tube (단열관을 위한 원통 환상공간 내에서의 복합 열전달)

  • Kang, B.H.;Yang, S.H.;Kwon, S.S.
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.7 no.4
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    • pp.633-641
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    • 1995
  • The effect of the gap width on conjugate heat transfer in the cylindrical annulus for an insulated tube has been studied numerically by the finite difference method. The parameters considered here are the Rayleigh number, Ra, the dimensionless insulated wall thickness, $W/D_i$ and the dimensionless gap width, S/W. As S/W increases, the mean wall temperature increases at the inside wall of annulus and decreases at the outside walls of annulus and the insulated tube at $S/W{\leq}0.5$, and then slightly increases at $Re=10^4$, $W/D_i=1.47$. The heat transfer rate decreases at $S/W{\leq}0.5$ and then increases apparently as S/W increases at $Re=10^4$, W/Df=1.47. Therefore, it is considered that $$S/W{\sim_=}0.5$$ is the optimum gap width for the effect of insulation at $Re=10^4$, $W/D_f=1.47$.

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Production of Re-188 (Rhenium-188 생산)

  • Yang, Seung-Dae;Suh, Yong-Sup;Kim, Sang-Uk;Lim, Sang-Moo
    • 대한핵의학회:학술대회논문집
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    • 1999.05a
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    • pp.189-192
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    • 1999
  • $^{188}Re$ (${\beta}^-=2.2$ MeV; ${\gamma}^-$=155 keV; $T_{1/2}$=16.9 hours) is an attractive therapeutic radioisotope which is produced from decay of reactor-produced tungsten-188 parent ($T_{1/2}$=69 days). $^{188}W$ has been produced from the double neutron capture reaction of $^{186}W.\;^{188}Re$ can be easily obtained by elution of saline on alumina based $^{188}W/^{188}Re$ generator, which is commercially available. Complexes labelled with $^{188}Re$ have been developed for the radiotherapy treatment of diseases because of the desirable nuclear properties of the radioisotope and it's chemical properties similar to those of technetium, a well established diagnostic agent.

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Center Determination for Cone-Beam X-ray Tomography

  • Narkbuakaew, W.;Ngamanekrat, S.;Withayachumnankul, W.;Pintavirooj, C.;Sangworasil, M.
    • 제어로봇시스템학회:학술대회논문집
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    • 2004.08a
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    • pp.1885-1888
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    • 2004
  • In order to render 3D model of the bone, the stack of cross-sectional images must be reconstructed from a series of X-ray radiographs, served as the projections. In the case where the distance between x-ray source and detector is not infinite, image reconstruction from projection based on parallel-beam geometry provides an error in the cross-sectional image. In such case, image reconstruction from projection based on conebeam geometry must be exercised instead. This paper is devoted to the determination of detector center for SART conebeam Technique which is critically effect the performance of the resulting 3D modeling.

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The Theoretical Analyses of the Soil Erosion and Conservation 1. The Soil Renewal and Erosion (토양의 침식과 보존에 관한 이론적 분석 1. 토양의 생성과 침식)

  • 장남기
    • Asian Journal of Turfgrass Science
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    • v.10 no.1
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    • pp.21-29
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    • 1996
  • The mathematical expression in the forest and grassland soils to express the general concepts involved in such terms "a soil erosion and soil renewal. " The net addition rate in the forest and grassland soils are represented by an equation of $(S_{rb}-S_{ra})-(S_{eb}-S_{ea})={\int}_a^bR(m, cl, re, b, t )dt-{\int}E(w, r, cl, re, ch, b, t)dt{\gtreqqless}0$ where $S_r$, is renewal soil, $S_e$ is soil erosion, and variable factors are m =parent material of soil, cl=climate, re=relief or topography, ch=soil characteristics, r=rain or water, w=wind, b=biota, and t = time.

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Planning for Re-engineering of Legacy Systems (레거시 시스템의 재공학을 위한 계획)

  • Kim, Chul-Hong;Cha, Jung-Eun;Yang, Young-Jong
    • 한국IT서비스학회:학술대회논문집
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    • 2003.11a
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    • pp.609-615
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    • 2003
  • 본 논문은 레거시 시스템을 컴포넌트 기반 시스템으로 재공학하는 절차 및 기법을 제공하는 마르미-RE의 전체 단계 중 계획 단계에 대한 상세한 프로세스를 서술한다. 계획 단계는 11개의 작업으로 이루어져 있고, 이들은 각각 4개의 활동인 현황 파악, 개선 비즈니스 도출, 개선 전략 수립, 개발 계획 수립으로 그룹핑 된다. 현황 파악 활동은 업무의 전반적인 정보 분석을 통해 조직의 구조와 업무의 흐름 및 문제점을 파악하고, 개선 비즈니스 모델 도출은 유스케이스 모델링과 객체 모델링을 통해 사용자의 요구사항을 수집하여 개선 업무 모델을 도출한다. 개선 전략 수립 활동은 변환을 위한 전략을 수립하고, 마지막으로 개발 계획 수립 활동에서 변환을 위한 프로젝트 계획서가 작성된다.

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