• Title/Summary/Keyword: cylinders

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Analysis on Induced Current Density inside Human Body by 60 Hz ELF Magnetic Fields (60Hz ELF자계에 의한 인체내부 유도 전류밀도 해석)

  • Min Suk Won;Song Ki Hyun
    • Proceedings of the KIEE Conference
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    • summer
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    • pp.581-583
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    • 2004
  • This paper analysed the induced current density characteristics inside human body by extremely low frequency magnetic fields according to varying conductivities of human model. Human model was composed of several organs and other parts of 곳 human body, whose shapes were spheroids or cylinders. Organs taken into account were the brain, heart, lungs, liver and intestines. Applying the boundary element method to the human model, effects of the organ conductivity difference to the induced current distribution were estimated.

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Aspect Ratio Effect of the Natural Convection in Horizontal Enclosure with an Array of Square

  • Lee J.R.;Ha M.Y.
    • 한국전산유체공학회:학술대회논문집
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    • 2003.10a
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    • pp.286-288
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    • 2003
  • The physical model considered here is a horizontal layer of fluid heated below and cooled above with a periodic array of evenly spaced square cylinders placed at the center of the layer, whose aspect ratio here varies from unity to six. Periodic boundary condition is employed along the horizontal direction to allow for lateral freedom for the convection cells. Two-dimensional solution for unsteady natural convection is obtained using an accurate and efficient Chebyshev spectral multi-domain methodology for a given Rayleigh numbers of $10^6$

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Determination of Thermal Shock Stress Intensity Factor for Elliptical Crack by Modified Vainshtok Weight Function Method (수정 Vainshtok 가중함수법에 의한 타원균열의 열충격 응력세기계수의 결정)

  • 이강용;김종성
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.19 no.2
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    • pp.463-474
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    • 1995
  • Modified Vainshtok weight function method is developed. The thermal shock stress intensity factors for elliptical surface cracks existed in the thin and thick walled cylinders are determined. The present results are compared with previous solutions and shown to be good agreement with them.

Generalized Cylinder based on Linear Interpolation by Direction Map

  • Kim, Hyun;Kim, Hyoung-Sun;Lee, Joo-Haeng
    • International Journal of CAD/CAM
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    • v.3 no.1_2
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    • pp.77-83
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    • 2003
  • We propose two algorithms to generate (1) polygonal meshes and (2) developable surface patches far generalized cylinders defined by contours of discrete curves. To solve the contour blending problem of generalized cylinder, the presented algorithms have adopted the algorithm and related properties of LIDM (linear interpolation by direction map) that interpolate geometric shapes based on direction map merging and group scaling operations. Proposed methods are fast to compute and easy to implement.

Geometrically Nonlinear Analysis of Cantilevered Cylindrical Shells under Lateral Load (탑상형 원통쉘의 휨내력에 관한 기하학적 비선형 해석)

  • 최현식
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1993.10a
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    • pp.55-62
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    • 1993
  • Elastic failures of cantilevered cylindrical shells subject to lateral load are caused mainly by geometrical nonlinearlity. Geometerally nonlinear analysis is call for so as to investigate failure mechanisms. In this paper the geometericlly nonlinear analysis of cantilevered cylindrical shells under transverse load by the Rayleigh-Ritz Method is presented to examine the collapse loads and the process of cross-sectional deformations. The critical stress for relatively long cylinders have a tendency to show low level in comparison with the classical buckling stress for compression.

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Lean Concrete Using the Site-crushed Recycled Aggregates (현장파쇄 재생골재 활용 빈배합 콘크리트)

  • 심재원;김진철;강혜진;조규성
    • Proceedings of the Korea Concrete Institute Conference
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    • 2003.05a
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    • pp.243-248
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    • 2003
  • To select the proper material for lean concrete, the recycled aggregates produced by 3 crushers, such as jaw, impact and mill-treated, were investigated for the gradation and the compaction, and strength of concrete made of them. The experiments for all the recycled aggregates used, showed that the cylinders made of them had 7-day compressive strengths over 50kgf/$cm_2$, the provision of qualification, and the OMCs are in the range 5.7% to 6.8%. Also, the unit cement contents for the impact-crushed are 158kg/$cm_2$.

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Back Projection Histogram Method in Homogeneous Field for Microwave Subsurface Radar

  • Tanaka, Masayuki;Ohyama, Shinji;Kobayashi, Akira
    • 제어로봇시스템학회:학술대회논문집
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    • 2000.10a
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    • pp.456-456
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    • 2000
  • The back projection histogram method has been proposed as the method to construct an image from waves reflected from a buried object for subsurface radar. This method is compose of two phases, i.e., a back projection image construction process and a back projection image superposition process. A simulation analysis of this method has been studied. In this paper, an experimental study is demonstrated in air as the homogeneous Held using three cylinders as buried objects.

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Numerical Analysis of Combined Natural and Forced Convection Around Cylinders (II) (실린더로부터 전달되는 혼합대류 열전달의 수치해석 (II))

  • Moon, S.H.;Shih, T.M.;Johnson, A.T.
    • Journal of Biosystems Engineering
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    • v.12 no.4
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    • pp.22-30
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    • 1987
  • 실린더로부터 Prandtl수가 0.7인 주변공기로 전달되는 혼합대류 열전달현상을 Stream-Vorticity 함수로 표시된 재배방정식으로부터 유한차분법으로 분석하였다. Nusselt수와 실린더 주변의 온도분포가 조사된 제1편에 이어 Reynolds수와 Gradhof수가 실린더 주변의 공기속도분포, 경계층 박리지점(Separation point), 실린더 표면에서의 마찰계수 및 실린더 주변에서의 압력분포에 미치는 영향을 분석하였다.

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A New Inverse Scattering Technique Using the Moment Method in the Spectral Domain, II: Numerical Simulation (파수영역에서 모멘트 방법을 이용한 새로운 역산란 방법, II : 수치계산)

  • Lee, Jae-Min;Kim, Se-Yun;Ra, Jung-Woong
    • Proceedings of the KIEE Conference
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    • 1988.07a
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    • pp.442-445
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    • 1988
  • In this paper, the reconstruction of complex permittivity distribution on a rectangular cross section of inhomogeneous dielectric cylinders is performed by employing the spectral inverse scattering scheme. Numerical simulations provide the superresolution to the permittivity profiles nearly regardless of the measurement locations of the scattered field and the permittivity distributions on the cross section.

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Orientation Correction of a Cylinder for Surface-Profile Measurement (원통 축 방향의 표면거칠기 측정을 위한 시료의 자세 보정)

  • 조남규
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.5 no.4
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    • pp.108-120
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    • 1996
  • A new technique and theory are proposed which correct orientation of a cylinder to perform a reliable measurement of the surface profile. We analyze characteristics of machined surfaces, e.g., ground, lapped and turned surfaces. Based upon the results. the optimum correction technique is derived by the statistical method. To verify the techinques, measurements are carried out by using the contact stylus profilometer on a controllable table. The measurement shows that surface information of cylinders can be acquired with high accuracy.

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