• 제목, 요약, 키워드: homogeneous extension

검색결과 45건 처리시간 0.039초

NONDEGENERATE AFFINE HOMOGENEOUS DOMAIN OVER A GRAPH

  • Choi, Yun-Cherl
    • 대한수학회지
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    • v.43 no.6
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    • pp.1301-1324
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    • 2006
  • The affine homogeneous hypersurface in ${\mathbb{R}}^{n+1}$, which is a graph of a function $F:{\mathbb{R}}^n{\rightarrow}{\mathbb{R}}$ with |det DdF|=1, corresponds to a complete unimodular left symmetric algebra with a nondegenerate Hessian type inner product. We will investigate the condition for the domain over the homogeneous hypersurface to be homogeneous through an extension of the complete unimodular left symmetric algebra, which is called the graph extension.

비동차 이차형식의 분포함수에 대한 안장점근사 (Saddlepoint Approximations to the Distribution Function of Non-homogeneous Quadratic Forms)

  • 나종화;김정숙
    • 응용통계연구
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    • v.18 no.1
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    • pp.183-196
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    • 2005
  • 본 논문에서는 다변량 정규분포하에서 비동차(non-homogeneous) 이차형식의 분포 함수에 대한 안장점근사법을 다루었다. 이는 Kuonen (1999)의 동차(homogeneous) 이차형식에 대한 안장점근사를 비동차의 경우로 확장한 것이다. 안장점근사의 적용을 위해 비동차 이차형식의 누율생성함수 및 관련 성질들을 유도하였다. 모의실험을 통해 안장점근사의 정도가 매우 뛰어남을 확인하였다.

HOMOTOPY FIXED POINT SETS AND ACTIONS ON HOMOGENEOUS SPACES OF p-COMPACT GROUPS

  • Kenshi Ishiguro;Lee, Hyang-Sook
    • 대한수학회지
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    • v.41 no.6
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    • pp.1101-1114
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    • 2004
  • We generalize a result of Dror Farjoun and Zabrodsky on the relationship between fixed point sets and homotopy fixed point sets, which is related to the generalized Sullivan Conjecture. As an application, we discuss extension problems considering actions on homogeneous spaces of p-compact groups.

Development of 3-D Stereo PIV and Its Application to a Delta Wing

  • Kim, Beom-Seok;Lee, Hyun;Choi, Jang-Woon;Kadooka, Yoshimasa;Tago, Yoshio;Lee, Young-Ho
    • 대한기계학회:학술대회논문집
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    • pp.658-663
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    • 2003
  • A process of 3-D stereo particle image velocimetry(PIV)was developed for the measurement of an illuminated sliced section field of 3-D complex flows. The present method includes modeling of camera by a calibrator based on the homogeneous coordinate system, transformation of the oblique-angled image to the right-angled image, identification of 2-D velocity vectors by 2-D cross-correlation equation, stereo matching of 2-D velocity vectors of two cameras, accurate calculation of 3-D velocity vectors by homogeneous coordinate system, removal of error vectors by a statistical method followed by a continuity equation criteria, and finally 3-D display as the post processing. An experimental system was also used for the application of the proposed method. Two high speed digital CCD cameras and an Argon-Ion Laser for the illumination were adopted to clarify the time-dependent characteristics of the leading edge extension(LEX) in a highly swept shape applied to a delta wing found in modern air-fighters.

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The Hilbert-Type Integral Inequality with the System Kernel of-λ Degree Homogeneous Form

  • Xie, Zitian;Zeng, Zheng
    • Kyungpook Mathematical Journal
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    • v.50 no.2
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    • pp.297-306
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    • 2010
  • In this paper, the integral operator is used. We give a new Hilbert-type integral inequality, whose kernel is the homogeneous form with degree - $\lambda$ and with three pairs of conjugate exponents and the best constant factor and its reverse form are also derived. It is shown that the results of this paper represent an extension as well as some improvements of the earlier results.

비특이항을 고려한 균질이방성체내 수평균열의 해석 (An Analysis of Flat-Crack in Homogeneous Anisotropic Solids Considering Non-Singular Term)

  • 임원균;최승룡;안현수
    • 대한기계학회논문집A
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    • v.24 no.1
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    • pp.69-78
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    • 2000
  • The one-parameter singular expression for stresses and displacements near a crack tip has been widely thought to be sufficiently accurate over a reasonable re ion for any geometry and loading conditions. In many cases, however subsequent terms of the series expansion are quantitatively significant, and so we now consider the evaluation of such terms and their effect on the predicted crack growth direction. For this purpose the problem of a cracked orthotropic plate subjected to a biaxial load is analysed. It is assumed that the material is ideal homogeneous anisotropic. BY considering the effect of the load applied parallel to the plane of the crack, the distribution of stresses and displacements at the crack tip is reanalyzed. In order to determine values for the angle of initial crack extension we employ the normal stress ratio criterion.

REIDEMEISTER ZETA FUNCTION FOR GROUP EXTENSIONS

  • Wong, Peter
    • 대한수학회지
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    • v.38 no.6
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    • pp.1107-1116
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    • 2001
  • In this paper, we study the rationality of the Reidemeister zeta function of an endomorphism of a group extension. As an application, we give sufficient conditions for the rationality of the Reidemeister and the Nielsen zeta functions of selfmaps on an exponential solvmanifold or an infra-nilmanifold or the coset space of a compact connected Lie group by a finite subgroup.

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2개의 성장 균열들의 상호작용에 관한 응력확대계수 해석 (Analysis of Stress Intensity Factors for Interacting Two Growing Cracks)

  • 박성완
    • 한국생산제조학회지
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    • v.9 no.5
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    • pp.47-57
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    • 2000
  • In this study, a fundamental approach to make clear the mechanism of the mutual interference and coalescence of stress fields in the vicinity of two crack tips on the process of their slow growth, using boundary element method. Automatic generation of quadratic discontinuous elements along both of the crack boundaries which can be defined by an arbitrary piece-wise straight geometry. The direction of the crack-extension increment is predicted by the maximum principal stress criterion, corrected to account for the discreteness of the crack extension. Along the computed direction, the crack is extended one increment. Automatic incremental crack-extension analysis with no remeshing, computation of the stress intensity factors by J-integral. Numerical stress intensity factors for two growing cracks in plane-homogeneous regions were determined.

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편향 인장 및 트렐리스 시험에 의한 직물 복합재료의 면내 전단 물성 평가 (Characterization of In-plane Shear Behaviors of Woven Fabrics by Bias-extension and Trellis-frame Tests)

  • 이원오;엄문광;변준형
    • Composites Research
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    • v.23 no.5
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    • pp.8-14
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    • 2010
  • 서로 다른 길이비를 갖는 세 종류의 유리 직물 복합재료(평직, 균형능직, 비균형능직)의 면내 전단 물성 평가를 위해 편향인장 시험을 실시하였다. 직물 복합재료의 전단각을 결정하기 위하여 인장 변형량과 직물의 크기에 기인한 이론식, 직접측정법 및 이미지 분석법등을 이용하여 서로의 장단점을 비교하여 보았으며, 편향 인장 시험의 기하구조를 이용하여 유도된 식을 통해 면내 전단력을 계산하였다. 또한 트렐리스 시험(trellis-frame test)에 의한 결과와의 비교를 통해 편향 인장 시험에 의한 전단 물성 측정법의 정확도를 평가하였다. 실험 결과, 이론식에 의한 전단각 계산법은 전단각이 30도 이내일 경우에 이미지를 통한 직접 측정의 결과와 유사하였으며, 면내 전단력은 평직이나 균형 능직과 같은 등방형 직물의 경우에만 측정 샘플의 길이비에 무관한 균일한 결과를 보였다. 또한 편향 인장 시험과 트렐리스 시험 모두 비등방성이 큰 직물에 대한 전단 평가를 수행하는 데 있어서 많은 편차를 나타내었다.