• 제목/요약/키워드: Geometric Structure

검색결과 991건 처리시간 0.032초

4-DIMENSIONAL CRITICAL WEYL STRUCTURES

  • Kim, Jong-Su
    • 대한수학회보
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    • 제38권3호
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    • pp.551-564
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    • 2001
  • We view Weyl structures as generalizations of Riemannian metrics and study the critical points of geometric functional which involve scalar curvature, defined on the space of Weyl structures on a closed 4-manifold. The main goal here is to provide a framework to analyze critical Weyl structures by defining functionals, discussing function spaces and writing down basic formulas for the equations of critical points.

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Buckling Strength Analysis of Box-Column Including the Coupling Effect Between Local and Global Buckling

  • Paik, Jeom-K.
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 1988년도 가을 학술발표회 논문집
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    • pp.36-42
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    • 1988
  • In this study, a formulation of the idealized plate element based upon the idealized structural unit method(ISUM) firstly proposed by Ueda et.al is made in an attempt to analyze the geometric nonlinear behaviour up to the buckling strength of thin-walled long structures like box-column structure including the coupling effect between local and global buckling. An application to the example box-column is also performed and it is found that the present method gives reliable results with consuming very short computing times and therefore is very useful for evaluation of the buckling strength of thin-walled long structures.

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점탄성 감쇠기를 이용한 주거용 건물의 진동제어 (Vibration control for residential building structure using viscoelastic damper)

  • 안상경;오정근;이성원;박현일;김원식;김영석
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2003년도 봄 학술발표회 논문집
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    • pp.127-132
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    • 2003
  • Through advance in construction techniques, engineering progress, availability of new materials, and economic considerations, buildings are becoming taller, lighter, and more flexible. In addition, today/s buildings are largely of regular geometric shape with smooth glass metal exteriors, which increase the likelihood of vortex shedding. The wind induced oscillation of the building, if not properly damped, could cause occupant discomfort and other problem. This paper will deal with residual building structure equipped with viscoelastic dampers. And the dampers are installed on the 42th story according to the maximum relative deformation.

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역학적 구조에 대한 Knowledge-based 시스템을 이용한 파라메트릭 설계 (Parametric design for mechanical structure using knowledge-based system)

  • 이창호;김병인;정무영
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국내학술편); Seoul National University, Seoul; 20-22 Oct. 1993
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    • pp.1018-1023
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    • 1993
  • In mechanical structure design area, many FEM (Finite Element Method) packages are used. But the design using FEM packages depends on an iterative trial and error manner and general CAD systems cannot cope with the change of parameters. This paper presents a methodology for building a designing system of a mechanical structure. This system can generate the drawing for a designed structure automatically. It consists of three steps: generation of a structure by selection of the parameters, stress analysis, and generation of a drawing using CAD system. FEM module and parametric CAD module are developed for this system. Inference engine module generates the parameters with a rule base and a model base, and also evaluates the current structure. The parametric design module generates geometric shapes automatically with given dimension. Parametric design is implemented with the artificial intelligent technique. In older to the demonstrate the effectiveness of the developed system, a frame set of bicycle was designed. The system was implemented on an SUN workstation using C language under OpenWindows environment.

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Integrability of the Metallic Structures on the Frame Bundle

  • Islam Khan, Mohammad Nazrul
    • Kyungpook Mathematical Journal
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    • 제61권4호
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    • pp.791-803
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    • 2021
  • Earlier investigators have made detailed studies of geometric properties such as integrability, partial integrability, and invariants, such as the fundamental 2-form, of some canonical f-structures, such as f3 ± f = 0, on the frame bundle FM. Our aim is to study metallic structures on the frame bundle: polynomial structures of degree 2 satisfying F2 = pF +qI where p, q are positive integers. We introduce a tensor field Fα, α = 1, 2…, n on FM show that it is a metallic structure. Theorems on Nijenhuis tensor and integrability of metallic structure Fα on FM are also proved. Furthermore, the diagonal lifts gD and the fundamental 2-form Ωα of a metallic structure Fα on FM are established. Moreover, the integrability condition for horizontal lift FαH of a metallic structure Fα on FM is determined as an application. Finally, the golden structure that is a particular case of a metallic structure on FM is discussed as an example.

Real projective structures on the (2,2,2,2)-orbifold

  • Jun, Jinha
    • 대한수학회보
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    • 제34권4호
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    • pp.535-547
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    • 1997
  • The (2, 2, 2, 2)-orbifold is a 2-dimensional orbifold with four order 2 cone points having 2-sphere as an underlying space. The (2, 2, 2, 2)-orbifold admits different geometric structures. The purpose of this paper is to find some real profective structures on the (2, 2, 2, 2)-orbifold.

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Calculation of the Dipole Moments for Transition Metal Complexes

  • Golding, R. M.;Ahn, Sang-Woon
    • Bulletin of the Korean Chemical Society
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    • 제2권2호
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    • pp.48-55
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    • 1981
  • A new approach in calculating the dipole moments for transition metal complexes has been proposed and the calculated results are tabulated with the experimental values. The calculated dipole moments are applied to the theoretical prediction or confirmation of the geometric structure for the transition metal complexes.

CHARACTERIZATIONS ON GEODESIC GCR-LIGHTLIKE SUBMANIFOLDS OF AN INDEFINITE KAEHLER STATISTICAL MANIFOLD

  • Rani, Vandana;Kaur, Jasleen
    • 호남수학학술지
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    • 제44권3호
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    • pp.432-446
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    • 2022
  • This article introduces the structure of GCR-lightlike submanifolds of an indefinite Kaehler statistical manifold and derives their geometric properties. The characterizations on totally geodesic, mixed geodesic, D-geodesic and D'-geodesic GCR-lightlike submanifolds have also been obtained.

효과적인 3차원 기하학적 구조 추정 및 모델링을 위한 텐서 보팅 기반 영역 분할 (Efficient 3D Geometric Structure Inference and Modeling for Tensor Voting based Region Segmentation)

  • 김상균;박순영;박종현
    • 대한전자공학회논문지SP
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    • 제49권3호
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    • pp.10-17
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    • 2012
  • 이미지 기반 3차원 장면은 비전 시스템, 게임, 가상현실 체험 등의 분야에서 쉽게 찾아볼 수 있다. 본 논문은 단일 영상으로부터 자동으로 3차원 가상 장면을 생성하기 위한 방법을 제안한다. 제안된 방법은 어린이용 도서의 팝업 이미지의 생성과 유사하다. 특히, 단일 외부 영상으로부터 장면의 3차원 기하학적 구조를 평가하기 위한 과분할 영상을 얻기 위해 텐서 보팅을 적용하였다. 텐서 보팅은 이미지의 균질 영역을 더욱더 부드러운 영역에 가깝게 만들며 영역 중심의 토큰은 매우 큰 saliency 값을 갖게 된다. 그리고 각 분할된 영역을 지면, 하늘, 수직성분 등의 대략적인 카테고리로 분류하고 라벨을 부여한다. 이 라벨은 간단한 가정 하에서 이미지를 팝업 모델로 변환시키기 위한 "잘라내기"와 "접기" 로 이용된다. 실험결과 제안된 방법은 복잡한 자연 영상에서도 성공적으로 영역 분할을 수행하였으며 분할된 영역 정보를 기반으로 구조 정보를 추론하여 3차원 팝업 영상으로 모델링하였다.