• 제목/요약/키워드: space intersection

검색결과 181건 처리시간 0.039초

가시 정보를 이용한 삼각망의 꼬임 찾기 (Finding Self-intersections of a Triangular Mesh by Using Visibility Maps)

  • 박상철
    • 한국CDE학회논문집
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    • 제9권4호
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    • pp.382-386
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    • 2004
  • This paper presents an algorithm for the triangular mesh intersection problem. The key aspect of the proposed algorithm is to reduce the number of triangle pairs to be checked for intersection. To this end, it employs two different approaches, the Y-group approach and the space partitioning approach. Even though both approaches have the same objective of reducing the number of triangular-triangular intersection (TTI) pairs, their inherent characteristics are quite different. While the V-group approach works by topology (reduces TTI pairs by guaranteeing no intersection among adjacent triangles), the space partitioning approach works by geometry (reduces TTI pairs by guaranteeing no intersection among distant triangles). The complementary nature of the two approaches brings substantial improvement in reducing the number TTI pairs.

Three-Dimensional Positioning Using EROS A Stereo Pairs

  • Teo, Tee-Ann;Chen, Liang-Chien
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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    • pp.606-608
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    • 2003
  • This paper investigates the accuracy of three-dimensional positioning for EROS A stereo pairs when different numbers of ground control points are employed. The major works of the proposed schemes include: (1) initialization of orientation parameters (2) preliminary orbit fitting, (3) orbit refinement using the least squares filtering technique, and (4) space intersection. The experiment includes validation of positioning accuracy for an EROS A in-track stereo pair when different number of check points are employed.

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차량측량시스템의 CCD 영상에 의한 3차원 위치결정 방법 비교 연구 (A Comparative Study on the 3D Positioning Methods by CCD Images of The Mobile Mapping System)

  • 정동훈
    • Spatial Information Research
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    • 제15권2호
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    • pp.169-180
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    • 2007
  • 정부 및 지자체 행정업무의 전산화와 통합시스템 구축이 증가함에 따라 차량측량시스템의 활용성이 점차 증대 돼 가고 있다. 이와 같은 요구에 따라 특정 지역의 시설물을 신속하게 측정해야 하는 경우가 발생하는데 이 경우에는 후처리방식보다는 실시간 현장처리방식이 필요하며 현장처리에 있어서는 정확도 못지않게 자료의 처리속도가 중요한 요소가 된다. 본 연구에서는 정확도와 처리속도 면에서 현장처리에 적합한 3차원 위치결정방법을 선정하기 위해 사진측량분야에서 사용되어 온 두 가지 공간전방교회법을 프로그램화하여 비교하였다. 특히, 해석적 공간전방교회법에 대해서는 기존의 근거리 지상사진 측량법을 차량의 이동에 따라 카메라의 위치와 자세가 변하는 차량측량시스템의 특성에 맞도록 수정하여 적용하였다. 비교결과, 정확도의 측면에서는 두 방법에서 차이가 거의 없었으나 계산에 소요되는 시간의 측면에서는 해석적 공간전방교회법이 약 1/3 정도로 나타났다.

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ON THE INTERSECTION OF TWO TORUS KNOTS

  • Lee, Sang-Youl;Lim, Yong-Do
    • East Asian mathematical journal
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    • 제16권1호
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    • pp.61-69
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    • 2000
  • We show that the intersection of two standard torus knots of type (${\lambda}_1$, ${\lambda}_2$) and (${\beta}_1$, ${\beta}_2$) induces an automorphism of the cyclic group ${\mathbb{Z}}_d$, where d is the intersection number of the two torus knots and give an elementary proof of the fact that all non-trivial torus knots are strongly invertiable knots. We also show that the intersection of two standard knots on the 3-torus $S^1{\times}S^1{\times}S^1$ induces an isomorphism of cyclic groups.

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광선 추적법과 공간 분할을 이용한 입체 도형의 표현 (The Representation of 3-D Objects Using Ray Tracing and Space Subdivision)

  • 김영일;조동욱;최병욱
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1987년도 전기.전자공학 학술대회 논문집(II)
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    • pp.1073-1076
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    • 1987
  • In this paper, a new ray tracing algorithm which uses space subdivision method is introduced. In order to reduce huge number of ray-surface intersection calculation, the space is subdivided as lattice that contains minimum number of objects. With lattice structure, the process that calculates unnecessary ray-surface intersection is eliminated.

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COCOMPACT F-BASES AND RELATION BETWEEN COVER AND COMPACTIFICATION

  • Lee, Sang-Deok;Kim, Chang-Il
    • 한국수학교육학회지시리즈B:순수및응용수학
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    • 제3권2호
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    • pp.163-171
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    • 1996
  • Observing that a locally weakly Lindel$\"{o}$f space is a quasi-F space if and only if it has an F-base, we show that every dense weakly Lindel$\"{o}$f subspace of an almost-p-space is C-embedded, every locally weakly Lindel$\"{o}$f space with a cocompact F-base is a locally compact and quasi-F space and that if Y is a dense weakly Lindel$\"{o}$f subspace of X which has a cocompact F-base, then $\beta$Y and X are homeomorphic. We also show that for any a separating nest generated intersection ring F on a space X, there is a separating nest generated intersection ring g on $\phi_{Y}^{-1}$(X) such that QF(w(X, F)) and ($\phi_{Y}^{-1}$(X),g) are homeomorphic and $\phi_{Y}_{x}$(g$^#$)=F$^#$.

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DOUBLE LINES IN THE QUINTIC DEL PEZZO FOURFOLD

  • Kiryong Chung
    • 대한수학회보
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    • 제60권2호
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    • pp.485-494
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    • 2023
  • Let Y be the quintic del Pezzo 4-fold defined by the linear section of Gr(2, 5) by ℙ7. In this paper, we describe the locus of double lines in the Hilbert scheme of coincs in Y. As a corollary, we obtain the desigularized model of the moduli space of stable maps of degree 2 in Y. We also compute the intersection Poincaré polynomial of the stable map space.

GIS를 이용하여 교차로를 고려한 도로선형 최적화 모델링 (The Road Alignment Optimization Modelling of Intersection Based on GIS)

  • 김동하;이준석;강인준
    • 한국측량학회:학술대회논문집
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    • 한국측량학회 2003년도 추계학술발표회 논문집
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    • pp.341-345
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    • 2003
  • This study develops modeling processes for alignment optimization considering characteristics of intersections using genetic algorithms and GIS for road alignment optimization. Since existing highway alignment optimization models have neglected the characteristics of intersections, they have shown serious weaknesses for real applications. In this paper, intersection costs include earthwork, right-of-way, pavement, accident, delay and fuel consumption costs that are sensitive and dominating to alignments. Also, local optimization of intersections for saving good alignment alternatives is developed and embedded. A highway alignment is described by parametric representation in space and vector manipulation is used to find the coordinates of intersections and other interesting points. The developed intersection cost estimation model is sufficiently precise for estimating intersection costs and eventually enhancing the performance of highway alignment optimization models. Also, local optimization of intersections can be used for improving search flexibility, thus allowing more effective intersections. It also provides a basis for extending the alignment optimization from single highways to networks. The presented two artificial examples show that the total intersection costs are substantial and sensitive to highway alignments.

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MORPHISMS BETWEEN FANO MANIFOLDS GIVEN BY COMPLETE INTERSECTIONS

  • Choe, Insong
    • 충청수학회지
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    • 제22권4호
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    • pp.689-697
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    • 2009
  • We study the existence of surjective morphisms between Fano manifolds of Picard number 1, when the source is given by the intersection of a cubic hypersurface and either a quadric or another cubic hypersurface in a projective space.

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