• Title/Summary/Keyword: normal vector

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3D Pointing for Effective Hand Mouse in Depth Image (깊이영상에서 효율적인 핸드 마우스를 위한 3D 포인팅)

  • Joo, Sung-Il;Weon, Sun-Hee;Choi, Hyung-Il
    • Journal of the Korea Society of Computer and Information
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    • v.19 no.8
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    • pp.35-44
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    • 2014
  • This paper proposes a 3D pointing interface that is designed for the efficient application of a hand mouse. The proposed method uses depth images to secure high-quality results even in response to changes in lighting and environmental conditions and uses the normal vector of the palm of the hand to perform 3D pointing. First, the hand region is detected and tracked using the existing conventional method; based on the information thus obtained, the region of the palm is predicted and the region of interest is obtained. Once the region of interest has been identified, this region is approximated by the plane equation and the normal vector is extracted. Next, to ensure stable control, interpolation is performed using the extracted normal vector and the intersection point is detected. For stability and efficiency, the dynamic weight using the sigmoid function is applied to the above detected intersection point, and finally, this is converted into the 2D coordinate system. This paper explains the methods of detecting the region of interest and the direction vector and proposes a method of interpolating and applying the dynamic weight in order to stabilize control. Lastly, qualitative and quantitative analyses are performed on the proposed 3D pointing method to verify its ability to deliver stable control.

Conus Crown Modeling for Teeth Reconstruction (치아재건을 위한 Conus 내관 모델링)

  • 엄성권;김병오;유재수;유관희
    • Proceedings of the Korean Information Science Society Conference
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    • pp.571-573
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    • 1999
  • 수공으로 이루어지는 치아 재건을 3차원 모델링을 통하여 좀 더 정확하고 빠르게 제작하는데 있어 Conus 내관을 정확히 모델링하는 것은 매우 중요하다. Conus 내관을 모델링하기 위해 치과 의사가 만든 구강의 석고 모형으로부터 얻은 3차원 정보에서 실제 치아와 갈아낸 부분과의 경계인 변연(margin)을 정확히 찾아야 한다. 본 논문에서는 변연을 찾기 위한 방법으로 면의 노말 벡터(normal vector)와 치아의 기준 벡터와의 각도의 변화량을 이용하는 방법을 제시한다. 또한 변연으로부터 컴퓨터로 Conus 내관을 제작하는 방법을 소개한다.

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ON TIMELIKE BERTRAND CURVES IN MINKOWSKI 3-SPACE

  • Ucum, Ali;Ilarslan, Kazim
    • Honam Mathematical Journal
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    • v.38 no.3
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    • pp.467-477
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    • 2016
  • In this paper, we study the timelike Bertrand curves in Minkowski 3-space. Since the principal normal vector of a timelike curve is spacelike, the Bertrand mate curve of this curve can be a timelike curve, a spacelike curve with spacelike principal normal or a Cartan null curve, respectively. Thus, by considering these three cases, we get the necessary and sufficient conditions for a timelike curve to be a Bertrand curve. Also we give the related examples.

노말 벡터를 고려한 자동차 서브프레임의 해석 알고리즘 구현

  • 이광일;양승한
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • pp.274-274
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    • 2004
  • 조향성능은 완성된 자동차를 평가하는 아주 중요한 요소이며, 운전자에게 직접적인 영향을 가지는 까닭으로 우선적으로 해결되어야 할 문제이다. 자동차의 조향성능과 관련된 자동차 요소로는 프런트 샤시 모듈이 있으며, 프런트 샤시 모듈의 자세는 구성 요소인 서브프레임의 조립자세에 의하여 결정된다. 서브프레임은 4개의 원통형 지지부로 이루어져 있으며, 차체와의 조립시 지지부에 물리적 접촉이 발생한다. 즉 공간상에서 서브프레임의 자세는 지지부의 조립위치에 의하여 결정이 되며, 서브프레임의 자세를 결정하기 위해서는 지지부에 대한 적절한 해석이 필요하다.(중략)

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Indoor environment recognition in depth image using domain knowledge (깊이 영상에서 도메인지식을 이용한 실내 환경 인식)

  • Kim, Su-Kyung;Choi, Hyung-Il
    • Proceedings of the Korean Society of Computer Information Conference
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    • pp.319-322
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    • 2014
  • 본 논문에서는 깊이 카메라로 받아들인 입력 영상의 3차원 공간 내에서 벽면을 분리하는 방법을 제안한다. 본 논문에서 제안하는 벽면이 구분된 영상은 벽면에 프로젝터를 투사하는 등의 3차원 공간 활용에 용이하다. 입력 영상에서의 좌표 점을 이용하여 법선 벡터를 검출하고, 법선 벡터를 통해 평면을 분리한다. 분리된 평면들을 실내 환경에서 알 수 있는 도메인 지식들에 기반하여 벽면으로 구분 된다.

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Determination of an Optimal Contact Pose for Object Recognition Using a Robot Hand (로봇 손의 물체 인식을 위한 최적 접촉포즈 결정 알고리즘)

  • 김종익;한헌수
    • Proceedings of the IEEK Conference
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    • pp.448-451
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    • 1999
  • In this paper, we propose a new object representation method and matching algorithm for object recognition using a 3-fingered robot hand. Each finger tip can measure normal vector and shapes of a contacting surface. Object is represented by the inter-surface description table where the features of a surface are described in the diagonal and the relations between two surfaces are in the upper diagonal. Based on this table, a fast and the efficient matching algorithm has been proposed. This algorithm can be applied to natural quadric objects.

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NOTE ON NULL HELICES IN $\mathbb{E}_1^3$

  • Choi, Jin Ho;Kim, Young Ho
    • Bulletin of the Korean Mathematical Society
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    • v.50 no.3
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    • pp.885-899
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    • 2013
  • In this paper, we study null helices, null slant helices and Cartan slant helices in $\mathb{E}^3_1$. Using some associated curves, we characterize the null helices and the Cartan slant helices and construct them. Also, we study a space-like curve with the principal normal vector field which is a degenerate plane curve.

$L_q$ estimation on the least energy solutions

  • Pahk, Dae-Hyeon;Park, Sang-Don
    • Journal of the Korean Mathematical Society
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    • v.32 no.2
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    • pp.329-339
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    • 1995
  • Let us consider the Neumann problem for a quasilinear equation $$ (I_\varepsilon) {\varepsilon^m div($\mid$\nabla_u$\mid$^{m-2}\nabla_u) - u$\mid$u$\mid$^{m-2} + f(u) = 0 in \Omega {\frac{\partial\nu}{\partial u} = 0 on \partial\Omega. $$ where $1 < m < N, N \geq 2, \varepsilon > 0, \Omega$ is a smooth bounded domain in $R^n$ and $\nu$ is the unit outer normal vector to $\partial\Omega$.

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BIHARMONIC SPACELIKE CURVES IN LORENTZIAN HEISENBERG SPACE

  • Lee, Ji-Eun
    • Communications of the Korean Mathematical Society
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    • v.33 no.4
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    • pp.1309-1320
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    • 2018
  • In this paper, we show that proper biharmonic spacelike curve ${\gamma}$ in Lorentzian Heisenberg space (${\mathbb{H}}_3$, g) is pseudo-helix with ${\kappa}^2-{\tau}^2=-1+4{\eta}(B)^2$. Moreover, ${\gamma}$ has the spacelike normal vector field and is a slant curve. Finally, we find the parametric equations of them.

Shape Design Optimization using Isogeometric Analysis Method (등기하 해석법을 이용한 형상 최적 설계)

  • Ha, Seung-Hyun;Cho, Seon-Ho
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • pp.216-221
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    • 2008
  • Shape design optimization for linear elasticity problem is performed using isogeometric analysis method. In many design optimization problems for real engineering models, initial raw data usually comes from CAD modeler. Then designer should convert this CAD data into finite element mesh data because conventional design optimization tools are generally based on finite element analysis. During this conversion there is some numerical error due to a geometry approximation, which causes accuracy problems in not only response analysis but also design sensitivity analysis. As a remedy of this phenomenon, the isogeometric analysis method is one of the promising approaches of shape design optimization. The main idea of isogeometric analysis is that the basis functions used in analysis is exactly same as ones which represent the geometry, and this geometrically exact model can be used shape sensitivity analysis and design optimization as well. In shape design sensitivity point of view, precise shape sensitivity is very essential for gradient-based optimization. In conventional finite element based optimization, higher order information such as normal vector and curvature term is inaccurate or even missing due to the use of linear interpolation functions. On the other hands, B-spline basis functions have sufficient continuity and their derivatives are smooth enough. Therefore normal vector and curvature terms can be exactly evaluated, which eventually yields precise optimal shapes. In this article, isogeometric analysis method is utilized for the shape design optimization. By virtue of B-spline basis function, an exact geometry can be handled without finite element meshes. Moreover, initial CAD data are used throughout the optimization process, including response analysis, shape sensitivity analysis, design parameterization and shape optimization, without subsequent communication with CAD description.

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