• Title/Summary/Keyword: projective

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Obtaining the Surface Orientation of Texture Image using the Texture Spectrum and Mathematical Morphology (텍스처 스펙트럼을 이용한 텍스처 영상의 표면 방향 추출)

  • Kim, Do-Nyun;Cho, Dong-Sub
    • Proceedings of the KIEE Conference
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    • 1995.07b
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    • pp.989-991
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    • 1995
  • In this paper, we present a new morphological texture spectrum approach to obtain a surface orientation using the variation of texture image caused by projective distortions. Under the assumption that the surface of texture image is smooth continuous, and specially plane or sphere, we apply the mathematical morphology and texture spectrum in order to compute the 3-D surface orientation. If the surface of texture image is plane, the surface orientation can be obtained through a simple procedure. If the surface of texture image is sphere, we find the centroids of texels, and may compute several major axes, their slopes, and vanishing points. Using the texture spectrum between the intersections of the vanishing points and the size of elements in each texels, we can find the surface orientation of texels on the sphere.

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DETERMINATION OF MINIMUM LENGTH OF SOME LINEAR CODES

  • Cheon, Eun Ju
    • Journal of the Chungcheong Mathematical Society
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    • v.26 no.1
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    • pp.147-159
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    • 2013
  • Hamada ([8]) and Maruta ([17]) proved the minimum length $n_3(6,\;d)=g_3(6,\;d)+1$ for some ternary codes. In this paper we consider such minimum length problem for $q{\geq}4$, and we prove that $n_q(6,\;d)=g_q(6,\;d)+1$ for $d=q^5-q^3-q^2-2q+e$, $1{\leq}e{\leq}q$. Combining this result with Theorem A in [4], we have $n_q(6,\;d)=g-q(6,\;d)+1$ for $q^5-q^3-q^2-2q+1{\leq}d{\leq}q^5-q^3-q^2$ with $q{\geq}4$. Note that $n_q(6,\;d)=g_q(6,\;d)$ for $q^5-q^3-q^2+1{\leq}d{\leq}q^5$ by Theorem 1.2.

A Note on the Chern Classes

  • Lee, K.A.;Lee, Ho.J.;Lee, He.J.;Chun, D.S.;Jeon, W.K.;Kim, Y.W.;Kim, I.S.
    • Honam Mathematical Journal
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    • v.9 no.1
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    • pp.135-147
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    • 1987
  • It is well known that there are two ways to define Chern classes of complex vector bundles. One gives the definition of Chern classes by the five axioms ([2]. [3], [4]). and an other defines Chern classes with the associated projective space bundle of a given bundle ([1]. [5]). The purpose of this paper is to describe the latter way in detail and to give new proofs of that our Chern classes satisfy the five axioms with respect to Chern classes (for example Theorem 5).

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CHARACTERIZATIONS OF REAL HYPERSURFACES OF TYPE A IN A COMPLEX SPACE FORM USED BY THE ζ-PARALLEL STRUCTURE JACOBI OPERATOR

  • Kim, Nam-Gil;Ki, U-Hang;Kurihara, Hiroyuki
    • Honam Mathematical Journal
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    • v.30 no.3
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    • pp.535-550
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    • 2008
  • Let M be a real hypersurface of a complex space form with almost contact metric structure $({\phi},{\xi},{\eta},g)$. In this paper, we study real hypersurfaces in a complex space form whose structure Jacobi operator $R_{\xi}=R({\cdot},{\xi}){\xi}$ is ${\xi}$-parallel. In particular, we prove that the condition ${\nabla}_{\xi}R_{\xi}=0$ characterize the homogeneous real hypersurfaces of type A in a complex: projective space $P_n{\mathbb{C}}$ or a complex hyperbolic space $H_n{\mathbb{C}}$ when $g({\nabla}_{\xi}{\xi},{\nabla}_{\xi}{\xi})$ is constant and not equal to -c/24 on M, where c is a constant holomorphic sectional curvature of a complex space form.

Some Siegel Threefolds with a Calabi-Yau Model II

  • Freitag, Eberhard;Manni, Riccardo Salvati
    • Kyungpook Mathematical Journal
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    • v.53 no.2
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    • pp.149-174
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    • 2013
  • In a previous paper, we described some Siegel modular threefolds which admit a Calabi-Yau model. Using a different method we give in this paper an enlarged list of such varieties. Basic for this method is a paper of van Geemen and Nygaard. They study a variety $\mathcal{X}$ that is the complete intersection of four quadrics in $\mathbb{P}^7(\mathbb{C})$. This is biholomorphic equivalent to the Satake compactification of $\mathcal{H}_2/{\Gamma}^{\prime}$ for a certain subgroup ${\Gamma}^{\prime}{\subset}Sp(2,\mathbb{Z})$ and it will be the starting point of our investigation. It has been pointed out that a (projective) small resolution of this variety is a rigid Calabi-Yau manifold $\tilde{\mathcal{X}}$. Then we will consider the action of quotients of modular groups on $\mathcal{X}$ and study possible resolutions that admits a Calabi-Yau model in the category of complex spaces.

(Σ, ∆)-Compatible Skew PBW Extension Ring

  • Hashemi, Ebrahim;Khalilnezhad, Khadijeh;Alhevaz, Abdollah
    • Kyungpook Mathematical Journal
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    • v.57 no.3
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    • pp.401-417
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    • 2017
  • Ever since their introduction, skew PBW ($Poincar{\acute{e}}$-Birkhoff-Witt) extensions of rings have kept growing in importance, as researchers characterized their properties (such as primeness, Krull and Goldie dimension, homological properties, etc.) in terms of intrinsic properties of the base ring, and studied their relations with other fields of mathematics, as for example quantum mechanics theory. Many rings and algebras arising in quantum mechanics can be interpreted as skew PBW extensions. Our aim in this paper is to study skew PBW extensions of Baer, quasi-Baer, principally projective and principally quasi-Baer rings, in the case when the base ring R is not assumed to be reduced. We just impose some mild compatibleness over the base ring R, and prove that these properties are stable over this kind of extensions.

Position Estimation of a Mobile Robot using Distance Error Weight Function (Distance Error Weight Function을 이용한 이동 로봇의 위치 추정 시스템의 설계)

  • Kho, Jee-Won;Park, Jae-Joon;Lee, Ki-Cheol;Park, Mig-Non
    • Proceedings of the KIEE Conference
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    • 1999.07g
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    • pp.3048-3050
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    • 1999
  • This paper suggests a position estimating algorithm using mono vision system with projective geometry method. Generally, 3-D information can not be easily extracted from mono vision system which is taken by a camera at a specific point. But this defect is overcome by adopting model-based image analysis and selecting lines and points on the ground as natural landmarks. And this paper suggests a method that estimates position from many natural landmarks by distance error weight function.

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Video-based Height Measurements of Multiple Moving Objects

  • Jiang, Mingxin;Wang, Hongyu;Qiu, Tianshuang
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.8 no.9
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    • pp.3196-3210
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    • 2014
  • This paper presents a novel video metrology approach based on robust tracking. From videos acquired by an uncalibrated stationary camera, the foreground likelihood map is obtained by using the Codebook background modeling algorithm, and the multiple moving objects are tracked by a combined tracking algorithm. Then, we compute vanishing line of the ground plane and the vertical vanishing point of the scene, and extract the head feature points and the feet feature points in each frame of video sequences. Finally, we apply a single view mensuration algorithm to each of the frames to obtain height measurements and fuse the multi-frame measurements using RANSAC algorithm. Compared with other popular methods, our proposed algorithm does not require calibrating the camera, and can track the multiple moving objects when occlusion occurs. Therefore, it reduces the complexity of calculation and improves the accuracy of measurement simultaneously. The experimental results demonstrate that our method is effective and robust to occlusion.

19세기 기하학에서의 ‘허’이론

  • 한경혜
    • Journal for History of Mathematics
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    • v.15 no.2
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    • pp.15-32
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    • 2002
  • The first part of this thesis gives some brief explanation of the theory and history of imaginary elements in analytic geometry in the 19th century. The second part of this thesis discusses the theory of imaginary elements of synthetic geometry in the first half of the 19th century. Then the next part mentions the theory of imaginary elements of geometry in the second half of that same century. Particularly Christian von Staudt's and Felix Klein's theories are handled in this part. Von Staudt, who has completed the system of the synthetic projective geometry, used ‘involution’ in order to introduce a new concept ‘imaginary elements’- imaginary points, imaginary lines and imaginary plane-in synthetic geometry. Klein applied von Staudt's theory as he convey the result of the research in algebraic geometry in a picture. Von Staudt's and Klein's research may be regarded as the top of the effort to investigate possible relationship between real and imaginary structures.

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THE SPACE OF FOURIER HYPERFUNCTIONS AS AN INDUCTIVE LIMIT OF HILBERT SPACES

  • Kim, Kwang-Whoi
    • Communications of the Korean Mathematical Society
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    • v.19 no.4
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    • pp.661-681
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    • 2004
  • We research properties of the space of measurable functions square integrable with weight exp$2\nu $\mid$x$\mid$$, and those of the space of Fourier hyperfunctions. Also we show that the several embedding theorems hold true, and that the Fourier-Lapace operator is an isomorphism of the space of strongly decreasing Fourier hyperfunctions onto the space of analytic functions extended to any strip in $C^n$ which are estimated with the aid of a special exponential function exp($\mu$|x|).