• Title/Summary/Keyword: M$\ddot{o}$bius

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A NOTE ON COMPACT MÖBIUS HOMOGENEOUS SUBMANIFOLDS IN 𝕊n+1

  • Ji, Xiu;Li, TongZhu
    • Bulletin of the Korean Mathematical Society
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    • v.56 no.3
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    • pp.681-689
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    • 2019
  • The $M{\ddot{o}}bius$ homogeneous submanifold in ${\mathbb{S}}^{n+1}$ is an orbit of a subgroup of the $M{\ddot{o}}bius$ transformation group of ${\mathbb{S}}^{n+1}$. In this note, We prove that a compact $M{\ddot{o}}bius$ homogeneous submanifold in ${\mathbb{S}}^{n+1}$ is the image of a $M{\ddot{o}}bius$ transformation of the isometric homogeneous submanifold in ${\mathbb{S}}^{n+1}$.

Reduced Electrical Coupling Effect and Miniaturized Antenna Using Quasi Möbius Strip with Via-Hole (Quasi Möbius Strip과 Via-Hole 구조를 응용한 선로결합 현상의 완화 및 소형화 설계)

  • Kim, Mi Jung;Park, Seong Gyoon;Ro, Soong Hwan
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.38B no.9
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    • pp.715-721
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    • 2013
  • Minimization techniques are adaptations of Helical structure, Meta material, multi-layer structure etc. But, Helical structure is not suited to minimization technique of RF circuit having single resonant frequency. Because it generate resonant frequency following as rotation of circumference. Meta material and multi layer structure have weakness of expenditure and complex structure. In addition, conventional three dimensional M$\ddot{o}$bius Strip and planar M$\ddot{o}$bius Strip are not two dimensional planar M$\ddot{o}$bius Strip that has weakness of electrical coupling effect. Therefore, in this paper, we proposed miniaturized and reduced electrical coupling effect antenna by adaptation of Quasi M$\ddot{o}$bius Strip that topology is same as three dimensional M$\ddot{o}$bius Strip with Via-Hole structure. According to the simulation result, physical circumferential length is 1/3 minimized compared with conventional ring antenna under the same resonant frequency. In addition, coupling effect is not nearly generates near to the resonant frequency, 2.4GHz.

CLASSES OF HYPERSURFACES WITH VANISHING LAPLACE INVARIANTS

  • Riveros, Carlos M.C.;Corro, Armando M.V.
    • Bulletin of the Korean Mathematical Society
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    • v.49 no.4
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    • pp.685-692
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    • 2012
  • Consider a hypersurface $M^n$ in $\mathbb{R}^{n+1}$ with $n$ distinct principal curvatures, parametrized by lines of curvature with vanishing Laplace invariants. (1) If the lines of curvature are planar, then there are no such hypersurfaces for $n{\geq}4$, and for $n=3$, they are, up to M$\ddot{o}$bius transformations Dupin hypersurfaces with constant M$\ddot{o}$bius curvature. (2) If the principal curvatures are given by a sum of functions of separated variables, there are no such hypersurfaces for $n{\geq}4$, and for $n=3$, they are, up to M$\ddot{o}$bius transformations, Dupin hypersurfaces with constant M$\ddot{o}$bius curvature.

Möbius Syndrome Demonstrated by the High-Resolution MR Imaging: a Case Report and Review of Literature

  • Hwang, Minhee;Baek, Hye Jin;Ryu, Kyeong Hwa;Choi, Bo Hwa;Ha, Ji Young;Do, Hyun Jung
    • Investigative Magnetic Resonance Imaging
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    • v.23 no.2
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    • pp.167-171
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    • 2019
  • $M\ddot{o}bius$ syndrome is a rare congenital condition, characterized by abducens and facial nerve palsy, resulting in limitation of lateral gaze movement and facial diplegia. However, to our knowledge, there have been few studies on evaluation of cranial nerves, on MR imaging in $M\ddot{o}bius$ syndrome. Herein, we describe a rare case of $M\ddot{o}bius$ syndrome representing limitation of lateral gaze, and weakness of facial expression, since the neonatal period. In this case, high-resolution MR imaging played a key role in diagnosing $M\ddot{o}bius$ syndrome, by direct visualization of corresponding cranial nerves abnormalities.

TWO MEROMORPHIC FUNCTIONS SHARING FOUR PAIRS OF SMALL FUNCTIONS

  • Nguyen, Van An;Si, Duc Quang
    • Bulletin of the Korean Mathematical Society
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    • v.54 no.4
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    • pp.1159-1171
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    • 2017
  • The purpose of this paper is twofold. The first is to show that two meromorphic functions f and g must be linked by a quasi-$M{\ddot{o}}bius$ transformation if they share a pair of small functions regardless of multiplicity and share other three pairs of small functions with multiplicities truncated to level 4. We also show a quasi-$M{\ddot{o}}bius$ transformation between two meromorphic functions if they share four pairs of small functions with multiplicities truncated by 4, where all zeros with multiplicities at least k > 865 are omitted. Moreover the explicit $M{\ddot{o}}bius$-transformation between such f and g is given. Our results are improvement of some recent results.

The Basis Number of the Cartesian Product of a Path with a Circular Ladder, a Möbius Ladder and a Net

  • Alzoubi, Maref Y.;Jaradat, Mohammed M.M.
    • Kyungpook Mathematical Journal
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    • v.47 no.2
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    • pp.165-714
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    • 2007
  • The basis number of a graph G is the least positive integer $k$ such that G has a $k$-fold basis. In this paper, we prove that the basis number of the cartesian product of a path with a circular ladder, a M$\ddot{o}$bius ladder and path with a net is exactly 3. This improves the upper bound of the basis number of these graphs for a general theorem on the cartesian product of graphs obtained by Ali and Marougi, see [2]. Also, by this general result, the cartesian product of a theta graph with a M$\ddot{o}$bius ladder is at most 5. But in section 3 we prove that it is at most 4.

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Unifying Method for Computing the Circumcircles of Three Circles

  • Kim, Deok-Soo;Kim, Dong-Uk;Sugihara, Kokichi
    • International Journal of CAD/CAM
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    • v.2 no.1
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    • pp.45-54
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    • 2002
  • Given a set of three generator circles in a plane, we want to find a circumcircle of these generators. This problem is a part of well-known Apollonius' $10^{th}$ Problem and is frequently encountered in various geometric computations such as the Voronoi diagram for circles. It turns out that this seemingly trivial problem is not at all easy to solve in a general setting. In addition, there can be several degenerate configurations of the generators. For example, there may not exist any circumcircle, or there could be one or two circumcircle(s) depending on the generator configuration. Sometimes, a circumcircle itself may degenerate to a line. We show that the problem can be reduced to a point location problem among the regions bounded by two lines and two transformed circles via $M{\ddot{o}}bius$ transformations in a complex space. The presented algorithm is simple and the required computation is negligible. In addition, several degenerate cases are all incorporated into a unified framework.