• Title/Summary/Keyword: symmetry

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RADIAL SYMMETRY AND SPHERICAL NODAL SET OF SOLUTIONS OF NONLINEAR ELLIPTIC EQUATIONS

  • Seok, Yong-Jing
    • Communications of the Korean Mathematical Society
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    • v.10 no.1
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    • pp.133-135
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    • 1995
  • In this note, we will investigate the radial symmetry of some kind of solutions of nonlinear ellipitic equations $$ \Delta U = f(U) $$ $$ (1.1) U = 0 in B $$ $$ U \in C^2 (\bar{B}) on \partial B$$ Here f is $C^1$ and B denotes a n-dimensional unit ball in $R^n$.

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The Effects of Initiation Side on Gait Symmetry in the Stroke Patients

  • Shin, Hwa-Kyung;Noh, Dae-Yong
    • The Journal of Korean Physical Therapy
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    • v.25 no.6
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    • pp.399-404
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    • 2013
  • Purpose: To investigate the effects of initiation side on gait symmetry in the chronic stroke patients. Methods: Twenty one patients with independent gait after stroke were divided into the paretic-leg gait initiation group (PLI) and the nonparetic-leg gait initiation group (NPLI). The symmetry ratio (SR) was calculated from of the spatiotemoral and kinematic parameter which measured by 3D motion analysis. Results: In the spatiotemporal variables, SR-step length and SR-velocity was significantly different between groups (p<0.05). In the kinematic variables, SR-TOAA and SR-SwPAA of the hip joint was significantly different between groups (p<0.05). Conclusion: We suggest that the initiating leg may influence on the gait symmetry of stroke patient These results will be a helpful reference in hemiplegic gait training or intervention.

Context-free multiple-object segmentation using attention operator based on modified generalized symmetry transform (일반화 대칭변환을 변형한 관심 연산자에 의한 사전 정보없는 다중 물체 분할)

  • 구태모;전준형;최흥문
    • Journal of the Korean Institute of Telematics and Electronics C
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    • v.34C no.4
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    • pp.36-44
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    • 1997
  • An efficient context-free multiple-object segmentation using attention operator based on modified generalized symmetry transform is proposed and implemented by modifying a radial basis function network. By using the difference of intensity gradient, instead of te intensity gradient itself, in generalized symmetry tranform so as to make the attention operator to preserve the edges of the objects shape, an efficient context-free multiple-object segementation is proposed in which no a priori shape informtion on the objects is requried. The attention operator is implemented by using a modified radial basis function network which can reflect symmetry, and by using te edge pyramid of the input image, both of the local and the global symmetry of the objects are reflected simultaneously to make the multiple-object with different sizes be segmented with a singel fixed-size $n\timesm$ can be done with O(n) complexity. The simulaton results show that the proposed algorithm can efficiently be used in context-free multiple-object segmentation even for the low contrast IR images as well as for the images from the camera.

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Eigenvalue Analysis of a Blower Impeller Using Cyclic Symmetry (송풍기 임펠러의 순환대칭성을 이용한 고유치해석)

  • 김창부;안영철
    • Journal of KSNVE
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    • v.10 no.3
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    • pp.523-530
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    • 2000
  • In this paper we present an efficient method for finite element vibration analysis of a structure with cyclic symmetry and applied it to calculating the natural vibration characteristics for a blower impeller. Blower impeller having a cyclically symmetric structure is composed of circumferentially repeated substructures., The whole-structure is partitioned into substructures and then finite element vibration analysis is performed for a substructure using transformed equations for each number of nodal diameter which are derived from discrete Fourier transform in consideration of the cyclic symmetry. natural vibration characteristics for three kinds of models which are blower impeller without support ring with small support ring and with large support ring are numerically analyzed and compared. Accuracy and efficiency of the present method are verified by comparison of results of the analysis with substructure and with whole-structure. Also the results of the analysis by cyclic symmetry module(SOL 115) of MSC/NASTRAN are presented and compared.

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Intelligence Robot control for real-time Measurement of three-dimension object using information (지능로봇트제어를 위한 영상정보의 실시간 3차원 위치측정)

  • Oh, Weon-Geun;Lee, Han-Sik
    • Proceedings of the KIEE Conference
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    • 1987.07b
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    • pp.1090-1093
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    • 1987
  • In this paper, we describe the principle, the procedure and calculation of the measurement. Finally the experimental results are shown and discussions are given. Interpreting of a skewed symmetry in the image as a real symmetry in the 3-D space provides strong constraints on 3-D sharp analysis. In order to apply the idea to the real scene, a method is presented which can find the skewed symmetry in the image of the skewed symmetrical object, even if it is occluded partly. there parameters of the skewed symmetry are estimated by examining peaks in two 2-D hough spaces, onto which the parameters of all candidates of boundary line segments for skewed symmetries are voted. The method is characterized with a small amount of computation, finding of multiple symmetry axes and inference of the occluded parts of the symmetrical object.

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FULL NON-RIGID GROUP OF 2,3,5,6-TETRAMETHYLEPYRAZINE AS WREATH PRODUCT AND ITS SYMMETRY

  • Arezoomand, Majid;Taeri, Bijan
    • Journal of applied mathematics & informatics
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    • v.27 no.3_4
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    • pp.915-931
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    • 2009
  • The non-rigid molecule group theory in which the dynamical symmetry operations are defined as physical operations is applied to deduce the character table of the full non-rigid molecule group (f-NRG) of 2,3,5,6-Tetramethylpyrazine The f-NRG of this molecule is seen to be isomorphic to the group $\mathbb{Z}_3{\wr}(\mathbb{Z}_2{\times}\mathbb{Z}_2)$, where $\mathbb{Z}_n$ is the cyclic group of order n, of order 324 which has 45 conjugacy classes. We determine the some properties and relations between characters of the group. Also, we examine the symmetry group of this molecule and show that its symmetry group is $\mathbb{Z}_2{\times}\mathbb{Z}_2$.

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A Test for Spherical Symmetry (구형 대칭성 검정에 대한 연구)

  • Park Cheolyong
    • The Korean Journal of Applied Statistics
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    • v.18 no.1
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    • pp.99-113
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    • 2005
  • In this article, we propose a chi-squared test of spherical symmetry. The advantage of this test is that the test statistic and its asymptotic p-value are easy to compute. The limiting distribution of the test statistic is derived under spherical symmetry and its accuracy, in finite samples, is studied via simulation. Also, a simulation study is conducted in which the power of our test is compared with those of other tests for spherical symmetry in various alternative distributions. Finally, an illustrative example of application to a real data is provided.

Analysis for Pure Translation and Couple Modes of an Elastically Suspended Rigid Body with Planes of Symmetry (대칭면을 갖는 단일 강체의 순수 병진 및 순 짝힘 모우드 해석)

  • 김동욱;최용제
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2002.05a
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    • pp.260-267
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    • 2002
  • For an elastically suspended rigid body with the planes of symmetry in a three dimensional space, a novel analysis fur the vibration modes is presented. From the decompositions of the stiffness and inertia matrices, the conditions for the existence of pure translation and pure couple modes are analyzed for an elastically suspended rigid body with the planes of symmetry. From this analysis, it can be showed that how the structure of stiffness and inertia must be related in order to produce the pure translation and pure couple modes when an elastically suspended rigid body has one, two, or three planes of symmetry.

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