• Title/Summary/Keyword: finite group

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An evaluation of the stress effect of different occlusion concepts on hybrid abutment and implant supported monolithic zirconia fixed prosthesis: A finite element analysis

  • Yesilyurt, Nilgün Gulbahce;Tuncdemir, Ali Riza
    • The Journal of Advanced Prosthodontics
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    • v.13 no.4
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    • pp.216-225
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    • 2021
  • PURPOSE. The aim of this study is to evaluate the effects of canine guidance occlusion and group function occlusion on the degree of stress to the bone, implants, abutments, and crowns using finite element analysis (FEA). MATERIALS AND METHODS. This study included the implant-prosthesis system of a three-unit bridge made of monolithic zirconia and hybrid abutments. Three-dimensional (3D) models of a bone-level implant system and a titanium base abutment were created using the original implant components. Two titanium implants, measuring 4 × 11 mm each, were selected. The loads were applied in two oblique directions of 15° and 30° under two occlusal movement conditions. In the canine guidance condition, loads (100 N) were applied to the canine crown only. In the group function condition, loads were applied to all three teeth. In this loading, a force of 100 N was applied to the canine, and 200-N forces were applied to each premolar. The stress distribution among all the components of the implant-bridge system was assessed using ANSYS SpaceClaim 2020 R2 software and finite element analysis. RESULTS. Maximum stress was found in the group function occlusion. The maximum stress increased with an increase in the angle of occlusal force. CONCLUSION. The canine guidance occlusion with monolithic zirconia crown materials is promising for implant-supported prostheses in the canine and premolar areas.

Non-conforming modes for improvement of finite element performance

  • Choi, Chang-Koon;Lee, Tae-Yeol
    • Structural Engineering and Mechanics
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    • v.14 no.5
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    • pp.595-610
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    • 2002
  • This paper presents an efficiency of various non-conforming (NC) modes in development of a series of new finite elements with the special emphasis on 4-node quadrilateral elements. The NC modes have been used as a key scheme to improve the behaviors of various types of new finite elements, i.e., Mindlin plate bending elements, membrane elements with drilling degrees of freedom, flat shell elements. The NC modes are classified into three groups according to the 'correction constants' of 'Direct Modification Method'. The first group is 'basic NC modes', which have been widely used by a number of researchers in the finite element communities. The basic NC modes are effective to improve the behaviors of regular shaped elements. The second group is 'hierarchical NC modes' which improve the behaviors of distorted elements effectively. The last group is 'higher order NC modes' which improve the behaviors of plate-bending elements. When the basic NC modes are combined with hierarchical or higher order NC modes, the elements become insensitive to mesh distortions. When the membrane component of a flat shell has 'hierarchical NC modes', the membrane locking can be suppressed. A number of numerical tests are carried out to show the positive effect of aforementioned various NC modes incorporated into various types of finite elements.

Design of Finite Field Multiplier for Elliptic Curve Cryptosystems (타원곡선 암호화 시스템을 위한 유한필드 곱셈기의 설계)

  • Lee, Wook;Lee, Sang-Seol
    • Proceedings of the KIEE Conference
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    • 2001.07d
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    • pp.2576-2578
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    • 2001
  • Elliptic curve cryptosystems based on discrete logarithm problem in the group of points of an elliptic curve defined over a finite field. The discrete logarithm in an elliptic curve group appears to be more difficult than discrete logarithm problem in other groups while using the relatively small key size. An implementation of elliptic curve cryptosystems needs finite field arithmetic computation. Hence finite field arithmetic modules must require less hardware resources to archive high performance computation. In this paper, a new architecture of finite field multiplier using conversion scheme of normal basis representation into polynomial basis representation is discussed. Proposed architecture provides less resources and lower complexity than conventional bit serial multiplier using normal basis representation. This architecture has synthesized using synopsys FPGA express successfully.

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PROJECTIVE SCHUR ALGEBRAS AS CLASS ALGEBRAS

  • Choi, Eun-Mi;Lee, Hei-Sook
    • Bulletin of the Korean Mathematical Society
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    • v.38 no.4
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    • pp.803-814
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    • 2001
  • A projective Schur algebra associated with a partition of finite group G can be constructed explicitly by defining linear transformations of G. We will consider various linear transformations and count the number of equivalent classes in a finite group. Then we construct projective Schur algebra dimension is determined by the number of classes.

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THE NIELSEN THEOREM FOR SEIFERT FIBERED SPACES OVER LOCALLY SYMMETRIC SPACES

  • RAYMOND, FRANK
    • Journal of the Korean Mathematical Society
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    • v.16 no.1
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    • pp.87-93
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    • 1979
  • In this note the geometric realization of a finite group of homotopy classes of self homotopy equivalences by a finite group of diffeomorphisms is investigated. In order for this to be accomplished an algebraic condition, which guarantees a certain group extension exists, must be satisfied. It is shown for a geometrically interesting class of aspherical manifolds, called injective Seifert fiber spaces over a locally symmetric space, that this necessary algebraic condition is also sufficient for geometric realization.

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STRUCTURES OF GEOMETRIC QUOTIENT ORBIFOLDS OF THREE-DIMENSIONAL G-MANIFOLDS OF GENUS TWO

  • Kim, Jung-Soo
    • Journal of the Korean Mathematical Society
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    • v.46 no.4
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    • pp.859-893
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    • 2009
  • In this article, we will characterize structures of geometric quotient orbifolds of G-manifold of genus two where G is a finite group of orientation preserving diffeomorphisms using the idea of handlebody orbifolds. By using the characterization, we will deduce the candidates of possible non-hyperbolic geometric quotient orbifolds case by case using W. Dunbar's work. In addition, if the G-manifold is compact, closed and the quotient orbifold's geometry is hyperbolic then we can show that the fundamental group of the quotient orbifold cannot be in the class D.

HIGHER CYCLOTOMIC UNITS FOR MOTIVIC COHOMOLOGY

  • Myung, Sung
    • Korean Journal of Mathematics
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    • v.21 no.3
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    • pp.331-344
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    • 2013
  • In the present article, we describe specific elements in a motivic cohomology group $H^1_{\mathcal{M}}(Spec\mathbb{Q}({\zeta}_l),\;\mathbb{Z}(2))$ of cyclotomic fields, which generate a subgroup of finite index for an odd prime $l$. As $H^1_{\mathcal{M}}(Spec\mathbb{Q}({\zeta}_l),\;\mathbb{Z}(1))$ is identified with the group of units in the ring of integers in $\mathbb{Q}({\zeta}_l)$ and cyclotomic units generate a subgroup of finite index, these elements play similar roles in the motivic cohomology group.

Code automorphism group algorithms and applications

  • Cho, Han-Hyuk;Shin, Hye-Sun;Yeo, Tae-Kyung
    • Communications of the Korean Mathematical Society
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    • v.11 no.3
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    • pp.575-584
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    • 1996
  • We investigate how the code automorphism groups can be used to study such combinatorial objects as codes, finite projective planes and Hadamard matrices. For this purpose, we write down a computer program for computing code automorphisms in PASCAL language. Then we study the combinatorial properties using those code automorphism group algorithms and the relationship between combinatorial objects and codes.

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On the History and the Irreducible Characters in Group Representations (군표현의 역사와 기약지표들)

  • Wang Moon-ok;Lee Kwang-suk
    • Journal for History of Mathematics
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    • v.18 no.1
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    • pp.75-84
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    • 2005
  • In this paper, we know the historical background in group representations and prove the properties such that a finite group G has non-trivial abelian normal subgroup in some condition for the irreducible character G and prove the properties of product of irreducible characters of finite groups.

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ON THE TATE-SHAFAREVICH GROUPS OVER BIQUADRATIC EXTENSIONS

  • Yu, Hoseog
    • Honam Mathematical Journal
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    • v.37 no.1
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    • pp.1-6
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    • 2015
  • Let A be an abelian variety defined over a number field K. Let L be a biquadratic extension of K with Galois group G and let III (A/K) and III(A/L) denote, respectively, the Tate-Shafarevich groups of A over K and over L. Assuming III(A/L) is finite, we compute [III(A/K)]/[III(A/L)] where [X] is the order of a finite abelian group X.