• Bulletin of the Korean Mathematical Society
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• v.58 no.4
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• pp.1031-1038
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• 2021

The main aim of this article is to study quantitative structure of finite simple exceptional groups F₄(2ⁿ) with n > 1. Here, we prove that the finite simple exceptional groups F₄(2ⁿ), where 2⁴ⁿ + 1 is a prime number with n > 1 a power of 2, can be uniquely determined by their orders and the set of the number of elements with the same order. In conclusion, we give a positive answer to J. G. Thompson's problem for finite simple exceptional groups F₄(2ⁿ).

• Journal of applied mathematics & informatics
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• v.8 no.3
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• pp.889-897
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• 2001

Based on the prime graph of a finite simple group, its order is the product of its order components (see[4]). It is known that Suzuki-Ree groups [6], $PSL_2(q)$ [8] and $E_8(q)$ [7] are uniquely deternubed by their order components. In this paper we prove that the simple groups $A_p$ are also unipuely determined by their order components, where p and p-2 are primes.

• Journal of applied mathematics & informatics
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• v.17 no.1_2_3
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• pp.217-227
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• 2005

Let G be a finite group and $\#$Cent(G) denote the number of centralizers of its elements. G is called n-centralizer if $\#$Cent(G) = n, and primitive n-centralizer if $\#$Cent(G) = $\#$Cent($\frac{G}{Z(G)}$) = n. In this paper we investigate the structure of finite groups with at most 21 element centralizers. We prove that such a group is solvable and if G is a finite group such that G/Z(G)$\simeq$$A_5$, then $\#$Cent(G) = 22 or 32. Moreover, we prove that As is the only finite simple group with 22 centralizers. Therefore we obtain a characterization of As in terms of the number of centralizers

• Journal of the Korean Mathematical Society
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• v.23 no.2
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• pp.201-215
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• 1986

• East Asian mathematical journal
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• v.30 no.3
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• pp.293-302
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• 2014

In this paper we provide a rigorous proof for the fact that there are exactly 8 connected Alexander quandles of order $2^5$ by combining properties of fixed point free automorphisms of finite abelian 2-groups and the classification of conjugacy classes of GL(5, 2). Furthermore we verify that six of the eight associated Alexander modules are simple, whereas the other two are semisimple.

• Journal of applied mathematics & informatics
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• v.17 no.1_2_3
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• pp.245-258
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• 2005

In this paper we prove that the alternating groups A_n, for n = p, p+1, p+2 and symmetric groups $S_n$, for n = p, p+1, where p$\ge$3 is a prime number, can be uniquely determined by their order components. As one of the important consequence of this characterization we show that the simple groups An, where n = p, p+1, P+2 and p$\ge$3 is prime, satisfy in Thompson's conjecture and Shi's conjecture.

• Bulletin of the Korean Mathematical Society
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• v.57 no.2
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• pp.449-457
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• 2020

The aim of this short paper is to show some rigidity results for the actions of certain finitely presented groups by homeomorphisms. As an interesting and special case, we show that the actions of Higman-Thompson groups by homeomorphisms on a cohomology manifold with a non-zero Euler characteristic should be trivial. This is related to the wellknown Zimmer program and shows that the actions by homeomorphism could be very much different from those by diffeomorphisms.

• Journal of the Korean Mathematical Society
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• v.45 no.1
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• pp.137-150
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• 2008

In this paper we will prove that the simple groups $B_p(3)\;and\;G_p(3)$, p an odd prime number, are 2-recognizable by the set of their order components. More precisely we will prove that if G is a finite group and OC(G) denotes the set of order components of G, then OC(G) = $OC(B_p(3))$ if and only if $G{\cong}B_p(3)\;or\;C_p(3)$.

• Proceedings of the KSME Conference
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• 2004.11a
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• pp.79-84
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• 2004

Strain energy due to the mechanical interaction between self-accommodation groups of martensitic phase transformation is called interaction energy. Evaluation of the interaction energy should be accurate since the energy appears in constitutive models for predicting the mechanical behavior of shape memory alloy. In this paper, the interaction energy is evaluated in terms of theoretical formulation and explicit finite element calculation. A simple example with two habit plane variants was considered. It was shown that the theoretical formulation assuming elastic interaction between the self-accommodation group and matrix gives larger interaction energy than explicit finite element calculation in which transformation softening is accounted for.

• Journal of applied mathematics & informatics
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• v.10 no.1_2
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• pp.167-174
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• 2002

A group G is said to be (l, n, n)-generated if it is a quotient group of the triangle group T(p,q,r)=(x,y,z|x$\^$p/=y$\^$q/=z$\^$r/=xyz=1). In [15], the question of finding all triples (l, m, n) such that non-abelian finite simple groups are (l , m, n)-generated was posed. In this paper we partially answer this question for the sporadic group He. We continue the study of (p, q, r) -generations of the sporadic simple groups, where p, q, r are distinct primes. The problem is resolved for the Held group He.