• Journal of the Korean Mathematical Society
• /
• v.39 no.3
• /
• pp.461-494
• /
• 2002

Let G = E${\ast}_{A}F$, where A is a finitely generated abelian subgroup. We prove a criterion for G to be {A}-double coset separable. Applying this result, we show that polygonal products of central subgroup separable groups, amalgamating trivial intersecting central subgroups, are double coset separable relative to certain central subgroups of their vertex groups. Finally we show that such polygonal products are conjugacy separable. It follows that polygonal products of polycyclic-by-finite groups, amalgamating trivial intersecting central subgroups, are conjugacy separable.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2001.05a
• /
• pp.729-734
• /
• 2001

A 3-dimentional finite element model for vibration analysis of steam-turbine blade groups is presented, employing the 3-dimentional incompatible brick element with 8 nodes. The skew coordinate system is introduced in the model for considering multi-axis symmetry and specialty of displacement constrain condition of blade groups. Vibration characteristics of blade groups are analyzed, and compared with experimental results.

• Journal of applied mathematics & informatics
• /
• v.7 no.1
• /
• pp.115-124
• /
• 2000

For a finite group G, #Cent(G) denotes the number of cen-tralizers of its clements. A group 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 compute the number of distinct centralizers of some finite groups and investigate the structure of finite groups with Qxactly SLX distinct centralizers. We prove that if G is a 6-centralizer group then ${\frac}{G}{Z(G)$${\cong}D_8$,$A_4$, $Z_2{\times}Z_2{\times}Z_2$ or $Z_2{\times}Z_2{\times}Z_2{\times}Z_2$.

• Journal of applied mathematics & informatics
• /
• v.8 no.3
• /
• pp.1009-1019
• /
• 2001

We introduce the concepts of TL-finite state machine, TL-kernel and TL-subfinite state machines, TL-kernel and TL-subfinite state machine and obtain some results concerning them.

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

• Communications of the Korean Mathematical Society
• /
• v.11 no.4
• /
• pp.917-924
• /
• 1996

We shall study some transfer theorems of finite groups with respect to a certain commutator subgroup, called "F-commutator" relative to any field F and apply the transfer to the fusion of a group H or to the focal subgroup of H.roup of H.

• Journal of the Chungcheong Mathematical Society
• /
• v.18 no.2
• /
• pp.223-232
• /
• 2005

We study only free actions of finite groups G on the 3-dimensional nilmanifold, up to topological conjugacy which yields an infra-nilmanifold of type 2.

• Kyungpook Mathematical Journal
• /
• v.56 no.1
• /
• pp.121-123
• /
• 2016

In this paper, we compute the number of distinct centralizers and commutativity degree of a class of finite groups. These computations produce a further class of examples of groups answering one question raised by Belcastro and Sherman and another one raised by Lescot.

• Kyungpook Mathematical Journal
• /
• v.59 no.2
• /
• pp.203-207
• /
• 2019

The commutativity degree of a finite group is the probability that two randomly chosen group elements commute. In this paper we give a sharp upper bound of commutativity degree of nonabelial groups in terms of their order.

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