• Journal of the Chungcheong Mathematical Society
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• v.22 no.3
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• pp.587-591
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• 2009

The structure of a TL-subgroup can be understood from the representations of the TL-sub group as meets of TL-subgroups containing the TL-subgroup. Indeed, the structure of the meet of TL-subgroups can easily be obtained from the structures of the TL-subgroups and the structures of the TL-subgroups may be more simple than the structure of the meet. In this paper, we discuss meet-reducibility of TL-subgroups.

• Journal of the Korean Mathematical Society
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• v.50 no.3
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• pp.579-589
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• 2013

A finite group G is called an NSN-group if every proper subgroup of G is either normal in G or self-normalizing. In this paper, the non-NSN-groups whose proper subgroups are all NSN-groups are determined.

• Bulletin of the Korean Mathematical Society
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• v.53 no.2
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• pp.601-614
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• 2016

Let $N_{g,s}$ denote the nonorientable surface of genus g with s boundary components. Recently Paris and Szepietowski [12] obtained an explicit finite presentation for the mapping class group $\mathcal{M}(N_{g,s})$ of the surface $N_{g,s}$, where $s{\in}\{0,1\}$ and g + s > 3. Following this work, we obtain a finite presentation for the subgroup $\mathcal{T}(N_{g,s})$ of $\mathcal{M}(N_{g,s})$ generated by Dehn twists.

• Communications of the Korean Mathematical Society
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• v.36 no.4
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• pp.835-840
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• 2021

In this paper, we compute the rational evaluation subgroup of the Hopf fibration S²ⁿ⁺¹ ↪ ℂP(n). We show that, for the Sullivan model 𝜙 : A → B, where A and B are the minimal Sullivan models of ℂP(n) and S²ⁿ⁺¹ respectively, the evaluation subgroup G_n(A, B; 𝜙) and the relative evaluation subgroup G^rel_n (A, B; 𝜙) of 𝜙 are generated by single elements.

• The Journal of the Korean Society for Microbiology
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• v.11 no.1
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• pp.23-26
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• 1976

The authors identified sixteen Shigella cultures, which were three cultures of subgroup A, ten cultures of subgroup B, three cultures of subgroup D and none of cultures belnoging to the subgroup C was detected as it was in previous year.

• Journal of Korean Society for Quality Management
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• v.35 no.2
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• pp.106-112
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• 2007

In statistical process control, it is assumed that the process data are independent. However, most of chemical processes such as semi-conduct processes do not satisfy the assumption because of presence of autocorrelation between process data. It causes abnormal out of control signal in the process control and misleading estimation in process capability. In this study, we adopted Shore's method to solve the problem and propose an optimal subgroup size to estimate the variance correctly for AR(1) processes. Especially, we focus on finding an actual subgroup size for small samples based on simulation study.

• Proceedings of the Korean Society for Quality Management Conference
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• 2007.04a
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• pp.302-309
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• 2007

To conduct statistical process control needs the assumption that the process data are independent. However, most of chemical processes, like a semi-conduct processes do not satisfy the assumption because of autocorrelation. It causes abnormal out of control signal in the process control and misleading process capability. In this study, we introduce that Shore's method to solve the problem and to find the optimal subgroup size to estimate variance for AR(l) model. Especially, we focus on finding an actual subgroup size for small samples using simulation. It may be very useful for statistical process control to analyze process capability and to make a Shewhart chart properly.

• Journal of the Korean Mathematical Society
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• v.52 no.1
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• pp.81-96
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• 2015

The intersection graph of a group G is an undirected graph without loops and multiple edges defined as follows: the vertex set is the set of all proper non-trivial subgroups of G, and there is an edge between two distinct vertices H and K if and only if $H{\cap}K{\neq}1$ where 1 denotes the trivial subgroup of G. In this paper we characterize all finite groups whose intersection graphs are planar. Our methods are elementary. Among the graphs similar to the intersection graphs, we may count the subgroup lattice and the subgroup graph of a group, each of whose planarity was already considered before in [2, 10, 11, 12].

• International Journal of Human Ecology
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• v.8 no.2
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• pp.47-60
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• 2007

While there is growing evidence regarding the subgroup-sensitive nature of risk factors among delinquent adolescents, researchers have paid little attention to the tracking of risks and needs by subgroups (e.g., gender, ethnicity, and the timing of onset for delinquency) among youth who are currently involved in the juvenile court system. Therefore, greater empirical attention directed toward subgroup-sensitive risk factors experienced by delinquent adolescents is thought to be both timely and necessary. A final convenience sample of 2167 court-involved adolescents in the US was used to specify subgroup-sensitive risks and needs. The results demonstrated that there were various levels of risks according to subgroups associated with gender, ethnicity, and onset for delinquency group. The findings of this study add to the extant literature on delinquency by demonstrating the importance of considering subgroups associated with gender, ethnicity, and the timing of onset for delinquency when practicing treatment or intervention programs with delinquent adolescents.

• BMB Reports
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• v.32 no.1
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• pp.25-27
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• 1999

Otitis media with effusion (OME) is an inflammatory disease of the middle ear cleft. Oxygen free radicals have been implicated in a variety of inflammatory disorders. Oxygen free radicals may also be involved in the pathogenesis of OME. To evaluate the involvement of oxygen free radicals in the pathogenesis of OME, the level of malondialdehyde, which gives an index of lipid peroxidation by oxygen free radicals, was measured by the reaction with thiobarbituric acid. Malondialdehyde level in the middle ear fluid from the OME group was higher than that in the normal control group. Malondialdehyde level in the middle ear fluid from a mucoid subgroup was higher than that in the serous subgroup. Malondialdehyde levels in the middle ear fluid from the serous subgroup was significantly correlated with symptom duration. The Pearson correlation coefficient between malondialdehyde levels in the middle ear fluid from the serous subgroup and symptom duration was 0.842 (P<0.05). These results indicate that lipid peroxidation by oxygen free radicals may be involved in the pathogenesis of human OME.