• Journal of the Korean Mathematical Society
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• v.36 no.6
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• pp.1021-1031
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• 1999

In this paper we introduce matrix representations of polygroups over hyperrings and show such representations induce representations of the fundamental group over the corresponding fundamental ring. We also introduce the notion of a polygroup hyperring generalizing the notion of a group ring. We establish homo-morphisms among various polygroup hyperrings.

• Honam Mathematical Journal
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• v.36 no.3
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• pp.695-706
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• 2014

Various properties of digital covering spaces have been substantially used in studying digital homotopic properties of digital images. In particular, these are so related to the study of a digital fundamental group, a classification of digital images, an automorphism group of a digital covering space and so forth. The goal of the present paper, as a survey article, to speak out utility of digital covering theory. Besides, the present paper recalls that the papers [1, 4, 30] took their own approaches into the study of a digital fundamental group. For instance, they consider the digital fundamental group of the special digital image (X, 4), where X := $SC^{2,8}_4$ which is a simple closed 4-curve with eight elements in $Z^2$, as a group which is isomorphic to an infinite cyclic group such as (Z, +). In spite of this approach, they could not propose any digital topological tools to get the result. Namely, the papers [4, 30] consider a simple closed 4 or 8-curve to be a kind of simple closed curve from the viewpoint of a Hausdorff topological structure, i.e. a continuous analogue induced by an algebraic topological approach. However, in digital topology we need to develop a digital topological tool to calculate a digital fundamental group of a given digital space. Finally, the paper [9] firstly developed the notion of a digital covering space and further, the advanced and simplified version was proposed in [21]. Thus the present paper refers the history and the process of calculating a digital fundamental group by using various tools and some utilities of digital covering spaces. Furthermore, we deal with some parts of the preprint [11] which were not published in a journal (see Theorems 4.3 and 4.4). Finally, the paper suggests an efficient process of the calculation of digital fundamental groups of digital images.

• The Journal of Korean Academic Society of Nursing Education
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• v.22 no.3
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• pp.255-263
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• 2016

Purpose: The purpose of this study was to identify whether self-directed fundamental nursing practice using a smart phone affected self-efficacy, practice satisfaction, and skill competency of nursing students. Methods: This was a nonequivalent control group pretest-posttest quasi-experimental design. The participants were 40 children in the experimental group and 40 in the control group. In experimental group, self-directed fundamental nursing practice using a smart phone was given to nursing students. Data for this study was collected from 25 March 2015 to 10 April 2015. The data were analyzed using SAS 21.0. Results: In self-efficacy and skill competency, there were no statistically significant differences between the experimental group and control group. In practice satisfaction, there were statistically significant differences between the experimental group and the control group. Conclusion: The results indicate that self-directed fundamental nursing practice using smartphone video is effective in practice satisfaction. Therefore, this intervention can be utilized in nursing practice education as an effective educational device.

• Honam Mathematical Journal
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• v.25 no.1
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• pp.153-162
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• 2003

Recently, the generalized digital $(k_{0},\;k_{1})$-continuity and its properties are investigated. Furthermore, the k-type digital fundamental group for digital image has been studies with the generalized k-adjacencies. The main goal of this paper is to find some properties of the k-type digital fundamental group of Boxer and to investigate some properties of minimal simple closed k-curves with relation to their embedding into some spaces in ${\mathbb{Z}}^n(2{\leq}n{\leq}3)$.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.5 no.1
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• pp.81-93
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• 1998

The effectiveness of medication video tapes in teaching fundamental nursing skills was investigated using experimental research methodology. Data was collected from 153 students attending fundamental nursing practice classes of two junior colleges and two universities. The subjects were randomly assigned to two groups, one was an experimental group of 74 subjects and the other was a control group of 79 subjects. The independent variable was learning type and the dependent variables were the degree of knowledge achievement and nursing skills achievement regarding medication. The research hypotheses of this study were as follows : 1) There will be a significant difference between the experimental group and the control group in the degree of knowledge achievement about medication. 2) There will be a significant difference between the experimental group and the control group in the nursing skills achievement about medication. The data was analyzed with the SPSSWIN program and the t-test, number of subjects and percentiles were then examined. The findings of this study are as follows : 1) There was a significant difference between the experimental group and the control group in the knowledge achievement about medication using P<.05. 2) There was no significant difference between the experimental group and the control group in the nursing skill achievement about medication using P<.05. 3) This study suggests that medication video tapes in the education of fundamental nursing skills are effective for knowledge achievement. As a result, medication video tapes can be effectively utilized for the education of nursing skills regarding medication.

• Bulletin of the Korean Mathematical Society
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• v.48 no.1
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• pp.129-140
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• 2011

The aim of this paper is to study the structure of the fundamental group of a closed oriented Riemannian manifold with positive scalar curvature. To be more precise, let M be a closed oriented Riemannian manifold of dimension n (4 $\leq$ n $\leq$ 7) with positive scalar curvature and non-trivial first Betti number, and let be $\alpha$ non-trivial codimension one homology class in $H_{n-1}$(M;$\mathbb{R}$). Then it is known as in [8] that there exists a closed embedded hypersurface $N_{\alpha}$ of M representing $\alpha$ of minimum volume, compared with all other closed hypersurfaces in the homology class. Our main result is to show that the fundamental group ${\pi}_1(N_{\alpha})$ is always virtually free. In particular, this gives rise to a new obstruction to the existence of a metric of positive scalar curvature.

• Bulletin of the Korean Mathematical Society
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• v.50 no.2
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• pp.537-542
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• 2013

• Korean Journal of Mathematics
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• v.7 no.1
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• pp.131-138
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• 1999

We introduce an extended Jiang subgroup $J(f,x_0,G)$ of the fundamental group of a transformation group as a generalization of the Jiang subgroup $J(f,x_0)$ and show some properties of this extended Jiang subgroup.

• Communications of the Korean Mathematical Society
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• v.11 no.3
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• pp.825-829
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• 1996

We prove that if G is the fundamental group of a closed surface or a Seifert fibered space and K is a finitely generated subgroup of G, and if for any element g in G there exists an integer $n_g$ such that $g^{n_g}$ belongs to K, then K is of finite index in G.

• Journal of Digital Convergence
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• v.14 no.6
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• pp.285-294
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• 2016

The purpose of this study was to examine the effectiveness(knowledge of core fundamental nursing skills, clinical competency, self-efficacy and learning motivation) of education program for core fundamental nursing skills focusing on endotracheal suctioning using recording video with smartphone and formative feedback for nursing school students. Subjects consisted of 54 sophomore nursing students, an experimental group(n=27) and a control group(n=27). The education for core fundamental nursing skills using recording video to smartphone and individual formative feedback was provided to students in an experimental group. The traditional method with self-directed practice for 4 hours was offered to a control group. The education program for core fundamental nursing skills using recording video with smartphone and formative feedback was effective in promoting knowledge of core fundamental nursing skills, clinical competency, self-efficacy and learning motivation. Based on our results, this program can be recommended as an effective educational program for the nursing students to improve their core fundamental nursing skills.