• Communications of the Korean Mathematical Society
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• v.22 no.2
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• pp.297-303
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• 2007

In this paper, we study on C-closed spaces, SC-closed spaces and related spaces. We show that a sequentially compact SC-closed space is sequential and as corollaries obtain that a sequentially compact space with unique sequential limits is sequential if and only if it is C-closed [7, 1.19 Proposition] and every sequentially compact SC-closed space is C-closed. We also show that a countably compact WAP and C-closed space is sequential and obtain that a countably compact (or compact or sequentially compact) WAP-space with unique sequential limits is sequential if and only if it is C-closed as a corollary. Finally we prove that a weakly discretely generated AP-space is C-closed. We then obtain that every countably compact (or compact or sequentially compact) weakly discretely generated AP-space is $Fr\acute{e}chet$-Urysohn with unique sequential limits, for weakly discretely generated AP-spaces, unique sequential limits ${\equiv}KC{\equiv}C-closed{\equiv}SC-closed$, and every continuous surjective function from a countably compact (or compact or sequentially compact) space onto a weakly discretely generated AP-space is closed as corollaries.

• Journal of the Chungcheong Mathematical Society
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• v.29 no.4
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• pp.565-572
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• 2016

In this paper, the concept of $PC^{\star}$-closed sets is introduced. $PC^{\star}$-closed sets contain $pre^*_I$-open and $pre^*_I$-closed sets, ${\mathcal{RPC}}_I$ and $pre^*_I$-closed sets, ${\mathcal{RPC}}_I$ and weakly $I_{rg}$-closed sets.

• The Pure and Applied Mathematics
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• v.29 no.1
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• pp.93-102
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• 2022

The impact of programming languages in the research sector has helped lot of researchers to broaden their view and extend their work without any limitation. More importantly, even the complex problems can be solved in no matter of time while converting them into a programming language. This convenience provides upper hand for the researchers as it places them in a comfort zone where they can work without much stress. With this context, we have converted the research problems in Topology into programming language with the help of Python. In this paper, we have developed a Python program to find the weaker form of closed sets namely alpha closed set, semi closed set, pre closed set, beta closed set and regular closed set.

• Bulletin of the Korean Mathematical Society
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• v.20 no.2
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• pp.95-97
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• 1983

In this paper, we show a necessary and sufficient condition for QHC spaces to be S-closed. T. Thomson introduced S-closed spaces in [2]. A topological space X is said to be S-closed if every semi-open cover of X admits a finite subfamily such that the closures of whose members cover the space, where a set A is semi-open if and only if there exists an open set U such that U.contnd.A.contnd.Cl U. A topological space X is quasi-H-closed (denote QHC) if every open cover has a finite subfamily whose closures cover the space. If a topological space X is Hausdorff and QHC, then X is H-closed. It is obvious that every S-closed space is QHC but the converse is not true [2]. In [1], Cameron proved that an extremally disconnected QHC space is S-closed. But S-closed spaces are not necessarily extremally disconnected. Therefore we want to find a necessary and sufficient condition for QHC spaces to be S-closed. A topological space X is said to be semi-locally S-closed if each point of X has a S-closed open neighborhood. Of course, a locally S-closed space is semi-locally S-closed.

• Journal of the Korean Institute of Rural Architecture
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• v.19 no.3
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• pp.1-8
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• 2017

Recently, the number of closed rural schools is increasing due to the decrease in school age population. This study aims to comparative analysis of utilization policies for closed schools in Korea and Japan. The results are as follows. First, Both Korea and Japan was expected to increase the number of closed schools since the standard of abolition of small schools has been strengthened. Second, In Korea, it was possible to know the detailed information of closed schools through 'Eduinfo' website, but it was hard to know the detailed information of utilization cases of closed schools. On the other hand, Japan not only provided information about the unused school facilities but also introduced the utilization cases of closed schools and financial support system for utilization of closed school. It was characterized by linking with the information of unused schools and company, NPO, elderly welfare facility, etc. Third, In korea Superintendent established plans to use closed schools to respond flexibly to local circumstances. Japan simplified the procedures for closed schools to promote the utilization of closed schools. Finally, In Japan, there was various financial support system. But in Korea, it supported the cost of subsidy reduction, free loan, maintenance and management and operation.

• Journal of the Korean Institute of Rural Architecture
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• v.25 no.3
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• pp.27-35
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• 2023

This study aims to provide implications for Korea's efficient application policies for closed schools by identifying the current status of how closed schools are revitalized in Japan and their supportive measures. In Japan, a total of 2,215 schools have closed from 1992 to 2001, and 8,580 schools from 2002 to 2020, with 10,709 closures occurring from 1992 to 2020. The average number is about 369 per year. In terms of the overall trend, the number of closed schools have been put into use and the numbers have increased from 70% in 2013 to 74% in 2020. To summarize the characteristics of the use, first, there is a complex phenomenon in which the use of closed schools are becoming more diverse. Second, closed schools are most often revitalized as educational facilities for residents, followed by social sports facilities, social education facilities and cultural facilities. Third, the use of closed schools in the industries are increasing as they are used as "corporal facilities and start-up support facilities". In order to promote the use of closed schools, the Ministry of Education, Culture, Sports, Science and Technology in Japan promoted the simplification and elasticity of property disposal procedures in 2008. Since 2010, the disclosure of information on closed facilities and matching service between providers and users have been unified through the "Let's Connect to the Future ~ Closed School for All" project. The Cabinet Office including the four offices, and five central governments are advocating the use of closed schools by promoting subsidy support projects.

• Journal of Industrial Technology
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• v.4
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• pp.25-27
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• 1984

위상 공간 X의 모든 Semi-open cover에 대하여 그들의 closure의 합이 X를 cover한 유한 부분 속이 존재할 때 위상 공간X를 S-closed라고 한다. 이 논문에서는 S-closed와 semi-closed set 사이의 관계를 조사하였고 Haussdorff 공간과 S-closed 공간에서 extremally disconnected와 semi-continuous의 성질을 조사하였다.

• Kyungpook Mathematical Journal
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• v.27 no.2
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• pp.127-134
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• 1987

The purpose of this paper is to introduce a topological space named an F-closed space. This space is properly contained between an S-closed space [17] and a quasi H-closed space [14], and between a nearly compact space [15] and a quasi H-closed space. We will investigate properties of F-closed spaces, and improve some results in [2], [7] and [17].

• 제어로봇시스템학회:학술대회논문집
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• 1995.10a
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• pp.396-399
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• 1995

This paper presents a new formulation of the kinematics of closed-chain mechanisms and its applications to obtaining the kinematic solutions and analyzing the singularities. Closed-chain mechanisms under consideration may have the redundancy in the number of joints. A closed-chain mechanism can be treated as the parallel connection of two open-chains with respect to a point of interest. The kinematics of a closed-chain mechanism is then obtained by imposing the kinematic constraints of the closed-chain on the kinematics of the two open-chains. First, we formulate the kinematics of a closed-chain mechanism using the kinematic constraint between the controllable active joints and the rest of joints, instead of the kinematic constraint between the two open-chains. The kinematic formulation presented in this paper is valid for closed-chain mechanisms with and without the redundancy. Next, based on the derived kinematics of a closed-chain mechanism, we provide the kinematic solutions which are more physically meaningful and less sensitive to numerical instability, and also suggest an effective way to analyze the singularities. Finally, the computational cost associated with the kinematic formulation is analyzed.

• The Journal of Sustainable Design and Educational Environment Research
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• v.11 no.3
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• pp.13-24
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• 2012

Since the number of students in farming and fishing communities have been widely decreased due to industrialization and urbanization along with a low birth rate. As a result, the number of closed schools has reached 3,386 in 2010. The number is still increased because of continuous decrease in the number of population engaged in farming and fishing. Explore the possibility for the development of closed schools facilities, this researching is showing us that the closed schools have associated with the local community closely. For this reason, we need to promote these closed school facilities to utilizing purposes as appropriate to the needs of the times and with that we can explore too the possibility of a variety of regional development concept, how underdeveloped regions can be activated. Therefore, first on this study is progressed theoretical study of utilizing of closed schools and the strengthening of regional competitiveness as a framework and we consider characteristics of the closed schools utilizing. Second, we choose the case, where the utilizing of closed schools have realized to purpose of regional development conceptions with the strengthening of regional competitiveness. Third, we would like to prove several possibilities with results of date-analysis and formulate some suggestion for be continued future planning of utilizing of closed schools. education.