• 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.

• 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].

• The Mathematical Education
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• v.21 no.1
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• pp.19-21
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• 1982

In this paper, we define the z-S-closed spaces using the notions of zero-sets and S-closed spaces introduced by T. Thompson, and investigate some properties of these spaces. We also obtain the following results. If a space X is z-S-closed, then every cover of z-regular semiopen sets has a finite proximate subcover. A z-extremally disconnected z-QHC space is z-S-closed, z-S-closed is contagious.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.41 no.6 s.324
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• pp.79-86
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• 2004

In the integration of Sommerfeld type for space domain Green's function, a accurate closed-from Green's function method provides more exact solution than the typical complex image method and two-level method. The accurate closed-form Green's function method is applied to obtain the space domain Green's functions of planar structures with general sources. Please put the abstract of paper here.

• 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.

• Communications of the Korean Mathematical Society
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• v.30 no.3
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• pp.277-282
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• 2015

We obtain some conditions for disconnectedness of a topological space in terms of maximal and minimal open sets, and some similar results in terms of maximal and minimal closed sets along with interrelations between them. In particular, we show that if a space has a set which is both maximal and minimal open, then either this set is the only nontrivial open set in the space or the space is disconnected. We also obtain a result concerning a minimal open set on a subspace.

• The Pure and Applied Mathematics
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• v.25 no.1
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• pp.49-57
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• 2018

We have introduced two new notions of convexity and closedness in functional analysis. Let X be a real normed space, then $C({\subseteq}X)$ is functionally convex (briefly, F-convex), if $T(C){\subseteq}{\mathbb{R}}$ is convex for all bounded linear transformations $T{\in}B$(X, R); and $K({\subseteq}X)$ is functionally closed (briefly, F-closed), if $T(K){\subseteq}{\mathbb{R}}$ is closed for all bounded linear transformations $T{\in}B$(X, R). By using these new notions, the Alaoglu-Bourbaki-Eberlein-${\check{S}}muljan$ theorem has been generalized. Moreover, we show that X is reflexive if and only if the closed unit ball of X is F-closed. James showed that for every closed convex subset C of a Banach space X, C is weakly compact if and only if every $f{\in}X^{\ast}$ attains its supremum over C at some point of C. Now, we show that if A is an F-convex subset of a Banach space X, then A is bounded and F-closed if and only if every element of $X^{\ast}$ attains its supremum over A at some point of A.

• Journal of architectural history
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• v.14 no.3 s.43
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• pp.53-76
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• 2005

Through a field study of the folk houses, 'Closed ㄱㄴ Type' in Goyang-si, Gyonggj-do, focused on the dweller's life by the method of ethnographic interview, observation, and physical survey. L and opposite L type of inner and outer buildings form a closed inner court, and innermost backyard for woman is enclosed by fence. Form and space of the house contains dweller's traditional life. Outer space of a front gate becomes semiprivate space, for thrashing and piling up harvest and raising vegetables and pigs. Confucius principle does not fully dominate dweller's life of ancestral rite at Daecheong floor, and separation of man's and woman's quarter. Superstitious worship activities took place for lord of site and house. In everyday life, Anbang, inner main room, is assigned for parent's quarter instead of woman's quarter, and Geornbang, next room, was for son's family. Anbang has symbolic meaning for a place of deathbed. House contains agricultural activities, crop harvesting, thrashing, putting into storage, hulling rice, and keeping grain near kitchen. At present, rooms are needed more; sheds are made into rooms, rooms are enlarged toward outside, half outside space like Daechong floor becomes interior space by sash screen. And modern facilities of kitchen and bathroom are equipped for convenience. At the end, meaning and generative principle of those forms are discovered.

• Journal of the Korean Institute of Rural Architecture
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• v.18 no.4
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• pp.17-24
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• 2016

Since the users have direct access to search and browse freely, the open access system has been employed to all the usual modern libraries. However, library space shortage problem created by the continuously increasing printed materials caused the degradation of usability and quality of the library space. Open Access system is superior in user convenience but is inferior in space efficiency. Keeping the open access system is considered as one of the reasons of the space shortage problem. Even though the closed access system does not provide free access or easy browsing for the uses, it's space efficiency is much higher than the open access system. The closed access system should be employed as a plan to relieve space shortage problem. Since the closed access system does not allow the public direct access to books, it is very economical. It also provides much better space efficiency with higher book shelving density. In this article, closed access library system models and their characteristics are examined as the reduction plans for the library space shortage problems.

• The Mathematical Education
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• v.13 no.2
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• pp.29-31
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• 1974

P.Zenor에 의해서 Monotonically Normal space가 정의되었으며 그후 R. Health와 D. Lutzer에 의해서 Linearly ordered topological space가 Monotonically Normal 임을 증명했다. 한편 Zenor는 Monotonically Normal Space의 hereditary에 관한 것을 question으로 남겼는데 Health와 Lutzer가 증명했고 또 그 증명보다 더 간단한 증명을 Calos R. Boyers가 증명했다[3]. 뿐만 아니라 그 결과로서 Linearly ordered topological space와 Elastic space 가 Monotonically Normal space임을 밝혔다. 또 [4]에서 Gary Gruenhage가 Monotonically Normal space가 Elastic space가 안됨을 counterexample을 들어서 증명했다. 결론적으로 Monotonically Normal spare와 Elastic space는 완전히 분리되었다. 또 Elastic space의 closed continuous image는 paracompact이고 Monotonically Normal 임을 증명했다. 이 논문에서는 본인이 밝힌 것은 Monotonically Normal space의 closed continuous image가 Mono tonically Normal임을 밝혔다.