• Title/Summary/Keyword: semi-closed

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A note on S-closed space (S-closed 공간에 관하여)

  • Han, Chun-Ho
    • 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.

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R-SEMI-GENERALIZED FUZZY CONTINUOUS MAPS

  • Min, Won Keun;Park, Chun-Kee
    • Korean Journal of Mathematics
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    • v.15 no.1
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    • pp.27-37
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    • 2007
  • In this paper, we introduce the concepts of r-semi-generalized fuzzy closed sets, r-semi-generalized fuzzy open sets, r-semi-generalized fuzzy continuous maps in fuzzy topological spaces and investigate some of their properties.

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A NOTE ON S-CLOSED SPACES

  • Woo, Moo-Ha;Kwon, Taikyun;Sakong, Jungsook
    • 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.

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On a Generalization of Closed Sets

  • Caldas, Miguel;Ganster, Maximilian;Georgiou, Dimitrios N.;Jafari, Saeid;Popa, Valeriu
    • Kyungpook Mathematical Journal
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    • v.47 no.2
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    • pp.155-164
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    • 2007
  • It is the objective of this paper to study further the notion of ${\Lambda}_s$-semi-${\theta}$-closed sets which is defined as the intersection of a ${\theta}$-${\Lambda}_s$-set and a semi-${\theta}$-closed set. Moreover, introduce some low separation axioms using the above notions. Also we present and study the notions of ${\Lambda}_s$-continuous functions, ${\Lambda}_s$-compact spaces and ${\Lambda}_s$-connected spaces.

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ON SOFT REGULAR-OPEN(CLOSED) SETS IN SOFT TOPOLOGICAL SPACES

  • HUSSAIN, SABIR
    • Journal of applied mathematics & informatics
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    • v.36 no.1_2
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    • pp.59-68
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    • 2018
  • In this paper, We define and explore the characterizations and properties of soft regular open(closed) and soft semi-regular sets in soft topological spaces. The properties of soft extremally disconnected spaces are also introduced and discussed. The findings in this paper will help researcher to enhance and promote further study on soft topology to carry out a general framework for their applications in practical life.

ON SOME NEW MAXIMAL AND MINIMAL SETS VIA θ-OPEN SETS

  • Caldas, Miguel;Jafari, Saeid;Moshokoa, Seithuti P.
    • Communications of the Korean Mathematical Society
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    • v.25 no.4
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    • pp.623-628
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    • 2010
  • Nakaoka and Oda ([1] and [2]) introduced the notion of maximal open sets and minimal closed sets in topological spaces. In this paper, we introduce new classes of sets called maximal $\theta$-open sets, minimal $\theta$-closed sets, $\theta$-semi maximal open and $\theta$-semi minimal closed and investigate some of their fundamental properties.

GENERALIZED FUZZY CLOSED SETS ON INTUITIONISTIC FUZZY TOPOLOGICAL SPACES

  • Kim, Jin Tae;Lee, Seok Jong
    • Journal of the Chungcheong Mathematical Society
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    • v.35 no.3
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    • pp.243-254
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    • 2022
  • In this paper, we introduce three different concepts of closed sets on the intuitionistic fuzzy topological spaces, i.e., the generalized fuzzy (r, s)-closed, semi-generalized fuzzy (r, s)-closed, and generalized fuzzy (r, s)-semiclosed sets on intuitionistic fuzzy topological spaces in Šostak's sense. Also we investigate their properties and the relationships among these generalized fuzzy closed sets.

STUDY ON TOPOLOGICAL SPACES WITH THE SEMI-T½ SEPARATION AXIOM

  • Han, Sang-Eon
    • Honam Mathematical Journal
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    • v.35 no.4
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    • pp.707-716
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    • 2013
  • The present paper consists of two parts. Since the recent paper [4] proved that an Alexandroff $T_0$-space is a semi-$T_{\frac{1}{2}}$-space, the first part studies semi-open and semi-closed structures of the Khalimsky nD space. The second one focuses on the study of a relation between the LS-property of ($SC^{n_1,l_1}_{k_1}{\times}SC^{n_2,l_2}_{k_2}$, k) relative to the simple closed $k_i$-curves $SC^{n_i,l_i}_{k_i}$, $i{\in}\{1,2\}$ and its normal k-adjacency. In addition, the present paper points out that the main theorems of Boxer and Karaca's paper [3] such as Theorems 4.4 and 4.7 of [3] cannot be new assertions. Indeed, instead they should be attributed to Theorems 4.3 and 4.5, and Example 4.6 of [10].

Effect of strain-rate on deformation behavior of semi-solid material (반용융 재료의 변형거동에 대한 변형률 속도의 영향)

  • 황재호;고대철;최재찬
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1997.04a
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    • pp.777-781
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    • 1997
  • In this study, the effect of strain-rate and inital solid fraction on the deformation behaviour of semi-solid material is investigated, when semi-solid forging is performed by the process of closed-die compression using A356 alloy of which the above results can be practically applied for industrical purpose. In order to simulate densification in the deformation of semi-solid material, the semi-solid material is assumed to be composed of solid region following rigid visco-plastic material, the liquid region following Darcy's law for the liquid flow saturated in the interstitial space. Simulation results of closed-die compression and simple upsetting under different strain-rate and initial solid fraction are compared.

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Evaluation of Ventilation Rate and External Air Mixing Ratio in Semi-closed Loop Ventilation System of Pig House Considering Pressure Loss (압력손실을 고려한 양돈시설의 반폐회로 환기시스템의 환기량 및 혼합비율 평가)

  • Park You-me;Kim Rack-woo;Kim Jun-gyu
    • Journal of The Korean Society of Agricultural Engineers
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    • v.65 no.1
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    • pp.61-72
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    • 2023
  • The increase in the rearing intensity of pigs has caused deterioration in the pig house's internal environment such as temperature, humidity, ammonia gas, and so on. Traditionally, the widely used method to control the internal environment was through the manipulation of the ventilation system. However, the conventional ventilation system had a limitation to control the internal environment, prevent livestock disease, save energy, and reduce odor emission. To overcome this problem, the air-recirculated ventilation system was suggested. This system has a semi-closed loop ventilation type. For designing this system, it was essential to evaluate the ventilation rates considering the pressure loss of ducts. Therefore, in this study, pressure loss calculation and experiment were conducted for the quantitative ventilation design of a semi-closed loop system. The results of the experiment showed that the inlet through which external air flows should always be opened. In addition, it was also found that for the optimum design of the semi-closed loop ventilation system, it was appropriate to install a damper or a backflow prevention device rather than a ventilation fan.