Results 21 to 30 of about 70 (67)
International Journal of Mathematics and Mathematical Sciences, Volume 21, Issue 3, Page 459-462, 1998., 1996 We prove that a countable connected Hausdorff space in which the intersection of every pair of connected subsets is connected, cannot be locally connected, and also that every continuous function from a countable connected, locally connected Hausdorff space, to a countable connected Hausdorff space in which the intersection of every pair of connected ...
V. Tzannes
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On the inverse image of Baire spaces
International Journal of Mathematics and Mathematical Sciences, Volume 20, Issue 3, Page 423-432, 1997., 1996 In 1961, Z. Frolik proved that if f is an open and continuous mapping of a metrizable separable space X onto Baire space Y and if the point inverses are Baire spaces, then X is a Baire space. We give a generalization to semi‐continuous and semi‐open mapping of this theorem and extended it to the several types of mappings.
Mustafa Çiçek
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Application on local discrete expansion
International Journal of Mathematics and Mathematical Sciences, Volume 19, Issue 4, Page 747-750, 1996., 1995 The process of changing a topology by some types of its local discrete expansion preserves s‐closeness, S‐closeness, semi‐compactness, semi‐Ti, semi‐Ri, i ∈ {0, 1, 2}, and extremely disconnectness. Via some other forms of such above replacements one can have topologies which satisfy separation axioms the original topology does not have.
M. E. Abd El-Monsef +2 more
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International Journal of Mathematics and Mathematical Sciences, Volume 17, Issue 4, Page 687-692, 1994., 1994 In this paper we study θ‐regularity and its relations to other topological properties. We show that the concepts of θ‐regularity (Janković, 1985) and point paracompactness (Boyte, 1973) coincide. Regular, strongly locally compact or paracompact spaces are θ‐regular.
Martin M. Kovár
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International Journal of Mathematics and Mathematical Sciences, Volume 15, Issue 1, Page 57-64, 1992., 1989 A strong form of continuity of functions between topological spaces is introduced and studied. It is shown that in many known results, especially closed graph theorems, functions under consideration are R‐continuous. Several results in the literature concerning strong continuity properties are generalized and/or improved.
Ch. Konstadilaki-Savvapoulou +1 more
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International Journal of Mathematics and Mathematical Sciences, Volume 14, Issue 4, Page 709-714, 1991., 1990 We construct two countable, Hausdorff, almost regular spaces I(S), I(T) having the following properties: (1) Every continuous map of I(S) (resp, I(T)) into every Urysohn space is constant (hence, both spaces are connected). (2) For every point of I(S) (resp.
V. Tzannes
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Applications of δ‐Open Sets via Separation Axioms, Covering Properties, and Rough Set Models
Journal of Mathematics, Volume 2025, Issue 1, 2025.In this article, we make use of δ‐open sets to establish some topological concepts related to separation axioms and covering properties and to propose novel topological rough set models. We first demonstrate that the classes of regular‐open and δ‐open subsets of a finite topological space are equivalent when this space has the property of ∂(A)∩∂(B)⊆∂(A
Tareq M. Al-Shami +2 more
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Separation properties of the Wallman ordered compactification
International Journal of Mathematics and Mathematical Sciences, Volume 13, Issue 2, Page 209-221, 1990., 1990 The Wallman ordered compactification ω0X of a topological ordered space X is T2‐ordered (and hence equivalent to the Stone‐Čech ordered compactification) iff X is a T4‐ordered c‐space. In particular, these two ordered compactifications are equivalent when X is n dimensional Euclidean space iff n ≤ 2.
D. C. Kent, T. A. Richmond
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A note of almost continuous mappings and Baire spaces
International Journal of Mathematics and Mathematical Sciences, Volume 6, Issue 1, Page 197-199, 1983., 1982 We prove the following theorem: THEOREM. Let Y be a second countable, infinite R0‐space. If there are countably many open sets 01, 02, …, 0n, … in Y such that 01⫋02⫋…⫋0n⫋…, then a topological space X is a Baire space if and only if every mapping f : X → Y is almost continuous on a dense subset of X. It is an improvement of a theorem due to Lin and Lin [
Jing Cheng Tong
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Выявление бактерии Klebsiella oxytoca VN13 в окружающей среде методом биолюминесценции
, 1994 The continuous expression of the Photobacterium leiognathi 54D10 lux genes coding for the bioluminescence was obtained in Klebsiella oxytoca VN13. Chromosomally and plasmid-encoded bioluminescence of strains constructed was used to monitor their survival
Kozyrovska, N.A +4 more
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