• Title/Summary/Keyword: compact sets

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ON CANTOR SETS AND PACKING MEASURES

  • WEI, CHUN;WEN, SHENG-YOU
    • Bulletin of the Korean Mathematical Society
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    • v.52 no.5
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    • pp.1737-1751
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    • 2015
  • For every doubling gauge g, we prove that there is a Cantor set of positive finite $H^g$-measure, $P^g$-measure, and $P^g_0$-premeasure. Also, we show that every compact metric space of infinite $P^g_0$-premeasure has a compact countable subset of infinite $P^g_0$-premeasure. In addition, we obtain a class of uniform Cantor sets and prove that, for every set E in this class, there exists a countable set F, with $\bar{F}=E{\cup}F$, and a doubling gauge g such that $E{\cup}F$ has different positive finite $P^g$-measure and $P^g_0$-premeasure.

GENERALIZED BI-QUASI-VARIATIONAL-LIKE INEQUALITIES ON NON-COMPACT SETS

  • Cho, Yeol Je;Chowdhury, Mohammad S.R.;Ha, Je Ai
    • Communications of the Korean Mathematical Society
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    • v.32 no.4
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    • pp.933-957
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    • 2017
  • In this paper, we prove some existence results of solutions for a new class of generalized bi-quasi-variational-like inequalities (GBQVLI) for (${\eta}-h$)-quasi-pseudo-monotone type I and strongly (${\eta}-h$)-quasi-pseudo-monotone type I operators defined on non-compact sets in locally convex Hausdorff topological vector spaces. To obtain our results on GBQVLI for (${\eta}-h$)-quasi-pseudo-monotone type I and strongly (${\eta}-h$)-quasi-pseudo-monotone type I operators, we use Chowdhury and Tan's generalized version of Ky Fan's minimax inequality as the main tool.

MAXIMAL INVARIANCE OF TOPOLOGICALLY ALMOST CONTINUOUS ITERATIVE DYNAMICS

  • Kahng, Byungik
    • Journal of the Korean Mathematical Society
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    • v.59 no.1
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    • pp.105-127
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    • 2022
  • It is known that the maximal invariant set of a continuous iterative dynamical system in a compact Hausdorff space is equal to the intersection of its forward image sets, which we will call the first minimal image set. In this article, we investigate the corresponding relation for a class of discontinuous self maps that are on the verge of continuity, or topologically almost continuous endomorphisms. We prove that the iterative dynamics of a topologically almost continuous endomorphisms yields a chain of minimal image sets that attains a unique transfinite length, which we call the maximal invariance order, as it stabilizes itself at the maximal invariant set. We prove the converse, too. Given ordinal number ξ, there exists a topologically almost continuous endomorphism f on a compact Hausdorff space X with the maximal invariance order ξ. We also discuss some further results regarding the maximal invariance order as more layers of topological restrictions are added.

Optimal Design of I-type Girders in 2-Span Continuous Steel Bridges by LRFD (LRFD에 의한 연속보 주부재의 조밀 및 비조밀 단면 최적화 설계)

  • Gook, Joong-Sik;Shin, Yung-Seok
    • Journal of Korean Society of Steel Construction
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    • v.12 no.3 s.46
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    • pp.329-337
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    • 2000
  • The Load and Resistance Factor Design(LRFD) Specification defines two sets of limiting width-to-thickness ratios. On the basis of these limiting values, steel sections are subdivided into three categories: compact, noncompact, and slender sections. In this paper, I-Type girders of a 2 span continuous steel bridge are divided into compact and non-compact sections and analyzed. In the design process, an optimization formulation was adopted and ADS, a Fortran program for Automated Design Synthesis, was used. In this study, we studied about change of the section between compact and non-compact using optimization formulation.

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On the Conditon of Tightness for Fuzzy Random Variables

  • Joo, Sang-Yeol
    • Proceedings of the Korean Reliability Society Conference
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    • 2002.06a
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    • pp.303-303
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    • 2002
  • We obtain the necessary and sufficient condition of tightness for a sequence of random variables in the space of fuzzy sets with compact support in R.

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SOFT SOMEWHERE DENSE SETS ON SOFT TOPOLOGICAL SPACES

  • Al-shami, Tareq M.
    • Communications of the Korean Mathematical Society
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    • v.33 no.4
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    • pp.1341-1356
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    • 2018
  • The author devotes this paper to defining a new class of generalized soft open sets, namely soft somewhere dense sets and to investigating its main features. With the help of examples, we illustrate the relationships between soft somewhere dense sets and some celebrated generalizations of soft open sets, and point out that the soft somewhere dense subsets of a soft hyperconnected space coincide with the non-null soft ${\beta}$-open sets. Also, we give an equivalent condition for the soft csdense sets and verify that every soft set is soft somewhere dense or soft cs-dense. We show that a collection of all soft somewhere dense subsets of a strongly soft hyperconnected space forms a soft filter on the universe set, and this collection with a non-null soft set form a soft topology on the universe set as well. Moreover, we derive some important results such as the property of being a soft somewhere dense set is a soft topological property and the finite product of soft somewhere dense sets is soft somewhere dense. In the end, we point out that the number of soft somewhere dense subsets of infinite soft topological space is infinite, and we present some results which associate soft somewhere dense sets with some soft topological concepts such as soft compact spaces and soft subspaces.

P-EXTREMAL FUNCTIONS AND BERNSTEIN-MARKOV PROPERTIES ASSOCIATED TO COMPACT SETS IN ℝd

  • Anh, Hoang Thieu;Chi, Kieu Phuong;Dieu, Nguyen Quang;Long, Tang Van
    • Bulletin of the Korean Mathematical Society
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    • v.59 no.4
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    • pp.811-825
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    • 2022
  • Given a compact subset P ⊂ (ℝ+)d and a compact set K in ℂd. We concern with the Bernstein-Markov properties of the triple (P, K, 𝜇) where 𝜇 is a finite positive Borel measure with compact support K. Our approach uses (global) P-extremal functions which is inspired by the classical case (when P = Σ the unit simplex) in [7].

APPROXIMATION IN LIPSCHITZ ALGEBRAS OF INFINITELY DIFFERENTIABLE FUNCTIONS

  • Honary, T.G.;Mahyar, H.
    • Bulletin of the Korean Mathematical Society
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    • v.36 no.4
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    • pp.629-636
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    • 1999
  • We introduce Lipschitz algebras of differentiable functions of a perfect compact plane set X and extend the definition to Lipschitz algebras of infinitely differentiable functions of X. Then we define the subalgebras generated by polynomials, rational functions, and analytic functions in some neighbourhood of X, and determine the maximal ideal spaces of some of these algebras. We investigate the polynomial and rational approximation problems on certain compact sets X.

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Characterizations of Compactness in Fuzzy Topological Spaces

  • Chung, S.H.
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 1997.10a
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    • pp.57-59
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    • 1997
  • The concept of fuzzy sets was introduced by Zad도 in his highly influential paper [5]. Using this concept, Chang [1] introduced a notion of fuzzy topological spaces which formally is the same one as for ordinary topological spaces. Observing that with Chang's definition constant maps between fuzzy topological spaces are not necessarily continuous, Lowen [2] gave an alternative and more natural definition for a fuzzy topological spaces and characterized the fuzzy compact spaces by means of prefilters in [4]. In this paper we give new characterizations of fuzzy compact spaces introduced in [2]. These results explain more clearly fuzzy compactness in fuzzy topological spaces.

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