• Title/Summary/Keyword: East Asian mathematics

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CONDITIONS IMPLYING NORMALITY

  • Kim, An-Hyun
    • East Asian mathematical journal
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    • v.16 no.1
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    • pp.49-55
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    • 2000
  • In this paper we find some classes of operators implying normaity. The main result is as follows. If T is restriction-convexoid and is reduced by each of its eigenspaces corresponding to isolated eigenvalues, which is a class including hyponormal operators, and if $\sigma$(T) is countable then T is diagonal and normal.

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A STUDY ON BAER AND P.P. NEAR-RINGS

  • Cho, Yong-Uk
    • East Asian mathematical journal
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    • v.16 no.1
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    • pp.105-110
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    • 2000
  • Baer rings were introduced by Kaplansky [3] to abstract various properties of rings of operators on a Hilbert spaces. On the other hand, p.p. rings were introduced by A. Hattori [2] to study the torsion theory. In this paper we introduce Baer near-rings and p.p. near-rings and study some properties and give some examples.

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FUZZY D-CONTINUOUS FUNCTIONS

  • Akdag, Metin
    • East Asian mathematical journal
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    • v.17 no.1
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    • pp.1-17
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    • 2001
  • In this paper, fuzzy D-continuous function is defined. Some basic properties of this continuity are summarized; and sufficient conditions on domain and/or ranges implying fuzzy D-continuity of fuzzy D-continuous functions are given. Also fuzzy D-regular space is defined and by using fuzzy D-continuity, the condition which is equivalent to fuzzy D-regular space, is given.

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INDEFINITE TRANS-SASAKIAN MANIFOLD WITH A TRANSVERSAL HALF LIGHTLIKE SUBMANIFOLD

  • Jin, Dae Ho
    • East Asian mathematical journal
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    • v.33 no.5
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    • pp.533-542
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    • 2017
  • We study the geometry of indefinite trans-Sasakian manifold ${\bar{M}}$ admitting a half lightlike submanifold M such that the structure vector field of ${\bar{M}}$ belongs to the transversal vector bundle of M. We prove several classification theorems of such an indefinite trans-Sasakian manifold.

SYMBOLS OF MINIMUM TYPE AND OF ZERO CLASS IN EXPONENTIAL CALCULUS

  • LEE, Chang Hoon
    • East Asian mathematical journal
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    • v.34 no.1
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    • pp.29-37
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    • 2018
  • We introduce formal symbols of product type, of zero class, and of minimum type and show that the formal power series representations for $e^p$ and $e^q$ are formal symbols of product type giving the same pseudodifferential operator, where p and q are formal symbols of minimum type and p - q is of zero class.

EXISTENCE OF POSITIVE SOLUTIONS FOR THE SECOND ORDER DIFFERENTIAL SYSTEMS WITH STRONGLY COUPLED INTEGRAL BOUNDARY CONDITIONS

  • Lee, Eun Kyoung
    • East Asian mathematical journal
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    • v.34 no.5
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    • pp.651-660
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    • 2018
  • This paper concerned the existence of positive solutions to the second order differential systems with strongly coupled integral boundary value conditions. By using Krasnoselskii fixed point theorem, we prove the existence of positive solutions according to the parameters under the proper nonlinear growth conditions.

PARAMETRIZED PERTURBATION RESULTS ON GLOBAL POSITIVE SOLUTIONS FOR ELLIPTIC EQUATIONS INVOLVING CRITICAL SOBOLEV-HARDY EXPONENTS AND HARDY TEREMS

  • Kim, Wan Se
    • East Asian mathematical journal
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    • v.34 no.5
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    • pp.549-570
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    • 2018
  • We establish existence and bifurcation of global positive solutions for parametrized nonhomogeneous elliptic equations involving critical Sobolev-Hardy exponents and Hardy terms. The main approach to the problem is the variational method.