• 호남수학학술지
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• 제41권4호
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• pp.697-705
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• 2019

The article studies the concept of a (𝜑, 𝜓)-biflat and (𝜑, 𝜓)-amenable Banach algebra A, where 𝜑 is a continuous homomorphism on A and 𝜓 ∈ Φ_A. We show if A has a (𝜑, 𝜓)-virtual diagonal, then A is (𝜑, 𝜓)- biflat. In the case where 𝜑(A) is commutative we prove that (𝜑, 𝜓)- biflatness of A implies that A has a (𝜑, 𝜓)-virtual diagonal.

• 충청수학회지
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• 제12권1호
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• pp.63-72
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• 1999

We introduce a concept of fuzzy linearity: A function $F:L^0(X){\rightarrow}\mathbb{R}$ is fuzzy linear if $F[({\alpha}{\wedge}f){\vee}(b{\wedge}g)]=[a{\wedge}F(f)]{\vee}[b{\wedge}F(g)]$ for $f,g{\in}L^0(X)$ and a, b > 0. We show that a fuzzy integral is fuzzy linear if the measure is fuzzy c-additive.

• 충청수학회지
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• 제18권2호
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• pp.145-159
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• 2005

In this paper we introduced the concept of perfect folding defined on $E^2$ which equipped by perfect k-coloring of r-monohedral tillings. Then we studied the different cases of perfect foldings of 4-monohedral and 3-monohedral tillings of $E^2$. Also the permutations describe each folding are obtained.

• 충청수학회지
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• 제22권3호
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• pp.353-358
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• 2009

In [6], the author introduced the concepts of $s\gamma$-open sets and $s\gamma$-continuous functions. In this paper, we introduce the concept of weak $s\gamma$-continuity which is a generalization of $s\gamma$-continuity and weak continuity and investigate characterizations for such functions.

• 충청수학회지
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• 제28권2호
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• pp.269-286
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• 2015

In this paper, we extend the concept of the pseudo differential operators in the usual Schwartz's distribution spaces to the one of the generalized pseudo differential operators in the Beurling's generalized distribution spaces. And we shall investigate some properties of the generalized pseudo differential operators including the generalized pseudo local property. Finally, we will study the smoothness and properly supported property of these operators.

• 대한수학회논문집
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• 제18권1호
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• pp.59-63
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• 2003

Let A be a $C^*$-algebra and $K_{A}$ its Pedersen's ideal. A is called a PCS-algebra if the multiplier $\Gamma(K_{A})\;of\;K_{A}$ is the multiplier M(A) of A. J. Mack [5]characterized PCS-algebras by weak compactness on the spectrum of A. We give a new simple proof of this Mack's result using the concept of semicontinuity and N. C. Phillips' description of $\Gamma(K_{A})$.

• 대한수학회논문집
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• 제26권3호
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• pp.405-416
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• 2011

In this paper, we first introduce the concept of left strongly simple po-semigroups, then we discuss properties and characterizations nil-extensions of left strongly simple po-semigroups and semilattices of leftstrongly simple po-semigroups. Finally, we give some characterizations of the chain of left strongly simple po-semigroups.

• 대한수학회논문집
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• 제31권3호
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• pp.433-445
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• 2016

In the present paper, we expand the domain of work on the concept of semiderivations in 3-prime near-rings through the study of structure and commutativity of near-rings admitting semiderivations satisfying certain differential identities. Moreover, several examples have been provided at places which show that the assumptions in the hypotheses of various theorems are not altogether superfluous.

• 대한수학회보
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• 제44권4호
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• pp.641-649
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• 2007

We in this note introduce a concept, so called ${\pi}-Armendariz$ ring, that is a generalization of both Armendariz rings and 2-primal rings. We first observe the basic properties of ${\pi}-Armendariz$ rings, constructing typical examples. We next extend the class of ${\pi}-Armendariz$ rings, through various ring extensions.

• 대한수학회보
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• 제44권4호
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• pp.841-849
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• 2007

In this paper we discuss the Hyers-Ulam-Rassias stability of a system of first order linear recurrences with variable coefficients in Banach spaces. The concept of the Hyers-Ulam-Rassias stability originated from Th. M. Rassias# stability theorem that appeared in his paper: On the stability of the linear mapping in Banach spaces, Proc. Amer. Math. Soc. 72 (1978), 297-300. As an application, the Hyers-Ulam-Rassias stability of a p-order linear recurrence with variable coefficients is proved.