• Honam Mathematical Journal
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• v.33 no.4
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• pp.499-518
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• 2011

We obtain the interval-valued fuzzy subgroups generated by interval-valued fuzzy sets and some properties preserved by a ring homomorphism. Furthermore, we introduce the concepts of interval-valued fuzzy coset and study some of it's properties.

• Journal of the Chungcheong Mathematical Society
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• v.20 no.4
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• pp.495-501
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• 2007

In this paper the relative regionally regular relation is defined and it will be given the necessary and sufficient conditions for the relation to be an equivalence relation.

• The Pure and Applied Mathematics
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• v.22 no.2
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• pp.179-184
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• 2015

In this paper we discuss a functional approach to obtain a lattice-like structure in d-algebras, and obtain an exact analog of De Morgan law and some other properties.

• Journal of the Korean Mathematical Society
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• v.32 no.3
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• pp.371-387
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• 1995

Let X be a compact polyhedron, H a normal subgroup of the fundamental group $\pi_1(X)$ of X and $f : X \longrightarrow X$ a selfmap such that $f_piH \subset H$, where f_\pi : \pi_1(X) \longrightarrow \pi_1(X)$ is the induced homomorphism by f.

• Bulletin of the Korean Mathematical Society
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• v.41 no.4
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• pp.709-721
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• 2004

A punctured torus ${\Sigma}$(1, 1) is a building block of oriented surfaces. In this paper we formulate the matrix presentations of elements of the Teichmuller space of a punctured torus using the matrix presentations of a pair of pants ${\Sigma}$(0, 3) and the gluing method.

• Communications of the Korean Mathematical Society
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• v.10 no.3
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• pp.519-525
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• 1995

By using an exact sequence of extension groups corresponding to an isogeny of a Drinfeld module we investigate which extension classes are coming from Hom(G,C). In the last section of this paper an example was given where the connecting homomorphism can be explictly computed.

• Bulletin of the Korean Mathematical Society
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• v.43 no.2
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• pp.333-341
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• 2006

We analyze a detailed picture of the algebraic structure of $C^*$-algebras generated by isometric representations of the non-amenable semigroup P = {0,2,3,...,N,...}.

• Bulletin of the Korean Mathematical Society
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• v.43 no.3
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• pp.653-655
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• 2006

We give a simple proof of the statement that if T is a bounded linear operator on a complex HIlbert space then T is Fredholm if and only if ${\pi}(T)$ is not a TDZ, where ${\pi}(\cdot)$ is the Catkin homomorphism.

• Communications of the Korean Mathematical Society
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• v.11 no.3
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• pp.649-655
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• 1996

A positive, disjoint linear map $\phi : A \to B$ of C^*$-algebras preserves absolute values if any *-anti-homomorphism $\psi : A \to B$ is skew-hermitian with respect to every commutators of unitary elements.

• Bulletin of the Korean Mathematical Society
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• v.38 no.3
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• pp.435-441
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• 2001

We obtain a characterization of linear operators on vector spaces and homomorphisms on algebras applying the stability properties of functional equations.