• Bulletin of the Korean Mathematical Society
• /
• v.30 no.2
• /
• pp.193-199
• /
• 1993

A hereditary $C^{*}$-subalgebra B of a $C^{*}$-algebra A is said to be full if B is not contained in any proper closed two-sided ideal in A, so each hereditary $C^{*}$-subalgebra of a simple $C^{*}$-algebra is always full. It is well known that every $C^{*}$-algebra is strong Morita equivalent to its full hereditary $C^{*}$-subalgebra, but the strong Morita equivalence of a $C^{*}$-algebra A and its hereditary $C^{*}$-subalgebra B does not imply the fullness of B, ingeneral. We present the following lemma for our computational convenience in the course of the proof of the main theorem. Note that $L_{B}$, $L_{B}$$^{*}$ and $L_{B}$ $L_{B}$$^{*}$ are all .alpha.-invariant whenever B is .alpha.-invariant under the action .alpha. of G.a. of G.a. of G.a. of G.f G.

• Communications of the Korean Mathematical Society
• /
• v.27 no.3
• /
• pp.431-439
• /
• 2012

Characterizations of $\mathcal{N}$-subalgebra of type (${\in}$, ${\in}{\vee}q$) are provided. The notion of $\mathcal{N}$-subalgebras of type ($\bar{\in}$, $\bar{\in}{\vee}\bar{q}$) is introduced, and its characterizations are discussed. Conditions for an $\mathcal{N}$-subalgebra of type (${\in}$, ${\in}{\vee}q$) (resp. ($\bar{\in}$, $\bar{\in}{\vee}\bar{q}$) to be an $\mathcal{N}$-subalgebra of type (${\in}$, ${\in}$) are considered.

• Kyungpook Mathematical Journal
• /
• v.55 no.4
• /
• pp.859-870
• /
• 2015

The notion of quasi-valuation maps based on a subalgebra and an ideal in BCK/BCI-algebras is introduced, and then several properties are investigated. Relations between a quasi-valuation map based on a subalgebra and a quasi-valuation map based on an ideal is established. In a BCI-algebra, a condition for a quasi-valuation map based on an ideal to be a quasi-valuation map based on a subalgebra is provided, and conditions for a real-valued function on a BCK/BCI-algebra to be a quasi-valuation map based on an ideal are discussed. Using the notion of a quasi-valuation map based on an ideal, (pseudo) metric spaces are constructed, and we show that the binary operation * in BCK-algebras is uniformly continuous.

• Journal of applied mathematics & informatics
• /
• v.7 no.2
• /
• pp.685-692
• /
• 2000

We introduce the notion of T-fuzzy circled subalgebras, and obtain some related results.

• Communications of the Korean Mathematical Society
• /
• v.12 no.3
• /
• pp.513-519
• /
• 1997

We show that each orthomodular lattice containing only atomic nonpath-connected blocks is a full subalgebra of an irreducible path-connected orthomodular lattice and there is a path-connected orthomodualr lattice L containing a weakly path-connected full subalgebra C(x) for some element x in L.

• Journal of the Chungcheong Mathematical Society
• /
• v.22 no.3
• /
• pp.399-408
• /
• 2009

A bipolar fuzzy translation and a bipolar fuzzy S-extension of a bipolar fuzzy subalgebra in a BCK/BCI-algebra are introduced, and related properties are investigated.

• Communications of the Korean Mathematical Society
• /
• v.17 no.3
• /
• pp.451-457
• /
• 2002

Let (R, m, k) be a maximal commutative k-subalgebra of M$\sub$n/(k) where the index of nilpotency i(m) of m is 3. If the socle of R is of special case, then we can construct some isomorphic maximal commutative subalgebras.

• Honam Mathematical Journal
• /
• v.34 no.4
• /
• pp.585-596
• /
• 2012

The notions of a $\mathcal{N}$-subalgebra, a (strong) $\mathcal{N}$-ideal of BH-algebras are introduced, and related properties are investigated. Characterizations of a coupled $\mathcal{N}$-subalgebra and a coupled (strong) $\mathcal{N}$-ideals of BH-algebras are given. Relations among a coupled $\mathcal{N}$-subalgebra, a coupled $\mathcal{N}$-ideal and a coupled strong $\mathcal{N}$ of BH-algebras are discussed.

• Communications of the Korean Mathematical Society
• /
• v.9 no.2
• /
• pp.265-270
• /
• 1994

In 1966, Iseki [2] introduced the notion of BCI-algebras which is a generalization of BCK-algebras. Lei and Xi [3] discussed a new class of BCI-algebra, which is called a p-semisimple BCI-algebra. For p-semisimple BCI-algebras, a subalgebra is an ideal. But a subalgebra of an arbitrary BCI/BCK-algebra is not necessarily an ideal. In this note, a BCI/BCK-algebra that every subalgebra is an ideal is called a normal BCI/BCK-algebra, and we give characterizations of normal BCI/BCK-algebras. Moreover we give a positive answer to the problem which is posed in [4].(omitted)

• Communications of the Korean Mathematical Society
• /
• v.28 no.4
• /
• pp.709-721
• /
• 2013

The notions of coupled N-subalgebra, coupled (positive implicative) N-ideals of $d$-algebras are introduced, and related properties are investigated. Characterizations of a coupled $\mathcal{N}$-subalgebra and a coupled (positive implicative) $\mathcal{N}$-ideals of $d$-algebras are given. Relations among a coupled $\mathcal{N}$-subalgebra, a coupled $\mathcal{N}$-ideal and a coupled positive implicative $\mathcal{N}$-ideal of $d$-algebras are discussed.