• Korean Journal of Mathematics
• /
• 제19권1호
• /
• pp.53-59
• /
• 2011

We study some properties of integrable semigroup and its generator, and then we establish convergence of integrable semigroups on the norming dual pairs.

• 대한수학회지
• /
• 제42권6호
• /
• pp.1231-1249
• /
• 2005

By employing Chebotarev and Fagnola's sufficient conditions for conservativity of minimal quantum dynamical semigroups [7, 8], we construct the conservative minimal quantum dynamical semigroups generated by noncommutative elliptic operators in the sense of [2]. We apply our results to concrete examples.

• 대한수학회보
• /
• 제53권1호
• /
• pp.39-48
• /
• 2016

In this paper we extend Takahashi's fixed point theorem on discrete semigroups to general semi-topological semigroups. Next we define the semi-asymptotic non-expansive action of semi-topological semi-groups to give a partial affirmative answer to an open problem raised by A.T-M. Lau.

• 대한수학회논문집
• /
• 제20권4호
• /
• pp.751-763
• /
• 2005

For a given gauge invariant state $\omega$ on the CAR algebra A isomorphic with the C$\ast$ -algebra of $2{\times}2$ complex matrices, we construct a family of quantum Markov semigroups on A which leave w invariant. By analyzing their generators, we decompose the algebra A into four eigenspaces of the semigroups and show some properties.

• Journal of applied mathematics & informatics
• /
• 제27권5_6호
• /
• pp.1447-1457
• /
• 2009

In this paper we define intuitionistic fuzzy interior ideals in ordered semigroups. We prove that in regular(resp. intra-regular and semisimple) ordered semigroups the concepts of intuitionistic fuzzy interior ideals and intuitionistic fuzzy ideals coincide. We prove that an ordered semi group is intuitionistic fuzzy simple if and only if every intutionistic fuzzy interior ideal is a constant function. We characterize intra-regular ordered semi groups in terms of interior (resp. intuitionistic fuzzy interior) ideals.

• 대한수학회보
• /
• 제49권1호
• /
• pp.99-107
• /
• 2012

The concept of Hilbert space dissipative norm was introduced in [8] to obtain necessary and sufficient conditions for exponential stability of contraction semigroups. In the present paper we show that the same concept can also be used to derive further properties of contraction semigroups, as well as to characterize strongly stable semigroups that are not exponentially stable.

• Journal of applied mathematics & informatics
• /
• 제17권1_2_3호
• /
• pp.559-565
• /
• 2005

In this paper, we establish the convergence of semigroups that are strongly continuous on (0, $\infty$). By using Laplace transform theory, we show some properties of semigroups and the convergence result.

• Korean Journal of Mathematics
• /
• 제7권1호
• /
• pp.111-116
• /
• 1999

In this paper, we introduce the concepts of quasi retract ideals and quasi retract topological semigroups which are weaker than those of retract ideals and retract topological semigroups, respectively. We prove that every $n$-th power ideal of a commutative power cancellative power ideal topological semigroup is a quasiretract ideal.

• 대한수학회보
• /
• 제33권2호
• /
• pp.213-219
• /
• 1996

In this note we study the representations on Hilbert space of involutive semigroups, i.e., semigroups endowed with an involutive antiautomorphism. This subject is studied by K. H. Neeb, and some interesting results are ivestigated ([3]).

• Korean Journal of Mathematics
• /
• 제14권1호
• /
• pp.95-100
• /
• 2006

In this paper we give some new characterizations of the intra-regular ordered semigroups in terms of bi-ideals and quasi-ideals, bi-ideals and left ideals, bi-ideals and right ideals of ordered semigroups.