• Bulletin of the Korean Mathematical Society
• /
• v.56 no.4
• /
• pp.939-959
• /
• 2019

Using generalized graded crossed products, we give necessary and sufficient conditions for a simple algebra over a Henselian valued field (under some hypotheses) to have Kummer subfields. This study generalizes some known works. We also study many properties of generalized graded crossed products and conditions for embedding a graded simple algebra into a matrix algebra of a graded division ring.

• Bulletin of the Korean Mathematical Society
• /
• v.36 no.3
• /
• pp.503-512
• /
• 1999

Over a field k, every schur k-algebra is a cyclotomic algebra due to Brauer-Witt theorem. Similarly every projective Schur k-division algebra is itself a radical algebra by Aljadeff-Sonn theorem. We study the two theorems over a certain commutative ring, and prove similar results over regular domain containing a field.

• Korean Journal of Logic
• /
• v.15 no.1
• /
• pp.1-16
• /
• 2012

This paper deals with Kripke-style semantics for fuzzy logics. As an example we consider a Kripke-style semantics for the uninorm based fuzzy logic UL. For this, first, we introduce UL, define the corresponding algebraic structures UL-algebras, and give algebraic completeness results for it. We next introduce a Kripke-style semantics for UL, and connect it with algebraic semantics.

• Korean Journal of Logic
• /
• v.14 no.1
• /
• pp.55-76
• /
• 2011

Fixed-point conjunctive left-continuous idempotent uninorms have been introduced (see e.g. [2, 3]). This paper studies a system for such uninorms. More exactly, one system obtainable from IUML (Involutive uninorm mingle logic) by dropping involution (INV), called here WUML (Weak Uninorm Mingle Logic), is first introduced. This is the system of fixed-point conjunctive left-continuous idempotent uninorms and their residua with weak negation. Algebraic structures corresponding to the system, i.e., WUML-algebras, are then defined, and algebraic completeness is provided for the system. Standard completeness is further established for WUML and IUML in an analogy to that of WNM (Weak nilpotent minimum logic) and NM (Nilpotent minimum logic) in [4].