Periodic Behaviors of Quantum Cellular Automata (2007)
Inokuchi, Shuichi, Mizoguchi, Yoshihiro, Lee, Hyen Yeal, Kawahara, Yasuo, 井口, 修一, 溝口, 佳寛, ...
Kyushu University 21st Century COE Program Development of Dynamic Mathematics with High Functionality
TARSKI’S FIXED POINT THEOREM IN DEDEKIND CATEGORIES (2006)
Kawahara, Yasuo, Honda, Kazumasa, 河原, 康雄, 本多, 和正
Tarski's fixed point theorem for complete lattices is a fundamental theorem in lattice theory and is very useful for computer science applications. This paper will show a general result in Dedekind...
TREE EXPRESSIONS AND THEIR PRODUCT FORMULA (2003)
Inokuchi, Shuichi, Kawahara, Yasuo, 井口, 修一, 河原, 康雄
In this paper we propose tree expressions which represent transition diagrams of finite transition systems by algebraic formulas. We consider the cartesian product of transition systems and present a...
Demonic orders and quasi-totality in Dedekind categories (2002)
Kawahara, Yasuo, Okuma, Hitomi, 河原, 康雄, 大隈, ひとみ
This paper presents a proof of the associativity of demonic composition of relations in Dedekind categories and shows that the demonic composition is monotonic with respect to two demonic orderings...
INFORMATIONAL REPRESENTABILITY FOR CONTEXTS IN DEDEKIND CATEGORIES (2002)
Okuma, Hitomi, MacCaull, Wendy, Kawahara, Yasuo, 大隈, ひとみ, 河原, 康雄
This paper presents a categorical formulation for association rules in information systems. MacCaull developed a tableaux style calculus that is sound and complete for the implication problem for...
Informational representability for contexts in Dedekind categories (2002)
Okuma, Hitomi, MacCaull, Wendy, Kawahara, Yasuo, 大隈, ひとみ, 河原, 康雄
This paper presents a categorical formulation for association rules in information systems. MacCaull developed a tableaux style calculus that is sound and complete for the implication problem for...
CRISPNESS IN DEDEKIND CATEGORIES (2001)
Kawahara, Yasuo, Furusawa, Hitoshi, 河原, 康雄, 古澤, 仁
This paper studies notions of scalar relations and crispness of relations in terms of Dedekind categories. It is well-known that a category of $ L $-relations in the sense of Goguen is a Dedekind...
Groups are one of the most fundamental notions in mathematics. This paper provides a foundation of group theory in allegories. Almost all results in the paper can be applied to theory of fuzzy groups.
RELATIONAL ASPECTS OF RELATIONAL DATABASE DEPENDENCIES (2000)
Okuma, Hitomi, Kawahara, Yasuo, 大隈, ひとみ, 河原, 康雄
This paper presents a relational treatment of inference rules for functional and multivalued dependencies in relational databases, to show the soundness and the completeness of the inference rules in...
A small final coalgebra theorem (2000)
Kawahara, Yasuo, Mori, Masao, 河原, 康雄, 森, 雅生
This paper presents an elementary and self-contained proof of an existence theorem of final coalgebras for endofunctors on the category of sets and functions.
Hennessy-Milner Properties in Schröder Categories (2000)
Kawahara, Yasuo, Mori, Masao, 森, 雅生, 河原, 康雄
Proceedings of The Fouth International Symposium on Economic Informatics, pp 988--994, Bucharest, 6--9 May 1999．
Hennessy-Milner Properties in Schröder Categories (1999)
KAWAHARA, Yasuo, MORI, Masao, 河原, 康雄, 森, 雅生
This note presents a relational formalization of Hennessy-Milner properties in Schröder categories.
Tree Expressions and Their Product Formula (1999)
Inokuchi, Shuichi, KAWAHARA, Yasuo, 井口, 修一, 河原, 康雄
In this paper we propose tree expressions which express transition diagrams of finite dynamical systems by algebraic formula. And we consider the cartesian product of dynamical systems and get the...
Lattices in Dedekind Categories (1999)
Lattice structures are fundamental and useful in mathematics and theoretical computer science. It is well-known that lattice structures with meet and join operations satisfying associative,...
Crispness and Representation Theorem in Dedekind Categories (1997)
Kawahara, Yasuo, Furusawa, Hitoshi, 河原, 康雄, 古澤, 仁
This paper studies notions of scalar relations and crispness of relations.
Mori, Masao, Kawahara, Yasuo, 森, 雅生, 河原, 康雄
This paper studies a fuzzy graph rewriting with single pushout approach from a viewpoint of fuzzy relational calculus. Two possible kinds of matchings for fuzzy graph rewritings are given, namely, a...
Mori, Masao, Kawahara, Yasuo, 森, 雅生, 河原, 康雄
Proceedings of the Third International Seminar on The Use of Relational Methods in Computer Science, Hammamet, Tunisia, January 1997．
Categorical Representation Theorems of Fuzzy Relations (1996)
Kawahara, Yasuo, Furusawa, Hitoshi, Mori, Masao, 河原, 康雄, 古澤, 仁, 森, 雅生
his paper provides a notion of Zadeh categories as a categorical structure formed by fuzzy relations with sup-min composition, and proves two representation theorems for Dedekind categories (relation...
Categorical representation theorem of fuzzy relations (1996)
Kawahara, Yasuo, Furusawa, Hitoshi, Mori, Masao, 河原, 康雄, 古澤, 仁, 森, 雅生
his paper provides a notion of Zadeh categories as a categorical structure formed by fuzzy relations with sup-min composition, and proves two representation theorems for Dedekind categories (relation...
TRANSITION DIAGRAMS OF FINITE CELLULAR AUTOMATA (1996)
Lee, Hyen Yeal, Kawahara, Yasuo, 李, 鉉列, 河原, 康雄
This paper provides some simple recursive formulas generating transition diagrams of finite cellular automata with triplet local transition functions.
Transition Diagrams of Finite Cellular Automata (1995)
Lee, Hyen Yeal, Kawahara, Yasuo, 李, 鉉列, 河原, 康雄
This paper provies some simple recursive formulas generating transition diagrams of finite cellular automata with triplet local transition functions.
Period Lengths of Cellular Automata cam - 90 with Memory (1995)
Kawahara, Yasuo, Lee, Hyen Yeal, 河原, 康雄, 李, 鉉列
Cellular automata ca -90 have states 0 and I , and their dynamics, driven by the local transition rule 90, can be simply represented with Laurent polynomials over a finite field $ F2 = \left{0, 1...
This article presents a relational formalization of axiomatic set theory, including so-called ZFC and the anti-foundation axiom (AFA) due to P. Aczel. The relational frame-work of set theory provides...
An Algebraic Formalization of Fuzzy Relations (1995)
Kawahara, Yasuo, Furusawa, Hitoshi, 河原, 康雄, 古澤, 仁
This paper provides an algebraic formalization of mathematical structures formed by fuzzy relations with sup-min composition. A simple proof of a representation theorem for Boolean relation algebras...
A Small Final Coalgebra Theorem (1994)
Kawahara, Yasuo, Mori, Masao, 河原, 康雄, 森, 雅生
This paper presents an elementary and self-contained proof of an existence theorem of final coalgebras for endofunctors on the category of sets and functions.
Period lengths of cellular automata on square lattices with Rule 90 (1992)
Kawahara, Yasuo, Kumamoto, Satoru, Mizoguchi, Yoshihiro, Nomi, Masaya, Otsuka, Hiroshi, Shoudai, Takayoshi, ...
This paper studies two-dimensional cellular automatma $ca-90(m,n)$ having states 0 and 1 and working on a square lattice of size $(m-1) \times (n-1)$. All their dynamics, driven by the local...
ON DYNAMICAL BEHAVIORS OF CELLULAR AUTOMATA CA-60 (1992)
Lee, Hyen Yeal, Kawahara, Yasuo, 李, 鉉列, 河原, 康雄
Dynamical behaviors of som e particular cases of cellular automata $ ca-60(m) $ and $ ca-60(m, n) $ will be completely shown by representing their configurations as truncated polynomials.
Relational Graph Rewritings (1991)
Mizoguchi, Yoshihiro, Kawahara, Yasuo, 溝口, 佳寛, 河原, 康雄
to appear in Theoretical Computer Science A
This paper concerns the fundamentals on a new type of finite linear cellular automata with so-called local transition rule 90. Some problems about a few characteristic numbers associated with these...
APPLICATIONS OF RELATIONAL CALCULUS TO COMPUTER MATHEMATICS (1988)
Relational calculus is applicable to some aspects of computer mathematics such as representing non-determinism of automata theory and theory of algorithms. In this note the author gives other proofs...
A SYMBOLIC CALCULUS OF REGULAR EXPRESSIONS (1987)
Mizoguchi, Yoshihiro, Otsuka, Hiroshi, Kawahara, Yasuo, 溝口, 佳寛, 大塚, 寛, 河原, 康雄
To implement Ginzburg's equality check procedure for regular expressions by using personal computers, we propose a new and more efficient axiom system consisting of an axiom and inference rules...
CATEGORICAL RELATIONAL DATABASE MODELS (1984)
A category of relational models and its quotient category are defined and their basic properties are discussed. Moreover a categorical join dependency and a category of adjoint models, which dualize...
Minimal Realization Theory for Tree Process Machines in Monoidal Categories (1980)
Kawahara, Yasuo, Yamaguchi, Meiri, 河原, 康雄
Dedicated to Professor Tatsuji Kudo on his sixtieth birthday