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An application of the theory of intuitionistic fuzzy multigraphs.

Krassimir Atanassov, B. K. Papadopoulos, A. Syropoulos (2004)

Mathware and Soft Computing

In a recent paper by one of the authors it has been shown that there is a relationship between algebraic structures and labeled transition systems. Indeed, it has been shown that an algebraic structures can be viewed as labeled transition systems, which can also be viewed as multigraphs. In this paper, we extend this work by providing an estimation of the transition possibilities between vertices that are connected with multiarcs.

An attractive class of bipartite graphs

Rodica Boliac, Vadim Lozin (2001)

Discussiones Mathematicae Graph Theory

In this paper we propose a structural characterization for a class of bipartite graphs defined by two forbidden induced subgraphs. We show that the obtained characterization leads to polynomial-time algorithms for several problems that are NP-hard in general bipartite graphs.

An exercise on Fibonacci representations

Jean Berstel (2001)

RAIRO - Theoretical Informatics and Applications - Informatique Théorique et Applications

We give a partial answer to a question of Carlitz asking for a closed formula for the number of distinct representations of an integer in the Fibonacci base.

An Exercise on Fibonacci Representations

Jean Berstel (2010)

RAIRO - Theoretical Informatics and Applications

We give a partial answer to a question of Carlitz asking for a closed formula for the number of distinct representations of an integer in the Fibonacci base.

Analyzing sets of phylogenetic trees using metrics

Damian Bogdanowicz (2011)

Applicationes Mathematicae

The reconstruction of evolutionary trees is one of the primary objectives in phylogenetics. Such a tree represents historical evolutionary relationships between different species or organisms. Tree comparisons are used for multiple purposes, from unveiling the history of species to deciphering evolutionary associations among organisms and geographical areas. In this paper, we describe a general method for comparing phylogenetic trees and give some basic properties of the Matching Split metric, which...

Antiassociative groupoids

Milton Braitt, David Hobby, Donald Silberger (2017)

Mathematica Bohemica

Given a groupoid G , , and k 3 , we say that G is antiassociative if an only if for all x 1 , x 2 , x 3 G , ( x 1 x 2 ) x 3 and x 1 ( x 2 x 3 ) are never equal. Generalizing this, G , is k -antiassociative if and only if for all x 1 , x 2 , ... , x k G , any two distinct expressions made by putting parentheses in x 1 x 2 x 3 x k are never equal. We prove that for every k 3 , there exist finite groupoids that are k -antiassociative. We then generalize this, investigating when other pairs of groupoid terms can be made never equal.

Approximations diophantiennes des nombres sturmiens

Martine Queffélec (2002)

Journal de théorie des nombres de Bordeaux

Nous établissons pour tout nombre sturmien (de développement dyadique sturmien) des propriétés d'approximation diophantienne très précises, ne dépendant que de l'angle de la suite sturmienne, généralisant ainsi des travaux antérieurs de Ferenczi-Mauduit et Bullett-Sentenac.

Arithmetics in numeration systems with negative quadratic base

Zuzana Masáková, Tomáš Vávra (2011)

Kybernetika

We consider positional numeration system with negative base - β , as introduced by Ito and Sadahiro. In particular, we focus on arithmetical properties of such systems when β is a quadratic Pisot number. We study a class of roots β > 1 of polynomials x 2 - m x - n , m n 1 , and show that in this case the set Fin ( - β ) of finite ( - β ) -expansions is closed under addition, although it is not closed under subtraction. A particular example is β = τ = 1 2 ( 1 + 5 ) , the golden ratio. For such β , we determine the exact bound on the number of fractional digits...

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