March 2019

Journal paper accepted

N. Madrid and M. Ojeda-Aciego. Functional degrees of inclusion and similarity between L-fuzzy sets. Fuzzy Sets and Systems 390:1-22, 2020
ABSTRACT Inclusion is one of the most basic relations between sets. In this paper, we show how to represent the degree of inclusion between two L-fuzzy sets via a function. Specifically, such a function determines the minimal modifications needed in an L-fuzzy set to be included (in Zadeh's sense) into another. To reach such a goal, firstly we present the notion of f-inclusion, which defines a family of crisp binary relations between L-fuzzy sets that are used as indexes of inclusion and, subsequently, we define the φ-degree of inclusion as the most suitable f-inclusion under certain criterion. In addition, we also present three φ-degrees of similarity definable from the φ-degree of inclusion. We show that the φ-degree of inclusion and the φ-degrees of similarities satisfy versions of many common axioms usually required for measures of inclusion and similarity in the literature.

Conference paper accepted

Inma P. Cabrera, P. Cordero, E. Muñoz and M. Ojeda-Aciego. A relational extension of Galois Connections. Intl Conf on Formal Concept Analysis (ICFCA), Frankfurt, 2019.

ABSTRACT In this paper, we focus on a twofold relational generalization of the notion of Galois connection. It is twofold because it is defined between sets endowed with arbitrary transitive relations and, moreover, both components of the connection are relations as well. Specifically, we introduce the notion of relational Galois connection between two transitive digraphs, study some of its properties and its relationship with other existing approaches in the literature.