A note on the admissibility of the centroid-based preorder for fuzzy numbers

Fuzzy numbers are defined by a membership function, which presents a challenge in comparing and ranking them. The centroid is a commonly used ranking tool as it provides a crisp representative value for a fuzzy number. However, while the centroid induces a total preorder, it lacks antisymmetry, whic...

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Detalles Bibliográficos
Autores: García-Zamora, Diego, Roldán López de Hierro, Antonio Francisco, Bustince Sola, Humberto
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2025
País:España
Institución:Universidad Pública de Navarra
Repositorio:Academica-e. Repositorio Institucional de la Universidad Pública de Navarra
OAI Identifier:oai:dnet:academicae__::4cd604cf4ca1975ed1b4cd2260bab5c0
Acceso en línea:https://hdl.handle.net/2454/56739
Access Level:acceso abierto
Palabra clave:Fuzzy numbers
Centroid
Admissible orders
Interval type-2 fuzzy sets
Trapezoidal fuzzy number
Descripción
Sumario:Fuzzy numbers are defined by a membership function, which presents a challenge in comparing and ranking them. The centroid is a commonly used ranking tool as it provides a crisp representative value for a fuzzy number. However, while the centroid induces a total preorder, it lacks antisymmetry, which can lead to indistinguishable rankings for different fuzzy numbers. This limitation has led to the development of admissible orders, which ensure a total order relation that refines the Klir–Yuan partial order. In this paper, we explore the admissibility of the centroid-based preorder. We begin by deriving general formulas for computing the centroid using Riemannian and Lebesguian integrals. Through examples, we show that the centroid does not generally form an admissible preorder, even for fuzzy numbers with continuous membership functions. We then focus on trapezoidal fuzzy numbers and prove that, within this class, the centroid defines an admissible preorder. Finally, we extend this result to interval type 2 fuzzy numbers, demonstrating that the centroid also induces an admissible preorder when the upper and lower membership functions are trapezoidal fuzzy numbers.