Linguistic modifiers and imprecise categories

Abstract

We study knowledge-based systems using fuzzy logic and we focus on the representation of knowledge through linguistic variables characterized by means of fuzzy qualifications or labels. We study a new form of linguistic modifier which slightly changes the qualifications through either a weakening or a reinforcement. This modifier is an important tool for approximate reasoning for two reasons: its use is equivalent to a simple rule given in a symbolic way, avoiding computations and compatible with the fuzzy logic; it enables gradual rules to be used in the context of deduction rules and corresponds to the idea of gradual changing of category.

On four noncommutative fuzzy connectives and their axiomatization

“…For instance, "very cheap" is more restrictive than "cheap" and "fairly high" is less demanding than "high". The meaning of the predicate "mod P" (where "mod" is a modifier) may be defined in a compositional way and different approaches have been advocated, among which: mod P (x) = ( P (x)) n (see [4]). …”

The Choquet Integral Applied to Ranking Therapies in Radiation Cystitis

“…We now wish to divide the linguistic terms into three groups recognized as a left group, a middle group and a right group. Albeit the trials of generating membership functions with modifiers for linguistic terms were already accomplished [1,6], we propose the authors' own procedure of adopting parametric sfunctions whose derivations can be followed in [9][10][11].…”

Quality measures for fuzzy predicates in conjunctive and disjunctive normal forms

“…Each fuzzy variable can be associated with adverbs called hedges, which are terms that modify the shape of fuzzy sets. Hedges have two primary behaviors: reinforcement, such as "very", or weakening, such as "little" (Bouchon-Meunier & Yao, 1992).…”