Rational Lukasiewicz logic and DMV-algebras

In this paper we present some results on the variety of divisible MV-algebras. Any free divisible MV-algebra is an algebra of continuous piecewise linear functions with rational coefficients. Correspondingly, Rational {\L}ukasiewicz logic is defined.Comment: Paper appeared in 2001. The last section of the paper contains mistake

Generalized continuous and left-continuous t-norms arising from algebraic semantics for fuzzy logics

This paper focuses on the issue of how generalizations of continuous and left-continuous t-norms over linearly ordered sets should be from a logical point of view. Taking into account recent results in the scope of algebraic semantics for fuzzy logics over chains with a monoidal residuated operation, we advocate linearly ordered BL-algebras and MTL-algebras as adequate generalizations of continuous and left-continuous t-norms respectively. In both cases, the underlying basic structure is that of linearly ordered residuated lattices. Although the residuation property is equivalent to left-continuity in t-norms, continuous t-norms have received much more attention due to their simpler structure. We review their complete description in terms of ordinal sums and discuss the problem of describing the structure of their generalization to BL-chains. In particular we show the good behavior of BL-algebras over a finite or complete chain, and discuss the partial knowledge of rational BL-chains. Then we move to the general non-continuous case corresponding to left-continuous t-norms and MTL-chains. The unsolved problem of describing the structure of left-continuous t-norms is presented together with a fistful of construction-decomposition techniques that apply to some distinguished families of t-norms and, finally, we discuss the situation in the general study of MTL-chains as a natural generalization of left-continuous t-norms

Many valued logics: interpretations, representations and applications

2015 - 2016This thesis, as the research activity of the author, is devoted to establish new connections and to strengthen well-established relations between different branches of mathematics, via logic tools. Two main many valued logics, logic of balance and L ukasiewicz logic, are considered; their associated algebraic structures will be studied with different tools and these techniques will be applied in social choice theory and artificial neural networks. The thesis is structured in three parts. Part I The logic of balance, for short Bal(H), is introduced. It is showed: the relation with `-Groups, i.e. lattice ordered abelian groups (Chapter 2); a functional representation (Chapter 3); the algebraic geometry of the variety of `-Groups with constants (Chapter 4). Part II A brief historical introduction of L ukasiewicz logic and its extensions is provided. It is showed: a functional representation via generalized states (Chapter 5); a non-linear model for MV-algebras and a detailed study of it, culminating in a categorical theorem (Chapter 6). Part III Applications to social choice theory and artificial neural network are presented. In particular: preferences will be related to vector lattices and their cones, recalling the relation between polynomials and cones studied in Chapter 4; multilayer perceptrons will be elements of non-linear models introduced in Chapter 6 and networks will take advantages from polynomial completeness, which is studied in Chapter 2. We are going to present: in Sections 1.2 and 1.3 all the considered structures, our approach to them and their (possible) applications; in Section 1.4 a focus on the representation theory for `-Groups and MV-algebras. Note that: algebraic geometry for `-Groups provides a modus operandi which turns out to be useful not only in theoretical field, but also in applications, opening (we hope) new perspectives and intuitions, as we made in this first approach to social theory; non-linear models here presented and their relation to neural networks seem to be very promising, giving both intuitive and formal approach to many concrete problems, for instance degenerative diseases or distorted signals. All these interesting topics will be studied in future works of the author. [edited by author]Questa tesi, come l’attivit`a di ricerca dell’autore, `e dedicata a stabilire nuove connessioni e a rafforzare le relazioni ben consolidate tra diversi settori della matematica, attraverso strumenti logici. Sono considerate due principali logiche a piu` valori, logic of balance e L ukasiewicz logic; le loro strutture algebriche associate verranno studiate con strumenti diversi e queste tecniche saranno applicate nella teoria della scelta sociale e nelle reti neurali artificiali. La tesi `e strutturata in tre parti. Part I Viene introdotta la Logic of balance. Viene mostrato: la relazione con `-Groups, gruppi abeliani ordinati reticolarmente (Chapter 2); una rappresentazione funzionale (Chapter 3); geometria algebrica della variet`a degli `-Groups con costanti (Chapter 4). Part II Viene fornita una breve introduzione storica della logica di L ukasiewicz e delle sue estensioni. Viene mostrato: una rappresentazione funzionale tramite stati generalizzati (Chapter 5); Un modello non lineare per le MV-algebre e uno studio dettagliato di esso, culminando in un teorema categoriale (Chapter 6). Part III Sono presentate applicazioni alla teoria delle scelte sociali e delle rete neurali artificiali. In particolare: le preferenze saranno correlate ai reticoli vettoriali e ai loro coni, richiamando la relazione tra polinomi e coni studiati nel Capitolo 4; I multilayer perceptrons saranno elementi di modelli non lineari introdotti nel Capitolo 6 e le reti prenderanno vantaggi dalla completezza polinomiale, studiata nel Capitolo 2. La geometria algebrica per gli `-Groups fornisce un modus operandi che risulta utile non solo nel campo teorico, ma anche nelle applicazioni, aprendo (speriamo) nuove prospettive e intuizioni, come abbiamo fatto in questo primo approccio alla teoria sociale; I modelli non lineari qui presentati e la loro relazione con le reti neurali sembrano molto promettenti, offrendo un approccio intuitivo e formale a molti problemi concreti, ad esempio malattie degenerative o segnali distorti. Tutti questi argomenti saranno oggetto di studio in opere future dell’autore. [a cura dell'autore]XV n.s. (XXIX

Fitting aggregation operators to data

Theoretical advances in modelling aggregation of information produced a wide range of aggregation operators, applicable to almost every practical problem. The most important classes of aggregation operators include triangular norms, uninorms, generalised means and OWA operators.With such a variety, an important practical problem has emerged: how to fit the parameters/ weights of these families of aggregation operators to observed data? How to estimate quantitatively whether a given class of operators is suitable as a model in a given practical setting? Aggregation operators are rather special classes of functions, and thus they require specialised regression techniques, which would enforce important theoretical properties, like commutativity or associativity. My presentation will address this issue in detail, and will discuss various regression methods applicable specifically to t-norms, uninorms and generalised means. I will also demonstrate software implementing these regression techniques, which would allow practitioners to paste their data and obtain optimal parameters of the chosen family of operators.<br /

Syntactic characterizations of classes of first-order structures in mathematical fuzzy logic

This paper is a contribution to graded model theory, in the context of mathematical fuzzy logic. We study characterizations of classes of graded structures in terms of the syntactic form of their first-order axiomatization. We focus on classes given by universal and universal-existential sentences. In particular, we prove two amalgamation results using the technique of diagrams in the setting of structures valued on a finite MTL-algebra, from which analogues of the Los--Tarski and the Chang--Los--Suszko preservation theorems follow

Intelligent Systems

This book is dedicated to intelligent systems of broad-spectrum application, such as personal and social biosafety or use of intelligent sensory micro-nanosystems such as "e-nose", "e-tongue" and "e-eye". In addition to that, effective acquiring information, knowledge management and improved knowledge transfer in any media, as well as modeling its information content using meta-and hyper heuristics and semantic reasoning all benefit from the systems covered in this book. Intelligent systems can also be applied in education and generating the intelligent distributed eLearning architecture, as well as in a large number of technical fields, such as industrial design, manufacturing and utilization, e.g., in precision agriculture, cartography, electric power distribution systems, intelligent building management systems, drilling operations etc. Furthermore, decision making using fuzzy logic models, computational recognition of comprehension uncertainty and the joint synthesis of goals and means of intelligent behavior biosystems, as well as diagnostic and human support in the healthcare environment have also been made easier

Fuzzy Sets, Fuzzy Logic and Their Applications

The present book contains 20 articles collected from amongst the 53 total submitted manuscripts for the Special Issue “Fuzzy Sets, Fuzzy Loigic and Their Applications” of the MDPI journal Mathematics. The articles, which appear in the book in the series in which they were accepted, published in Volumes 7 (2019) and 8 (2020) of the journal, cover a wide range of topics connected to the theory and applications of fuzzy systems and their extensions and generalizations. This range includes, among others, management of the uncertainty in a fuzzy environment; fuzzy assessment methods of human-machine performance; fuzzy graphs; fuzzy topological and convergence spaces; bipolar fuzzy relations; type-2 fuzzy; and intuitionistic, interval-valued, complex, picture, and Pythagorean fuzzy sets, soft sets and algebras, etc. The applications presented are oriented to finance, fuzzy analytic hierarchy, green supply chain industries, smart health practice, and hotel selection. This wide range of topics makes the book interesting for all those working in the wider area of Fuzzy sets and systems and of fuzzy logic and for those who have the proper mathematical background who wish to become familiar with recent advances in fuzzy mathematics, which has entered to almost all sectors of human life and activity