1994, Vol. I, Núm. 3
http://hdl.handle.net/2099/1493
ESTYLF'942021-10-23T13:27:31ZEditorial [4th. Congress of the Spanish Association of Fuzzy Logic and Technology: Blanes, 1994: selection of extended versions]
http://hdl.handle.net/2099/3671
Editorial [4th. Congress of the Spanish Association of Fuzzy Logic and Technology: Blanes, 1994: selection of extended versions]
Verdegay, José Luis; Esteva Massaguer, Francesc
2007-10-15T09:44:46ZVerdegay, José LuisEsteva Massaguer, FrancescMax-Min fuzzy neural networks for solving relational equations
http://hdl.handle.net/2099/2461
Max-Min fuzzy neural networks for solving relational equations
Blanco Morón, Armando; Delgado Calvo-Flores, Miguel; Requena Ramos, Ignacio
The Relational Equations approach is one of the most usual ones for describing (Fuzzy) Systems and in most cases, it is the final expression for other descriptions. This is why the identification of Relational Equations from a set of examples has received considerable atention in the specialized literature. This paper is devoted to this topic, more specifically to the topic of max-min neural networks for identification. Three methods of "learning" Fuzzy Systems are developed by combining the most desirable properties of two existing ones: Sayto-Mukaidono's technique and the so called "smoothed derivative" technique.
2007-03-05T17:51:43ZBlanco Morón, ArmandoDelgado Calvo-Flores, MiguelRequena Ramos, IgnacioThe Relational Equations approach is one of the most usual ones for describing (Fuzzy) Systems and in most cases, it is the final expression for other descriptions. This is why the identification of Relational Equations from a set of examples has received considerable atention in the specialized literature. This paper is devoted to this topic, more specifically to the topic of max-min neural networks for identification. Three methods of "learning" Fuzzy Systems are developed by combining the most desirable properties of two existing ones: Sayto-Mukaidono's technique and the so called "smoothed derivative" technique.On fuzzy temporal constraint networks
http://hdl.handle.net/2099/2460
On fuzzy temporal constraint networks
Vila, Lluís; Godo Lacasa, Lluís
Temporal Constraint Networks are a well-defined, natural and efficient formalism for representing temporal knowledge based on metric temporal constraints. They support the representation of both metric and some qualitative temporal relations and are provided with efficient algorithms based on CSP techniques. Recently, a generalization based on fuzzy sets has been proposed in order to cope with vagueness in temporal relations. In this paper we generalize some earlier definitions for Fuzzy Temporal Constraint Networks, we identify and define "interesting" queries in a fuzzy temporal constraint network, an explore a method for efficiently computing them in a specific case. Further analysis of some measures on possibility distributions turns out to be fundamental in order to precisely determine some of these queries. We discuss the advantages and shortcomings of various choices and propose specific alternatives which satisfactorily avoid the problems of previous proposals. The results presented in this paper can be useful in the design of a system for temporal reasoning under uncertainty. for instance, we have applied them to defining a possibilistic temporal logic where approximate and temporal representation and reasoning are consistently combined.
2007-03-05T17:49:02ZVila, LluísGodo Lacasa, LluísTemporal Constraint Networks are a well-defined, natural and efficient formalism for representing temporal knowledge based on metric temporal constraints. They support the representation of both metric and some qualitative temporal relations and are provided with efficient algorithms based on CSP techniques. Recently, a generalization based on fuzzy sets has been proposed in order to cope with vagueness in temporal relations. In this paper we generalize some earlier definitions for Fuzzy Temporal Constraint Networks, we identify and define "interesting" queries in a fuzzy temporal constraint network, an explore a method for efficiently computing them in a specific case. Further analysis of some measures on possibility distributions turns out to be fundamental in order to precisely determine some of these queries. We discuss the advantages and shortcomings of various choices and propose specific alternatives which satisfactorily avoid the problems of previous proposals. The results presented in this paper can be useful in the design of a system for temporal reasoning under uncertainty. for instance, we have applied them to defining a possibilistic temporal logic where approximate and temporal representation and reasoning are consistently combined.On the identity of fuzzy material conditionals
http://hdl.handle.net/2099/2459
On the identity of fuzzy material conditionals
Trillas i Gay, Enric; Cubillo Villanueva, Susana; Rodríguez de Soto, Adolfo
Given $\mu , \; \eta :X \rightarrow [0,1]$ we study when the equality $I_{\mu
}^{T}=I_{\eta }^{T}$ holds, $T$ being a continuous t-norm, and
$I_{\theta }^{T}$ the elemental preorder:\\
\[ I_{\theta }^{T}(y/x) = sup \{z\; ; \; T(\theta (x),z)\leq \theta (y) \}.
\]
2007-03-05T17:43:18ZTrillas i Gay, EnricCubillo Villanueva, SusanaRodríguez de Soto, AdolfoGiven $\mu , \; \eta :X \rightarrow [0,1]$ we study when the equality $I_{\mu
}^{T}=I_{\eta }^{T}$ holds, $T$ being a continuous t-norm, and
$I_{\theta }^{T}$ the elemental preorder:\\
\[ I_{\theta }^{T}(y/x) = sup \{z\; ; \; T(\theta (x),z)\leq \theta (y) \}.
\]Systolic architectures for fuzzy processing and their simulation
http://hdl.handle.net/2099/2458
Systolic architectures for fuzzy processing and their simulation
Salvador, Luis de; García, Marcos; Gutiérrez, Julio
This paper details the study of systolic architectures for fuzzy rules processing made at the Hardware and Advanced Control Laboratory - INTA. The theoretical basis of these architectures is described and analysed. Likewise, the resultant schematics are simulated using a hardware description language (VHDL) with standard cells from ES2. This gives us a very accurate assessment of their real performance. In this way we can detect the inherent shortcomings in this class of systems and we outline several ways of overcoming then.
2007-03-05T17:40:24ZSalvador, Luis deGarcía, MarcosGutiérrez, JulioThis paper details the study of systolic architectures for fuzzy rules processing made at the Hardware and Advanced Control Laboratory - INTA. The theoretical basis of these architectures is described and analysed. Likewise, the resultant schematics are simulated using a hardware description language (VHDL) with standard cells from ES2. This gives us a very accurate assessment of their real performance. In this way we can detect the inherent shortcomings in this class of systems and we outline several ways of overcoming then.An elemental processor of fuzzy SQL
http://hdl.handle.net/2099/2457
An elemental processor of fuzzy SQL
Medina Rodríguez, Juan Miguel; Pons Capote, Olga; Vila Miranda, María Amparo
This paper reports an alternative for implementing an SQL fuzzy extension on a Fuzzy Relational Database System. This proposal tries to build an FSQL processor using representation and manipulation mechanisms offered by the RDBMS which operates as a host. For this purpose, we are based our work on the formulation of a theoretical model of Fuzzy Relational Databases, on the adoption of a scheme for the representation and implementation of fuzzy information on conventional RDBMS, and on the tools for the development of applications available in the host RDBMS. Finally, the FSQL processor is able to translate sentences formulated in FSQL into classical SQL sentences executed directly by the RDBMS adopted as host.
2007-03-05T17:36:05ZMedina Rodríguez, Juan MiguelPons Capote, OlgaVila Miranda, María AmparoThis paper reports an alternative for implementing an SQL fuzzy extension on a Fuzzy Relational Database System. This proposal tries to build an FSQL processor using representation and manipulation mechanisms offered by the RDBMS which operates as a host. For this purpose, we are based our work on the formulation of a theoretical model of Fuzzy Relational Databases, on the adoption of a scheme for the representation and implementation of fuzzy information on conventional RDBMS, and on the tools for the development of applications available in the host RDBMS. Finally, the FSQL processor is able to translate sentences formulated in FSQL into classical SQL sentences executed directly by the RDBMS adopted as host.Fractal negations
http://hdl.handle.net/2099/2456
Fractal negations
Mayor Forteza, Gaspar; Calvo Sánchez, Tomasa
From the concept of attractor of a family of contractive affine transformations in the Euclidean plane R², we study the fractality property of the De Rham function and other singular functions wich derive from it. In particular, we show as fractals the strong negations called k-negations.
2007-03-05T17:33:35ZMayor Forteza, GasparCalvo Sánchez, TomasaFrom the concept of attractor of a family of contractive affine transformations in the Euclidean plane R², we study the fractality property of the De Rham function and other singular functions wich derive from it. In particular, we show as fractals the strong negations called k-negations.An approach to fuzzy temporal reasoning in medicine
http://hdl.handle.net/2099/2455
An approach to fuzzy temporal reasoning in medicine
Marín, R.; Barro Ameneiro, D. Senén; Palacios, F.; Ruiz, R.; Martín, F.
In this work we propose an approach for the application of a fuzzy temporal constraint model to intelligent patient monitoring tasks. After analyzing the requirements of the domain, we describe the approach that was followed in order to represent temporal information and solve queries on temporal relations. These processes require the cooperation of a temporal specialist with the domain reasoning mechanisms. The integration solution presented here corresponds to a stage of the implementation of FRESH, a tool for the development of intelligent monitoring systems for dynamic environments.
2007-03-05T17:29:59ZMarín, R.Barro Ameneiro, D. SenénPalacios, F.Ruiz, R.Martín, F.In this work we propose an approach for the application of a fuzzy temporal constraint model to intelligent patient monitoring tasks. After analyzing the requirements of the domain, we describe the approach that was followed in order to represent temporal information and solve queries on temporal relations. These processes require the cooperation of a temporal specialist with the domain reasoning mechanisms. The integration solution presented here corresponds to a stage of the implementation of FRESH, a tool for the development of intelligent monitoring systems for dynamic environments.A model of decision with lingustic knowledge
http://hdl.handle.net/2099/2454
A model of decision with lingustic knowledge
Lamata, M.T.
The aim of this paper is to develop a new aggregating method for the decision problem in which the possible values of rewards are known in linguistic terms. We show new operators for solving this problem, as well as the way in which OWA operators provide us with an adequate framework for representing the optimism degree of the decision maker in case we have no information about the real state.
2007-03-05T17:26:46ZLamata, M.T.The aim of this paper is to develop a new aggregating method for the decision problem in which the possible values of rewards are known in linguistic terms. We show new operators for solving this problem, as well as the way in which OWA operators provide us with an adequate framework for representing the optimism degree of the decision maker in case we have no information about the real state.The use of fuzzy connectives to design real-coded genetic algorithms
http://hdl.handle.net/2099/2453
The use of fuzzy connectives to design real-coded genetic algorithms
Herrera Triguero, Francisco; Lozano, M.; Verdegay, José Luis
Genetic algorithms are adaptive methods that use principles inspired by natural population genetics to evolve solutions to search and optimization problems. Genetic algorithms process a population of search space solutions with three operations: selection, crossover and mutation. A great problem in the use of genetic algorithms is premature convergence; the search becomes trapped in a local optimum before the global optimum is found. Fuzzy logic techniques may be used for solving this problem.
This paper presents one of them: the design of crossover operators for real-coded genetic algorithms using fuzzy connectives and its extension based on the use of parameterized fuzzy connectives as tools for tackling the premature convergence problem.
2007-03-05T17:24:14ZHerrera Triguero, FranciscoLozano, M.Verdegay, José LuisGenetic algorithms are adaptive methods that use principles inspired by natural population genetics to evolve solutions to search and optimization problems. Genetic algorithms process a population of search space solutions with three operations: selection, crossover and mutation. A great problem in the use of genetic algorithms is premature convergence; the search becomes trapped in a local optimum before the global optimum is found. Fuzzy logic techniques may be used for solving this problem.
This paper presents one of them: the design of crossover operators for real-coded genetic algorithms using fuzzy connectives and its extension based on the use of parameterized fuzzy connectives as tools for tackling the premature convergence problem.