Fuzzy certainty on fuzzy values
Antonio González; Nicolás Marín; Olga Pons; M. Amparo Vila — 2009
Control and Cybernetics
Fuzzy certainty on fuzzy values
Fuzzy numbers, definitions and properties.
Two different definitions of a Fuzzy number may be found in the literature. Both fulfill Goguen's Fuzzification Principle but are different in nature because of their different starting points. The first one was introduced by Zadeh and has well suited arithmetic and algebraic properties. The second one, introduced by Gantner, Steinlage and Warren, is a good and formal representation of the concept from a topological point of view. The objective of this paper is to analyze...
An elemental processor of fuzzy SQL.
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...
A survey of methods to evaluate quantified sentences.
The evaluation of quantified sentences is used to solve several problems. Most of the methods proposed in the literature are not satisfactory because they do not verify some intuitive properties. In this paper we propose an extension of both possibilistic and probabilistic methods, based on the Sugeno and the Choquet fuzzy integrals respectively, for the evaluation of type II sentences, the most general kind of sentences. These methods verify good properties, and they are shown to be better than...
Systems of possibilistic regressions: a case study in ecological inference.
This work introduces how possibilistic regression can be used in the case of non symmetrical triangular membership functions, building a system of regressions, so that suitable restrictions for each particular problem can be incorporated. We apply this methodology to the problem of ecological inference, in particular to the estimation of the electoral transition matrix. An experimentation with several examples shows the benefits of the new approach.
Client-server arquitecture for fuzzy relational databases.
This paper shows a FRDBMS architecture whose main characteristics are: 1) it is implemented entirely on classical RDBMS just using the resources provided by them, 2) it preserves all the operations and qualities of the host RDBMS and gives them more power adding new capabilities to deal with fuzzy information and 3) it provides a frame to develop applications which exploit fuzzy information.
Using genetic feature selection for optimizing user profiles.
Most of the techniques used in text classification are determined by the occurrences of the words (terms) appearing in the documents, combined with the user feedback over the documents retrieved. However, in our model, the most relevant terms will be selected from a previous fuzzy classification given by the genetic algorithm guided by the user feedback, but using techniques from Machine Learning. A feature selection process is carried out through a Genetic Algorithm in order to find the most discriminatory...
A first approach to the multipurpose relational database server.
In this paper, an architecture and an implementation of a multipurpose relational database server are proposed. This architecture enables classical queries to be executed, deductions to be made, and data mining operations to be performed on fuzzy or classical data. The proposal of this integration is to combine several ways of querying different types of data. In order to achieve this, a combination of existing meta-knowledge bases and new data catalog elements is presented. We also introduce a...
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