http://hdl.handle.net/2099/1488 Search the Channel search http://upcommons.upc.edu/revistes/simple-search http://hdl.handle.net/2099/1738 Title: Fuzzy morphological operators in image processing<br/><br/>Authors: Burillo López, Pedro; Frago Paños, Noé; Fuentes-González, Ramón<br/><br/>Abstract: First of all, in this paper we propose a family of fuzzy implication operators, which the generalised Luckasiewicz's one, and to analyse the impacts of Smets and Magrez properties on these operators. The result of this approach will be a characterisation of a proposed family of inclusion grade operators (in Bandler and Kohout's manner) that satisfies the axioms of Divyendu and Dogherty. Second, we propose a method to define fuzzy morphological operators (erosions and dilations). A family of fuzzy implication operators and the inclusion grade are the basis for this method. http://hdl.handle.net/2099/11013 Title: Mixed integer programming, general concept inclusions and fuzzy description logics<br/><br/>Authors: Straccia, U.; Bobillo, F.<br/><br/>Abstract: Fuzzy Description Logics (fuzzy DLs) have been proposed as a language todescribe structured knowledge with vague concepts. In [19], a solution basedon Mixed Integer Linear Programming has been proposed to deal with fuzzyDLs under Lukasiewicz semantics in which typical membership functions,such as triangular and trapezoidal functions, can be explicitly represented inthe language.A major theoretical and computational limitation so far is the inability todeal with General Concept Inclusions (GCIs), which is an important featureof classical DLs. In this paper, we address this issue and develop a calculusfor fuzzy DLs with GCIs under various semantics: classical logic, \Zadehsemantics", and Lukasiewicz logic. http://hdl.handle.net/2099/11012 Title: Advanced inference in fuzzy systems by rule base compression<br/><br/>Authors: Gegov, N.; Gobalakrishnan, N.<br/><br/>Abstract: This paper describes a method for rule base compression of fuzzy systems. The method compresses a fuzzy system with an arbitrarily large number of rules into a smaller fuzzy system by removing the redundancy in the fuzzy rule base. As a result of this compression, the number of on-line operations during the fuzzy inference process is significantly reduced without compromising the solution. This rule base compression method outperforms significantly other known methods for fuzzy rule base reduction. http://hdl.handle.net/2099/10936 Title: Approximation of proximities by aggregating T-indistinguishability operators<br/><br/>Authors: Garmendia, L.; Recasens, J.<br/><br/>Abstract: For a continuous Archimedean t-norm T a method to approximate a proximity relation R (i.e. a reflexive and symmetric fuzzy relation) by a T-transitive one is provided.It consists of aggregating the transitive closure R of R with a (maximal) T-transitive relation B contained in R using a suitable weighted quasi-arithmetic mean to maximize the similarity or minimize the distance to R. http://hdl.handle.net/2099/10935 Title: Fuzzy short-run control charts<br/><br/>Authors: Fonseca, D. J.; Elam, M. E.; Tibbs, L.<br/><br/>Abstract: Statistical control charts are useful tools in monitoring the state of a manufacturing process. Control charts are used to plot process data and compare it to the limits set for the process. Points plotting outside these limits indicate an out-of-control condition. Standard control charting procedures, however, are limited in that they cannot take into account the case when data is of a fuzzy nature. Another limitation of standard charting methods is when the data produced by the process is short-run data. Often, the situation where the data is short-run occurs in conjunction with data that is considered fuzzy. This paper dicusses the development of a fuzzy control chartting technique, called short-Run α-cut p Control Chart, to account for fuzzy data in a short-run situation. The developed chart parameters accounted for the fuzzy nature of the data in a short-run situation. The parameters were validated by comparing the false alarm rates for various combinations of subgroup numbers (m) and subgroup sizes (n). It was shown that for every combination of m and n, the Short-Run α-cut p Control Chart limits produced a lower false alarm rate than that of the standard fuzzy α-cut control chart. http://hdl.handle.net/2099/10934 Title: Evolutionary design of digital circuits using improved multi expression programming (IMEP)<br/><br/>Authors: Hadjam, F.Z.; Moraga, C.; Rahmouni, M.K.<br/><br/>Abstract: Evolutionary Electronics is a research area which involves application of Evolutionary computation in the domain of electronics. It is seen as a quite promising alternative to overcome some drawbacks of conventional design. In this paper we propose a methodology based on an Improved Multi Expression Programming (IMEP) to automate the design of combinational logic circuits in which we aim to reach the functionality and to minimize the total number of used gates. MEP is a genetic Programming variant that uses linear chromosomes for solution encoding. A unique MEP feature is its ability of encoding multiples solutions of a problem in a single chromosome. These solutions are handled in the same time complexity as other techniques that encode a single solution in a chromosome. This paper presents the main idea of an improved version of the MEP method, and shows positive preliminary experimental results. http://hdl.handle.net/2099/10932 Title: On two conditional entropies without probability<br/><br/>Authors: Vivona, D.; Divari, M.<br/><br/>Abstract: We generalize the conditional entropy without probability given by Benvenuti in [1] and we recognize that this form is the most general compatible with the given properties. Then we compare our form of conditional entropy given in [4] with Benvenuti’s one. http://hdl.handle.net/2099/10931 Title: On completeness results for predicate lukasiewicz, product, gödel and nilpotent minimum logics expanded with truth-constants<br/><br/>Authors: Esteva Massaguer, Francesc; Godo, L.; Noguera, C.<br/><br/>Abstract: In this paper we deal with generic expansions of first-order predicate logics of some left-continuous t-norms with a countable set of truth-constants. Besides already known results for the case of Lukasiewicz logic, we obtain new conservativeness and completeness results for some other expansions. Namely, we prove that the expansions of predicate Product, Gödel and Nilpotent Minimum logics with truth-constants are conservative, which already implies the failure of standard completeness for the case of Product logic. In contrast, the expansions of predicate Gödel and Nilpotent Minimum logics are proved to be strong standard complete but, when the semantics is restricted to the canonical algebra, they are proved to be complete only for tautologies. Moreover, when the language is restricted to evaluated formulae we prove canonical completeness for deductions from finite sets of premises. http://hdl.handle.net/2099/10930 Title: On the order type L-valued relations on L-powersets<br/><br/>Authors: Uljane, I.<br/><br/>Abstract: The research in the field of the so called Fuzzy Mathematics can be conditionally devided into two mainstreams: the first one emphasizes on the study of different fuzzy structures (topological, algebraic, analytical, etc.) on an ordinary set $X$, while $L$-valued sets $X$ (that are sets equipped with some $L$-valued equalities $E: X\times X \to L$, or, more generally, with $L$-valued relations $R: X \times X \to L$) are the starting point for the second one. ($L$ being a lattice usually with an additionally algebraic structure). The aim of this work is to discuss the problem how an $L$-valued relation given on a set $X$ can be extended to the $L$-valued relation $\R$ on the $L$-powerset $L^X$. This problem, is important, among other for the theory of $L$-fuzzy topological spaces in the sense of [15], [16]. http://hdl.handle.net/2099/10929 Title: Algorithms for classification based on k-NN<br/><br/>Authors: Laguía, Manuel; Castro, Juan L.<br/><br/>Abstract: In this paper we focus on methods that solve classification tasks based on distances, and we introduce some variants of the basic k-NN method adding up to 3 characteristics. The experiments reveal a relationship between the accuracy of 1-NN (distances) and the accuracy of the methods based on those distances. We propose a heuristics according to this observation and test its correctness. We study the usefulness of the proposed methods epsilon-ball, epsilon-ball^{k-NN} and epsilon-ball^{1-NN}, and make an exhaustive comparison using six different distance functions and 68 data sets, including UCI--Repository and artificial data sets. The proposed methods are useful and significantly outperform k-NN frequently. We have also found some evidence about the weakness of k-NN when the optimal value of $k$ varies in different regions along the space. http://hdl.handle.net/2099/10927 Title: Weakening of fuzzy relational queries: an absolute proximity relation-based approach<br/><br/>Authors: Bosc, P.; HadjAli, A.; Pivert, O.<br/><br/>Abstract: In this paper we address the problem of query failure in the context of flexible querying. We propose a fuzzy set–based approach for relaxing queries involving gradual predicates. This approach relies on the notion of proximity relation which is defined in an absolute way. We show how such proximity relation allows for transforming a given predicate into an enlarged one. The resulting predicate is semantically not far from the original one and it is obtained by a simple fuzzy arithmetic operation. The main features of the weakening mechanism are investigated and a comparative study with some methods proposed for the purpose of fuzzy query weakening is presented as well. Last, an example is provided to illustrate our proposal in the case of conjunctive queries. http://hdl.handle.net/2099/10926 Title: Homogeneity properties of hypercubes<br/><br/>Authors: Ovchinnikov, Sergei<br/><br/>Abstract: The paper reviews properties of hypercubes of arbitrary dimension from the metric geometry point of view. It is shown, in particular, that a hypercube is a homogeneous metric space with respect to a class of partial cubes. This generalizes the L1-rigidity property of finite partial cubes. http://hdl.handle.net/2099/10924 Title: Short note: counting conjectures<br/><br/>Authors: De Soto, Adolfo R.; Alvárez, A.; Trillas i Gay, Enric<br/><br/>Abstract: This paper only goal is to study what is, in some finite ortholattices, the number of conjectures, refutations, consequences, hypotheses and speculations. http://hdl.handle.net/2099/10923 Title: Characterizing Ordered Semigroups by Means of Intuitionistic Fuzzy Bi-ideals<br/><br/>Authors: Hong, Yongfa; Xu, Ruiping; Fang, Xianwen<br/><br/>Abstract: In this paper, we endow set S with the structure of an ordered semigroup and define “intuitionistic fuzzy” analogous for several notions that have been proved to be useful in the theory of ordered semigroups and give some equivalent conditions of these definitions. Then we characterize the completely regular and the strongly regular ordered semigroups by means of intuitionistic fuzzy bi-ideals. http://hdl.handle.net/2099/10919 Title: Existence of extremal solutions for fuzzy polynomials and their numerical solutions<br/><br/>Authors: Ezzati, R.; Abbasbandy, S.<br/><br/>Abstract: In this paper, we consider the existence of a solution for fuzzy polynomials anx^n + an−1x^n−1 + · · · + a1x + a0 = x,where ai, i = 0, 1, 2, · · · , n and x are positive fuzzy numbers satisfying certain conditions. To this purpose, we use fixed point theory, applying results such as the well-known fixed point theorem of Tarski, presenting some results regarding the existence of extremal solutions to the above equation.