Distinguishability of interval type-2 fuzzy sets data by analyzing upper and lower membership functions

This paper introduces a new general-purpose classification system able to face automatically a wide range of classification problems for labeled graphs. The proposed graph classifier explicitly embeds the input labeled graphs using the dissimilarity representation framework. We developed a method to optimize the dissimilarity space representation estimating the quadratic Rényi entropy of the underlying distribution of the generated dissimilarity values. The global optimization governing the synthesis of the classifier is implemented using a genetic algorithm and it is carried out by means of two operations that perform prototype selection and extraction on the input set of graphs. During the optimization step, we adopted a suitable objective function which includes the classification accuracy achieved by the whole classification model on a validation set. Experimental evaluations have been conducted on both synthetic and well-known benchmarking datasets, achieving competitive test set

In this paper, we deal with the problem of classification of interval type-2 fuzzy sets through evaluating their distinguishability. To this end, we exploit a general matching algorithm to compute their similarity measure. The algorithm is based on the aggregation of two core similarity measures applied independently on the upper and lower membership functions of the given pair of interval type-2 fuzzy sets that are to be compared. Based on the proposed matching procedure, we develop an experimental methodology for evaluating the distinguishability of collections of interval type-2 fuzzy sets. Experimental results on evaluating the proposed methodology are carried out in the context of classification by considering interval type-2 fuzzy sets as patterns of suitable classification problem instances. We show that considering only the upper and lower membership functions of interval type-2 fuzzy sets is sufficient to (i) accurately discriminate between them and (ii) judge and quantify their distinguishability. (C) 2014 Elsevier B. V. All rights reserved.