Recently, Rodríguez-Lallena and´Ubeda-Flores  have introduced a class of bivariate copulas which generalizes some known families such as the Farlie-Gumbel-Morgenstern distributions. In this paper we present multivariate generalizations of this class studying symmetry and dependence concepts, measuring the dependence among the components of each class,… (More)
In this paper we studied a three-parameter absolutely continuous bivariate distribution whose marginals are generalized exponential distributions. The proposed three-parameter bivariate distribution can be used quite effectively as an alternative to the Block and Basu bivariate exponential distribution. The joint probability density function, the joint… (More)
A new family of fuzzy implication operators is introduced. The proposed class is based on the conditional version of a copula function. Properties of these operators are studied and several examples illustrate our results.
In this paper, we introduce two transformations on a given copula to construct new and recover already-existent families. The method is based on the choice of pairs of order statistics of the marginal distributions. Properties of such transformations and their effects on the dependence and symmetry structure of a copula are studied.
Let be independent random variables with having half-logistic distribution with the scale parameter , for. Let be a random sample of size from a half-logistic distribution with the common scale parameter. The purpose of this paper is to study stochastic comparisons including usual stochastic ordering, hazard rate ordering and the dispersive ordering between… (More)
This paper provides some results on different types of con-vexity and concavity in the class of multivariate copulas. We also study their properties and provide several examples to illustrate our results.
It has been proved that sphericity testing for digraphs is an NP-complete problem. Here, we investigate sphericity of 3-connected single source digraphs. We provide a new combinatorial characterization of sphericity and give a linear time algorithm for sphericity testing. Our algorithm tests whether a 3-connected single source digraph with n vertices is… (More)