Jalal Chachi

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A novel approach is introduced to construct a fuzzy regression model when the data available of independent and dependent variables are fuzzy numbers. The approach, consisting on the least-squares method, uses the α-level sets of fuzzy observations to estimate the crisp parameters of the model. A competitive study shows the performance and efficiency(More)
Two general classes of similarity measures between intuitionistic fuzzy sets (hereafter IFSs) are introduced. Some properties of these measures are investigated with respect to some well-known reasonable axioms. It is shown that several similarity measures between IFSs introduced elsewhere can be expressed by these definitions as special cases. Some(More)
The goal of this paper is to handle the large variation issues in fuzzy data by constructing a variable spread multivariate adaptive regression splines (MARS) fuzzy regression model with crisp parameters estimation and fuzzy error terms. It deals with imprecise measurement of response variable and crisp measurement of explanatory variables. The proposed(More)
This study attempts to develop a least-absolutes fuzzy regression model for crisp input-fuzzy output data. To estimate the parameters in the proposed model, the generalized Hausdorff-metric on the space of LR-fuzzy numbers is used. The problem of estimation of the interested parameters relies on a non-linear optimization problem, which is also translated to(More)
The paper deals with the well-known notion of similarity measures between fuzzy sets and proposes a variety of similarity measures for fuzzy sets. Moreover, the paper proves that the proposed measures satisfy the properties of the axiomatic definition for similarity measures and introduces several theorems. Several illustrative and practical examples from(More)
Abstract: A fuzzy test for testing statistical hypotheses about an imprecise parameter is proposed for the case when the available data are also imprecise. The proposed method is based on the relationship between the acceptance region of statistical tests at level β and confidence intervals for the parameter of interest at confidence level 1 − β. First, a(More)
This paper extends the non-parametric Sign test to the case when available observations and underlying hypotheses about the population median are imprecise quantities. To do this, by using some elements of possibility theory, we suggest a ranking index among imprecise observations. The index is applied to extend the usual concepts of classical hypothesis(More)
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