aggregation function

In this paper, the class of S-generalized distances such that the involved t-conorms S are ordinal sums is discussed. It is shown that these S-generalized distances can be thought of as families of generalized distances with respect to some Archimedean t-conorms. We also deal with the S-generalized distance aggregations, which merge a family of S_{i}-generalized distances into a new S-generalized distance

In this study, a new method, called g-sum, is presented to join two posets together that generalizes the linear sum of two posets. Idempotent uninorms on a bounded chain are in one-to-one correspondence with special linear orders on it and g-sum can be used to construct such special linear orders.

There exist several versions of discrete counterpart of continuity in the framework of finite chains, e.g., the smoothness, the divisibility, intermediate-value property and the 1-Lipschitz property. In this paper, we first discuss the relationships among the smoothness, divisibility, intermediate-value property and 1-Lipschitz property. Second, we present complete characterizations of divisible associative aggregation operations on finite chains.

In this study, we focus on bivariate transformations of trivariate quasi-copulas. We characterize necessary and sufficient conditions of transformations that can be written in the form of compositions between two quasi-copulas and a quadratic polynomial function. The conditions only depend on the coefficients of the quadratic polynomial. The set of these coefficients is convex with linear-section boundary and it lies on the seven-dimensional Euclidean space. All extreme points of this set have been characterized via CAS and can be used to construct quasi-copulas. Construction examples are also given.

Extending and completing earlier results on lifting certain continuity properties of aggregation functions by super- and sub-additive transformations (J. Mahani Math. Res. Center 8 (2019) 37--51, and Iranian J. Fuzzy Sets 17 (2020) 2, 165--168), we prove that uniform continuity of multi-dimensional aggregation functions is preserved under super-additive transformations.

In an earlier paper by Seliga, Siran and the second author (J. Mahani Math. Res. Center 8 (2019) 37–51) on lifting continuity properties of aggregation functions to their super- and sub-additive transformations it was shown that uniform continuity is preserved by super-additive transformations in dimension 1. We give a shorter and more direct proof of this result and of a related linear bound on uniformly continuous aggregation functions.

Positive homogeneity is represented as a constraint 0-homogeneity and generalized into z-homogeneity, called also z-end point linearity. Several special z-homogeneous aggregation functions are studied, in particular semicopulas, quasi-copulas, copulas, overlap functions, etc.

In this paper we present construction of new fuzzy measures by applying extended aggregation function on a sequence of fuzzy measures. According to properties of applied aggregation function and properties of initial fuzzy measures, some properties of constructed fuzzy measure are proved. Additionally, one new extended aggregation function named extended weighted arithmetic mean of distorted arguments is introduced, and its relevant properties are proved. It is shown that this extended aggregation function, with appropriatedparameters, can be suitable for construction of new fuzzy measures. Other types of non-additive measures can be constructed in the same way, by applying aggregation function on the initial sequence of non-additive measures.

The way super- and sub-additive transformations of aggregation functions are introduced involve suprema and infima taken over simplexes whose dimensions may grow arbitrarily. Exact values of such transformations may thus be hard to determine in general. In this note we discuss methods of algorithmic approximation of such transformations.

This study discusses some variants of Ordered WeightedAveraging (OWA) operators and related information aggregation methods. Indetail, we define the Extended Ordered Weighted Sum (EOWS) operator and theExtended Ordered Weighted Averaging (EOWA) operator, which are applied inscientometrics evaluation where the preference is over finitely manyrepresentative works. As contrast, we also define the Infinite OrderedWeighted Sum (InOWS) operator and the Infinite Ordered Weighted Averaging(InOWA) operator, which are more suitable for the correspondingscientometrics evaluation where all of works of scholars are considered. Wealso define the family of Infinite Gaussian maxitive OWA weights functionand the family of Infinite Gaussian OWA weights function, and discuss someof their mathematical properties. Some illustrative examples, comparisonsand figures are provided to better expound their applicability inscientometrics evaluation.

We prove a continuity inheritance property for super- and sub-additive transformations of non-negative continuous multivariate functions defined on the domain of all non-negative points and vanishing at the origin. As a corollary of this result we obtain that super- and sub-additive transformations of continuous aggregation functions are again continuous aggregation functions.

We investigate possible extensions of various types of continuity of aggregation functionsto their super- and sub-additive transformations. More specically, we examine liftsof classical, uniform, Lipschitz and Holder continuities and dierentiability. The classical,uniform, and Lipschitz continuities turn out to be preserved by super- and sub-additivetransformations (albeit for uniform continuity and the super-additive case we prove itonly in dimension one), while the Holder continuity and dierentiability are not.

In this contribution connections between input fuzzy relations R1, . . . ,Rn on a set X and the output fuzzy relationRF = F(R1, . . . ,Rn) are studied. F is a function of the form F : [0, 1]n → [0, 1] and RF is called an aggregated fuzzyrelation. In the literature the problem of preservation, by a function F, diverse types of properties of fuzzy relationsR1, . . . ,Rn is examined. Here, it is considered the converse approach. Namely, fuzzy relation RF = F(R1, . . . ,Rn) isassumed to have a given property and then it is checked if fuzzy relations R1, . . . ,Rn have this property. Moreover, adiscussion on the mentioned two approaches is provided. The properties, which are examined in this paper, depend ontheir notions on binary operations B : [0, 1]2 → [0, 1]. By incorporating operation B these properties are generalizedversions of known properties of fuzzy relations.

Super- and sub-additive transformations of aggregation functions have been recently introduced by Greco, Mesiar, Rindone and \v{S}ipeky [The superadditive and the subadditive transformations of integrals and aggregation functions, {\it Fuzzy Sets and Systems} {\bf 291} (2016), 40--53]. In this article we give a survey of the recent development regarding the existence of aggregation functions with a preassigned super- and sub-additive transformation, and address approximation of these transformations. The underpinning feature of the presented results is dependence of global properties of super- and sub-additive transformations on local properties of aggregation functions.

Several fuzzy connectives, including those proposed by Lotfi Zadeh, can be seen as linear extensions of the Boolean connectives from the scale $\{0,1\}$ into the scale $[0,1]$. We discuss these extensions, in particular, we focus on the dualities arising from the Boolean dualities. These dualities allow to transfer the results from some particular class of extended Boolean functions, e.g., from conjunctive functions, into some other distinguished classes, e.g., into fuzzy implications. We also stress the role of aggregation functions in fuzzy set theory. Then we continue with several recent advances and new directions in aggregation theory. In particular, we discuss some generalizations of monotonicity, additivity and maxitivity issues. Finally, some applications of aggregation functions are sketched.