A Method for Image Reduction Based on a Generalization of Ordered Weighted Averaging Functions

In this paper we propose a special type of aggregation function which generalizes the notion of Ordered Weighted Averaging Function - OWA. The resulting functions are called Dynamic Ordered Weighted Averaging Functions --- DYOWAs. This generalization will be developed in such way that the weight vectors are variables depending on the input vector. Particularly, this operators generalize the aggregation functions: Minimum, Maximum, Arithmetic Mean, Median, etc, which are extensively used in image processing. In this field of research two problems are considered: The determination of methods to reduce images and the construction of techniques which provide noise reduction. The operators described here are able to be used in both cases. In terms of image reduction we apply the methodology provided by Patermain et al. We use the noise reduction operators obtained here to treat the images obtained in the first part of the paper, thus obtaining images with better quality.Comment: 32 pages, 19 figure

Bounded Generalized Mixture Functions

In literature, it is common to find problems which require a way to encode a finite set of information into a single data; usually means are used for that. An important generalization of means are the so called Aggregation Functions, with a noteworthy subclass called OWA functions. There are, however, further functions which are able to provide such codification which do not satisfy the definition of aggregation functions; this is the case of pre-aggregation and mixture functions. In this paper we investigate two special types of functions: Generalized Mixture and Bounded Generalized Mixture functions. They generalize both: OWA and Mixture functions. Both Generalized and Bounded Generalized Mixture functions are developed in such way that the weight vectors are variables depending on the input vector. A special generalized mixture operator, H, is provided and applied in a simple toy example

Nested formulation paradigms for induced ordered weighted averaging aggregation for decision‐making and evaluation

Existing extensions to Yager's ordered weighted aver-aging (OWA) operators enlarge the application rangeand to encompass more principles and properties relatedto OWA aggregation. However, these extensions do notprovide a strict and convenient way to model evaluationscenarios with complex or grouped preferences. Basedon earlier studies and recent evolutionary changes inOWA operators, we propose formulation paradigms forinduced OWA aggregation and a related weight functionwith self‐contained properties that make it possibleto model such complex preference‐involved evaluationproblems in a systematic way. The new formulationshave some recursive forms that provide more waysto apply OWA aggregation and deserve further studyfrom a mathematical perspective. In addition, the newproposal generalizes almost all of the well‐knownextensions to the original OWA operators. We providean example showing the representative use of suchparadigms in decision‐making and evaluation problems.This study was partly supported by Scientific Research Start‐up Foundation (grant no.184080H202B165), by Jiangsu ’s Philosophy and Social Science Fund (grant no. 18EYD005), and also by the Science and Technology Assistance Agency under contract no. APVV‐17‐0066. This study was also partially supported by the Spanish Ministry of Science and Technology under project no. TIN2016‐77356‐P (AEI/FEDER, UE)

The law of O-conditionality for fuzzy implications constructed from overlap and grouping functions

Overlap and grouping functions are special kinds of non necessarily associative aggregation operators proposed for many applications, mainly when the associativity property is not strongly required. The classes of overlap and grouping functions are richer than the classes of t-norms and t-conorms, respectively, concerning some properties like idempotency, homogeneity, and, mainly, the self-closedness feature with respect to the convex sum and the aggregation by generalized composition of overlap/grouping functions. In previous works, we introduced some classes of fuzzy implications derived by overlap and/or grouping functions, namely, the residual implications R-0-implications, the strong implications (G, N)-implications and the Quantum Logic implications QL-implications, for overlap functions O, grouping functions G and fuzzy negations N. Such implications do not necessarily satisfy certain properties, but only weaker versions of these properties, e.g., the exchange principle. However, in general, such properties are not demanded for many applications. In this paper, we analyze the so-called law of O-Conditionality, O(x, 1(x, y)) <= y, for any fuzzy implication I and overlap function O, and, in particular, for Ro-implications, (G, N)-implications, QL-implications and D-implications derived from tuples (O, G, N), the latter also introduced in this paper. We also study the conditional antecedent boundary condition for such fuzzy implications, since we prove that this property, associated to the left ordering property, is important for the analysis of the O-Conditionality. We show that the use of overlap functions to implement de generalized Modus Ponens, as the scheme enabled by the law of O-Conditionality, provides more generality than the laws of T-conditionality and U-conditionality, for t-norms T and uninorms U, respectively.This work was partially supported by the Spanish Ministry of Science and Technology under the project TIN2016-77356-P (AEI/FEDER, UE), and by the Brazilian funding agency CNPQ under Processes 305882/2016-3, 481283/2013-7, 306970/2013-9, 232827/2014-1 and 307681/2012-2