Search results for "t-norm"
showing 10 items of 30 documents
Compound conditionals, Fr\'echet-Hoeffding bounds, and Frank t-norms
2021
Abstract In this paper we consider compound conditionals, Frechet-Hoeffding bounds and the probabilistic interpretation of Frank t-norms. By studying the solvability of suitable linear systems, we show under logical independence the sharpness of the Frechet-Hoeffding bounds for the prevision of conjunctions and disjunctions of n conditional events. In addition, we illustrate some details in the case of three conditional events. We study the set of all coherent prevision assessments on a family containing n conditional events and their conjunction, by verifying that it is convex. We discuss the case where the prevision of conjunctions is assessed by Lukasiewicz t-norms and we give explicit s…
Fixed point theory for cyclic weak ϕ-contraction in fuzzy metric spaces
2012
In this paper, we introduce cyclic weak $\phi-$contractions in fuzzy metric spaces and utilize the same to prove some results on existence and uniqueness of fixed point in fuzzy metric spaces. Some related results are also proved besides furnishing illustrative examples.
Set-valued mappings in partially ordered fuzzy metric spaces
2014
Abstract In this paper, we provide coincidence point and fixed point theorems satisfying an implicit relation, which extends and generalizes the result of Gregori and Sapena, for set-valued mappings in complete partially ordered fuzzy metric spaces. Also we prove a fixed point theorem for set-valued mappings on complete partially ordered fuzzy metric spaces which generalizes results of Mihet and Tirado. MSC:54E40, 54E35, 54H25.
Quasi conjunction, quasi disjunction, t-norms and t-conorms: Probabilistic aspects
2013
We make a probabilistic analysis related to some inference rules which play an important role in nonmonotonic reasoning. In a coherence-based setting, we study the extensions of a probability assessment defined on $n$ conditional events to their quasi conjunction, and by exploiting duality, to their quasi disjunction. The lower and upper bounds coincide with some well known t-norms and t-conorms: minimum, product, Lukasiewicz, and Hamacher t-norms and their dual t-conorms. On this basis we obtain Quasi And and Quasi Or rules. These are rules for which any finite family of conditional events p-entails the associated quasi conjunction and quasi disjunction. We examine some cases of logical de…
Conjunction of Conditional Events and t-Norms
2019
We study the relationship between a notion of conjunction among conditional events, introduced in recent papers, and the notion of Frank t-norm. By examining different cases, in the setting of coherence, we show each time that the conjunction coincides with a suitable Frank t-norm. In particular, the conjunction may coincide with the Product t-norm, the Minimum t-norm, and Lukasiewicz t-norm. We show by a counterexample, that the prevision assessments obtained by Lukasiewicz t-norm may be not coherent. Then, we give some conditions of coherence when using Lukasiewicz t-norm
Triangular norms and conjunction of conditional events
2019
We study the relationship between a notion of conjunction among conditional events, introduced in recent papers, and the notion of Frank t-norm. By examining different cases, in the setting of coherence, we show each time that the conjunction coincides with a suitable Frank t-norm. In particular, the conjunction may coincide with the Product t-norm, the Minimum t- norm, and Lukasiewicz t-norm. We show by a counterexample, that the prevision assessments obtained by Lukasiewicz t-norm may be not coherent. Then, we give some conditions of coherence when using Lukasiewicz t-norm.
Optimization Under Fuzzy Max-t-Norm Relation Constraints
2019
Fuzzy relation equations and inequalities play an important role in many tools of fuzzy modelling and have been extensively studied. In many practical applications they are used as constraints in optimization. Algorithms for specific objective functions have been proposed by many authors. In this paper we introduce a method to convert a system of fuzzy relation constraints with max-t-norm composition to a linear constraint system by adding integer variables. A numerical example is provided to illustrate the proposed method.
Are local food chains more sustainable than global food chains? Considerations for assessment
2016
© 2016 by the authors; licensee MDPI, Basel, Switzerland. This paper summarizes the main findings of the GLAMUR project which starts with an apparently simple question: is "local" more sustainable than "global"? Sustainability assessment is framed within a post-normal science perspective, advocating the integration of public deliberation and scientific research. The assessment spans 39 local, intermediate and global supply chain case studies across different commodities and countries. Assessment criteria cover environmental, economic, social, health and ethical sustainability dimensions. A closer view of the food system demonstrates a highly dynamic local-global continuum where actors, whil…
Ekspertu novērtējumu agregācija, balstoties uz ekvivalences attiecību
2016
Darbs ir veltīts vispārinātā agregācijas operatora speciālai konstrukcijai, kas balstīts uz nestriktu ekvivalences attiecību. Darba mērķis ir aprakstīt kā var agregēt ekspertu novērtējumus gadījumā, kad starp novērtētiem objektiem pastāv līdzība, kas uzdota ar nestriktu ekvivalences attiecību. Piedāvātā metode ir ilustrētā ar ekonomiska rakstura piemēru.
Some new fixed point theorems in Menger PM-spaces with application to Volterra type integral equation
2014
Abstract We establish some fixed point theorems by introducing two new classes of contractive mappings in Menger PM-spaces. First, we prove our results for an α - ψ -type contractive mapping and then for a generalized β -type contractive mapping. Some examples and an application to Volterra type integral equation are given to support the obtained results.