Search results for "MATEMATICA"

Efficient checking of coherence and propagation of imprecise probability assessments

2000

We consider the computational difficulties in the checking of coherence and propagation of imprecise probability assessments. We examine the linear structure of the random gain in betting criterion and we propose a general methodology which exploits suitable subsets of the set of values of the random gain. In this way the checking of coherence and propagation amount to examining linear systems with a reduced number of unknowns. We also illustrate an example.

From imprecise probability assessments to conditional probabilities with quasi additive classes of conditioning events

2012

In this paper, starting from a generalized coherent (i.e. avoiding uniform loss) intervalvalued probability assessment on a finite family of conditional events, we construct conditional probabilities with quasi additive classes of conditioning events which are consistent with the given initial assessment. Quasi additivity assures coherence for the obtained conditional probabilities. In order to reach our goal we define a finite sequence of conditional probabilities by exploiting some theoretical results on g-coherence. In particular, we use solutions of a finite sequence of linear systems.

Imprecise probability assessments and the Square of Opposition

There is a long history of investigations on the square of opposition spanning over two millenia. A square of opposition represents logical relations among basic sentence types in a diagrammatic way. The basic sentence types, traditionally denoted by A (universal affirmative: ''Every S is P''), E (universal negative: ''No S is P''), I (particular affirmative: ''Some S are P''), and O (particular negative: ''Some S are not P''), constitute the corners of the square, and the logical relations--contradiction, contrarity, subalternation, and sub-contrarity--form the diagonals and the sides of the square. We investigate the square of opposition from a probabilistic point of view. To manage impre…

Probabilistic Logic under Coherence: Complexity and Algorithms

2005

In previous work [V. Biazzo, A. Gilio, T. Lukasiewicz and G. Sanfilippo, Probabilistic logic under coherence, model-theoretic probabilistic logic, and default reasoning in System P, Journal of Applied Non-Classical Logics 12(2) (2002) 189---213.], we have explored the relationship between probabilistic reasoning under coherence and model-theoretic probabilistic reasoning. In particular, we have shown that the notions of g-coherence and of g-coherent entailment in probabilistic reasoning under coherence can be expressed by combining notions in model-theoretic probabilistic reasoning with concepts from default reasoning. In this paper, we continue this line of research. Based on the above sem…

Contingency plan selection under interdependent risks

2021

Managing supply chain risks (SCRs) has become an increasingly strategic key factor over the last decade, aimed at pursuing and maintaining business success. These types of risks clearly pose an important challenge to managers nowadays, and evaluating uncertainty affecting business scenarios is crucial. Indeed, COVID-19 has been dangerously affecting supply chains of global manufacturers, and is indicated as a main trigger cause of supply chain disruptions for a huge number of enterprises. Major effects derived from epidemic outbreaks on supply chains should be further adequately investigated since enterprises have been adopting poor risk management plans [1] to face them. Many companies, fo…

Reproducing pairs of measurable functions

2017

We analyze the notion of reproducing pair of weakly measurable functions, which generalizes that of continuous frame. We show, in particular, that each reproducing pair generates two Hilbert spaces, conjugate dual to each other. Several examples, both discrete and continuous, are presented.

Fixed point results in cone metric spaces

2010

We prove a result on points of coincidence and common fixed points for three self mappings satisfying a weak generalized contractive type condition in cone metric spaces. We deduce some results on common fixed points for two self mappings satisfying a weak contractive type condition in cone metric spaces. This results generalize some well-known recent results.

On fixed points of Berinde’s contractive mappings in cone metric spaces

2010

In this paper we establish some common fixed point theorems for two self-mappings satisfying a generalized contractive condition. This result generalizes well known comparable results in the literature. As an application, a necessary and sufficient condition for a fixed point to be a periodic point for the mapping involved therein, without appealing to continuity, in a cone metric space is established.

Fixed point results in cone metric spaces for contractions of Zamfirescu type

2010

We prove a result on points of coincidence and common fixed points in cone metric spaces for two self mappings satisfying a weak generalized contractive condition of Zamfirescu type. We deduce some results on common fixed points for two self mappings satisfying a weak contractive type condition. These results generalize some well-known recent results.

La corrispondenza epistolare Brioschi-Genocchi.

2006

Presso il Dipartimento di Matematica e Applicazioni dell'Università di Napoli Federico II si è conservato un importante fondo ottocentesco di lettere inviate ad Angelo Genocchi dai più significatrivi matematici italiani dell'epoca. Il complesso di lettere era stato rimesso a Siacci, allora a Napoli, sul quale era caduto il compito di comporre un ampia biografia di Genocchi in occasione della sua morte. In questa nota vengono presentate e ampiamente commentate le lettere di Francesco Brioschi, il celebre fondatore del Politecnico di Milano. La corispondenza, abbastanza vasta ( si tratta di circa settanta lettere di Brioschi a Genocchi e di quattro di Genocchi a Brioschi, ritrovate negli arch…