Search results for "MATEMATICA"

Logical Conditions for Coherent Qualitative and Numerical Probability Assessments

2003

Large number asympotics for dispersed, non regular distributions of inclusions in a fluid

We shall describe the large number asymtpotics for systems consisting in a fluid surrounding a non regular distributions of inclusions. The fluid satisfies a given boundary (or initial-boundary) value problem (involving a second order operator of divergence form) in a perforated domain and the holes in the domain are occupied by the inclusions; fluid and inclusions are coupled by the boundary conditions only. These systems are meant as models at some "microscopic" scale for describing, in a suitable asymptotics, the behaviour at a macroscopic level of composite media. We shall give a general overview of the results about the homogenized limit of such a kind of systems obtained in previous w…

Matter-wave dark solitons in boxlike traps

2017

Motivated by the experimental development of quasihomogeneous Bose-Einstein condensates confined in boxlike traps, we study numerically the dynamics of dark solitons in such traps at zero temperature. We consider the cases where the side walls of the box potential rise either as a power law or a Gaussian. While the soliton propagates through the homogeneous interior of the box without dissipation, it typically dissipates energy during a reflection from a wall through the emission of sound waves, causing a slight increase in the soliton's speed. We characterize this energy loss as a function of the wall parameters. Moreover, over multiple oscillations and reflections in the boxlike trap, the…

Studies in thermal and dynamical duality

2011

Applications of topological *-algebras of unbounded operators to modified quons

2002

In this paper we discuss some applications of topological *-algebras of unbounded operators to what we call Modified Quons (MQ). In particular, the existence of the thermodynamical limit for some models of free and interacting modified quons is proved in the same framework proposed by the author in a recent paper for ordinary bosons.

States and representations of CQ∗ -algebras

1994

A class of quasi *-algebras which exhibits some analogy with C*-algebras is studied. The extension of some properties of C*-algebras which are relevant for physical applications (such as the GNS-representation) is discussed. Quasi *-algebras of linear operators in rigged Hilbert space are shown to be typical examples of the developed framework.

Nonlocal and rotational effects in superfluid turbulence

2008

We discuss phenomenological equations for the evolution of vortex tangle in counterflow superfluid turbulence, which takes into account the influence of the non local effects, both in absence and in the presence of rotation.

An Original Convolution Model to analyze Graph Network Distribution Features

2022

Modern Graph Theory is a newly emerging field that involves all of those approaches that study graphs differently from Classic Graph Theory. The main difference between Classic and Modern Graph Theory regards the analysis and the use of graph's structures (micro/macro). The former aims to solve tasks hosted on graph nodes, most of the time with no insight into the global graph structure, the latter aims to analyze and discover the most salient features characterizing a whole network of each graph, like degree distributions, hubs, clustering coefficient and network motifs. The activities carried out during the PhD period concerned, after a careful preliminary study on the applications of the…

Admissible perturbations of alpha-psi-pseudocontractive operators: convergence theorems

2015

In the last decades, the study of convergence of fixed point iterative methods has received an increasing attention, due to their performance as tools for solving numerical problems. As a consequence of this fact, one can access to a wide literature on iterative schemes involving different types of operators; see [2, 4, 5]. We point out that fixed point iterative approximation methods have been largely applied in dealing with stability and convergence problems; see [1, 6]. In particular, we refer to various control and optimization questions arising in pure and applied sciences involving dynamical systems, where the problem in study can be easily arranged as a fixed point problem. Then, we …

A stochastic dynamic model to evaluate the influence of economy and well-being on unemployment control

2018

[EN] This paper presents a stochastic dynamic mathematical model to study the evolution of the unemployment rate and other relevant related variables in a country. This model is composed by three basic interrelated subsystems: demographic, economic and wellbeing ones. A key aspect of this model is that it considers three UN well-being variables simultaneously: Human Development Index, Gender Empowerment Index and Gender Differentiation Index. These variables involve key concepts for human development, as Health, Education, Economy and Female Labor. With this model, the most outstanding variables found in the literature in relation with unemployment control can be used to design strategies a…