1,721,021 research outputs found
Pile di sabbia, dune, valanghe: modelli matematici per la materia granulare
No full textLo studio della materia granulare è un problema alquanto complesso per la varietà dei materiali coinvolti e dei fenomeni che si vorrebbero comprendere, oltre che di grande interesse per le numerose applicazioni pratiche. Per questo sono stati proposti modelli differenziali piuttosto raffinati in grado di riprodurre le proprietà principali di questi materiali. In questo articolo, dopo aver illustrato alcune di queste proprietà caratteristiche, viene analizzato in dettaglio un modello differenziale per la crescita delle pile di sabbia su di un supporto piano, e le informazioni che si possono trarre dalla sua analisi teorica e dalle relative simulazioni numeriche
On Bolza optimal control problems with constraints
No full textWe provide sufficient conditions for the existence and Lipschitz continuity of solutions to the constrained Bolza optimal control problem. Classical assumptions (such as superlinear growth conditions on the Lagrangian) are here replaced by conditions on the Hamiltonian that can be satisfied, for instance, by some Lagrangians with no growth. This paper extends our previous results in Existence and Lipschitz regularity of solutions to Bolza problems in optimal control to the state constrained case
Control Systems : Theory, Numerics and Applications
No full textCirca 30 interventi su vari aspetti del controllo ottimo e della controllabilita dei sistemi dinamici.
Conferenzieri Invitati:
Y. Achdou (Univ. PARIS 7)
A. Agrachev (SISSA)
F. Alabau-Boussouira (Univ. METZ)
J.P. Raymond (TOULOUSE)
J.M. Roquejoffre (TOULOUSE
Remarks on stochastic Navier-Stokes equations
No full textA theory of stochastic Navier-Stokes equations has been developed in recent years. A few basic facts and open problems are recalled, stressing the role and difference between the model with additive and with multiplicative transport noise. In view of the practical issue of numerical simulation of expected values, a few remarks on Girsanov transform and Kolmogorov equation are given
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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