1,721,059 research outputs found
An interpolatory approximation of the matrix exponential based on Faber polynomials
Full text linkIn this paper we introduce a method for the approximation of the matrix exponential obtained by interpolation in zeros of Faber polynomials. In particular, we relate this computation to the solution of linear IVPs. Numerical examples arising from practical problems are examined
RD-rational approximation of the matrix exponential operator
No full textRestricted Denominator (RD) rational approximations to the matrix exponential operator are constructed by interpolation in points related to Krylov subspaces associated to a rational transform of the particular matrix considered. Convergence analysis are provided. Numerical experiments show the effectiveness of the proposed methods in applications involving discretizations of differential operators
Interpolating functions of matrices on zeros of quasi-kernel polynomials
No full textThe paper deals with Krylov methods for approximating functions of matrices via interpolation. In this frame residual smoothing techniques based on quasi-kernel polynomials are considered. Theoretical results as well as numerical experiments illustrate the effectiveness of our approach
The computation of functions of matrices by truncated Faber series
No full textIn this paper we consider a method based on Faber polynomials for the approximation of functions of real nonsymmetric matrices. Particular attention is devoted to some functions that occur in practical problem, such as exp (z), . Finally we give some numerical results on a test matrix arising from the discretization of a second order partial differential operator
A rational Krylov method for solving time-periodic differential equations
No full textA rational Arnoldi method, for computing the action of a matrix function, is applied in the construction of a numerical scheme for solving time-periodic linear differential problems arising from the semidiscretization of parabolic problems. Theoretical and computational results illustrate the effectiveness of the approach
La Condition de vie et de travail des jeunes au prisme des enquetes de l'OIT d'une après-guerre à l’autre.
No full textIl saggio analizza le politiche sociali suggerite dall'Ufficio Internazionale del lavoro di Ginevra, e le loro eventuali applicazioni nel mondo occidentale europeo e nord-americano, nei confronti dei giovani e dei disagio e disoccupazione giovanile tra le due guerre mondiali, con particolare attenzione al primo dopoguerra e alla Crisi del 192
On the convergence of Krylov subspace methods for matrix Mittag-Leffler functions
Full text linkIn this paper we analyze the convergence of some commonly used Krylov subspace methods for computing the action of matrix Mittag-Leffler functions. As is well known, such functions find application in the solution of fractional differential equations. We illustrate the theoretical results by some numerical experiments
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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