1,721,029 research outputs found
Tecniche a basi ridotte per la ottimizzazione di configurazioni di innesto di bypass coronarici
No full textII volume raccoglie le relazioni presentate al Convegno dedicato a Eugenio Beltrami (1835-1899), grande matematico dell'800 che sotto la spinta poderosa di Francesco Brioschi, ed insieme a Luigi Cremona e Felice Casorati, portò la matematica italiana ad affermarsi a livello europeo. Beltrami fu grande matematico, in geometria differenziale e in fisica matematica.
omaggio a Eugenio Beltrami, 2007
Viene applicato un metodo a basi ridotte per equazioni alle derivate parziali su domini parametrizzati allo scopo di approssimare il flusso del sangue attraverso un bypass aorto-coronarico. L obiettivo del lavoro è quello di fornire (a) un analisi di sensività per grandezze geometriche rilevanti nella caratterizzazione della configurazione di innesto di un bypass e (b) una rapida e affidabile previsione del valore di certi funzionali integrali, denominati outputs (quali, per esempio, indici legati a grandezze fluidodinamiche). Le linee guida del lavoro sono finalizzate a (i) ottenere valide indicazioni circa le procedure di progetto e innesto chirurgico di un bypass, nella prospettiva futura dello sviluppo e dell uso di protesi bioartificiali, (ii) sviluppare metodi numerici per l ottimizzazione e la progettazione biomeccanica e, (iii) fornire una relazione di tipo input-output retta da modelli con complessità matematica e costi computazionali inferiori rispetto a quelli che si avrebbero risolvendo le equazioni della fluidodinamica mediante il metodo classico degli elementi finiti
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
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Numerical solution of parametrized Navier-Stokes equations by reduced basis methods
No full textWe apply the reduced basis method to solve Navier-Stokes equations in parametrized domains. Special attention is devoted to the treatment of the parametrized nonlinear transport term in the reduced basis framework, including the case of nonaffine parametric dependence that is treated by an empirical interpolation method. This method features (i) a rapid global convergence owing to the property of the Galerkin projection onto a space WN spanned by solutions of the governing partial differential equation at N (optimally) selected points in the parameter space, and (ii) the offline/online computational procedures that decouple the generation and projection stages of the approximation process. This method is well suited for the repeated and rapid evaluations required in the context of parameter estimation, design, optimization, and real-time control. Our analysis focuses on: (i) the pressure treatment of incompressible Navier-Stokes problem; (ii) the fulfillment of an equivalent inf-sup condition to guarantee the stability of the reduced basis solutions. The applications that we consider involve parametrized geometries, like e.g. a channel with curved upper wall or an arterial bypass configuration.CMC
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