1,720,967 research outputs found
Matrici e vettori. Corso di base di geometria e algebra lineare
No full textIl testo presenta gli elementi di geometria e di algebra lineare che sono alla base del programma abituale di un corso universitario di primo livello presso una facoltà tecnico-scientifica. Adottando un approccio scientifico e didattico rigoroso ed attento alla tradizione, gli autori propongono gli argomenti con un linguaggio semplice e chiaro, nell’ottica di facilitare l’apprendimento agli studenti del primo anno. A tale scopo ogni capitolo è arricchito da un gran numero di esercizi e di approfondimenti, mentre una ulteriore serie di esercizi proposti è resa disponibile al lettore sul sito internet del testo. Gli autori hanno scelto di svolgere una trattazione pressoché completa degli argomenti affrontati in un primo corso di geometria e/o di algebra lineare. Questo significa che il testo può essere utilizzato con finalità e modi diversi, sia nella scelta degli argomenti che nel livello degli approfondimenti, in funzione del numero di crediti formativi disponibili e delle specifiche esigenze del corso di studio. Tra gli insegnamenti ai quali questo libro offre un pieno supporto vanno certamente inclusi i corsi di geometria e di algebra lineare delle facoltà di Ingegneria dei vari indirizzi di laurea triennale, nonché i corsi di geometria del primo anno per matematici e per fisici delle facoltà di Scienze matematiche, fisiche e naturali. Tuttavia altri corsi, ad esempio a Statistica o ad Architettura o presso altre facoltà, possono trovare in questo testo un efficace e completo supporto formativo
(UNI)RATIONAL PARAMETRIZATIONS OF Rg,2, Rg,4AND Rg,6IN LOW GENERA
Get PDFThe moduli space Rg,2n parametrizes double covers of smooth curves of genus g ramified at 2n points. We will prove the (uni)rationality of Rg,2, Rg,4and Rg,6in low genera. Resume (Paramétrisations (uni)rationelles de Rg,2, Rg,4et Rg,6en petits genres) L'espace de modules Rg,2n paramétrise les revêtements doubles de courbes lisses de genre g ramifiés en 2n points. Nous montrons la (uni)rationalité de Rg,2, Rg,4et Rg,6en petits genres
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Get PDFWe 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
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