1,721,399 research outputs found
Cosmic microwave background anisotropies and the large scale structure of the universe
No full textWe discuss the implications of the COBE/DMR detection of Cosmic Microwave Background anisotropies on inflationary models for the large scale structure of the universe. We also discuss the constraints set on these models from current upper limits on the Cosmic Microwave Background anisotropies at small and intermediate angular scales, and from the local abundance of X-ray galaxy clusters
Il cantiere aperto della didattica. Una strategie di innovazione oltre le riforme
No full textLo studio promosso dalla Direzione Generale per l’Università del Ministero e della Ricerca e dalla Facoltà di Scienze della Comunicazione della Sapienza si focalizza sul riformismo didattico nella XIV Legislatura e sui cambiamenti organizzativi e culturali introdotti nel mondo accademico da nuove norme fondate sull’autonomia e sulla responsabilità delle scelte.
Dalla revisione delle classi di laurea alla nuova mappa di “requisiti necessari”, la prima parte del volume ricostruisce il quadro dei vincoli e opportunità delineato dall’attuazione dell’autonomia didattica, anche nella transizione alla XV Legislatura. Inoltre alcuni contributi delle Conferenze dei Presidi analizzano l’impatto dei nuovi ordinamenti in specifiche aree disciplinari, testimoniando il clima di confronto sui paradigmi della formazione e sulla cultura della riforma favorito dall’innovazione normativa.
Il capitolo conclusivo presenta, infine, i primi risultati di una ricerca intervento sull’autonomia didattica promossa alla Sapienza dalla Facoltà di Scienze della Comunicazione, con uno specifico zoom sulla rappresentazione della riforma offerta dalla stampa italiana e, di fatto, sui “luoghi comuni” dominati nel discorso pubblico.The study, sponsored by the Directorate General of the Ministry for University and Research and the Faculty of Communication Sciences of Sapienza, focuses on the educational reform in the XIV Legislature and the organizational and cultural changes introduced in the academic world with new rules based on autonomy and the responsibility of choices. The book reconstructs the context of the constraints and opportunities outlined by the implementation of teaching autonomy. In addition, some contributions of the Conference of Deans analyze the impact of new regulations in specific subject areas, testifying to the climate of confrontation on the paradigms of education and culture of reform favored by innovation legislation
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
Cosmological Constraints from Low-Redshift Data
No full textIn this paper we summarise the constraints that low-redshift data—such as supernovae
Ia (SN Ia), baryon acoustic oscillations (BAO) and cosmic chronometers (CC)—are
able to set on the concordance model and its extensions, as well as on inhomogeneous
but isotropic models. We provide a broad overlook into these cosmological scenarios
and several aspects of data analysis. In particular, we review a number of systematic
issues of SN Ia analysis that include magnitude correction techniques, selection bias
and their influence on the inferred cosmological constraints. Furthermore, we examine the isotropic and anisotropic components of the BAO data and their individual
relevance for cosmological model-fitting. We extend the discussion presented in earlier works regarding the inferred dynamics of cosmic expansion and its present rate
from the low-redshift data. Specifically, we discuss the cosmological constraints on
the accelerated expansion and related model-selections. In addition, we extensively
talk about the Hubble constant problem, then focus on the low-redshift data constraint
on H0 that is based on CC. Finally, we present the way in which this result compares
to the high-redshift H0 estimate and local (redshift zero) measurements that are in
tension
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