1,721,481 research outputs found
Link-based survival additive models under mixed censoring to assess risks of hospital-acquired infections
Full text linkThe majority of methods available to model survival data only deal with right censoring. However, there are many applications where left, right and/or interval censoring simultaneously occur. A methodology that is capable of handling all types of censoring as well as flexibly estimating several types of covariate effects is presented. The baseline hazard is modelled through monotonic P-splines. The model’s parameters are estimated using an efficient and stable penalised likelihood algorithm. The proposed framework is evaluated in simulation, and illustrated using an original data example on time to first hospital infection or in-hospital death in cirrhotic patients. A peak of risk in the first week since hospitalisation is identified, together with a non-linear effect of Model for End-Stage Liver Disease (MELD) score. The GJRM R package, with an implementation of our approach, is freely available on CRAN
Indici WISC-IV e profili cognitivi in bambini con DSA: uno studio empirico
No full textLo studio sull’intelligenza è sempre più orientato all’individuazione dei processi e meccanismi che la supportano, come la memoria di lavoro e la velocità di elaborazione, in popolazione con sviluppo tipico e atipico (Cornoldi et al., 2014). Il presente contributo si propone di verificare i profili cognitivi delineati dalla scala WISC-IV (Wechsler Intelligence Scale for Children, 2012), ottenuti da indici specifici (ICV, IRP, IML, IVE) e compositi (IAG e ICC), in 56 bambini (età media 122 mesi) con diagnosi DSA. I risultati evidenziano una discrepanza tra le misure di abilità generale e di processing in tutti i profili esaminati, come dimostrato da Giofrè & Cornoldi (2015). Emerge inoltre una differente compromissione delle abilità misurate dagli indici a seconda del tipo di DSA: come evidenziato da Poletti (2014), i dislessici mostrano deficit specifici nella velocità di elaborazione, mentre i discalculici hanno maggiori difficoltà nella memoria di lavoro e nel ragionamento fluido
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
Numerical characterization of the observational Point Spread Function of the VST telescope
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