1,720,985 research outputs found
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
The ENEA neutron personal dosimetry service
No full textThe ENEA Radiation Protection Institute has been operating the only neutron personal dosimetry service in Italy since the 1970s. Since the 1980s the service has been based on PADC (poly allyl diglycol carbonate) for fast neutron dosimetry, while thermal neutron dosimetry has been performed using thermoluminescence (TL) dosemeters. Since the service was started, a number of aspects have undergone evolution. The latest and most important changes are as follows: in 1998 a new PADC material was introduced in routine, since 2001 TL thermal dosimetry has been based on LiF(Mg,Cu,P) [GR-200] and 7LiF(Mg,Cu,P) [GR-207] detectors and since 2003 a new image analysis reading system for the fast neutron dosemeters has been used. Herein an updated summary of how the service operates and performs today is presented. The approaches to calibration and traceability to estimate the quantity of Hp(10) are mentioned. Results obtained at the performance test of dosimetric services in the EU member states and Switzerland sponsored by the European Commission and organised by Eurados in 1999 are reported. Last but not least, quality assurance (QA) procedures introduced in the routine operation to track the whole process of dose evaluation (i.e. plastic QA, acceptance test, test etching bath reproducibility and 'dummy customer' (blind test) for each issuing monitoring period) are presented and discussed
Field Parameters and Operational Quantities for the ICRU Sphere with Reference Photon Beams - Part 2 - Monte Carlo Calculations of Backscattered Spectra and Backscattered Mean Energy Angular Distribution
No full textVariations 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
Test di qualità del materiale CR39 per dosimetria neutronica: risultati e messa a punto dei criteri di accettabilità
No full textIl dosimetro per neutroni veloci, attualmente in uso presso il Servizio di Dosimetria Personale dell'Istituto di Radioprotezione dell'ENEA, è costituito da un rivelatore a tracce di PADC (polyallyl-diglicol-carbonate), commercialmente denominato CR-39, prodotto dalla ditta Intercast Europe S.p.A. di Parma. Gli studi effettuati, sia sulla composizione chimica del materiale che sulle modalità di trattamento dello stesso nel corso degli ultimi anni, finalizzati al miglioramento delle caratteristiche dosimetriche (sensibilità, segnale di fondo, soglia di rivelazione, dipendenza della risposta dall'energia dei neutroni incidenti), hanno condotto alla scelta di rivelatore di CR-39 addizionato con 0,1 % di DOP (Dioctylphthalate).Una volta stabilita la composizione ottimale del materiale, è stato necessario però attuare una procedura di test di accettazione di una partita di rivelatori. Nel caso del CR39, ciò significa effettuare un test su campioni di rivelatori appartenenti a ciascuna lastra di un gruppo di lastre appartenenti allo stesso ciclo di produzione. A questo scopo sono stati stabilite le procedure del test di controllo sulla intera partita ed i criteri di accettabilità. Sono presentati i risultati dei test su partite relative a diversi anni di produzione.In collaborazione con la Intercast Europe S.p.A., è stato inoltre avviato uno studio allo scopo di valutare quali parametri legati al ciclo di produzione influenzano, e in che misura, la qualità del materiale. Diversi fattori del processo di produzione, infatti, quali la zona di iniezione della miscela nello stampo, la posizione della lastra e la non uniformità del calore all'interno del forno, possono essere causa della possibile disomogeneità CR-39 e comprometterne le prestazioni dosimetriche. Nel presente lavoro sono presentati i risultati del test di accettazione effettuato su di una intera lastra di materiale prodotto nel 2003 (circa 1000 rivelatori). I risultati ottenuti hanno permesso di verificare le procedure di controllo di qualità esistenti (tempistica, dimensione e modalità scelta campioni) e convalidare i criteri di accettabilità.Gli studi effettuati hanno confermato l'importanza dei test di accettazione del materiale di rivelazione ai fini di assicurare all'utente una migliore qualità ed affidabilità del servizio di dosimetria fornito
Monte Carlo Technique Applications in the Field of Radiation Dosimetry at the ENEA Radiation Protection Institute: a Review
No full textAppropriate 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
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