1,721,431 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
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
I materiali e le coloriture dei cotti decorativi del Chiostro piccolo
No full textIl Chiostro piccolo della Certosa di Pavia, costruito negli anni 1462 – 1472, è caratterizzato dalla presenza di intonaci colorati e fregi ed ornamenti in terra cotta, sia modellata che a stampo, che presentano tutt’ora tracce di coloritura, in genere di colore rosso. Con lo scopo di identificare la cromia originale del chiostro ed ottenere maggiori informazioni sulle tecniche di costruzione e di decorazione del passato, si è proceduto ad uno studio sistematico di numerosi campioni prelevati sia dagli elementi decorativi in cotto, che dagli intonaci e malte di allettamento, posizionati su tutti e quattro i lati del Chiostro. E’ noto che la conoscenza dei materiali e di come essi sono stati impiegati, oltre ad aumentare le notizie sulle tecniche artistiche, costituisce una fonte di interesse per gli storici, in quanto è possibile identificare con chiarezza le differenti sovrapposizioni e i rifacimenti posteriori.1, 2
Le indagini relative allo studio dei material costituenti le finiture colorate hanno previsto l’utilizzo di diverse metodologie di studio 3. Piccoli frammenti dei campioni prelevati sono stati inglobati in resina poliestere e lucidati per ottenere sezioni trasversali lucide. L'osservazione al microscopio ottico di tali sezioni ha permesso di studiare la struttura stratigrafica, cioè la sovrapposizione dei diversi strati di colore. Microanalisi chimica per via umida e strumentale (utilizzando un microscopio elettronico a scansione connesso ad un sistema di microanalisi EDS), test di solubilità e colorazione specifica sono state eseguite sulle sezioni o su altri frammenti dei campioni per identificare pigmenti e leganti, costituenti i diversi strati di finiture colorate.
Per lo studio delle caratteristiche composizionali, strutturali e tessiturali dei cotti sono state eseguite analisi mineralogico-petrografiche. Lo studio è stato condotto in sezione sottile al microscopio polarizzatore ed in diffrattometria ai raggi X, su frammenti macinati in mortaio d’agata, per verificare la composizione mineralogica e la presenza di minerali non risolvibili otticamente.
Per gli intonaci e le malte lo studio delle caratteristiche composizionali è stato condotto utilizzando sia l’analisi diffrattometrica ai raggi X, che osservando i campioni al microscopio stereoscopico e le rispettive sezioni sottili al microscopio polarizzatore4. L’analisi granulometrica della frazione sabbiosa è stata eseguita mediante setacciatura, dopo aver eliminato il legante, disaggregando i campioni con gli ultrasuoni in acqua deionizzata
THE EFFECT OF MICROSTRUCTURE ON FRACTURE TOUGHNESS OF POLYCRYSTALLINE ALUMINA
No full textA study of the dependence of the fracture toughness on the microstructural morphology of polycrystalline materials is presented. The microstructure of several aluminas was characterized by thermal etching and image analysis. The fracture toughness of these materials was then determined by bridge-indentation pre-cracking followed by a four-point bending test procedure. A SEM investigation of the mechanisms of crack propagation was also carried out. The observed microstructure-related fracture toughness responses are discussed
Different techniques to quantify pore-space lengths in porous rocks and artificial porous media
No full textDispelling 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
- …
