1,720,963 research outputs found
Un nuovo villaggio della Cultura di Catignano: il sito di Colle Cera presso Loreto Aprutino (Pescara)
No full text
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
Chemical investigations of bitumen from Neolithic archaeological excavations in Italy by GC/MS combined with principal component analysis
No full textAn analytical protocol involving microwave assisted solvent extraction and fractionation on silica gel columns followed by gas chromatography/mass spectrometry (GC/MS) and principal component analysis (PCA) of the chromatographic data was used for the characterization of bituminous residues sampled from Neolithic flint flakes and potsherds recovered from archaeological excavations in Abruzzo and Apulia (Italy). The analytical protocol was optimized and primarily tested in the study of geological bitumen (used as reference materials) from rocks and sediments of central-southern Italy (Abruzzo, Sicily and Lazio), and subsequently used to characterize the archaeological bitumen. Since bitumen is usually present in very low amounts in archaeological objects, we paid attention to improve the extraction efficiency of terpanes and steranes, the main soluble components of bitumen. The highest efficiency was obtained using microwave assisted extraction with a mixture of n-hexane/dichloromethane/methanol (80:15:5, v/v/v). Given that the composition of the bitumen varies depending on the area of origin, the results obtained from the archaeological materials allowed us not only to draw hypotheses on the possible function of tools/objects from which the bitumen is sampled, but also to obtain information on its geographical origin. In particular, PCA, used as a tool for an extensive analysis of chromatographic data, enabled us to correlate the quantitative chemical composition and the geographical origin of the samples, and finally to distinguish bitumen originating from the different Italian sites, based on their molecular profiles
La gestione dei rifiuti speciali nel Complesso ospedaliero Università - USL 1 di Sassari
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
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
- …
