1,721,080 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
Petrology of lavas from the 2004–2005 flank eruptionof Mt. Etna, Italy: inferences on the dynamics of magmain the shallow plumbing system
No full textFollowing the 2001 and 2002–2003 flank eruptions,
activity resumed at Mt. Etna on 7 September 2004
and lasted for about 6 months. This paper presents new
petrographic, major and trace element, and Sr–Nd isotope
data from sequential samples collected during the entire
2004–2005 eruption. The progressive change of lava
composition allowed defining three phases that correspond
to different processes controlling magma dynamics inside
the central volcano conduits. The compositional variability
of products erupted up to 24 September is well reproduced
by a fractional crystallization model that involves magma
already stored at shallow depth since the 2002–2003
eruption. The progressive mixing of this magma with a
distinct new one rising within the central conduits is clearly
revealed by the composition of the products erupted from
24 September to 15 October. After 15 October, the
contribution from the new magma gradually becomes
predominant, and the efficiency of the mixing process ensures the emission of homogeneous products up to the end
of the eruption. Our results give insights into the complex
conditions of magma storage and evolution in the shallow
plumbing system of Mt. Etna during a flank eruption.
Furthermore, they confirm that the 2004–2005 activity at
Etna was triggered by regional movements of the eastern
flank of the volcano. They caused the opening of a complex
fracture zone extending ESE which drained a magma stored
at shallow depth since the 2002–2003 eruption. This process
favored the ascent of a different magma in the central
conduits, which began to be erupted on 24 September
without any significant change in eruptive style, deformation,
and seismicity until the end of eruption
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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