1,721,387 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Nature of two massive protostellar candidates: IRAS 21307+5049 and IRAS 22172+5549
No full textWe present observations of continuum and molecular lines towards the protostar candidates IRAS 21307+5049 and IRAS 22172+5549. Single-dish maps in the 12CO (2-1), 13COI (2-1), HCO+I (1-0) lines and 850 μm continuum are compared with interferometric maps in the 12CO (1-0) line and 3 mm continuum, and with mid- and near-infrared images. Also, single-pointing spectra of the CH3C2H (6-5), (8-7) and (13-12) lines observed towards IRAS 21307+5049, and H2 and [FeII] line emission observed towards IRAS 22172+5549, are presented. A plausible interpretation of our data based on the continuum maps and spectral energy distributions is that two components are present: a compact molecular core, responsible for the continuum emission at wavelengths longer than ∼25;μm, and a cluster of stars located close to the center of the core, but not spatially coincident with it, responsible for the emission at shorter wavelengths. The core is approximately located at the center of the associated molecular outflow, detected for both sources in the 12CO (1-0) and (2-1) lines. The cores have masses of ∼50;M⊙, and luminosities of ∼103;L⊙. The outflows parameters are consistent with those typically found in high-mass young stellar objects. Our results support the hypothesis that in these sources the luminosity is dominated by accretion rather than by nuclear burning. We conclude that the sources embedded inside the cores are likely protostars with mass ∼ 5-8;M⊙
Nature of two massive protostellar candidates: IRAS 21307+5049 and IRAS 22172+5549
No full textWe present observations of continuum and molecular lines towards the
protostar candidates IRAS 21307+5049 and IRAS 22172+5549.
Single-dish
maps in the 12CO (2–1), C18O (2–1), H13CO+ (1–0) lines and 850 μm
continuum are compared with interferometric maps in the 12CO (1–0) line and
3 mm continuum, and with mid- and near-infrared images. Also, single-pointing
spectra of the CH3C2H (6–5), (8–7) and (13–12) lines observed towards
IRAS 21307+5049, and H2 and [FeII] line emission observed towards
IRAS 22172+5549, are presented. A plausible interpretation of our data
based on the continuum maps and spectral energy distributions is that
two components are present: a compact molecular core, responsible for the
continuum emission
at wavelengths longer than ~m, and a cluster of stars
located close to the center of the core, but not spatially coincident
with it, responsible for the emission at shorter wavelengths.
The core is approximately located at the center of the
associated molecular outflow, detected for both sources in the 12CO (1–0) and
(2–1) lines. The cores have masses of ~,
and luminosities of ~. The outflows parameters
are consistent with those typically found in high-mass
young stellar objects.
Our results support the hypothesis that in these sources the luminosity
is dominated by accretion rather than by nuclear burning.
We conclude that the sources embedded inside the cores are likely
protostars with mass ~
Variations on the Author
Get PDF“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
Get PDFWe 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
Get PDFWe 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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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