1,724,668 research outputs found
[Carolina & Northwestern Ry., Engine Drawing Card, Sketch No. 5735]
No full textThis engine drawing card was created for Carolina & Northwestern Railway, Class 10-34E. Section N-10 E. Sketch 5735. Copy Spec. B6308
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
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
The anti-glitching gamma-ray pulsar PSR J1522–5735
No full textContext. A small number of pulsar glitches have been identified as anti-glitches or spin-down glitches, where the overall contribution to the pulsar’s rotation frequency is negative. A notable example of a spin-down glitch was observed in the rotation-powered pulsar PSR J1522–5735, a radio-quiet gamma-ray pulsar discovered by blind searches in the three-year data from the Fermi Large Area Telescope (LAT).
Aims. This work aims to search for PSR J1522–5735’s glitches using Fermi-LAT data from over 15 years of observations.
Methods. The weighted H-test statistic was applied to identify glitches and evaluate the related changes in pulsar’s spin parameters. The timing solution based on these results was further refined by maximisation of the unbinned likelihood. The Bayesian information criterion was used to set an appropriate number of parameters in the timing solution to avoid overfitting.
Results. The analysis revealed eight glitch events: a regular spin-up glitch, a spin-up glitch over-recovered to a spin-down, and six anti-glitches. These events were radiatively quiet, exhibiting no significant variations in the shape of the pulse profile or energy flux.
Conclusions. The results may suggest that an internal mechanism is responsible for spin-down glitch phenomena
Galaxy populations of double cluster RX J1053.7+5735 at z = 1.13
No full textWe present a study of the galaxy population in the cluster RX J1053.7+5735,
one of the most distant
X-ray selected clusters of galaxies and one which also shows an unusual
double-lobed X-ray morphology,
indicative of a possible equal-mass cluster merger.
The cluster was discovered during
the ROSAT deep pointings in the direction of the Lockman Hole.
Using Keck-DEIMOS
spectroscopic observations of galaxies
in the 2\farcm0 1\farcm5 region surrounding
RX J1053.7+5735, we
secured redshifts for six
galaxies
in the range
, with a mean redshift .
This mean redshift agrees well with the
cluster X-ray redshift previously estimated
from
the cluster X-ray Fe-K line,
confirming the presence of a cluster at .
Galaxies with concordant redshifts
are located in both eastern and western sub-clusters of
the double cluster structure,
which indicates that
both sub-clusters are at similar redshifts.
This result is also consistent with a previous
claim that both eastern and western X-ray lobes
have similar X-ray redshifts.
Based on their
separation of ~250 kpc,
these results support the interpretation that
RX J1053.7+5735 is an equal-mass cluster merger taken
place at , although
further direct evidence for a dynamical state of the cluster is
needed to make a more definitive statement about
the cluster merging state.
The six galaxies have a line-of-sight velocity
dispersion ~ 650 km s-1,
and
all six show clear absorption features of CaII H and K and
several Balmer lines that are typical of early galaxies at the present
epoch, in agreement with their colors.
A color–magnitude diagram, constructed from
deep optical/NIR observations of the RX J1053.7+5735 field,
shows a clear red color sequence.
There is an indication that the red sequence
in RX J1053.7+5735 lies ~0.3 to the blue of the Coma line,
qualitatively consistent with previous studies investigating
other clusters at .
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
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