1,720,978 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
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
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
Electron dynamics in inner-shell photo-ionization, dielectronic recombination and electron impact excitation
Full text linkThis dissertation includes three main topics: Dynamics of outgoing inner shell photoionized electrons
and Auger decay electrons,
an investigation into the recently proposed mechanism of
below threshold dielectronic recombination and
electron impact fine-structure excitation of Ne+ and Ne2+ at very low temperatures.
For the first topic, we compare our time-dependent
numerical method with a widely used analytical one at different photo-electron
energies. We determine that the time-dependent
numerical method is more accurate in the low and medium energy region.
We apply this method to investigate
inner shell photo-ionization followed by Auger decay in Kr at low energies
(including as low as zero atomic units of energy). We investigate
an interesting feature in the relative angular distribution
of the outgoing electrons.
To confirm the validity of this phenomenon, we use a Classical Trajectory Monte Carlo Method
to re-simulate the process, with similar results being generated.
A physical mechanism is identified for the unusual features in the relative angular distribution.
The second topic concerns a newly proposed mechanism
for dielectronic recombination. The traditional definition for
dielectronic recombination only counts the contribution of
above threshold (or positive energy) resonances which can be accessed via free electrons.
This definition leads to several problems when the temperature is very low. For example,
the dielectronic recombination coefficient becomes very sensitive to the energy position
of resonances and whether they are above or below threshold.
Moving a resonance by a few meV from above to below threshold
can change the dielectronic recombination rate coefficient by large values,
often factors of 10 or 100.
A new recombination mechanism was proposed recently, pointing
out that certain below threshold resonances should
also be counted in the rate coefficient calculation due to an interaction
with Rydberg electrons.
This new mechanism has not been an experimentally confirmed. We proposed that below
threshold satellite line observation can be used
to prove the existence of this new mechanism. We also develop a method
to identify ions with near threshold
resonances and several key ions are selected to re-evaluate their
dielectronic recombination rate coefficient
with the inclusion of below threshold resonances contributions.
For the last topic, we calculate collision strengths, effective collision
strengths and excitation rate coefficients for fine-structure electron
impact excitation of Ne and Ne using
different R-matrix techniques and different target expansions. We compare
target energies and Einstein A coefficients with NIST values, and
compare calculated effective collision strengths with existing values.
A recommended dataset is provided for each ion, along with an estimate
of the uncertainty in the collision data. This work has important applications
in ultra-low temperature astrophysical plasmas
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
Non-perturbative calculations of atomic data for applications in laboratory fusion and astrophysical plasmas
Full text linkResults are presented for non-perturbative quantal calculations of atomic data for application in laboratory fusion and astrophysical plasmas. One of the key issues in laboratory
fusion plasmas is the accurate modeling of impurity transport of wall material as it is ablated into the plasma. In support of experiments at Wisconsin-Madison, new ionization
cross sections for Al and Al2+ were generated. These are supplemented with previous non-
perturbative calculations for Al+ and new distorted-wave calculations for the remaining ions.
This new ionization dataset is compared with previous semi-empirical calculations and literature values, and the likely implications for impurity transport modeling are discussed.
For the application to astrophysical plasmas, a recent development in supernova remnant
X-ray emission is considered. The emission from less abundant iron-peak elements (Mn, Cr,
Co and Ni) from supernova remnant plasmas has been detected and represents a potentially
useful diagnostic opportunity to determining elemental abundances in these plasmas, and to
test current supernova models. However, the studies are currently hampered by a lack of
K-shell atomic data for many of the Fe-peak elements. Thus, R-matrix calculations for the
electron-impact excitation of Ne-like Cr, Mn, Fe, Co and Ni ions are calculated. Collisional-
radiative modeling is used to produce emissivities for each of these ions. The results are
compared with X-ray spectra from the Tycho supernova remnant plasma, and abundances
for Cr and Mn are derived. Evidence is presented that the line commonly identified as Fe
Kβ is blended with another line, possibly the Co Kα feature. To assess the possibility that
this line originates from a neighboring charge state of Fe, new atomic data for F-like Fe-peak
elements are produced. The future direction of this work, and the potential applications of
the data are also discussed
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