1,720,999 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
Surface Modification of Additively Manufactured Parts for End-Use Surgical Instruments
No full textAdditive manufacturing (AM) is a fast developing industry, with the aerospace, automotive and
medical industries readily embracing the new technology. AM provides numerous benefits for design
and production, however, one of the major problems preventing metal AM from overtaking
conventional machining and casting processes is the high surface roughness of AM parts. In the medical
industry, additive manufacturing is revolutionising medical devices with custom implant designs, and
there is similar potential for complex surgical tools. These specialized parts require well finished
surfaces that are able to be easily cleaned to prevent the spread of infection as well as being
aesthetically pleasing or functional. In this thesis mass finishing and post-processing of additively
manufactured parts were examined with the aim of producing end-use surgical instruments via
additive manufacturing.
Using the selective laser melting method, designed 17-4 PH stainless steel samples with various surface
orientations and types were printed for investigating various surface finishing methods. 2D stylus
profilometry was used to quantify the surface roughness and a scanning electron microscope was used
to observe the sample surfaces. Energy dispersive X-ray spectroscopy was used to measure the surface
elemental composition to investigate the contamination of the surfaces throughout post-processing.
The initial surface roughness of the samples was very high (Ra=13.5±2.0μm, Wa=4.0±1.5μm,
Pv=103.8±17.7μm: inclined surface).
Chemical polishing methods using hydrochloric acid and hydrofluoric + nitric acid solutions were shown
to be relatively ineffective at significantly reducing the surface roughness. Mechanical mass finishing
processes, abrasive blasting and centrifugal disc finishing, were also investigated. Of the abrasive
blasting processes white oxide vapour blasting produced the smoothest surfaces (Ra=2.1±0.4μm,
Wa=3.2±1.1μm, Pv=25.3±4.8μm: inclined surface), but still not comparable to machined surfaces.
Centrifugal disc finishing with ceramic media reduced roughness significantly, but the external radii
significantly increased congruently and internal surfaces were unaffected by this process. After white
oxide blasting, centrifugal finishing for 4 hours and performing a final glass bead blast, the smoothest
surface was obtained (Ra=0.6±0.1μm, Wa=0.9±0.3μm, Pv=6.9±1.5μm: inclined surface). The order of
these operations was also of significance as white oxide blasting after centrifugal finishing resulting in
rougher surfaces. Contamination with aluminium oxide particles from white oxide blasting was able to
be removed by glass bead blasting and then using a citric acid passivation to reduce the glass particle
contamination. Wire electric discharge machining (a common process to remove AM parts from the
build platform) of wrought Ti6Al4V and 17-4 PH stainless steel showed high amounts of copper and
zinc present on the surface. Removal of these contaminants was attempted using acidic solutions.
Titanium wire-cut surfaces responded only to a hydrofluoric and nitric acid solution. However, for
stainless steel wire-cut surfaces, citric acid was found to reduce the levels appropriately, but
hydrofluoric acid also outperformed citric acid by completely removing the contaminants.
A process was determined to produce end-use surgical instruments. After printing, the parts should be
removed from the build plate via wire electric discharge machining. The supports should then be
broken and the surfaces with scaffold support attached should be machined/linished to flatten this
extremely rough surface. White oxide vapour blasting then centrifugal finishing should be used to cut
down the remaining surfaces before the parts are heat treated. After heat treatment critically
dimensioned surfaces should be machined and then the part should be glass bead blasted to remove
the oxide scale and provide the final finish. A citric acid cleaning procedure then passivates the surface
and reduces surface contaminants. When designing and manufacturing a part in this way, the process
should be adapted to the key specifications of the part and its surface
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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