1,726,114 research outputs found
High-fidelity simulation of shock-wave/boundary layer interactions
No full textWe perform direct numerical simulations of impinging shock-boundary layer
interaction on a flat plate, in which the shock is not orthogonal to the boundary layer flow. The
analysis relies on an idealized configuration, where a spanwise flow component is used to
introduce the effect of the sweep angle between a statistically two-dimensional boundary layer and
the shock. A quantitative comparison is carried out between the swept case and the corresponding
unswept one, and the effect of the domain spanwise width is examined. The analysis reveals that,
while the time-averaged swept flow characteristics are basically unaffected by the choice of the
domain width, the spectral dynamics of the flow dramatically changes with it. For very narrow
domains, a pure two-dimensional, low-frequency component can be detected, which resembles the
low-frequency oscillation of the unswept case. The present work is also devoted to compare the
performance of Digital Filtering (DF) and Recycling-Rescaling methods (RR) in reaching an
equilibrium state for the Direct Numerical Simulation (DNS) of a turbulent boundary layer. We
performed two sets of DNS of supersonic and hypersonic boundary layers, based on previous
numerical studies. It is found that, overall, the RR method is the most appropriate choice, to quickly
reach a correct trend of the wall pressure fluctuations, whereas the DF method is more capable in
obtain small deviations of the skin friction coefficient with respect to the benchmark
CECI A TUÉ CELA
No full textSeries: Actualités
Published in Le Charivari
Original text: CECI A TUÉ CELAhttps://commons.und.edu/daumier-prints/2383/thumbnail.jp
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
Reynolds number effects and outer similarity of pressure fluctuations in turbulent pipe flow
No full textWe study the structure of pressure fluctuations in turbulent pipe flow, up to friction Reynolds number Re-tau = 6000, using standard spectral decomposition and proper orthogonal decomposition (POD). The mean pressure distribution is found to be qualitatively different from the case of channel flow, with an additional mean pressure difference caused by combined centrifugal and swirling effects. The variance of the pressure fluctuations exhibits a wide region with negative logarithmic decay with the wall distance, due to the presence of a hierarchy of wall-attached eddies, which we clearly trace in spectral maps, and which are generally isotropic in nature. On the other hand, the largest eddies are strongly non-isotropic, and are mainly elongated in the azimuthal direction. POD is used to prove self-similarity of the attached eddies, whose typical scales are found to be linearly proportional to the wall distance of their center
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
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