1,720,959 research outputs found
Analyses of Different Approaches for Virtual Towing Tank Uncertainty Assessment
No full textThe assessment for the resistance of a new ship under design can be performed through
the Experimental Fluid Dynamics (EFD) or the Computational Fluid Dynamics (CFD)
approach; both have their own Uncertainty Assessment (UA). In CFD field, the Verification
and Validation (V&V) procedures take into account the approximations for numerical
issues and the assumptions adopted to describe the physical phenomena to assess UA.
Different theoretical approaches have become available over time; nevertheless, a single
comprehensive solution to achieve the UA remains still unknown because as the theoret-
ical methodology varies, the outcome changes. In current work, four different literature
approaches will be augmented to perform a V&V analysis for two kinds of model hulls,
tested at different speeds and compared with the experimental data. The investigations
performed among results lead to the division of all the approaches into the three and four
solutions families and to define a robust procedure to identify a reasonable value for the
numerical uncertainty assessment. Regarding the robustness and the UA of the approaches,
the first family proved successful in only 55% of cases with a UA mean value below 2.01%,
while the second one always provides a quantification but with a mean value of 6.65%
Analysis of the Virtual Towing Tank Accuracy by Means of a New EFD Database
No full textThis work introduces to the field of comparisons between the
Experimental Fluid Dynamics (EFD) and Computational Fluid Dynamics (CFD).
The ship resistance prediction can be, nowadays, performed by CFD techniques, but
the accuracy of the result obtained is not still well identified. The notable absence
of an extensive and freely accessible database, where both ships geometry and
experimental data are available, induced the scientific community to organize
workshops to investigate both the field of Verification and, most importantly, of the
Validation (commonly named: V&V). In this work, through the use of an open-
source viscous based code (i.e. OpenFOAMv8), and the availability of a significant
experimental database, it has been tested a well-consolidated procedure to perform
CFD calculations, with the aim to seed a comparative EFD vs. CFD repository
which consists of about one-hundred simulations performed for fifteen different hull
shapes. The generated repository has been analysed, in order to extract statistical
considerations and assess potential correlations between the differences (among
CFD calculations and EFD results) and other physical parameters. The main output
of this analysis consists in having defined a mean absolute difference between
physical and virtual towing tank tests of 3.2% with a standard deviation of 2.17%
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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