1,721,001 research outputs found
Modellazione di colate detritiche ai volumi finiti: simulazione delle fasi iniziali di erosione e di transizione della fase liquida al miscuglio solido-liquido
No full textModeling shallow water flows on general terrains
No full textA formulation of the two-dimensional shallow water equations adapted to general and complex terrains
is proposed. Its derivation starts from the observation that the typical approach of depth integrating the
Navier–Stokes equations along the direction of gravity forces is not exact in the general case of a tilted
curved bottom. We claim that an integration path that better adapts to the shallow water hypotheses
follows the “cross-flow” surface, i.e., a surface that is normal to the velocity field at any point of the do-
main. Because of the implicitness of this definition, we approximate this “cross-flow” path by performing
depth integration along a local direction normal to the bottom surface, and propose a rigorous deriva-
tion of this approximation and its numerical solution as an essential step for the future development of
the full “cross-flow” integration procedure. We start by defining a local coordinate system, anchored on
the bottom surface to derive a covariant form of the Navier–Stokes equations. Depth integration along
the local normals yields a covariant version of the shallow water equations, which is characterized by
flux functions and source terms that vary in space because of the surface metric coefficients and related
derivatives. The proposed model is numerically discretized with a first order FORCE-type Godunov Finite
Volume scheme that allows straight forward implementation of spatially variable fluxes. We investigate
the validity of our SW model and the effects of the geometrical characteristics of the bottom surface
by means of three synthetic test cases that exhibit non negligible slopes and surface curvatures. The re-
sults show the importance of taking into consideration bottom geometry even for relatively mild and
slowly varying curvatures. By comparison with the numerical solution of vertically integrated models, we
observe differences of almost 20%, in particular for the peak values and the shape of the hydrographs
calculated at given sections of the fluid domai
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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