1,721,099 research outputs found
Lagrangian properties as derived from drifter data for oil spill model applications in the Mediterranean Sea
No full text
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
MEDSLIK-II, a Lagrangian marine surface oil spill model for short-term forecasting – Part 2: Numerical simulations and validations
No full textIn this paper we use MEDSLIK-II, a Lagrangian marine surface oil spill model
described in Part 1 (De Dominicis et al., 2013), to simulate oil slick transport
and transformation processes for realistic oceanic cases, where satellite or
drifting buoys data are available for verification. The model is coupled with
operational oceanographic currents, atmospheric analyses winds and remote
sensing data for initialization. The sensitivity of the oil spill simulations
to several model parameterizations is analyzed and the results are validated
using surface drifters, SAR (synthetic aperture radar) and optical satellite
images in different regions of the Mediterranean Sea. It is found that the
forecast skill of Lagrangian trajectories largely depends on the accuracy of
the Eulerian ocean currents: the operational models give useful estimates of
currents, but high-frequency (hourly) and high-spatial resolution is
required, and the Stokes drift velocity has to be added, especially in
coastal areas. From a numerical point of view, it is found that a realistic
oil concentration reconstruction is obtained using an oil tracer grid
resolution of about 100 m, with at least 100 000 Lagrangian particles.
Moreover, sensitivity experiments to uncertain model parameters show that the
knowledge of oil type and slick thickness are, among all the others, key
model parameters affecting the simulation results. Considering acceptable for
the simulated trajectories a maximum spatial error of the order of three
times the horizontal resolution of the Eulerian ocean currents, the
predictability skill for particle trajectories is from 1 to 2.5 days
depending on the specific current regime. This suggests that
re-initialization of the simulations is required every day
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
MEDSLIK-II, a Lagrangian marine surface oil spill model for short-term forecasting – Part 1: Theory
Full text linkThe processes of transport, diffusion and transformation of surface oil in
seawater can be simulated using a Lagrangian model formalism coupled with
Eulerian circulation models. This paper describes the formalism and the
conceptual assumptions of a Lagrangian marine surface oil slick numerical model and
rewrites the constitutive equations in a modern mathematical framework. The
Lagrangian numerical representation of the oil slick requires three different
state variables: the slick, the particle and the structural state variables.
Transformation processes (evaporation, spreading, dispersion and coastal
adhesion) act on the slick state variables, while particle variables are
used to model the transport and diffusion processes. The slick and particle
variables are recombined together to compute the oil concentration in water,
a structural state variable. The mathematical and numerical formulation of
oil transport, diffusion and transformation processes described in this
paper, together with the many simplifying hypothesis and parameterizations,
form the basis of a new, open source Lagrangian surface oil spill model,
the so-called MEDSLIK-II, based on its precursor MEDSLIK (Lardner et al., 1998, 2006; Zodiatis et al., 2008a).
Part 2 of this paper describes the applications of
the model to oil spill simulations that allow the validation of the model
results and the study of the sensitivity of the simulated oil slick to
different model numerical parameterizations
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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