1,721,127 research outputs found
A 3D Lagrangian micromixing dispersion model LAGFLUM and its validation with a wind tunnel experiment
No full textA stochastic numerical model, LAGFLUM (LAGrangian FLUctuation Model), is developed to determine the mean and the fluctuation statistics of scalar fields generated in 3D turbulent flows from continuous sources. The model couples a macromixing scheme with a micromixing scheme. The macromixing scheme, based on the so called "well-mixed" criterion, is utilized to evaluate the mean concentration, while the micromixing IECM (Interaction by Exchange with the Conditional Mean) scheme is integrated to calculate the higher statistical moments of the concentration. The model LAGFLUM is tested by comparison with the MUST (Mock Urban Setting Test) wind tunnel experiment, which is the laboratory counterpart of the original (real-atmosphere) MUST experiment. In both these experiments the dispersion of a passive tracer in a 3D flow field, in the presence of obstacles, is measured. Using a flow field reconstructed from the experimental flow measurements, the ensemble mean, standard deviation, intensity of fluctuations and skewness of the concentration predicted by LAGFLUM are compared with the available measurements. The results show a generally good agreement between the observations and the simulation, in particular for the mean and the standard deviation of the concentration. Predictions obtained with the flow field replaced by a flow field calculated using a numerical model and with the IECM model replaced by the IEM (Interaction by Exchange with the Mean) model are also compared with the measurements. (C) 2012 Elsevier Ltd. All rights reserved
LAGFLUM, a stationary 3D Lagrangian stochastic numerical micromixing model for concentration fluctuations: validation in canopy turbulence, on the MUST wind tunnel experiment
No full textA stationary three-dimensional Lagrangian stochastic numerical model, LAGrangian FLUctuation Model (LAGFLUM), was developed by coupling a macromixing with a micromixing scheme, to determine the mean and the variance of concentration for a passive scalar in 3D turbulent flows. The model was tested by comparison with the (MUST) Mock Urban Setting Test wind tunnel experiment, where the dispersion of a passive tracer in a 3D stationary flow field, in the presence of obstacles, was analysed. The means and the standard deviations of concentration reproduced by LAGFLUM were compared with the available measurements. The results show a good performance of the model. Copyright © 2011 Inderscience Enterprises Ltd
A comparison between IECM and IEM Lagrangian models
No full textA three-dimensional Lagrangian stochastic model to evaluate pollutant dispersion in terms of both mean and fluctuating concentration fields has been developed. The mean concentration field is predicted by using a macromixing model, while the micromixing scheme IECM (Interaction by Exchange with the Conditional Mean) is adopted to determine the moments of concentration. The results agree with experimental data and with other numerical studies found in literature. The performance of a second micromixing scheme, namely, the IEM (Interaction by Exchange with the Mean), is tested. Some inaccuracies of the IEM model are evaluated by comparison against measurements and IECM results
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
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