1,721,074 research outputs found
Approximation and reconstruction of the electrostatic field in Wire-plate precipitators by a low-order model.
No full textCurrent-density approximation for efficient computation of the electrostatic field in wire-plate precipitators
No full textIn this paper, numerical computation of ionic space charge and electric field produced by corona discharge in an electrostatic precipitator is addressed. The problem is defined by a reduced set of the Maxwell equations. The efficiency of numerical iterative computations is significantly improved by deriving an initial field as close as possible to the final solution from an approximation of the current-density field J. Different techniques to approximate J are proposed. A first analytic approximation (J) over tilde is derived, which verifies by construction the boundary conditions of the problem and, in particular, gives the correct average value at the plate. A second approximation is also considered, which contains a free parameter that can be computed by an optimization procedure based on the known value of the potential at the wire. Finally, Karhunen-Loeve (KL) decomposition is used and the current-density field is expressed as the sum of (J) over tilde and of a linear combination of few KL basis functions. The coefficients can be determined again by an optimization algorithm. Starting from these approximated J fields, a procedure is proposed to obtain, at negligible computational cost, an estimate of the complete electrostatic field. It is shown that this estimate is in all cases much closer to the exact solution than guesses typically employed in the literature. Hence, when it is used as initialization for standard numerical solvers, this significantly improves the efficiency of the numerical algorithm. In particular, the initialization based on the second approximation gives a significant efficiency gain without any noticeable additional cost
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
Le territoire de Lille-Métropole sous l'emprise de la médiatisation des projets urbains
No full textUrban regeneration in the cities of the Nord-Pas-de-Calais region could have taken specific forms, if the forms of their own identity had first been taken into consideration. First as free cities and then as cities of trade and industry, their urban morphology expresses the importance given to transport axes to provide their structure, and to terrace houses as the type of housing. Those large forms resulting from the rational assembling of terrace houses established a specific urban landscape.
During the two last centuries of urban history, the reference to Paris in the 1 9th century, then to other forms of embellishment, of reconstruction and of new towns, were used as models for development of the urban territory. Urban projects to day are in the grip of the media : their reality seems less important than their capacity to gather actors behind a slogan and to catch the attention of the press and of an internationnal audience. Urban marketing becomes a perequisite to any urban project and under this change of priority, the cultural identity of a territory moulded through century of history no longer comes as an essential basis for the future of the areas.La régénération urbaine des villes du Nord-Pas-de-Calais aurait pu prendre des formes originales, si l'on avait bien voulu considérer, auparavant, les formes de leur identité. Villes libres et bourgeoises, puis villes de commerce et d'industrie, leur tissu urbain exprime l'importance accordée aux axes de transport comme axe structurant et l'intérêt porté sur la maison de ville en rang comme type d'habitat. Ces grandes formes issues des réseaux et ses petites formes issues de l'assemblage raisonné de maisons mitoyennes ont fondé un paysage urbain original.
Au cours des deux derniers siècles d'histoire urbaine, la référence à Paris au XIXe siècle puis à d'autres formes d'embellissements, de reconstructions et de villes nouvelles ont servi de modèle à l'essor du territoire urbain. Aujourd'hui, le projet urbain s'affiche sous l'emprise de la médiatisation, et la réalité du projet apparaît moins importante que sa capacité à rassembler des acteurs derrière l'affiche d'un slogan, et à drainer l'attention d'une presse et d'un public international. Le marketing urbain devient un élément préalable du projet urbain, et dans cette transformation des ordres de priorité, l'identité culturelle d'un territoire façonné par des siècles d'histoire n'apparaît pas comme une donnée essentielle de l'avenir des lieux.Joseph-Francois Didier. Le territoire de Lille-Métropole sous l'emprise de la médiatisation des projets urbains. In: Hommes et Terres du Nord, 2000/1. Villes et enjeux urbains du Nord - Pas-de-Calais. pp. 23-29
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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