1,720,974 research outputs found
Piani di rilevamento per la stima dei parametri normativi della qualità dell'aria
No full textLa stima della qualità dell'aria richiede che i dati rilevati possano essere confrontati con alcuni parametri normativi così da poter stabilire se quelli rilevati sono prossimi o addirittura superano i livelli di guardia o di allarme. Nella nota si discute sul modo in cui i dati possono essere rilevati e confrontati
Algorithms for space, time and content aggregation of air quality statistics
No full textOfficial statistics on air quality are usually published either as simple averages of pollutant concentrations at single monitoring stations over long time intervals, or as simple averages of concentration values collected at the set of stations which belong to a monitoring network. Rules are needed to aggregate the elementary air quality data over space, time, and content of pollution, for the intelligence of cause-and-effect relations of pollution with health, demographic, ecological, and developmental statistics. In this paper, a model for time, space, and content aggregation of elementary pollution data, which is statistically optimal for air quality estimation, is put forward. Systems of weights for the estimation of the pollution level over a region, during an observational period, are deduced from the model. The expected value and the estimate variance of an air quality index which combines together normalised elementary indicators of atmospheric pollution are analytically determined. An index for the mediation of stratum estimates over an area is suggested, too
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
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