1,721,177 research outputs found
The climatic characteristics of extreme precipitations for short-term intervals in the watershed of Lake Maggiore
No full textAlpine and Mediterranean areas are undergoing a
profound change in the typology and distribution of rainfall.
In particular, there has been an increase in consecutive nonrainy
days, and an escalation of extreme rainy events. The
climatic characteristic of extreme precipitations over shortterm
intervals is an object of study in the watershed of Lake
Maggiore, the second largest freshwater basin in Italy (located
in the north-west of the country) and an important resource for
tourism, fishing and commercial flower growing. The historical
extreme rainfall series with high-resolution from 5 to
45 min and above: 1, 2, 3, 6, 12 and 24 h collected at different
gauges located at representative sites in the watershed of Lake
Maggiore, have been computed to perform regional frequency
analysis of annual maxima precipitation based on the Lmoments
approach, and to produce growth curves for different
return-period rainfall events. Because of different rainfallgenerating
mechanisms in the watershed of Lake Maggiore
such as elevation, no single parent distribution could be found
for the entire study area. This paper concerns an investigation
designed to give a first view of the temporal change and
evolution of annual maxima precipitation, focusing particularly
on both heavy and extreme events recorded at time
intervals ranging from few minutes to 24 h and also to create
and develop an extreme storm precipitation database, starting
from historical sub-daily precipitation series distributed over
the territory. There have been two-part changes in extreme
rainfall events occurrence in the last 23 years from 1987 to
2009. Little change is observed in 720 min and 24-
h precipitations, but the change seen in 5, 10, 15, 20, 30, 45,
60, 120, 180 and 360 min events is significant. In fact, during
the 2000s, growth curves have flattened and annual maxima
have decreased
Assessment of Trends in Extreme Precipitation Events: A Case Study in Piedmont (North-West Italy)
No full textIntensification of heavy precipitation as discussed in climate change studies has become a public concern, but it has not yet been examined well with observed data, particularly with data at short temporal scale like hourly and sub-hourly data. The original data set was retrieved by using an automated recovery approach. We chose four stations, namely, Vercelli (since 1927), Bra (since 1933), Lombriasco (since 1939) and Pallanza (since 1950) which are located in the northwest of Italy. We assessed trends for durations from 5 min to 12 h in seasonal, annual maxima, and number and magnitude of exceedances of the 95th percentile. Split sample tests have been undertaken to assess differences in quantile estimates derived using a Generalised Pareto distribution fitted to Peaks-Over-Threshold series. The statistical analyses performed include parametric and non-parametric tests. Mostly, we cannot reject the trend stationarity hypothesis. There is no uniform trend on extreme events in the whole area. However, some trends are evident and significant for specific stations and specific indices. Specifically, it is obvious that extreme rainfall events have risen in the last 20 years only for short durations
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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