1,720,986 research outputs found
Variants of the Palmer Drought Severity Index for Portugal using fine resolution gridded datasets
No full textMonthly time series of the Self-Calibrating Palmer Drought Severity Index (SC-PDSI) and SC-MedPDSI, a modified PDSI for the Mediterranean environment, are computed for Portugal using high-resolution gridded datasets of monthly precipitation totals retrieved from the PT02 daily gridded dataset, and monthly averages of maximum and minimum temperature purposefully developed. The datasets have 0.2 ̊ × 0.2 ̊ spatial resolution and cover the period 1950–2003. The effects of the weighing and self-calibrating (SC) methods are studied by comparing the SC-PDSI and SC-MedPDSI with the corresponding indices computed using the original calibration for Portugal. Particular attention is given to the frequency of wet and dry events. The two indices are compared with the SPI on 9-month time scale (SPI-9) computed using the PT02 dataset. Results show that extreme events are less frequent when using the SC indices, and that there is a significant agreement between the SPI-9 and the SC-PDSI or the SC-MedPDSI. Moreover, the space and time variability of the indices are analysed using the Principal Component Analysis (PCA). The spatial patterns identify two sub-regions consistently with previous studies. The Modified Mann-Kendal test is applied to the PC score time serie
Development of high-resolution gridded datasets of monthly temperature in Portugal
No full textHigh-resolution gridded datasets of monthly minimum and maximum temperature with 0.2 ̊ × 0.2 ̊ spatial resolution (approximately 20 km) are generated for Portugal covering the period 1950–2003. At the purpose of their application in a wide range of climatological and hydrological studies over Portugal and the Iberian Peninsula, the time period and the spatial resolution are intentionally set to be the same of the daily gridded datasets recently developed for Portugal (PT02, only precipitation) and Spain (Spain02, precipitation, and minimum and maximum temperature). The Ordinary Kriging method is used to produce the temperature fields interpolated from 36 meteorological stations regularly distributed over Portugal. The performance and accuracy of the interpolation method are evaluated using a cross-validation approach and the estimated errors. The correlation analysis is performed to assess the degree of agreement between observations and the gridded outputs, represented by the grid points surrounding the stations. Furthermore, the representativeness of the new datasets for the study area is evaluated analyzing the capability of the gridded data in reproducing the seasonal time variability and spatial patterns of the temperature variables over Portugal
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Get PDFWe 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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