1,721,005 research outputs found
Alternatives for Geosensors Networks Data Analysis
No full textGeosensors networks are dense wireless networks of small, low-cost sensors, which collect and disseminate environmental data of a vast geographical area. These networks hold the promise of revolutionizing sensing in a wide range of application. Despite the large amount of research in this field, little effort has been done to establish how to deal with the data collected by these networks. This paper examines this emerging subject and identifies alternatives for geosensors data analysis.Pages: 94-10
Compatibilização de populações entre malhas censitárias diferentes com o uso de imagens de sensores orbitais
No full textStudying data attached to census tracts such as population along time often brings a difficulty: these areal units can change from a census to another one. A solution to this problem is to spatialize the tracts population of a census and reaggregate this spatialized data using the geographical definition for the tracts of the other census. Despite being simple, this solution needs to assume the spatial distribution of the population over the tract area is homogeneous. This paper proposes an alternative to make population data attached to different census tracts compatible. The idea is to spatialize the tracts population using orbital images by regression linear models. Since the involved pixels datasets are often big, a fraction of the pixels in each tract is sampled to be used in the regression model. We have studied the influence of this fraction on the quality of the population estimates attached to the new census tracts. Using the whole dataset to spatialize the population, the proposed procedure has overestimated the total population by 3.4% and the absolute error at the tracts level has been 1.9% (median value). For sample fractions lower than 75%, this approach tends to overestimate the total population (macro level) as well as the tract population (micro level). However, the greater the sample fraction, the smaller and more homogeneous the error at micro level. Therefore, when the most part of the dataset can be used, we consider the proposed procedure a good alternative to make population compatible over different tracts definitions.Pages: 952-95
Integração entre SIG e Modelos Inferenciais Bayesianos
No full textO objetivo deste artigo é descrever o estado da arte da integração entre SIG e Modelos Inferenciais Bayesianos, considerando os softwares utilizados nas duas áreas. Para isto, aborda a natureza da análise estatística de dados espaciais, em particular, a estatística espacial, inserindo neste contexto os Modelos Inferenciais Bayesianos. Por fim, descreve o que já é possível em termos de integração entre os softwares de SIG e os de estatística espacial e entre os softwares de SIG e os de Modelos Inferenciais Bayesianos, apontando lacunas a serem preenchidas.Pages: 292-29
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
- …
