1,721,203 research outputs found
Higher-order asymptotic corrections and their application to the Gamma Variance Model
Full text linkWe present improved methods for calculating confidence intervals and
-values in situations where standard asymptotic approaches fail due to small
sample sizes. We apply these techniques to a specific class of statistical
model that can incorporate uncertainties in parameters that themselves
represent uncertainties (informally, "errors on errors") called the Gamma
Variance Model. This model contains fixed parameters, generically called
, that represent the relative uncertainties in estimates of
standard deviations of Gaussian distributed measurements. If the
parameters are small, one can construct confidence intervals and -values
using standard asymptotic methods. This is formally similar to the familiar
situation of a large data sample, in which estimators for all adjustable
parameters have Gaussian distributions. Here we address the important case
where the parameters are not small and as a consequence the
asymptotic distributions do not represent a good approximation. We investigate
improved test statistics based on the technology of higher-order asymptotics
( approximation and Bartlett correction).Comment: 19 pages, 8 figure
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
Statistical Models with Uncertain Error Parameters - "Errors On Errors" - and their Application to Particle Physics
Full text linkIn particle physics, data are collected and compared to theoretical predictions by constructing a statistical model that captures both the intrinsic stochastic nature of the measurement process and potential biases introduced by approximations in theoretical predictions and in the modeling of the experimental setup, referred to as systematic uncertainties. However, these uncertainties are often derived from limited data or estimated through ad-hoc procedures, introducing uncertainty in the uncertainty itself - informally referred to as ``error-on-error''. The Gamma Variance Model (GVM) is a statistical framework developed to address this issue by explicitly treating systematic uncertainties as imperfect estimates of unknown error parameters. This effectively incorporates errors-on-errors into the statistical model. A key practical consequence is that the GVM naturally reduces sensitivity to outliers and captures internal tensions within datasets by treating them as an additional source of uncertainty. In this thesis, the mathematical properties of the GVM are studied, and the model is extended to simplify its application in practical contexts, such as the combination of measurements and the fitting of physical parameters. These developments are applied to relevant physics examples, demonstrating the practical use of the model. Applications include a study of the 7-8 TeV ATLAS–CMS top-quark mass combination, an investigation of the W-boson mass discrepancy between the CDF result and the ATLAS and CMS measurements, and the fitting of parton distribution functions
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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