1,720,995 research outputs found
On the convergence of the Laplace approximation and noise-level-robustness of Laplace-based Monte Carlo methods for Bayesian inverse problems
Full text linkThe Bayesian approach to inverse problems provides a rigorous framework for the
incorporation and quantification of uncertainties in measurements, parameters and
models. We are interested in designing numerical methods which are robust w.r.t. the
size of the observational noise, i.e., methods which behave well in case of concentrated
posterior measures. The concentration of the posterior is a highly desirable situation
in practice, since it relates to informative or large data. However, it can pose a computational
challenge for numerical methods based on the prior measure. We propose to
employ the Laplace approximation of the posterior as the base measure for numerical
integration in this context. The Laplace approximation is a Gaussian measure centered
at the maximum a-posteriori estimate and with covariance matrix depending on the
logposterior density. We discuss convergence results of the Laplace approximation
in terms of the Hellinger distance and analyze the efficiency of Monte Carlo methods
based on it. In particular, we show that Laplace-based importance sampling and
Laplace-based quasi-Monte-Carlo methods are robust w.r.t. the concentration of the
posterior for large classes of posterior distributions and integrands whereas prior-based
importance sampling and plain quasi-Monte Carlo are not. Numerical experiments are
presented to illustrate the theoretical findings
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
MAP estimators for nonparametric Bayesian inverse problems in Banach spaces
Full text linkIn order to rigorously define maximum-a-posteriori estimators for
nonparametric Bayesian inverse problems for general Banach space valued
parameters, we derive and prove certain previously postulated but unproven
bounds on small ball probabilities. This allows us to prove existence of MAP
estimators in the Banach space setting under very mild assumptions on the
loglikelihood. As a similar statement so far (as far as the author is aware)
only existed in the Hilbert space setting, this closes an important gap in the
literature.Comment: This preprint contained incomplete ideas and even some errors. These
gaps and mistakes have been closed by a recent preprint: arXiv:2207.00640 Due
to the fact that the techniques and the scope have changed as well as the
author list, I would like to withdraw this preprin
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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