1,720,968 research outputs found
pdglasso: Graphical Lasso for Coloured Gaussian Graphical Models for Paired Data
No full textR package implementing Graphical Lasso for Coloured Gaussian Graphical Models for Paired Data. Further information available at the url
Semiparametric finite mixture of regression models with Bayesian P-splines
No full textA semiparametric finite mixture of regression models is defined, with concomitant information assumed to influence both the component weights and the conditional means. The contribution of a concomitant variable is flexibly specified as a smooth function represented by cubic splines. A Bayesian estimation procedure is proposed and an empirical analysis of the baseball salaries dataset is illustrated
Bayesian variable selection in linear regression models with non-normal errors
No full textMultiple linear regression is a prime statistical tool used to discover potential
relationships between an outcome and some explanatory variables of interest.
One of the common required assumptions is for the error terms in the model to be
Gaussian. Instead of assuming normality, an alternative is to use a finite mixture of
normal distributions, allowing for a more flexible definition of the heterogeneity structure
of the data. We use this approach to develop a Bayesian linear regression model
with non-normal errors, and through variable selection we focus on finding active
predictors effectively contributing to explaining patterns in the observations
Overlapping mixture models for network data (manet) with covariates adjustment
No full textNetwork data often come in the form of actor-event information, where two types of nodes comprise the very fabric of the network. Examples of such networks are: people voting in an election, users liking/disliking media content, or, more generally, individuals - actors - attending events. Interest lies in discovering communities among these actors, based on their patterns of attendance to the considered events. To achieve this goal, we propose an extension of the model introduced in [5]: our contribution injects covariates into the model, leveraging on parsimony for the parameters and giving insights about the influence of such characteristics on the attendances. We assess the performance of our approach in a simulated environment
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
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