1,723,725 research outputs found
Independent component analysis using Gaussian mixture models
No full textThis paper discusses a method for performing independent component analysis exploiting Gaussian mixture models (GMMs). Previously most techniques that combine these method shave used GMMs to model the source signals. This paper considers a parsimonious method for modelling the observed signals. The GMM is fitted to the observed data using a modified version of the expectation maximisation algorithm
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
Topographic expressions of mantle dynamics in the Mediterranean
No full textThe surface of the Earth is the ever-changing expression of the dynamic processes occurring at depth and at or above its surface. However, our ability to “read” landscapes in terms of their underlying tectonic or climatic forcing remains rudimentary. During the last decade, particular attention has been drawn to the deep dynamic contributions to topography, related to the stresses that are produced at the base of the lithosphere by mantle convection, and their relevance compared to the (iso)static component of topography. Here, we use examples from the Mediterranean and estimate residual and dynamic topography. We then compare those with surface uplift from geology for specific regions to disentangle the dynamic from the static components. Considering the different topographic signatures of tectonic processes (e.g. actual, residual, and dynamic topography as well as uplift rates) jointly provides a powerful way to distinguish between the contributions of mantle, crustal, and surface processes. Such an approach might bring us closer to reading topographic expressions in terms of their geological cause
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