1,721,015 research outputs found
Feasibility of a 10 MW Doubly Fed Induction Generator for Direct-Drive Wind Turbines
No full textThe study considers 10 MW, 600 poles, doubly fed induction generator, allowing direct-drive units with reduced size converter. The work relies on a lumped parameters design and on finite element verifications, and it compares some of its results to the findings of recent literature. The results of the paper evidenced a borderline feasibility of the considered
generator
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
Functional Magnetic Resonance Imaging: comparison between activation maps and computation pipelines in a clinical context
Full text linkIn this study new evaluation strategies for comparing different Statistical
Parametric Maps computed from fMRI time series analysis software tools
are proposed. The aim of our work is to assess and quantitatively evaluate
the statistical agreement of activation maps. Some pre-processing steps are
necessary to compare SPMs (Statistical Parametric Maps), including segmen-
tation and co-registration
Cryogenic Characterization of Copper-Wound Linear Tubular Actuators
No full textElectrical machine power density can be increased by liquid nitrogen (LN) cooling, since these machines operate at low resistivity and have a high heat transfer coefficient. This paper describes the experiments carried out on a short stroke tubular linear permanent magnet machine with copper windings
and LN cooling. A cryogenic test rig for linear actuators was designed and built, and tests were carried out aimed at high lighting inherent current limiting capability, electric parameter variation in the fall from room to cryogenic temperatures, and actuator high thrust density. Shear stress reaches 17.8 kN/m2, and thrust-to-copper-loss ratio is 4 N W−1/2 , which are significantly better compared to conventional actuator
2-D Mechanical and Magnetic Analysis of a 10 MW Doubly Fed Induction Generator for Direct-Drive Wind Turbines
No full textDirect-drive wind turbines often require full
size converters, especially for latest offshore 10 MW units.
This paper contributes to the evaluation of 10 MW, 600
poles, doubly fed induction generators, possibly enabling
to reduce the converter size. The work relies on a lumped
parameters design procedure and on finite elements
mechanical and magnetic verifications, which seem to
confirm the technical feasibility of the machine
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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