1,721,081 research outputs found
Mircea Popescu şi corespondenţii săi: Ştefan Baciu, N. P. Comnen, Neagu Djuvara, Mircea Eliade, Vintilă Horia, Virgil Ierunca, Petru Iroaie, Alexandrina Mititelu
Full text linkMircea Popescu was a professor, literary critic and journalist who lived almost all his life in exile, in Italy, where he promoted the Romanian culture permanently. He has a very rich correspondence with Ștefan Baciu, N.P. Comnen, Neagu Djuvara, Mircea Eliade, Vintilă Horia, Virgil Ierunca, Petru Iroaie and Alexandrina Mititelu. Due to his daughter-in-law, Mrs. Simona Coleş-Popescu, we’ll include some unpublished letters sent by his friends and Romanian writers in a book dedicated to Mircea Popescu’s literary activity. In this article we publish two of them
Hairpin Windings for Traction Machines: Analysis and Comparison
No full textThis work investigates circulating currents and additional losses in hairpin windings with multiple parallel paths when a weak symmetry pattern is adopted. The theoretical rules for designing hairpin windings may lead to configurations not completely preventing parasitic currents in the parallel branches, especially in heavy saturation conditions. Often, the proposed configurations in the literature present a weak symmetry between the parallel branches. This paper considers a typical hairpin winding configuration to compute the actual currents in the parallel paths. For this purpose, machine models are driven by an external three-phase circuit and finite element analyses are carried out. The main goal is to explain the causes of circulating currents. The analysis is repeated using different rotor topologies and keeping respectively the same stator design, overall machine volume and hairpin winding pattern to look into the different effects in windings induced by parasitic currents
Embedded finite-element solver for computation of brushless permanent-magnet motors
Full text linkThis paper describes the theory underlying the formulation of a “minimum set” of finite-element solutions to be used in the design and analysis of saturated brushless permanent-magnet motors. The choice of finite-element solutions is described in terms of key points on the flux–MMF diagram. When the diagram has a regular shape, a huge reduction in finite-element analysis is possible with no loss of accuracy. If the loop is irregular, many more solutions are needed. This paper describes an efficient technique in which a finite-element solver is associated with a classical – -axis circuit model in such a way that the number of finite-element solutions in one electrical half-cycle can be varied between 1 and 360. The finite-element process is used to determine not only the average torque but also the saturated inductances as the rotor rotates
Thermal Analysis of Duplex Three-Phase Induction Motor Under Fault Operating Conditions
No full textThis paper describes a thermal model for a duplex three-phase induction machine for fault-tolerant applications. The three- and six-phase variations of the duplex three-phase machine operation under fault conditions are considered. Different winding configurations are investigated. Thermal analysis is performed using analytical and finite-element models. An experimental validation is presented for load operating conditions. © 1972-2012 IEEE
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
- …
