1,721,101 research outputs found
Introduzione: Sostenibilità, Beni comuni e Inclusione per una vera Responsabilità Sociale di Territorio
No full textInquadramento teorico del tema oggetto del volume che raccoglie le ricerche del progetto "Cooperiamo per l'Economia del Buon Vivere Comune (cod. 652-1-948-2016) Finanziato a valere sul POR FSE 2014-2020 di Regione Veneto, DGR 948/2016
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
Performance analysis of FCS-MPC and Pi-resonant fault-tolerant controllers for WECS
No full textOne of the most attractive features of multiphase machines is the fault-tolerant capability it possesses due to the higher number of phases. Different post-fault control strategies based on hysteresis, Pi-resonant and predictive techniques have been recently proposed. They all proved their capabilities to withstand fault situations and to preserve the fundamental component of the air-gap field, while achieving minimum losses, maximum torque per-ampere and reducing torque vibrations. Nonetheless due to its recent implementation, no thorough study has been done comparing the performance of these controllers. In this paper two open-phase fault-tolerant control schemes, based on Pi-resonant and predictive control techniques, for five-phase induction machines, are compared through simulation results
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
Direct Torque Control for induction machines: A technology status review
No full textAmong all control methods for induction motor drives, Direct Torque Control (DTC) is considered particularly interesting being independent of machine rotor parameters and requiring no speed or position sensors. The basic DTC scheme is characterized by the absence of coordinate transformations, current regulators and PWM signals generators. In spite of its simplicity, DTC allows a good torque control in steady state and transient operating conditions to be obtained. However, the presence of hysteresis controllers for flux and torque lead to torque and current ripple and variable switching frequency operation for the voltage source inverter. This paper is aimed to briefly recall DTC principles and their intrinsic problems, and to discuss possible control strategies to improve the operating characteristics. Due to its basic principle, DTC technique is well suited for exploiting the improved number of voltage vectors available with multilevel and multiphase converters. A discussion is also carried out in order to emphasize the potentiality of induction motor drives based on these new power converter topologies
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
A Space Vector Modulation Strategy for Matrix Converters Minimizing the RMS Value of the Load Current Ripple
No full textIn this paper an analytical approach to predict the current ripple in an inductive load fed by a matrix converter controlled with Space Vector Modulation is presented. The analysis aims at determining the optimal modulation strategy that minimizes the rms value of the load current ripple. The minimization procedure is based on the analysis of the locus described by the current ripple in the d-q reference frame. As a result, a set of equations which allows the on-line calculation of the optimal SVM switching pattern is found. It has been verified that it is possible to obtain a current ripple lower than that of traditional SVM strategies, and with a reduced number of commutations. Experimental results are provided to confirm the theoretical approach
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
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