1,721,360 research outputs found
"App immuni" tra tutela della salute e protezione dei dati personali: un difficile bilanciamento
No full text"App immuni" - base giuridica a livello sovranazionale . nuova normativa nazionale sul sistemaa di "contract tracing" - controllo giurisdizionale da parte delle Corti europe
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
Effects of Gyroscopic Phenomena on Tuned Vibration Absorbers Design and Performance
No full textThis paper explores the dynamics of rotating Tuned Vibration Absorbers (TVAs), focusing on the phenomena arising from gyroscopic effects. Some products from Leonardo Helicopters (LH) can have a TVA fitted in the rotor mast, counteracting the in-plane vibratory loads of the rotor directly at their source, implying that the absorber rotates with the rotor itself. Although gyroscopic effects are negligible for most of the LH TVAs, specific design choices may have notable impacts on tuning and performance. An analytical model is implemented, demonstrating that the gyroscopic terms influence the dynamics causing a frequency displacement of the anti-resonance evaluated without considering this effect. Additionally, a regression analysis investigates the interplay between this phenomenon and the physics of the system, revealing how to optimize the design to mitigate gyroscopic effects. Finally, the performance of the TVA is analyzed as a coupled problem, showing that the anti-resonance effectiveness is reduced by the orthogonal contribution introduced by the gyroscopic matrix
High-Fidelity Modelling of Actuation Systems for Nonlinear Aeroservoelastic Analysis of Tiltrotor
No full textRecent evolutions in regulatory practices place an increasing emphasis on nonlinear aeroservoelastic analysis to prevent adverse phenomena like Limit Cycle Oscillations (LCO). Thanks to enhanced computational capabilities, this field is set to take an even more important role in the certification process of new aircraft, and in particular of tiltrotor, together exploiting the increasing ability to build multidisciplinary and high-fidelity modelling of complex aeronautical systems. In this paper, a comprehensive model of a tiltrotor control surface actuation system is introduced, capable of accurately representing the main nonlinear features and helping to better comprehend their origin. The model includes the entire control chain, starting from the Flight Control System (FCS) logic and getting to the control surface structure, passing through the hydraulic servo-actuator and the related mechanical linkages. The behavior of the servo-actuator model as a subsystem and the one of the entire control chain are compared to experimental data. Finally, a simplified nonlinear aeroservoelastic simulation shows the potential effects of the nonlinearities present in the system
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