1,721,102 research outputs found
Development and HIL validation of observer-based monitoring algorithms of battery packs for eVTOL UAV applications
No full textBattery management systems significantly impact the performance of electric Vertical Take Off and Landing Unmanned Aerial Vehicles (eVTOL UAVs). In UAVs powered by multiple battery packs, optimising energy and power to extend cycle life and flight time requires monitoring of state of charge and temperature with a limited number of sensors. To achieve this, the battery pack electro-thermal model is first identified using a dedicated test and validated with experimental data from a current load profile based on a flight mission simulation of the reference UAV. A comprehensive analysis based on convergence speed, computational burden, and disturbance rejection is then conducted to determine the most suitable monitoring algorithm among three widely used observers: the Luenberger Observer (LO), Extended Kalman Filter Observer (EKFO), and Sliding Mode Observer (SMO). The comparison shows that the LO offers the best balance. To mitigate ageing sensitivity in state of temperature estimation, the observer uses the actual terminal voltage to compute heat generation rather than relying solely on model-predicted voltage. This accounts for resistive degradation and enhances robustness, though severe ageing needs a dedicated state of health estimator. The selected observer is validated in real time through a Hardware in the Loop test
Conception préliminaire de carters pour actionneurs
No full textCe projet est une étude centrée sur la conception préliminaire des actionneurs pour les applications aéronautiques. Toutes les parties de l’avion, et spécialement les ailes sont soumises à fortes vibrations a cause des turbines. Des éléments, d’importance vitale, comme les actionneurs doivent réussir des tests expérimentaux concernant ces vibrations.
Cette étude a été inspirée par un type d’actionneur qui se cassait au même point pendant des essais réels. Notre objectif initial a donc été l’étude de cet actionneur pour détecter quelle était la cause de cette rupture. Ensuite nous avons développé une méthodologie et des outils pour solutionner des problèmes plus généraux du même type.Outgoin
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe 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
Conception préliminaire de carters pour actionneurs
No full textCe projet est une étude centrée sur la conception préliminaire des actionneurs pour les applications aéronautiques. Toutes les parties de l’avion, et spécialement les ailes sont soumises à fortes vibrations a cause des turbines. Des éléments, d’importance vitale, comme les actionneurs doivent réussir des tests expérimentaux concernant ces vibrations.
Cette étude a été inspirée par un type d’actionneur qui se cassait au même point pendant des essais réels. Notre objectif initial a donc été l’étude de cet actionneur pour détecter quelle était la cause de cette rupture. Ensuite nous avons développé une méthodologie et des outils pour solutionner des problèmes plus généraux du même type.Outgoin
Variations on the Author
No full text“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
No full textWe 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
Conception préliminaire de carters pour actionneurs
No full textCe projet est une étude centrée sur la conception préliminaire des actionneurs pour les applications aéronautiques. Toutes les parties de l’avion, et spécialement les ailes sont soumises à fortes vibrations a cause des turbines. Des éléments, d’importance vitale, comme les actionneurs doivent réussir des tests expérimentaux concernant ces vibrations.
Cette étude a été inspirée par un type d’actionneur qui se cassait au même point pendant des essais réels. Notre objectif initial a donc été l’étude de cet actionneur pour détecter quelle était la cause de cette rupture. Ensuite nous avons développé une méthodologie et des outils pour solutionner des problèmes plus généraux du même type.Outgoin
Dispelling the Myths Behind First-author Citation Counts
No full textWe 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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