1,720,954 research outputs found
Rotorcraft Safety: A Simulator-based Training Perspective
Full text linkTraining has the potential to inject a “safety vaccination” into the rotorcraft community by reducing the number of accidents. The term training should not be intended only in a strict sense, i.e., as pilot technical skills training, but more broadly as risk avoidance and safety culture training. As in the case of vaccination, where immunity is created only when applied on a large scale, helicopter accidents will not be eradicated until every player in the rotorcraft community is involved in the safety enhancement process. In particular, as outlined by accident and safety reports, a reduction in the helicopter accident rate cannot be accomplished disregarding pilots’ training and the contribution that _ight simulators can provide to both training and certi_cation. This paper provides an overview of the research into simulator training for helicopter pilots conducted as part of the European Joint Doctorate NITROS (Network for Innovative Training on Rotorcraft Safety). An approach that requires an in-depth analysis of the actual training task is adopted for two different maneuvers, namely hover and autorotation. This approach enables the training developer to understand what are the aspects of the actual training situation that should be reproduced in the simulated training situation to avoid ineffective training and negative transfer of skills. Moreover, such an approach allows to identify differences in terms of requirements between the training of basic and advanced maneuvers and between initial and recurrent training. The results of three different pilot-in-theloop experiments, performed to explicitly con_rm the effectiveness of developed training programs and to understand whether certain elements of the simulation can foster the development of superior _ying skills, are summarized in this paper.Control & Simulatio
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
Investigation of the Effects of Autorotative Flare Index Variation on Helicopter Flight Dynamics in Autorotation
Full text linkAutorotation is a flight condition whereby the engine of a helicopter is no longer supplying power to the main rotor system, which is driven solely by the upward flow of the air moving through the rotor. For helicopters, autorotation is a common emergency procedure performed by pilots to safely land the vehicle in the event of a power failure or tail-rotor failure. In the classic analysis of dynamic stability of helicopters in powered flight, it is common practice to neglect the effect of variation of rotor angular velocity, as the rotorspeed is constant. However, this assumption is no longer justified in case of autorotative flight. Therefore, the rotorspeed becomes an additional degree-of-freedom in autorotation, giving rise to a new stability mode that couples with classical rigid-body modes. The present paper aims at understanding the role of the rotorspeed degree-of-freedom in modifying the stability characteristics in autorotation of rotor systems with different autorotative flare indexes. Results show that the helicopter dynamics are considerably affected in autorotation as a consequence of the fact that the rotorspeed degree of freedom couples with the heave subsidence mode. Therefore, autorotation requires a different control strategy by the pilot and should not be mistakenly considered only as an energy management task. Furthermore, the autorotative flare index, used to characterize the autorotative performance during the preliminary design phase of a new helicopter, provides only energy information. Indeed, this paper demonstrates that high values of this index, representative of good autorotative performance in terms of available energy over required energy, may lead to degraded stability characteristics of the helicopter in autorotation.Control & Simulatio
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
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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