1,721,020 research outputs found
Numerical Investigation of Three-Dimensional Ice Formation on a Wing with Leading Edge Tubercles
No full textThis work numerically investigates the influence of sinusoidal leading-edge characteristics, often described as wavy leading edge wings or wings with tubercles, on aircraft icing. Initially, the flow prediction of clean wavy wings is compared to experimental data for model validation. A series of test cases based on the experimental geometry is subsequently established with varying wave amplitudes and lengths. The icing assessment is conducted numerically using the three-dimensional PoliMIce ice accretion toolkit. Firstly the influence of the three-dimensional flow behaviour on the collection efficiency is evaluated. The simulations demonstrate that wavy leading edges with shorter wave lengths and higher wave amplitudes increase the localised impingement of super-cooled water droplets during impact. Secondly the influence of the wavy leading edge profile on the ice shapes is assessed for both the rime and glaze ice regime. The results show that the maximum ice thickness is in the vicinity of the wave peaks and troughs meanwhile the mid-sections of the waves have significantly lower levels of ice accretion. The future perspective of this work is to assess the potential for improving the efficiency of anti-icing and de-icing systems using wavy leading-edges
Helicopter Shipboard Operation: Effect of Atmospheric Boundary Layer on Turbulent Ship Airwake and Rotor Aerodynamic Loads
No full textThis paper studies the effect of two different boundary layer models on the airwake of the Simple Frigate Shape 1 and further on the unsteady aerodynamic loads of a scaled helicopter model operating inside the ship airwake. The unsteady airwake of the isolated SFS1 is computed in a time-accurate approach using the open-source SU2 solver, implementing two types of boundary conditions: a Uniform Flow (UF) and a steady Atmospheric Boundary Layer (ABL), where the reduction of the velocity due to the surface roughness is also considered. The simulations are performed in two wind conditions, including headwind and 30◦ from the port-side (R30). The airwake data are implemented into a multibody simulation of a scaled helicopter model, developed using the open-source multibody software MBDyn, based on the one-way coupling approach. Hover tests are performed at different positions with respect to the deck and the unsteady aerodynamic loads are compared in frequency domain. In addition to the increase of unsteadiness in the red wind compared to the headwind simulation, the results indicate that in both wind conditions, the unsteadiness is reduced with the presence of the steady ABL. Since the unsteady loads are expected to directly affect the pilot workload, the results highlight the importance of modelling a realistic boundary layer considering both steady and turbulent profiles
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
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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