1,720,959 research outputs found
Process parameter auto-adaptation strategy for one-up drilling of CFRP/aluminium hybrid stack
No full textThe aerospace sector is looking for lighter, more robust, and less fuel-consuming aircraft by using advanced lightweight materials. Fibre-reinforced polymers and lightweight alloys are pivotal to this aim, owing to their favourable strengthto-weight ratio and mechanical properties. Therefore, assembling hybrid stacks of these materials ofers customisation opportunities to optimise performance and structural integrity. This research explores one-up drilling techniques for hybrid stacks of carbon fbre-reinforced polymer (CFRP) laminates and aluminium alloy sheets, which are essential in the fabrication of advanced aircraft structures. The experimental procedure consists of frst drilling individual materials separately to optimise the process parameters for each material and then drilling a hybrid stack confguration (CFRP/AA7075-T6) with an innovative approach using spindle active power monitoring to implement a self-adapting strategy of process parameters at the interface between the two materials. This fexible methodology ofers a practical solution for streamlining the drilling process in aerospace application
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Get PDFWe 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
Smart process parameters adaptation for drilling of CFRP and AA7075 stacks
No full textThis work explores a self-adaptive strategy for one-up drilling of CFRP/AA7075-T6 stacks, leveraging spindle active power monitoring for real-time parameter adjustments. The method enables precise detection of the material interface, ensuring optimal process conditions for each material without requiring additional sensors. Key quality metrics—burr height and delamination factor—were analysed under various switching conditions. Results reveal that switching parameters when the cutting edge fully engages the aluminium layer minimizes interface defects and enhances hole quality. The strategy proves superior to compromise parameter sets, reducing delamination in CFRP and burr formation in AA7075-T6, while maintaining productivity. This adaptive approach demonstrates high reliability and industrial applicability, offering significant improvements in hybrid material drilling for aerospace manufacturing
Evaluating the impact of boundary conditions and clamping force in robotic one-up drilling of hybrid stacks
No full textThe rapid increase in air traffic and the growing focus on more sustainable solutions require improvements in fuel efficiency and cost reduction, highlighting the importance of lightweight materials in aircraft manufacturing. This study investigates the one-up drilling process of Carbon Fibre Reinforced Polymer and AA7075-T6 stack, focusing on the influence of process parameters, drilling boundary conditions and clamping force on the hole quality. A robotic drilling system was used to study both ideal and non-ideal boundary conditions. Under ideal boundary conditions, optimal drilling parameters were identified: a cutting speed of 85 m/min and a feed rate of 0.01 mm/rev for CFRP, and 60 m/min with 0.05 mm/rev for AA7075-T6. Therefore, parameter switching strategies were implemented to improve hole quality at the material transition zone. Then, under non-ideal boundary condition, variable clamping forces (0 N, 250 N, and 400 N) were applied by the robot's end effector, demonstrating that higher clamping forces significantly reduce interlayer gaps, leading to up to 60.27 % reduction in entry burr and 16.10 % decrease in delamination factor. This comprehensive approach provides deeper understanding on how process parameters and boundary conditions affect both hole quality and tool forces, offering new insights for optimising drilling processes in aerospace manufacturing
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
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