1,721,271 research outputs found
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
A proposal of a unique formula for computing compliance in bolted joints
Full text linkThe connection system between mechanical parts with the greatest advantages in terms of production is the threaded connection. This type of connection has considerable stiffness but also high weight. Often the search for the reduction of the masses clashes with the limits dictated by production needs. A considerable effort has been made in making screws with higher performance materials and therefore guaranteeing greater tightening forces with smaller cross sections, but there have not been as many notable developments on the method of determining the compliance of tightened elements. The classical theory identifies three different conditions for calculating deformability, which are sometimes not easy to interpret and implement. The use of numerical techniques such as finite elements allows designers to be very precise, but requires a great deal. To facilitate the work of the designers and provide them with a more manageable tool to better understand the type of threaded connection to be designed, the present work proposes an analytical formulation that allows a quick assessment of the compliance value of the clamped elements, regardless of the geometric relationships and materials. To achieve this, starting from a literature analysis, a parametric finite element model was developed and, based on the results obtained, a formula is proposed that covers all the possible scenarios for determining compliance. The results were compared with the classical theory in order to verify the correctness and applicability of the formulation. At the moment the formulation is valid for screws whereas for the bolts with nut unified formula is under investigation
Finite element modeling of residual stress and geometrical error formations in selective laser melting of metals
Full text linkRecent works, both numerical and experimental, on residual stress and geometrical errors in selective laser melting-produced parts highlighted the preponderance of these phenomena. However, their mechanisms of appearance are not yet fully explained. An in-house finite element model was developed and implemented to reproduce their formations. The consistence of the model with existing simulation results and with respect to experimental observations was checked. Simulations were then performed using a computational design of experiments to better comprehend the underlying phenomena and the influence of the laser speed and power. Relationships between process parameters and residual stress, plastic strain, and geometrical errors formations have been put into evidence which can support optimization procedures at design stage
Design of a differential system focused on reusability and payload hosting capabilities for a rover based on rocker-bogie locomotion mechanism
No full textUse of Nitrogen-Doped Carbon Nanodots for the Photocatalytic Fluoroalkylation of Organic Compounds
No full textThe use of amine‐rich N‐doped carbon nanodots (NCNDs) for the photochemical radical perfluoroalkylation of organic compounds is reported. This operationally simple approach occurs under mild conditions producing valuable new C−C bonds. The chemistry is driven by the ability of NCNDs to directly reach an electronically excited state upon light absorption, thereby successively triggering the formation of reactive radical species from simple perfluoroalkyl iodides. Preliminary mechanistic studies are also reported
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