1,721,127 research outputs found
How a Rear Steering System May Improve Motorcycle Dynamics, 328 Int. J. Vehicle Design,
No full textThis research investigates how motorcycle dynamics may be improved by applying a steering system on the rear wheel. The study is carried out using a widely validated multi-body model of motorcycle and rider. Two types of rear steering systems are compared: a self-steering wheel coupled with a spring-damper assembly and a controlled steering wheel, whose steering angle is governed accordingly to a first-order relationship between front and rear steering angle. In general, any rear steering system transfers energy from weave mode to wobble mode. Thus, both solutions stabilise high-speed weave, but increase instability when braking. The passive system shows unexpected reactions when accelerating in cornering condition, whereas the active system is almost neutral
Acoustic wave simulation by spectral methods
No full textAdvantages of dealing with acoustic wave equations by high-order methods are their enhanced accuracy and the possibility of using fewer points per minimum wavelength. On the other hand, they require a more sophisticated mathematical theory. A numerical treatment by spectral weak collocation approximation is presented. Numerical aspects concerning stability, convergence and time-advancing schemes are discussed. Absorbing boundary conditions are introduced to fit realistic physical situations with a suitable mathematical description
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
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