1,720,982 research outputs found
Vibrational power flow in the moving belt passing through a tensioner
No full textBecause of the high performance and low weight requirements for modern machines including engines, the belts servicing high dynamic loads at high speed tend to be very susceptible to the transferred vibration. In this paper, a method is proposed for obtaining the physical characteristics of the transverse vibrational power flow through moving rubber belts. The governing equation is derived by applying Hamilton's principle to the description of the flexural vibrations in axially moving belts, where the tensioner is considered to be a one-degree-of-freedom system, The total power flow calculated and measured in the moving belt is the sum of:the true power flow and the power component associated:with the steady medium motion. Consequently, any component that is due solely to the belt movement should be subtracted from the total power flow in order to obtain the true, net power flow. This concept is employed in calculating the transverse vibrational power flow through belt-pulley systems that include a tensioner. An equivalent system including an idler instead of the tensioner is also considered, and the observed power flow in this condition is ascribed to the power flow due only to the movement of the medium. The results of analysis show that the vibrational power of the two belt-spans flows into the tensioner. It is shown-that the energy flow, measured by using two laser sensors, agrees reasonably well with the predicted results. (C) 2000 Academic Press
Measurement of Vibrational Power Transmission in Belt-Pulley System by Using the Power Flow Method
No full textIdentification of Vibration Transmission through Belt-Pulley Systems by Using the Structural Intensity Method
No full textOn the Percision Mearurement of Bulk Acoustic Properties of Absorbing Materials in an Impedance Tube
No full text
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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