1,721,151 research outputs found
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
Assessing Environmental Impacts of Two Stroke Outboard Motor Lubricants Using Tank Testing and Simple Dispersion Model
No full textVariations 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
Under Water Emissions from a Two-Stroke Outboard Engine-A Comparison between an EAL and an Equivalent Mineral Lubricant
No full textAppropriate 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
Comparison of 4-ball and 5-ball rolling contact fatigue tests on lubricated Si3N4/steel contact
No full textAccelerated four-ball and five-ball rolling tests were performed on HIPed Si3N4 ball samples (rough lapped with surface
roughness value Ra0.08 μm and Rq0.118 μm) in fully lubricated condition. The contact load and the stress cycles per minute
for four-ball rolling and five-ball rolling tests were maintained the same. The rolling track appearances of five-ball tests reveal
severe sliding occurred. In one case, the opposite arc cracks were generated all over the two sides of the rolling track, and this
could not be explained by simplified kinematics model. The failure mechanisms were discussed, which suggest the sliding on the
two sides of the track was in the opposite direction
Parameter optimization by Taguchi Methods for finishing advanced ceramic balls using a novel eccentric lapping machine
No full textThe final finishing process of advanced ceramic balls used in hybrid precision bearings constitutes two-thirds of the total manufacturing cost, and hence effective and economic finishing methods and processes are critical to their widespread application. A novel eccentric lapping machine is designed and manufactured. Hot isostatically pressed silicon nitride ball blanks (diameter 13.25 mm) are used to investigate the feasibility of accelerating the ball finishing process while maintaining high surface quality. Taguchi methods are used during the first step of finishing to optimize lapping parameters; the L9 (3(4)) four-parameter, three-level orthogonal array is used to design the experiment. Experimental results reveal that this novel eccentric lapping method is very promising; a material removal rate of 40 mum/h is achievable. The optimum lapping condition is found to be high speed, high load and high paste concentration with 60 mum diamond particles. The analysis of variance shows that the most significant lapping parameter is lapping load, which accounts for 50 per cent of the total, followed by lapping speed (31 per cent); the particle size and paste concentration only account for 12 per cent and 7 per cent respectively. A comparison with previous lapping experiments and the mechanism of material removal are also discussed briefly
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