1,720,988 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
Some remarks on the use of TaqI to detect highly repetitive DNA sequences in human chromosomes
No full textIn the attempt to conclude investigation of the action of restriction endonucleases on eukaryote chromosomes, we carried out a series of experiments digesting in situ human metaphase chromosomes with AluI/TaqI followed by Giemsa staining. We focused on the centromeric regions of chromosomes1, 2 and 16 and noted that those areas appeared as intensely stained blocks after AluI digestion, but were dramatically reduced in size or completely destroyed after subsequent TaqI treatment. These results permitted us to draw some conclusions on the highly repetitive DNA composition of these regions, in terms of alphoid and classical satellite DNAs
An Experimental Investigation on Aerospace Quality Gears Operating in Loss of Lubrication Condition
No full textThis paper shows the results of an experimental study
carried out on spur gears for aerospace applications operating
in loss of lubrication. The aim of this work was to establish a
baseline for gear behavior under oil off conditions. A total
amount of 40 tests were performed with gears made from 2
materials operating at different levels of sliding speed and
contact pressure. In some cases the bulk temperature was
measured to evaluate the heating of the running gear. A more
relevant wear and heating of the gears was observed with the
increase of the contact pressure rather than with the increase of
the sliding speed. In all the tests the transmission was able to
transfer the required power. However some tests were stopped
before the required time because of the overcoming of the rig
safety threshold. The results showed a different oil off time
depending on the material
Rolling Bearing Monitoring Using Classification Techniques
No full textIn this paper an automatic method for condition monitoring of rolling element bearings, based on classification techniques, is proposed. The method, applied to the vibration signals of bearings monitored on two experimental test rigs, seems to overcome the limits of the traditional methods of vibration analysis. In particular, it can automatically diagnose various types of defects, which may occur, one at a time or simultaneously, on one or more bearings. Actually, the guidelines of the proposed method establish a standard methodology for automatic diagnosis that can be applied to all cases in which one can collect an appropriate number of signals related to the basic types of defects to be monitored.
Finally, the robustness of the method to noise was also studied by analysing the trend of correct classification of the signals as function of the signal-to-noise ratio
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