1,721,017 research outputs found
Reliable high speed transfer with the le Croy CAMAC-GPIB interface
No full textThe author presents modifications to the original instructions, which make it possible to have a reliable high speed transfer from a CAMAC transient recorder to a computer by means of a Le Croy CAMAC-GPIB interface.SCOPUS: ar.jinfo:eu-repo/semantics/publishe
Effect of the geometrical parameters on an absolute calibration
No full textThe intensity measured in an absolute calibration, carried out with a tungsten ribbon lamp, is theoretically computed as a function of the geometrical parameters involved in the experiment. The theoretical computations, confirmed by the experimental measurements, make it possible to place the lamp as close as possible to the detector and thereby improve the accuracy of the absolute calibration.SCOPUS: ar.jinfo:eu-repo/semantics/publishe
Side-on intensity measurements with a cylindrical collimation channel
No full textThe theory developed to analyse the effect of a hollow cylindrical collimation channel on absolute calibration is applied to side-on intensity measurements carried out on a cylindrical plasma. The computation shows that the ratio of the absolute calibration integration factor to the side-on measurements integration factor may not be equal to one, as expected. Therefore, this ratio should be computed in order to obtain accurate absolute emission coefficients.SCOPUS: ar.jinfo:eu-repo/semantics/publishe
Contribution to the definition of the power bands limits of sleep EEG by linear prediction
No full textThe linear prediction method has been applied to compute the power spectra distribution in 10 healthy young men (aged 17 to 26). For each subject, the local extrema positions have been detected and grouped as a function of their frequency. The computation of a mean frequency distribution for the extrema position, on the 10 subjects, allowed for the definition of eight frequency power bands. The time evolution of these power bands during the first NREM episode has been computed and averaged for the 10 subjects. The cross-correlation analysis demonstrated the relevance of three bands in the range 0-8.10 Hz: delta ]0-2.78] Hz, theta 1 ]2.78-5.42] Hz, theta 2 ]5.42-8.10] Hz. Our extrema study leads to the division of the beta range ]16.25-25.00] Hz into three bands. However, their time evolution does not support the usefulness of the partitioning of the beta range, probably resulting from our too low sampling frequency.SCOPUS: ar.jinfo:eu-repo/semantics/publishe
The effect of light-pipes measurements on the determination of the emissivity by Abel inversion
No full textThe determination of the emissivity of a cylindrical plasma by the Abel inversion assumes that the side-on intensity is measured on one straight line. A deconvolution procedure is proposed for light-pipes measurements. It is shown that beyond a critical width of the input channel, systematic errors may appear in the reconstructed emissivity.SCOPUS: ar.jinfo:eu-repo/semantics/publishe
Error attenuation in Abel inversion
No full textA data approximation technique is presented for solving numerically the Abel integral equation. The side-on intensity is developed in a set of even powers. The optimization of the number of terms in the expansion makes it possible to control the smoothing of the data, and thereby strongly reduces the effects of experimental errors. The results are compared with those obtained by other methods, demonstrating the utility of this technique. © 1982.SCOPUS: ar.jinfo:eu-repo/semantics/publishe
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
Variations 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
Appropriate 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
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