1,721,016 research outputs found
Application of the parametric bootstrap method to determine statistical errors in quantitative X-ray microanalysis of thin films
No full textWe applied the parametric bootstrap to the X-ray microanalysis of
Si-Ge binary alloys, in order to assess the dependence of the Ge
concentrations and the local film thickness, obtained by using
previously described Monte Carlo methods, on the precision of the
measured intensities. We show how it is possible by this method
to determine the statistical errors associated with the
quantitative analysis performed in sample regions of different
composition and thickness, but by doing only one measurement. We
recommend the use of the bootstrap for a broad range of applications for
quantitative microanalysis to estimate the precision of the final
results and to compare the performances of different methods to
each other. Finally, we exploited a test based on bootstrap
confidence intervals to ascertain if, for given X-ray intensities,
different values of the estimated composition in two points of the
sample are indicative of an actual lack of homogeneity
Quantitative thin film X-ray microanalysis by STEM/HAADF: Statistical analysis for precision and accuracy determination.
No full textSilicon-germanium thin films have been analysed by EDS
microanalysis in a FEG-STEM equip-ped with a high angular
dark-field detector (STEM/HAADF). Several spectra have been
acquired in the same homogeneous area of the cross-sectioned
sample by drift-corrected linescan acquisitions. The Ge
concentrations and the local film thickness have been obtained by
using a previously described Monte-Carlo based `2 tilt-angle'
method. While the concentrations are in excellent agreement with
the known values, the resulting confidence intervals are not as
good as expected from the precision in beam positioning and tilt
angle position and read out offered by our state-of-the-art
microscope. The Gaussian shape of the SiK_alpha and GeK_alpha X-ray intensities allows one to use the parametric bootstrap method of statistics, whereby it becomes possible to perform the same quantitative analysis in sample regions of different composition and thickness, but by doing only one measurement at the two angles
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
Additional Microstructural Analysis on the Samples Examined in the Paper ‘Are High Resolution Resistometric Methods Really Useful for the Early Detection of Electromigration Damage?'
No full textStrain field reconstruction in shallow trench isolation structures by CBED and LACBED
No full textUsing a combination of the CBED and the LACBED techniques in the transmission electron microscopy (TEM), we have investigated the strain field in the silicon active region of a shallow trench isolation structure, underlying a TiSi2 layer. Starting from the analysis of the deformation in a sample, thinned for TEM analysis, we have reconstructed the displacement field, simulating the split HOLZ lines visible in the experimental CBED patterns. From the comparison between the experimental LACBED patterns, taken in a suitable sample orientation to evidence the stressors distribution in the polycrystalline silicide layer, and the corresponding dynamically simulated ones, we have reproduced the strain field in the unthinned, bulk sample. (c) 2006 Elsevier B.V. All rights reserved
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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