1,720,978 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
The influence of polarisation and image charges on Electron-Impurity Scattering in High Degeneracy, Nanometre Scale Silicon wrap-round gate MOSFETs - art. no. 012009
No full textAtomistic impurities in the channel of a nano-wire silicon MOSFET with wrapround gate and highly doped and degenerate source and drain are shown to be strongly screened by polarisation (image charge effects) arising from carriers that are confined to source and drain when the channel screening length exceeds the channel length. The image charge effects on a given atomistic ionized impurity depend significantly on its location in the channel. The model is based on an exact analysis of the Poisson equation using Fourier-Bessel analysis in cylindrical coordinates. Close to source or drain the analytically computed total and differential scattering rates correspond to a form of dipole scattering. The source and drain may separately or together contribute to the screening of the atomistic impurity depending on its location and the channel screening length. The net effect of the infinite sequence of fully developed screened image charges induced by the atomistic impurity is to substantially reduce impurity scattering by at least an order of magnitude and to enhance the back scattering. The theory is illustrated for a 5 nm channel devic
Performance variability in wrap-round gate silicon nano-transistors: a 3D self-consistent NEGF study of ballistic flows for atomistically-resolved source and drain - art. no. 012026
No full textA recently developed 3D self-consistent Non-equilibrium Green Function technique is used to study technologically identical silicon wrap-round gate 3D nanowire devices each of which has a different atomistically-resolved spatial distribution of dopants in the source and drain but in the absence of inhomogeneities in the channel/oxide interface and for an undoped channel. The simulations broadly confirm the conclusions of an earlier theoretical study of granularity effects on drive current that was limited by being two-dimensional and used a strongly inhomogeneous but continuum model of the doping profile in source and drain. However, the 3D nature of the flows makes it easier for charge to re-distribute around the regions of strong attractive potential. The stronger inhomogeneity effects in current density and charge density and the large inter-device variability predicted by 2D models are therefore over-estimate
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
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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