1,721,002 research outputs found
Gate Bias Dependence of Flicker Noise in Graphene as a Result of Carrier Statistics
No full textFlicker noise in graphene has been investigated by several authors and a variety of behaviors of its power spectral density have been observed as a function of the backgate bias. In particular, in bilayer graphene, but also in a few samples of monolayer graphene, a minimum of flicker noise has been observed at the Dirac point, and several explanations have been proposed. An interesting theory exploited screening of a trapped carrier and the peculiar properties of the graphene bandstructure to explain the observed features of flicker noise. We have developed a different approach that leads to analogous results starting from the mass-action law and from the observation that the prevalent components of flicker noise are slow compared to the generation-recombination times of carriers. Here we further develop such a model and apply it to a wider range of situations. We rely on the preservation of the electric neutrality of the conductor and, as a result of the mass-action law, of the product of electron and hole concentrations. A direct consequence of these two constraints is that near the Dirac point a trapping event leads to screening by both types of carriers (electrons and holes) and to no net variation of the total available number of carriers. As a result of the symmetry between the transport properties of electrons and holes in graphene, the preservation of the total number of carries leads to the disappearance of generation-recombination noise (which is at the basis of flicker noise, that can be interpreted as a superposition of Lorentzian generation-recombination spectra) in this circumstance. On the other hand, far away from the Dirac point a trapping event leads to a variation of the number of carriers by one unit, as in ordinary doped semiconductors, thereby without any suppression of
flicker noise. If we perform a numerical calculation of the flicker noise power spectral density as a function of the carrier concentration, we obtain a good match with the experimental data for bilayer graphene. The observed behavior for monolayer graphene, which does not usually exhibit a minimum at the Dirac point, can be retrieved taking into consideration a disorder model resulting from the presence of randomly located impurities
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
General Nano-Electromagnetic Quantum Phase Space Model (FWF Project P33609)
No full textFWF project: General Nano-Electromagnetic Quantum Phase Space Model
Acknowledgment: Austrian Science Fund (FWF) [10.55776/P33609]
Project website: https://dx.doi.org/10.55776/P3360
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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