1,720,974 research outputs found
Thermal stability of Mo-based Schottky contact for AlGaN/GaN HEMT
No full textThe reliability of Mo-based Schottky contact for an AlGaN=GaN
HEMT after a thermal storage test is reported. Electrical and chemical
analyses demonstrate the stability of Mo=Au gate for a GaN HEMT
after a 2000 h ageing test at temperatures up to 340C
Characterisation of AlGaN/GaN HEMT epitaxy and devices on composite substrates
No full textThis paper shows results obtained on AlGaN/GaN HEMTs
processed on epitaxy grown on composite substrates. The
results are very promising for the fabrication of low cost high
power microwave transistors for wireless communication
systems. The composite substrates constitute a valuable
alternative to the silicon since better thermal properties are
expected
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
Effects of buffer compensation strategies on the electrical performance and RF reliability of AlGaN/GaN HEMTs
Full text linkThe effects of buffer compensation strategies on the electrical performance and RF reliability of AlGaN/GaN HEMTs have been studied by means of static and dynamic I-V measurements, drain-current transient spectroscopy, XRD, and RF stress tests. Devices equipped with C-doped and Fe-doped GaN buffer feature improved subthreshold behaviour (lower source-to-drain leakage current, and lower DIBL) and improved RF reliability. As a drawback, devices equipped with Fe- and C-doping experience higher dynamic current dispersion, ascribed to higher concentration of the deep levels E2 (0.56 eV/10- 15 cm2) and E4 (0.84 eV/10- 14 cm2)
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
Impact of proton fluence on DC and trapping characteristics in InAlN/GaN HEMTs
No full textAbstract Robustness of InAlN/GaN devices under proton radiation is investigated. Several proton fluences ranging from 1 × 1014 to 4 × 1014 have been considered on two typologies of devices. Displacement damage is found to be the major responsible of device DC degradation leading to threshold voltage positive shift, ON resistance increase and drain current decrease, in all cases well correlated with proton fluence. Negligible difference is noticed in displacement damage effects measured on different device typologies. Furthermore, device geometry does not influence the impact of proton radiation on main DC parameters, either if gate width or length are considered. Radiation significantly affects trapping properties. A good correlation between the so-called current collapse increase and proton fluence is demonstrated when a high gate drain voltage value is imposed as trapping condition. Moreover radiation enhances the contribution of dynamic ON resistance and transconductance peak variation on current collapse increase. © 2015 Elsevier Ltd
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