1,720,971 research outputs found
The effect of hot electron stress on the DC and microwavecharacteristics of AlGaAs/InGaAs/GaAs PHEMTs
No full textThis work reports on hot electron reliability of 0.25 μm Alo.25−Ga0.75As/In0.2Ga0.8As/GaAs PHEMTs from the viewpoint of both DC and RF characteristics. The changes of DC and RF behavior after high drain bias stressing are shown to be strongly correlated. Both can be attributed to a decrease of the threshold voltage, yielding different effects on gain depending on the bias point and circuitry chosen for device operation: a fixed current bias scheme is shown to minimize the changes induced by the stress
Hot electron degradation of the DC and RF characteristics of AlGaAs/InGaAs/GaAs PHEMTs
No full textThis paper reports on hot electron (HE) degradation of 0.25-μm Al0.25Ga0.75As/In0.2Ga0.8 As/GaAs PHEMT's by showing the effects of the hot electron stress on both the dc and rf characteristics. The changes of dc and rf behavior after stress turn out to be strongly correlated. Both can be attributed to a decrease of the threshold voltage yielding different effects on the device gain depending on the bias point chosen for device operation and on the bias circuit adopted: a fixed current bias scheme will minimize the changes induced by the stress. The work also presents a study of the dependence of device degradation on the stress bias conditio
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
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
Effect of passivation on the hot electron degradation of lattice-matched InAlAs/InGaAs/InP HEMTs
No full textPassivated devices show a permanent decrease of drain current and transconductance at high gate bias. The degradation is attributed to negative charge accumulation at the surface leading to cap depletion, and tends to be weaker in selectively etched gate devices, where the cap is laterally etched away much more. This dc effect is mirrored by a reduction of the current gain cutoff frequency in the same bias range. Some devices experience as a consequence of the stress, a permanent threshold voltage increase and a transconductance compression similar to that of the passivated samples. Others show a temporary reduction of the threshold voltage resulting in an increase of the drain current for fixed gate and drain bias
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