1,720,970 research outputs found
Accurate Analytical Thermal Model of the Heating Element in Micromachined Gas Sensors
No full textIn this paper, a simple analytical model of the steady -state thermal behavior of a Pt microheater for micromachined gas sensors is presented. It is demonstrated that simple resistance vs. power measurements, coupled with a suitable thermal model, are sufficient for a precise determination of the sensor temperature
A resistometric method to characterize electromigration at the wafer level
No full textElectromigration resistometric measurements at the wafer level cannot be carried out with adequate precision using standard DC techniques, due to high, non-stable thermoelectric voltages arising at the pad/probe-tip interface. In this work an AC resistometric technique is proposed, which allows the detection of very small resistance changes in the early stages of electromigration process. Measurements were carried out at different temperatures and an activation energy was extracted. The validity of the Matthiessen's rule for the interpretation of electromigration data was studied. Its applicability was not proved: experimental data showed that the resistance changes can be explained in terms of geometrical variations even in the first stages of electromigration
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
Improved Electrical Characterization of Al-Ti Ohmic Contacts on p-type Ion Implanted 6H-SiC
No full textReal-time monitoring of sub-ppb concentrations of aromatic volatiles with a MEMS-enabled miniaturized gas-chromatograph
No full textMicromachined gas-chromatographic (GC) components in combination with high sensitivity MOX detectors and novel pre-concentration materials were utilized to develop a miniaturized, portable, stand-alone sub-ppb level monitoring system for aromatic volatile organic compounds (VOC). Using metal oxide semiconductor (MOX) gas sensors as detectors in a GC system, the intrinsic analytic selectivity of GC is exploited in a simplified architecture with on-board generated carrier gas. The work reported here includes the study of innovative pre-concentration materials, the micromachining of GC components and devices, the fabrication and characterization of complete system prototypes, and the development of application-specific control electronics. The results of both laboratory trials and successful real-world cross-validation with a reference analyzer are described
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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