1,720,969 research outputs found
Electromagnetic compatibility and interference practical analyses for beam waveguide ground antennas
No full textThe Sardinia Radio Telescope (SRT) is currently operated by the Italian astrophysics institute (INAF). Following its upgrade to transmission (TX) capabilities, planned by the Italian Space Agency (ASI) for the commanding of deep space probes, an electromagnetic compatibility (EMC) analysis is performed in order to evaluate the impact on the reception (RX) capabilities currently used by the radio astronomers. Using the same simulation AIDS, an electromagnetic interference (EMI) study is performed with respect to the main auxiliary ground station equipment and in the event of overflying aircrafts. The biological hazard is finally evaluated on human beings
The Sardinia Radio Telescope Upgrade to Telemetry, Tracking and Command: Beam Squint and Electromagnetic Compatibility Design
No full textThis paper describes the most recent improvements for the upcoming upgrade to telemetry, tracking and command
(TT&C) capabilities for the Sardinia Radio Telescope (SRT), a 64-m antenna tailored for radio-astronomical observations
of cosmic radio sources located in the outer space. Due to the TT&C improvement, the SRT will represent one
of the Europe's main establishments for the support of present and future deep space missions. The first part of this
paper is dedicated to the Gaussian Beam synthesis of the SRT feeding system, called beam waveguide, fashioned
to maximize the antenna illumination and spillover efficiency. The best design parameters have been retrieved through
a rapid and efficient optimization analysis and verified by means of physical optics simulations. In accordance with the
obtained results from the Gaussian formulation, further in-depth studies have been undertaken in order to investigate
a technique able to overcome the so-called beam squint issue, a typical drawback that occurs during the tracking process
of active spacecrafts. The proposed approach manages to automatically attain and quickly the best antenna
beam steering strategy to correct the squint issue by means of a field-matching algorithm. Finally, this paper reports
the analyses developed for electromagnetic hazard predictions, which shall be carefully taken into consideration for
the safety of personnel working close to the high-power radiating installations and for preventing the astronomical receivers
located near the Prime and the Gregorian foci from being damaged when the antenna is transmitting
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
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
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