1,721,105 research outputs found
Reflect-array Antenna
No full textAn antenna comprises a plurality of re-radiating elements arranged in at least one plane being parallel to a fixed surface. The arrangement is adapted such that electromagnetic radiation emitted from the re-radiating elements in response to electromagnetic radiation arriving from a predetermined direction interferes constructively at a feed location. Additionally, the antenna comprises a feed provided at the feed location. In a method of manufacturing an antenna, the arrangement of the plurality of re-radiating elements may be calculated and the re-radiating elements can be provided in the at least one plane substantially parallel to the substrate. An apparatus for manufacturing an antenna may comprise a data processor adapted to calculate the arrangement of the plurality of re-radiating elements and means for forming the plurality of re-radiating elements
Concentric square ring elements for dual band reflectarray antenna
No full textA preliminary study of advanced radiating elements for a dual band reflectarray antenna is presented. The resulting antenna has properties of reduced weight and thickness, and it can be employed as the ground station antenna for an ultralight UAV in the framework of a research program on a platform for emergency radio services: it can be easily mounted (stowed) on the roof of a vehicle and deployed when in operatio
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
ANN characterization of printed reflectarray elements
No full textThe design of printed reflectarray antennas (RAs) could be quite complex and computationally expensive, since the need of providing high performances and satisfying requirements that could be also in contrast each other could require the use of a large number of re-radiating advanced element configurations. A possible strategy for the RA design could be therefore of carrying it out adopting an evolutionary optimization tool. In this work, an artificial neural network (ANN) model of the RA single element is presented as convenient interface between antenna design and global optimization algorithms. In order to prove the effectiveness of the model, it will be used in the design of a dual-band dual-layer reflectarray
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
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