1,720,966 research outputs found
Comparative study of mutual coupling on microstrip antennas for wireless local area network (WLAN) application
No full textThe increasing in interest of wearable antenna for military, sport, and medical applications may replace the uses of wired-communication network to wireless and wearable network. . In this paper, three shapes of the antennas which resonate at 2.4GHz and 5.2 GHz have been designed using jeans with the permittivity constant of 1.7 as the dielectric. The mutual coupling of the array antenna for the various shapes has been analyzed in H-plane and E-plane configuration respectively. The mutual coupling for the antenna in E-plane configuration has shown more sensitive toward the variation of distance between the elements, with compared to the elements in H-plane arrangement
Wearable textile antenna on electromagnetic band gap (EBG) for WLAN applications
No full textThis paper presents a new dual band wearable textile antenna for on body application, at 2.4 GHz and 5.2 GHz. The performance of the antenna is described with the integration of an electromagnetic band gap (EBG) structure. The antenna and EBG structure are made of jeans material which has a dielectric constant of 1.7, with the thickness of 1.2 mm and 0.025 loss tangent. The conductive component used in this paper is copper tape with thickness of 0.02 mm. The EBG array consists of 6 elements which are arranged in circular pattern surrounding the antenna patch. The effect of placing the EBG below the conventional antenna is studied and compared with the performance of the antenna alone. The gains of the antenna are improved by 63.7% and 121.4% at 2.4 GHz and 5.2 GHz respectively after integrating the EBG structure. At least 10 dB of backward radiation is reduced with the presence of the EBG structure. The integration of EBG with the conventional antenna has improved the antenna performance. The simulated and measured return loss, together with E-plane and H-plane polar pattern are presented in this paper for both conditions
A low profile switchable pattern directivity antenna using circular sectorized EBG
No full textIn this paper, a low profile patch antenna switchable radiation pattern diversity with total thickness of less than ?0/14 has been established.. The novel antenna structure is based on a conformal patch antenna operating in TM01 mode is integrated over an electromagnetic band gap (EBG) surface to provide a beam scanning antenna. The circular EBG elements are arranged in 6-sectors and the vias on each sector of the EBG are switched in and out to steer the
beam into that sectors. The reflection coefficients for the antenna when the vias are switched remain stable. The simulation and experimentation results have shown that the antenna power pattern directed toward the sector, without via or the middle of sectors, without via. Overall a flexible low profile beam steering antenna is demonstrated. The antenna is designed for wireless network application especially to improve the system performance in multipath propagation environment. Furthermore, the low profile antenna makes it suitable to be used in vehicular application
A technique of scan blindness elimination for planar phased array antenna using miniaturized EBG
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Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Get PDFWe 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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