1,720,973 research outputs found
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
H-shaped terahertz patch antenna with metamaterials for biomedical applications
Get PDFThis paper presents the design and simulation of an H-shaped terahertz microstrip patch antenna integrated with a metamaterial (MTM) layer to enhance performance for biomedical sensing applications. The antenna modeled using high frequency structure simulator (HFSS), is optimized for 4.37 THz operation. While FR4 is used in simulations for baseline analysis, alternative low-loss substrates such as polyimide or quartz are recommended for practical THz applications. The antenna design uses an FR4 substrate with a dielectric constant of 4.4 and a thickness of 2 μm. Ground plane, feed line, and patch are made of copper material. The integration of the MTM enhance clearly the antenna characteristics. This integration helps to improve the antenna impedance matching; the reflection coefficients was enhanced from -25.01 to -63.10 dB. Additionally, this integration boost also the antenna radiation characteristics, increasing the gain from 2.62 to 3.86 dB and the directivity from 3.57 to 4.97 dB
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
SPATIAL MODELING OF THE TRANSMISSION CHANNEL FOR THZ RADIO COMMUNICATION SYSTEM
No full textDue to the growing demand for high speed wireless communication systems, it is crucial to look for new technology that can support this need. Indeed, THz technology has the potential to provide high data rate and multimedia applications for wireless communication system. In this paper, we evaluate the channel impulse response and the channel transfer function of terahertz system. The objective of this work is to propose an appropriate channel model for the THz bands. For this reason, we build a static model based on the existing Saleh-Valenzuela model. we have modified this classical model to adapt it to the THz context. The proposed model takes into account propagation losses and multipath propagation to provide designers with the impulse and frequency response of the channel, as well as their variations over time for mobile channels. Simulation results have shown that the distance between transmitter and receiver play a major role. Besides, multi-path effect introduces notches in the channel and create bands in which the channel become more selective. Moreover, the increase in the carrier frequency lied to a high path loss. These issues produce inter symbols interference which affect the performance of overall system. Therefore, to simulate an entire system including transmitters and receivers we should take into account this bands in order to get good reliability
Study and design of a patch antenna for biomedical applications
No full textThis work presents the performance of a Dual-band patch antenna with L-shaped slot for biomedical applications. The antenna works at 2.4 GHz and 3.33 GHz. A semi-flexible substrate material which is “Taconic TLX (tm)” with a relative dielectric constant, ℇr of 2.55, loss tangent, tan δ of 0.0019 and thickness, h of 0.7 mm has been proposed to be the isolant element of the antenna. The size of the antenna is 60 x 55 mm². The slots in the rectangular radiating patch were introduced to produce the resonant frequencies of 2.4GHz and 3.33GHz. The simulations of the microstrip patch antenna shows the reflection coefficient, S11 of -31.67 dB and -20.25 dB at 2.4 GHz and 3.27 GHz respectively. The proposed antenna shows a peak gain of 5.01 dB at 2.4 GHz. The results were obtained using HFSS (high frequency structured simulator) software
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