1,721,042 research outputs found
Conformal butterfly antennas for Ultra-Wideband Radio Direction finding applications
No full textWe present the design and full-wave analysis of conformal butterfly antennas for Ultra-Wideband (UWB) Radio Direction Finders (RDFs). The impact of the conformal deformation on the antenna performance is evaluated, a suitable antenna cover is designed, and single antenna elements for a RDF covering the band from 250MHz to 3.5GHz are optimized. Impact of coupling between antenna elements is evaluated, and a novel calibration technique is presented in order to compensate for the mutual coupling between array elements, variations in the antenna characteristics, and the effects of the antenna supporting structure. © 2010 EuMA
Non-Invasive Reflectometry-Based Detection of Melanoma by Piezoelectric Micro-Needle Antenna Sensors
Full text linkThe electromagnetic characterization of piezoelectric micro-needle antenna sensors for fully non-invasive detection of cancer-related anomalies of the skin is presented. To this end, a full-wave finite-difference time-domain procedure is adopted to analyze the performance of the considered class of devices in terms of circuital characteristics and near-field radiation properties as a function of the curvature radius of the relevant sensing probe. This analysis is, in turn, useful to gain a physical insight into the processes which affect the behavior of the structure and, hence, the accuracy in the detection of possible malignant lesions of the skin. In particular, by using the mentioned modeling approach, an extensive parametric study is carried out to analyze the effect produced on the sensor response by variations of the complex permittivity of the skin due to the presence of anomalous cells and, in this way, obtain useful discrimination diagrams
for the heuristic evaluation of the exposure level to the cancer risk
Design and Full-Wave Analysis of Piezoelectric Micro-Needle Antenna Sensors for Enhanced Near-Field Detection of Skin Cancer
Full text linkThe design and full-wave analysis of piezoelectric micro-
needle antenna sensors for minimally invasive near- ̄eld detection of cancer-related anomalies of the skin is presented. To this end, an accurate locally conformal ̄nite-di®erence time-domain procedure is adopted. In this way, an insightful understanding of the physical processes detecting the characteristics of the considered class of devices is achieved. This is important to improve the structure reliability, so optimizing the design cycle. In this regard, a suitable sensor layout is described, and discussed in detail. The major benefit of the proposed system stems from the potential for obtaining a superior performance in terms of input impedance matching and efficiency, in combination with an electronically tunable steering property of the near-field radiation intensity which can be profitably used to
enhance the illumination and, hence, the localization of possible
malignant lesions in the host medium. By using the detailed modeling approach, an extensive parametric study is carried out to analyze the effect produced on the sensor response by variations of the complex permittivity of the skin due to the presence of anomalous cells, and thus useful heuristic discrimination formulas for the evaluation of the exposure level to cancer risk are derived
Accurate Modeling of Ultra-Short Electromagnetic Pulse Scattering using a Locally Conformal Finite-Difference Time-Domain Scheme
No full text
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
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