1,721,156 research outputs found
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
Computation of Ohmic Losses in Arbitrarily Shaped Waveguide Structures Using Perturbation of Boundary Conditions and BI-RME Method
No full textIn this work, ohmic losses present in arbitrarily shaped waveguide-based structures are rigorously considered. For such purpose, a software tool based on the perturbation of the boundary conditions on the metallic walls of the waveguides combined with an Integral-Equation (IE) analysis technique is proposed. In order to obtain the modal chart of waveguides with arbitrary cross-section, the Boundary Integral – Resonant Mode Expansion (BI-RME) method is also employed. To show the advantages of the proposed technique a computer-aided design software package based on this modal analysis tool has been applied to predict the propagation loss effects in complex waveguide components.Ministerio de Economía y Competitividad (MINECO), TEC2013-47037-C5-4-R
Study of Periodic Dielectric Frequency-selective Surfaces under 3D Plane Wave Incidence
Get PDFA periodic Dielectric Frequency-Selective Surface (DFSS) is studied under 3D plane-wave incidence, whose unit cell in the periodic direction is composed of a dielectric grating and a homogeneous dielectric layer. The structure is excited by a linearly polarized plane-wave. The procedure for computing the Brillouin diagram of the structure under 2D plane-wave incidence with TE or TM polarization was already described by the authors, and the extension to the 3D incidence case has been performed in a similar way. Following the same formalism, it has been obtained the Generalized Scattering Matrix (GSM) of one period of the infinite periodic lattice. This requires the knowledge of the modal spectrum in both homogeneous and periodic dielectric media. To this end, a numerical technique based on a vectorial modal method originally proposed by the authors has been used. Once the S matrix of one period of the periodic medium is computed, the corresponding generalized ABCD matrix of the unit cell can be easily derived, which provides a standard multimodal eigenvalue matrix problem whose solution yields the transverse field distributions and the modal propagation constants in the periodic lattice. In the 3D incidence case, a given number of modes considered in the construction of the ABCD matrix yields the dispersion diagram of TE and TM modes simultaneously. The identification of the modes can be easily performed through the comparison of their dispersion diagram with the reflectance spectra of the structure under a given incidence polarization (TE or TM). Finally, some numerical result effects, varying the incidence direction of the exciting plane-wave in the dispersion diagram of an Electromagnetic Band Gap (EBG) material, are shown.This work was supported by the Ministerio de Economía y Competitividad, Spanish Government, under the coordinated projects TEC2013-47037-C5-4-R and TEC2013-47037-C5-1-R
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
Green's functions for 2D periodic structures and applications to the analysis of waveguide components
No full textIn this paper different and efficient acceleration techniques for the evaluation of two-dimensional Green's functions with 1D and 2D periodicities are discussed. The proposed summation numerical methods are based on the appropiate extraction of different asymptotic terms in the spectral domain representation of the corresponding Green's functions. The paper provides insight into the different formulation choices, including numerical results that illustrate the advantages and drawbacks when the techniques are applied to a particular problem. This acceleration techniques allows the implementation of efficient integral equation techniques for the analysis of a wide variety of H-plane microwave passive components composed of conducting and dielectric posts and discontinuities.This work has been carried out under the financial support of the public research projects, Ministerio de Educación y Ciencia Ref. TEC2013-47037-C5-5-R and Fundación Séneca de la Región de Murcia Ref. 19494/PI/14, and the pre-doctoral research program of the Universidad Politécnica de Cartagena Ref. R-100/16
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
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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