1,720,995 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
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
MODELS OF BASIC ELECTROMAGNETIC WAVES IN THE BI-ISOTROPIC MEDIUM WITH SPACE DISPERSION
Get PDFA mathematical models describing the propagation of monochromatic electromagnetic waves in the biisotropic medium with space dispersion is being developed. Modeling is based on the transformation of integro-differential equations for bi-isotropic medium to the differential equations electrodynamics, containing electrical and magnetic polarizations in operator form with differential Laplace operator. Within the developed model it is analytically constructed a full system of basic plane, spherical and cylindrical electromagnetic fields extending in the homogeneous bi-isotropic medium with space dispersion
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
Mathematical model of shielding monochromatic electromagnetic fields by means of plane screens made of permalloy
Get PDFA method for solving a boundary-value problem of penetration of plane monochromatic electromagnetic fields through the plane screen made of permalloy is developed. Setting the boundary-value problem is based on the use of differential Maxwell equations and complementary nonlinear differential equation for the field of magnetization, characterizing permalloy. The classical boundary conditions of continuity of the tangential components of the fields and complementary boundary conditions for the field of magnetization on the front surfaces of the screen are used. To simplify the solution of the boundary-value problem as a result of exclusion of the values of the second infinitesimal order, included in nonlinear equation, the nonlinear task is transformed into linear one. The roots (wave numbers) of dispersion algebraic equation of a fourth-order, characterizing the electromagnetic fields in the layer made of permalloy, are constructed. A complete system of four forward and four backward counter-propagating electromagnetic waves in the permalloy layer is formed. The two-sided boundary conditions connecting electromagnetic fields on both sides of the screen are obtained. An analytical solution of the boundary-value problem with two-sided boundary conditions is performed. The amplitudes of reflected and transmitted through the screen electromagnetic fields are analytically calculated
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
MODEL FOR CALCULATING EFFECTIVE PARAMETERS OF MATRIX COMPOSITES FROM BI-ISOTROPIC PARTICLES WITH REGARD MULTIPLE REFLECTIONS OF ELECTROMAGNETIC FIELD
No full textA method for calculation of the effective material parameters of matrix composites, consisting of magnetodielectric conducting matrix with a set of bi-isotropic spherical fractions, is developed. Under the calculations of parameters, taking into account a multiple scattering of the field between particles, a new type of addition theorems, connecting basic spherical electromagnetic fields relating to different particles, is used. The developed method allows to calculate the effective parameters for the composites with sufficiently dense ensemble of the fractions
MULTIPLE FOCUSING OF ELECTROMAGNETIC FIELD OF MAGNETIC DIPOLE BY MEANS OF PLANE-PARALLEL TWO-LAYER LENS FROM METAMATERIALS
No full textA method of analytical solution of the boundary-value problem of electromagnetic field penetration of point magnetic dipole through the infinite planar leans (screen) from the focusing metamaterials is suggested. It is demonstrated, that for the lenses with special combinations of material parameters in layers the series of focuses are formed: one is over the screen and three is in front of the screen in the half-space of point source of the excitation field. The summary field of focuses in front of the lens is equal to the sum of fields of magnetic and electric dipoles
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