1,720,987 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
Backward uniqueness of 2D and 3D convective Brinkman-Forchheimer equations and its applications
Get PDFIn this work, we consider the two- and three-dimensional convective
Brinkman-Forchheimer (CBF) equations (or damped Navier--Stokes equations) on a
torus :
where
and is the absorption exponent. For and
( for ), we first show the
backward uniqueness of deterministic CBF equations by exploiting the
logarithmic convexity property and the global solvability results available in
the literature. As a direct consequence of the backward uniqueness result, we
first derive the approximate controllability with respect to the initial data
(viewed as a start controller). Secondly, we apply the backward uniqueness
results in the attractor theory to show the zero Lipschitz deviation of the
global attractors for 2D and 3D CBF equations. By an application of
log-Lipschitz regularity, we prove the uniqueness of Lagrangian trajectories in
2D and 3D CBF flows and the continuity of Lagrangian trajectories with respect
to the Eulerian initial data. Finally, we consider the stochastic CBF equations
with a linear multiplicative Gaussian noise. For and
( for ), we show the pathwise backward
uniqueness as well as approximate controllability via starter controller
results. In particular, the results obtained in this work hold true for 2D
Navier--Stokes equations
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
Absolute continuity of the solution to stochastic generalized Burgers-Huxley equation
Get PDFThe present work deals with the global solvability as well as absolute
continuity of the law of the solution to stochastic generalized Burgers-Huxley
(SGBH) equation driven by multiplicative space-time white noise in a bounded
interval of . We first prove the existence of a unique local mild
solution to SGBH equation with the help of a truncation argument and
contraction mapping principle. Then global solvability results are obtained by
using uniform bounds of the local mild solution and stopping time arguments.
Later, we establish a comparison theorem for the solution of SGBH equation
having higher order nonlinearities and it plays a crucial role in this work.
Then, we discuss the weak differentiability of the solution to SGBH equation in
the Malliavin calculus sense. Finally, we obtain the absolute continuity of the
law of the solution with respect to the Lebesgue measure on , and
the existence of density with the aid of comparison theorem and weak
differentiability of the solution
Large deviation principle for a class of stochastic partial differential equations with fully local monotone coefficients perturbed by L\'evy noise
Get PDFThe asymptotic analysis of a class of stochastic partial differential
equations (SPDEs) with fully locally monotone coefficients covering a large
variety of physical systems, a wide class of quasilinear SPDEs and a good
number of fluid dynamic models is carried out in this work. The aim of this
work is to develop the large deviation theory for small Gaussian as well as
Poisson noise perturbations of the above class of SPDEs. We establish a
Wentzell-Freidlin type large deviation principle for the strong solutions to
such SPDEs perturbed by L\'evy noise in a suitable Polish space using a
variational representation (based on a weak convergence approach) for
nonnegative functionals of general Poisson random measures and Brownian
motions. The well-posedness of an associated deterministic control problem is
established by exploiting pseudo-monotonicity arguments and the stochastic
counterpart is obtained by an application of Girsanov's theorem
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