1,720,999 research outputs found
Kantorovich-type modifications of certain discrete-type operators on the positive real axis
No full textThe paper is concerned with the approximation properties of a modification of Kantorovich-type of a general class of operators of discrete-type. Such a modification was introduced by Agratini in 2015; in particular, we focus on extending its approximation properties in several function spaces, including polynomial weighted spaces of any degree as well as Lp-spaces. Some estimates of the rate of convergence are also obtained
FUNCTIONAL IMAGING IN RECTAL PROLAPSE
No full textImaging data has gained relevance in the preoperative assessment of severe pelvic organ prolapse, including vaginal vault descent, enterocele, rectocele and cystocele
On some representation formulae for operator semigroups in terms of integrated means
Full text linkThe aim of the paper is to develop some representation formulae for strongly continuous operator
semigroups on Banach spaces, in terms of limits of integrated means with respect to some given family
of probability Borel measures and other parameters.
The cases where these limits hold true pointwise or uniformly on compact subintervals are discussed
separately. In order to face them different methods have been required: the former case has been
studied by using purely functional-analytic methods, the latter one by involving methods arising from
Approximation Theory.
The paper also contains some estimates of the rate of convergence in terms of the rectified modulus of
continuity and the second modulus of continuity.
In a final section some illustrative examples and applications are provided
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
On a class of elliptic-parabolic equations on unbounded intervals
No full textWe study a class of degenerate elliptic second order differential operators acting on some
polynomial weighted function spaces on [0, +∞[. We show that these operators are the generators
of C_0-semigroups of positive operators which, in turn, are the transition semigroups associated with
right-continuous normal Markov processes with state space [0, +∞]. Approximation and qualitative
properties of both the semigroups and the Markov processes are investigated as well. Most of the
results of the paper depend on a representation of the semigroups we give in terms of powers of
particular positive operators of discrete type we introduced and studied in a previous paper
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
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