1,721,093 research outputs found
On a Characterization of Orthogonality with respect to a Particular Sequences of Random Variables in L^2
No full textThis note deals with the orthogonality between sequences of random variables.
The main idea of the note is to apply the results on equidistant systems of points in a Hilbert
space to the case of the space L
2(
,F, P) of real square integrable random variables. The
main result gives a necessary and sufficient condition for a particular sequence of random
variables (elements of which are taken from sets of equidistant elements of L2(
,F, P)) to
be orthogonal to some other sequence in L2(
,F, P). The result obtained is interesting
from the point of view of the time series analysis, since it can be applied to a class of sequences
random variables that exhibit a monotonically increasing variance. An application
to ergodic theorem is also provided
On the asymptotic behavior of the sequence and series of running maxima from a real random sequence
No full textFor a sequence {X-n, n >= 1} of random variables, set Y-n = max(1 = 1} is a sequence of constants to be specified. We obtain the limiting behavior of the sequences of positive and negative parts of {Y-n, n >= 1} when the tail distribution of {X-n, n >= 1} satisfies suitable "exponential-type" conditions. Next, we consider the rate convergence of the positive part to zero (results similar to complete convergence)
An application of φ-subgaussian technique to Fourier analysis
No full textWe present an application to random Fourier series for φ-subgaussian random variables. In particular, we generalize previously known notions of dependence for random variables by introducing the concept of F-manageable random variables, and consider Fourier series of F-manageable φ-subgaussian random variables. Gaussian series are then a particular case of the series considered in the paper. Conditions for the uniform convergence of such series in probability are established and a rate of convergence is investigated. Moreover, the results are new even for the case of independent random variables
On the complete convergence for arrays of rowwise extended negatively dependent random variables
No full textA general result for the complete convergence of arrays of rowwise extended negatively dependent random variables is derived. As its applications eight corollaries for complete convergence of weighted sums for arrays of rowwise extended negatively dependent random variables are given, which extend the corresponding known results for independent case
On the Strong Rates of Convergence for Arrays of Rowwise Negatively Dependent Random Variables
No full textThe strong convergence rate and complete convergence results for arrays of rowwise
negatively dependent random variables are established. The results presented
generalize the results of Chen et al. [1] and Sung et al. [2]. As applications, some
well-known results on independent random variables can be easily extended to the
case of negatively dependent random variables
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
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
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