Search results for "52"

The impact of spatial correlation on the statistical properties of the capacity of nakagami-m channels with MRC and EGC

2011

Published version of an article published in the journal: EURASIP Journal on Wireless Communications and Networking. Also available from the publisher at: http://dx.doi.org/10.1186/1687-1499-2011-116. OA In this article, we have studied the statistical properties of the instantaneous channel capacitya of spatially correlated Nakagami-m channels for two different diversity combining methods, namely maximal ratio combining (MRC) and equal gain combining (EGC). Specifically, using the statistical properties of the instantaneous signal-to-noise ratio, we have derived the analytical expressions for the probability density function (PDF), cumulative distribution function (CDF), level-crossing rat…

Brief an Garlieb H. Merkel

1798

Ms. 930a, Nr. 13, Bl. 35r-[36v] August Hennings. Brief an Garlieb H. Merkel, Ploen, den 20. Dece[mber] 1798 Autora rokraksts / Autograph, vācu val. / Deutsch [3] lpp. / S. Attēlu numuri / Bildnummern: 930a-013-1, 930a-013-2, 930a-013-3 Hennings, der dänische Amtmann in Plön und Bekannte des dänischen Ministers Schimmelmann, schreibt in seiner Funktion als Herausgeber der Zeitschrift „Genius der Zeit“ an Merkel. Er kündigt an, einen Aufsatz zu drucken, in dem Merkel Partei für seinen Schriftstellerkollegen Johann(es) Falk ergreift, worum ihn dieser in einem anderen Brief gebeten hat (vgl. Ms. 930a-012). Merkels Aufsatz soll in der Februarausgabe 1799 erscheinen. Der Aufsatz sowie der hier üb…

Robust dynamic cooperative games

2009

Classical cooperative game theory is no longer a suitable tool for those situations where the values of coalitions are not known with certainty. Recent works address situations where the values of coalitions are modelled by random variables. In this work we still consider the values of coalitions as uncertain, but model them as unknown but bounded disturbances. We do not focus on solving a specific game, but rather consider a family of games described by a polyhedron: each point in the polyhedron is a vector of coalitions’ values and corresponds to a specific game. We consider a dynamic context where while we know with certainty the average value of each coalition on the long run, at each t…

The rank of random regular digraphs of constant degree

2018

Abstract Let d be a (large) integer. Given n ≥ 2 d , let A n be the adjacency matrix of a random directed d -regular graph on n vertices, with the uniform distribution. We show that the rank of A n is at least n − 1 with probability going to one as n grows to infinity. The proof combines the well known method of simple switchings and a recent result of the authors on delocalization of eigenvectors of A n .

The smallest singular value of a shifted $d$-regular random square matrix

2017

We derive a lower bound on the smallest singular value of a random d-regular matrix, that is, the adjacency matrix of a random d-regular directed graph. Specifically, let $$C_1<d< c n/\log ^2 n$$ and let $$\mathcal {M}_{n,d}$$ be the set of all $$n\times n$$ square matrices with 0 / 1 entries, such that each row and each column of every matrix in $$\mathcal {M}_{n,d}$$ has exactly d ones. Let M be a random matrix uniformly distributed on $$\mathcal {M}_{n,d}$$ . Then the smallest singular value $$s_{n} (M)$$ of M is greater than $$n^{-6}$$ with probability at least $$1-C_2\log ^2 d/\sqrt{d}$$ , where c, $$C_1$$ , and $$C_2$$ are absolute positive constants independent of any other parameter…

Random time-changes and asymptotic results for a class of continuous-time Markov chains on integers with alternating rates

2021

We consider continuous-time Markov chains on integers which allow transitions to adjacent states only, with alternating rates. We give explicit formulas for probability generating functions, and also for means, variances and state probabilities of the random variables of the process. Moreover we study independent random time-changes with the inverse of the stable subordinator, the stable subordinator and the tempered stable subodinator. We also present some asymptotic results in the fashion of large deviations. These results give some generalizations of those presented in Di Crescenzo A., Macci C., Martinucci B. (2014).

On the Ambiguous Consequences of Omitting Variables

2015

This paper studies what happens when we move from a short regression to a long regression (or vice versa), when the long regression is shorter than the data-generation process. In the special case where the long regression equals the data-generation process, the least-squares estimators have smaller bias (in fact zero bias) but larger variances in the long regression than in the short regression. But if the long regression is also misspecified, the bias may not be smaller. We provide bias and mean squared error comparisons and study the dependence of the differences on the misspecification parameter.

On the ambiguous consequences of omitting variables

2015

This paper studies what happens when we move from a short regression to a long regression (or vice versa), when the long regression is shorter than the data-generation process. In the special case where the long regression equals the data-generation process, the least-squares estimators have smaller bias (in fact zero bias) but larger variances in the long regression than in the short regression. But if the long regression is also misspecified, the bias may not be smaller. We provide bias and mean squared error comparisons and study the dependence of the differences on the misspecification parameter.

Entrevista a Nora Strejilevich

2019

Cognitive Deficits in Chronic Stroke Patients: Neuropsychological Assessment, Depression, and Self-Reports

2017

&lt;b&gt;&lt;i&gt;Background:&lt;/i&gt;&lt;/b&gt; Following stroke, clinicians are challenged to detect and untangle symptoms of cognitive dysfunction and mood disorders. Additionally, they need to evaluate the informative value of self-reports to identify patients in need of further attendance. &lt;b&gt;&lt;i&gt;Aims:&lt;/i&gt;&lt;/b&gt; To examine the association between neuropsychological measures, symptoms of depression, and self-reported cognitive function. &lt;b&gt;&lt;i&gt;Methods:&lt;/i&gt;&lt;/b&gt; One-hundred and five chronic stroke patients underwent assessment covering 6 cognitive domains and answered the Hospital Anxiety and Depression Scale and the Memory and Thinking Scale f…