Browsing by Author "Papadatos, Nickos"

Now showing items 1-20 of 26

    • Article  

      An application of a density transform and the local limit theorem 

      Cacoullos, Theophilos; Papadatos, Nickos; Papathanasiou, Vassilis (2002)
      Consider an absolutely continuous random variable X with finite variance σ2. It is known that there exists another random variable X* (which can be viewed as a transformation of X) with a unimodal density, satisfying the ...
    • Article  

      Bounds on expectation of order statistics from a finite population 

      Balakrishnan, N.; Charalambides, Charalambos A.; Papadatos, Nickos (2003)
      Consider a simple random sample X1,X2,...,Xn, taken without replacement from a finite ordered population ∏ = {x1 ≤ x2 ≤ ⋯ ≤ XN} (n ≤ N), where each element of ∏ has equal probability to be chosen in the sample. Let X1:n ≤ ...
    • Article  

      Bounds on expectations of L-statistics from without replacement samples 

      Papadatos, Nickos; Rychlik, T. (2004)
      Consider a simple random sample taken without replacement from a finite ordered population, where each element of the population has equal probability to be chosen in the sample. In the present paper, the best possible ...
    • Article  

      Characterizations of discrete distributions using the Rao-Rubin condition 

      Papadatos, Nickos (2005)
      Consider the multivariate splitting model N = N1 + ⋯ + Nk, where N1,..., Nk, k ≥ 3, are arbitrary (not necessarily independent) random variables (r.v.'s) taking values in ℕ = {0, 1,...}, and assume that the Rao-Rubin ...
    • Article  

      The discrete Mohr and Noll inequality with applications to variance bounds 

      Afendras, Georgios; Papadatos, Nickos; Papathanasiou, Vassilis (2007)
      In this paper, we provide Poincaré-type upper and lower variance bounds for a function g(X) of a discrete integer-valued random variable (r.v.) X, in terms of the (forward) differences of g up io some order. To this end, ...
    • Article  

      Distribution and expectation bounds on order statistics from possibly dependent variates 

      Papadatos, Nickos (2001)
      Let X1,X2,...,Xn be n random variables with an arbitrary n-variate distribution. We say that the X's are maximally (resp. minimally) stable of order j(j∈{1,2,...,n}), if the distribution F(j) of max{Xk1,...,Xkj} (resp. ...
    • Article  

      Exact bounds for the expectations of order statistics from non-negative populations 

      Papadatos, Nickos (1997)
      Some new exact bounds for the expected values of order statistics, under the assumption that the parent population is non-negative, are obtained in terms of the population mean. Similar bounds for the differences of any ...
    • Article  

      Expectation bounds on linear estimators from dependent samples 

      Papadatos, Nickos (2001)
      Let X1,X2,...,Xn be a sample of arbitrary, possibly dependent, random variables, with possibly different marginal distributions, and denote by X1:n≤X2:n≤≤Xn:n the corresponding order statistics. Using the notation μi=EXi ...
    • Article  

      An extended Stein-type covariance identity for the Pearson family with applications to lower variance bounds 

      Afendras, Georgios; Papadatos, Nickos; Papathanasiou, Vassilis (2011)
      For an absolutely continuous (integer-valued) r.v. X of the Pearson (Ord) family, we show that, under natural moment conditions, a Stein-type covariance identity of order k holds (cf. [Goldstein and Reinert, J. Theoret. ...
    • Article  

      An extension of the disc algebra, II 

      Nestoridis, Vassilis; Papadatos, Nickos (2014)
      We identify the complex plane with the open unit disc by the homeomorphism. This leads to a compactification of, homeomorphic to. The Euclidean metric on induces a metric on. We identify all uniform limits of polynomials ...
    • Article  

      A generalization of variance bounds 

      Papadatos, Nickos; Papathanasiou, Vassilis (1996)
      Upper and lower bounds for the variance of a random variable are obtained in terms of the density-quantile function. Some applications of these bounds to order statistics are given.
    • Article  

      Heteroscedastic one-way ANOVA and lack-of-fit tests 

      Akritas, Michael G.; Papadatos, Nickos (2004)
      Recent articles have considered the asymptotic behavior of the one-way analysis of variance (ANOVA) F statistic when the number of levels or groups is large. In these articles, the results were obtained under the assumption ...
    • Article  

      Intermediate order statistics with applications to nonparametric estimation 

      Papadatos, Nickos (1995)
      A generalization of order statistics, is presented. Using this generalization, nonparametric confidence intervals are constructed for the quantiles of an absolutely continuous distribution. Finally, an application, concerning ...
    • Article  

      Linear estimation of location and scale parameters using partial maxima 

      Papadatos, Nickos (2012)
      Consider an i. i. d. sample X 1*, X 2*,..., X n*, from a location-scale family, and assume that the only available observations consist of the partial maxima (or minima) sequence, X 1:1*,X 2:2*,..., X n:n*, where X j:j* = ...
    • Article  

      Maximizing the expected range from dependent observations under mean–variance information 

      Papadatos, Nickos (2016)
      In this article we derive the best possible upper bound for E[maxi{Xi} − mini{Xi}] under given means and variances on n random variables Xi. The random vector (X1, . . . , Xn) is allowed to have any dependence structure, ...
    • Article  

      Maximum variance of order statistics 

      Papadatos, Nickos (1995)
      Yang (1982, Bull. Inst. Math. Acad. Sinica, 10(2), 197-204) proved that the variance of the sample median cannot exceed the population variance. In this paper, the upper bound for the variance of order statistics is derived, ...
    • Article  

      A note on maximum variance of order statistics from symmetric populations 

      Papadatos, Nickos (1997)
      The maximum variance of order statistics from a symmetrical parent population is obtained in terms of the population variance. The proof is based on a suitable representation for the variance of order statistics in terms ...
    • Article  

      On matrix variance inequalities 

      Afendras, Georgios; Papadatos, Nickos (2011)
      Olkin and Shepp [2005, A matrix variance inequality. J. Statist. Plann. Inference 130, 351-358] presented a matrix form of Chernoff's inequality for Normal and Gamma (univariate) distributions. We extend and generalize ...
    • Article  

      Poisson approximation for a sum of dependent indicators: An alternative approach 

      Papadatos, Nickos; Papathanasiou, Vassilis (2002)
      The random variables X1, X2,...,Xn are said to be totally negatively dependent (TND) if and only if the random variables Xi and Σj≠i Xj are negatively quadrant dependent for all i. Our main result provides, for TND 0-1 ...
    • Article  

      Self-inverse and exchangeable random variables 

      Cacoullos, Theophilos; Papadatos, Nickos (2013)
      A random variable Z will be called self-inverse if it has the same distribution as its reciprocal Z -1. It is shown that if Z is defined as a ratio, X / Y, of two rv's X and Y (with P[X=0]=P[Y=0]=0), then Z is self-inverse ...