arXiv subjects

Dragan Radulovic

Publications and source records attributed to Dragan Radulovic.

4 recordsLinked to original sources

arXiv2017

Weak Convergence of Stationary Empirical Processes

We offer an umbrella type result which extends weak convergence of the classical empirical process on the line to that of more general processes indexed by functions of bounded variation. This extension is not contingent on the type of dependence of the underlying sequence of random variables. As a consequence we establish weak convergence for stationary empirical processes indexed by general classes of functions under alpha mixing conditions.

math.ST↗

arXiv2015

Weak convergence of empirical copula processes indexed by functions

Weak convergence of the empirical copula process indexed by a class of functions is established. Two scenarios are considered in which either some smoothness of these functions or smoothness of the underlying copula function is required. A novel integration by parts formula for multivariate, right continuous functions of bounded variation, which is perhaps of independent interest, is proved. It is a key ingredient in proving weak convergence of a general empirical process indexed by functions of bounded variation.

math.ST↗

arXiv2013

An asymptotic total variation test for copulas

We propose a new goodness-of-fit test for copulas, based on empirical copula processes and their nonparametric bootstrap counterparts. The standard Kolmogorov-Smirnov type test for copulas that takes the supremum of the empirical copula process indexed by half spaces is extended by test statistics based on the supremum of the empirical copula process indexed by partitions of Ln rectangles with Ln slowly tending to infinity. Although the underlying empirical process does not converge, it is proved that the p-values of our new test statistic can be consistently estimated by the bootstrap. Simulations confirm that the power of the new procedure is higher than the power of the standard Kolmogorov-Smirnov test for copulas.

math.ST↗

arXiv2003

On the multiresolution structure of Internet traffic traces

Internet traffic on a network link can be modeled as a stochastic process. After detecting and quantifying the properties of this process, using statistical tools, a series of mathematical models is developed, culminating in one that is able to generate ``traffic'' that exhibits --as a key feature-- the same difference in behavior for different time scales, as observed in real traffic, and is moreover indistinguishable from real traffic by other statistical tests as well. Tools inspired from the models are then used to determine and calibrate the type of activity taking place in each of the time scales. Surprisingly, the above procedure does not require any detailed information originating from either the network dynamics, or the decomposition of the total traffic into its constituent user connections, but rather only the compliance of these connections to very weak conditions.

math.PR↗