arXiv subjects

N. D. Gagunashvili

Publications and source records attributed to N. D. Gagunashvili.

5 recordsLinked to original sources

arXiv2012

Kernel based unfolding of data obtained from detectors with finite resolution and limited acceptance

A kernel based procedure for correcting experimental data for distortions due to the finite resolution and limited detector acceptance is presented. The unfolding problem is known to be an ill-posed problem that can not be solved without some a priori information about solution such as, for example, smoothness or positivity. In the approach presented here the true distribution is estimated by a weighted sum of kernels, with the width of the kernels acting as a regularization parameter responsible for the smoothness of the result. Cross-validation is used to determine an optimal value for this parameter. A numerical example with a simulation study of systematical and statistical errors is presented to illustrate the procedure.

physics.data-an↗

arXiv2011

Parametric fitting of data obtained from detectors with finite resolution and limited acceptance

A goodness-of-fit test for the fitting of a parametric model to data obtained from a detector with finite resolution and limited acceptance is proposed. The parameters of the model are found by minimization of a statistic that is used for comparing experimental data and simulated reconstructed data. Numerical examples are presented to illustrate and validate the fitting procedure.

physics.data-an↗

arXiv2009

Chi-Square Tests for Comparing Weighted Histograms

Weighted histograms in Monte Carlo simulations are often used for the estimation of probability density functions. They are obtained as a result of random experiments with random events that have weights. In this paper, the bin contents of a weighted histogram are considered as a sum of random variables with a random number of terms. Generalizations of the classical chi-square test for comparing weighted histograms was proposed. Numerical examples illustrate an application of the tests for the histograms with different statistics of events and different weighted functions. The proposed tests can be used for the comparison of experimental data histograms with simulated data histograms, as well as for the two simulated data histograms.

physics.data-an↗

arXiv2008

Goodness of fit tests for weighted histograms

Weighted histogram in Monte-Carlo simulations is often used for the estimation of a probability density function. It is obtained as a result of random experiment with random events that have weights. In this paper the bin contents of weighted histogram are considered as a sum of random variables with random number of terms. Goodness of fit tests for weighted histograms and for weighted histograms with unknown normalization are proposed. Sizes and powers of the tests are investigated numerically.

physics.data-an↗

arXiv2006

Comparison of weighted and unweighted histograms

Two modifications of the chi square test for comparing usual(unweighted) and weighted histograms and two weighted histograms are proposed. Numerical examples illustrate an application of the tests for the histograms with different statistics of events. Proposed tests can be used for the comparison of experimental data histograms against simulated data histograms and two simulated data histograms.

physics.data-an↗