# Doc. RNDr. Viktor Witkovský, CSc.

## Research Focus:

- Research of exact and approximate mathematical and statistical methods for small sample sizes.
- Theoretical and computational aspects of statistical inference.
- Statistical inference for linear and non-linear mixed effects models.
- Methods and algorithms for computing and combining the probability distributions for statistical applications.
- Models and methods for measurement and metrology: determination of uncertainties in measurement, interlaboratory comparisons, calibratioj.
- Data analysis and applications of statistical methods.

## Education:

- 1981-1986, Faculty of Mathematics and Physics, Comenius University, Bratislava, Slovakia, field of study “Probability and mathematical statistics”,
- 1986, awarded title RNDr. (Rerum Naturalis Doctor), Faculty of Mathematics and Physics Comenius University, Bratislava, Slovakia,
- 1989-1992, PhD study,Institute of Measurement and Measuring Technique, Slovak Academy of Sciences, Bratislava
- 1993, awarded title CSc. (Candidate of Sciences – equivalent to PhD) field of study “Probability and mathematical statistics”, Mathematical Institute, Slovak Academy of Sciences, Bratislava, Slovakia
- 1997, awarded scientific degree IIa – independent scientific worker
- 2005, habilitation – Docent of Mathematics, Faculty of Mathematics, Physics and Informatics, Comenius University, Bratislava, Slovakia

## Functions:

- 2019: Director, Institute of Measurement Science, Slovak Academy of Sciences, Bratislava, Slovakia (IMS SAS)
- 2006 – 2018: Vice-Director, IMS SAS, (2006-2010, 2010-2014, 2014-2018)
- 2005 – 2018: Chair of the Scientific Board, IMS SAS, (2005-2009, 2009-2013, 2013-2018)
- 1998 – 2018: Head of the Department of Theoretical Methods, IMS SAS
- 1998-2006: Scientific Secretary, IMS SAS

## PhD Students:

- Mgr. Michal Teplan, PhD (2006). PhD Thesis: Audio-visual stimulation and relaxation, linear and nonlinear EEG measures. Advisor: RNDr. Anna Krakovská, CSc. Field of study: 39-52-9 Bionics and Biomechanics, Institute of Measurement Science, Slovak Academy of Sciences, Bratislava, June 21, 2006.
- Mgr. Barbora Arendacká, PhD (2009). PhD Thesis: Interval estimators for a variance component in mixed linear models with two variance components. Field of study: 11-06-9 Probability and Mathematical Statistics, Institute of Measurement Science, Slovak Academy of Sciences, Bratislava, June 16, 2009.
- Mgr. Kristína Mezeiová, PhD (2009).PhD Thesis: Nonlinear and spectral characteristics of sleep electroencephalogram. Advisor: RNDr. Anna Krakovská, CSc. Field of study: 39-52-9 Bionics and Biomechanics, Institute of Measurement Science, Slovak Academy of Sciences, Bratislava, November 26, 2009.
- Mgr. Gejza Wimmer, PhD (2010). PhD Thesis: Models, methods and algorithms for longitudinal data analysis. Field of study: 9-1-9 Applied Mathematics, Mathematical Institute, Slovak Academy of Sciences, August 27, 2010.
- Ing. Katarína Bartošová, PhD (2010). Téma dizertačnej práce: Statistical methods and algorithms for research on molecular diagnosis of pulmonary diseases. Field of study: 39-52-9 Bionics and Biomechanics, Institute of Measurement Science, Slovak Academy of Sciences, Bratislava, September 21, 2010.
- Mgr. Martina Chvosteková, PhD (2011). PhD Thesis: Simultaneous two-sided tolerance intervals in the linear regression model. Field of study: 5.2.54 Measurement Technique, Institute of Measurement Science, Slovak Academy of Sciences, Bratislava, November 25, 2011.
- Mgr. Ivana Pobočíková, PhD (2012). PhD Thesis: Selected methods and algorithms for statistical analysis of clinical trials. Field of study: 9.1.9. Applied Mathematics, Faculty of Humanitarian Sciences, University of Žilina, April 12, 2012.
- RNDr. Ján Klacso, PhD (2013). PhD Thesis: Mathematical Analysis of the Transmission Mechanism of Monetary Policy of the National Bank of Slovakia. Advisor: RNDr. František Hajnovič. Field of study: 9.1.9. Applied Mathematics, Faculty of Mathematics, Physics and Informatics, Comenius University, Bratislava, August 26, 2013.
- Mgr. Jozef Jakubík, PhD (2018). PhD Thesis: Methods of statistical inference for analysis of high dimensional data using linear mixed models. Field of study: 5.2.54 Measurement Technique, Institute of Measurement Science, Slovak Academy of Sciences, Bratislava, August 28, 2018.

## Selected Publications:

- WITKOVSKÝ V. Computing the distribution of a linear combination of inverted gamma variables. Kybernetika. 2001, 37(1), 79-90.
- WITKOVSKÝ V. On the exact computation of the density and of the quantiles of linear combinations of t and F random variables. Journal of Statistical Planning and Inference. 2001, 94(1), 1-13.
- WITKOVSKÝ V. Exact distribution of positive linear combinations of inverted chi-square random variables with odd degrees of freedom. Statistics & Probability Letters. 2002, 56(1), 45-50.
- WITKOVSKÝ V. Estimation, Testing, and Prediction Regions of the Fixed and Random Effects by Solving the Henderson’s Mixed Model Equations Invited paper. Measurement Science Review. 2012, 12(6), 234-48.
- WITKOVSKÝ, V. – WIMMER, G. – DUBY, T. Logarithmic Lambert W × F random variables for the family of chi-squared distributions and their applications. In Statistics & Probability Letters, 2015, 96, 223-231.
- WITKOVSKÝ, V. – WIMMER, G. – ĎURIŠ, S. On statistical methods for common mean and reference confidence intervals in interlaboratory comparisons for temperature. In International Journal of Thermophysics, 2015, 36(8), 2150-2171.
- KÖNING, R. – WIMMER, Gejza – WITKOVSKÝ, V. Ellipse fitting by nonlinear constraints to demodulate quadrature homodyne interferometer signals and to determine the statistical uncertainty of the interferometric phase. In Measurement Science and Technology, 2014, 25(11), p. 115001.
- KUSHCH, I. – ARENDACKÁ, Barbora – ŠTOLC, Svorad – MOCHALSKI, P. – FILIPIAK, W. – SCHWARZ, K. – SCHWENTNER, L. – SCHMID, A. – DZIEN, A. – LECHLEITNER, M. – WITKOVSKÝ, V. – MIEKISCH, W. – SCHUBERT, J. – UNTERKOFLER, K. – AMANN, A. Breath isoprene – aspects of normal physiology related to age, gender and cholesterol profile as determined in a proton transfer reaction mass spectrometry study. In Clinical Chemistry and Laboratory Medicine, 2008, 46(7), 1011-1018.
- SCHULZ, E. – TIEMANN, L. – WITKOVSKÝ, V. – SCHMIDT, P. – PLONER, M. Gamma oscillations are involved in the sensorimotor transformation of pain. In Journal of Neurophysiology, 2012, 108, 1025-1031.
- SCHULZ, E. – MAY, E.S. – POSTORINO, M. – TIEMANN, L. – NICKEL, M.M. – WITKOVSKÝ, V. – SCHMIDT, P. – GROSS, J. – PLONER, M. Prefrontal gamma oscillations encode tonic pain in humans. In Cerebral Cortex, 2015, 25(11), 4407-4414.