UTIA homepage Department of Stochastic Informatics

Staff Conferences Grants Cooperation Courses Publications Anotations

Research Topics

The Department concentrates on mathematical research in the following areas.
  1. Information in statistical experiments and optimal statistical decisions (estimation, testing, classification), with emphasis on maximum entropy, minimum divergence methods, and asymptotic theory.
  2. Robust statistical procedures and their applications in various statistical environments, including adaptivity and self-organization. Regression analysis.
  3. Statistical inference in random processes and random fields. Applications in stochastic optimization, change-point, optimum investment portfolios, and image and speech processing.

Personnel

Head of Department:

Pavel Boček computer science, optimal statistical algorithms
26605 2596 bocek@utia.cas.cz

Assistant:

Iva Marešová tel. 26605 2466 stochinf@utia.cas.cz, maresova@utia.cas.cz

Research Fellows:

Lucie Fajfrová probability theory, interacting particle systems
26605 2396 fajfrova@utia.cas.cz
Tomáš Hobza nonparametric density estimates
26605 2041 hobza@km1.fjfi.cvut.cz, hobza@utia.cas.cz
Marie Hušková regression analysis, change point problem, non-parametric methods
221913 277 huskova@karlin.mff.cuni.cz
Martin Janžura limit theorems for random fields and processes, image processing, information - theoretic methods in probability and statistics
26605 2572 janzura@utia.cas.cz
Zbyněk Koldovský indepenent component analysis blind single separation convolutive mixtures
26605 2292 koldovsk@utia.cas.cz
Michal Kupsa dynamical systems, ergodic theory, point processes, probability and statistics
26605 2284 kupsa@kti.mff.cuni.cz
Petr Lachout weak convergence of probability measures, asymptotic theory of random processes and fields, robust statistics
221913 289 lachout@karlin.mff.cuni.cz, lachout@utia.cas.cz
Tomáš Marek time series analysis
26605 2244 marek@utia.cas.cz
Jiří Michálek random processes, statistical inference in stochastic processes, statistical process control
26605 2241 michalek@utia.cas.cz
Jan Nielsen image and signal analysis
26605 2284 jnielsen@utia.cas.cz
Antonín Otáhal random processes and random fields, stochastic methods in signal and image processing
602 358219 otahal@utia.cas.cz
Tomáš Pazák measures on Boolean algebras and set theory
26605 2396 pazak@math.cas.cz
Michaela Prokešová probability theory
26605 2396 prokesov@utia.cas.cz
Petr Salaba probability analysis for service, reliability
26605 2252 salaba@utia.cas.cz
Jan Seidler stochastic analysis, stochastic partial differential equations
26605 2041 seidler@utia.cas.cz
Jan Swart stochastic partial differential equations
26605 2584 swart@utia.cas.cz
Jan Šindelář theory of complexity and its application in probability and statistics, alternative theories of data processing
26605 2440 sindelar@utia.cas.cz
Petr Tichavský system and signal theory, independent component analysis, wireless communications analysis
26605 2292 tichavsk@utia.cas.cz
Igor Vajda information theory, mathematical statistics
26605 2204 vajda@utia.cas.cz
Jan Ámos Víšek robust statistics and econometrics, regression analysis, adaptive statistical methods, statistical computations, applications in economy and medicine
222 112 318 visek@mbox.fsv.cuni.cz
Petr Volf survival analysis, nonparametric regression, smoothing methods, statistical reliability testing
26605 2431 volf@utia.cas.cz
Karel Vrbenský computer science, optimal statistical algorithms
26605 2252 vrbensky@utia.cas.cz

Postgraduate Students:

David Kraus theory of random point processes, event history analysis

International Cooperation

Members of the Department participated in joint research with their colleagues from Universities in

University Boards:

Editorial Boards:

Representation in International Societies:

Recent Activities:

Grants and Projects:

Teaching and Supervising Activities:

University Courses

36 courses on subjects related to the research field of the department were read.

Conferences:

Conferences - Organization:

Prague Stochastics 2006 a joint session of 7th Prague Symposium on Asymptotic Statistics and 15th Prague Conference on Information Theory, Statistical Decision Functions and Random Processes, Prague, August 21,-,25, 2006 (together with KPMS MFF UK, 169 participants, 130 abroad)

Conferences - Participations:

17 lectures, 3 of them invited, have been delivered at international conferences, including

Publications

UTIA library

Anotations

Blind Source Separation

Blind Source Separation consists of recovering original signals from their mixtures when the mixing process is unknown. In biomedicine, namely in MEG and EEG signal processing, one of the most popular algorithms nowadays is SOBI (Second Order Blind Identification). We proposed a procedure for fast implementation of the Weights-Adjusted SOBI (WASOBI) algorithm for asymptotically optimal separation of Gaussian autoregressive (AR) sources. The procedure employs fast computation of the optimum weight matrix, as well as an elaborate scheme for minimization of the associated weighted Least-Squares criterion. The resultant complexity is O(d2M2+d3M), where d is the number of sources and M is the required number of estimated correlation matrices. Our procedure allows separation of more than 100 sources in order of tens of seconds in Matlab. Simulations verify that the algorithm still attains the corresponding Cramér-Rao bound, even in these high dimensions.

Divergences and Informations in Statistics and Information Theory

Basic properties of f-divergences are proved in a new simpler manner. New relations to sufficiency and deficiency are established and new applications in estimation and testing are proposed. Statistical information of De Groot and the classical information of Shannon are shown to be extremal cases of a newly introduced class of so-called Arimoto informations.

Robustness of Median Estimator in Bernoulli Logistic Regression

The paper of T. Hobza and L. Pardo: On Robustness of Median Estimator in Bernoulli Logistic Regression published in the Proceedings of the Prague Stochastics 2006, presents generalized logistic regression models which include the classical model with binary responses governed by the Bernoulli law depending on the logistic regression function. The median estimator of the logistic regression parameters employing smoothed data in the discrete case, introduced in Hobza et al (2005), is considered. Sensitivity of this estimator to contaminations of the logistic regression data is studied by simulations and compared with the sensitivity of some robust estimators previously introduced to logistic regression. The median estimator is demonstrated to be more robust for higher levels of contamination.