Marek Brabec

Dept. of Statistical Modelling

Institute of Computer Science of the Czech Academy of Sciences

Location: Institute of Computer Science, Pod Vodárenskou věží 2, 180 00 Prague, Czechia

   Room 318

Date:   Tuesday 12 November 2024

Time: 13:00 CET

Abstract:

We will formulate a physically motivated dynamical model of indoor radon concentrations from first principles. Since not only concentrations, but also time-varying radon entry rates are of interest in real situations, measurements are bivariate – consisting of radon and tracer gas concentrations. Being motivated by underlying physical model based on a nonlinear system of two differential equations, we formulate a structured state-space model allowing for estimation of all (functional) quantities of interest reflecting salient statistical features of the problem carefully. Then, we postulate a fully Bayesian model and estimation strategy. From there, we obtain estimates of radon concentration, radon entry rate and ventilation rate from posterior (in the form of smoother to use standard Time-series methodology). We will show the approach on real measurement campaign data using Stan MCMC computations.

Keywords: State-space, Bayesian modeling, ODE.

References: 

1. Brabec,M.-Jílek,K. (2012): Dynamic Assessment of Radon Source in Buildings, Based on Tracer Gas Experiment Statistical Modeling. Chapter 8 in: Handbook of Radon: Properties, Applications and Health (Li,Z. and Feng,C., eds.), Nova Publishers, ISBN: 978-1-62100-177-5

2. Froňka,A.-Jílek,K.-Moučka,L.-Brabec,M. (2011): Significance of independent radon entry rate and air exchange rate assessment for the purpose of radon mitigation effectiveness proper evaluation: case studies. Radiation Protection Dosimetry, 145, 2-3, 133-137

3. Brabec,M.-Jílek,K. (2010): Simplified Radon Entry Rate Estimation Methodology from Tracer and Radon Concentrations Based on Functional Data Analysis Approach, Horizons in World Physics. Volume 270, Editor: Albert Reimer, Nova Science Publisher’s, Inc., Hauppauge, New York, ISBN: 978-1-61728-995-8

4. Brabec,M.-Jílek,K. (2009): Dynamical model for indoor radon concentration monitoring. Environmetrics. 20:718-729

5. Brabec, M., Jilek, K. (2007): State-space dynamic model for estimation of radon entry rate, based on Kalman filtering, Journal of Environmental Radioactivity, 98, 285-297

6. Jílek,K.-Thomas,J.-Brabec,M. (2008): QA programme for radon and its short-lived progeny measuring instruments in NRPI Prague. Radiation Protection Dosimetry; doi: 10.1093/rpd/ncn113