1. Department for Applied Mathematics, University of Freiburg, Germany
2. University of Ljubljana, Faculty of Civil and Geodetic Engineering, Ljubljana, Slovenia
3. Institute of Information Theory and Automation, Czech Academy of Sciences, Praha 8, Czechia
4. Faculty of Civil Engineering, Czech Technical University, Thákurova 7, CZ-166 29 Praha 6, Czechia
5. Department of Mathematics, Faculty of Science, University of South Bohemia, České Budějovice, Czechia