[1] ASCR, Inst Thermomech, Dept Ultrasound Methods, CZ-18208 Prague 8, Czech Republic
[2] Charles Univ Prague, Fac Math & Phys, Sokolovskci 83, CZ-18675 Prague 8, Czech Republic
[3] ASCR, Dept Decis Making, Inst Informat Theory & Automat, CZ-18208 Prague 8, Czech Republic
[4] Czech Tech Univ, Fac Civil Engn, CZ-166 Prague 6, Czech Republic
[5] Rhein Westfal TH Aachen, Dept Math, D-52056 Aachen, Germany