[1] Czech Acad Sci, Inst Thermomech, Dolejskova 5, Prague 18200, Czech Republic
[2] Czech Tech Univ, Dept Tech Math, Jugoslavskych Partyzanu 1580, Prague 16000, Czech Republic
[3] Univ Chem & Technol, Dept Math Informat & Cybernet, Tech 5, Prague 16628, Czech Republic
[4] Univ West Bohemia, Dept Power Syst Engn, Univ 8, Plzen 30100, Czech Republic