1. Assistant Professor, College of Engineering and Computer Science, California State Univ., 18111 Nordhoff St., Northridge, CA 91330 (corresponding author).
2. Professor, Slovak Academy of Sciences, Institution of Construction and Architecture, Dubravska cesta 9 845 03 Bratislava 45 Slovak Republic.
3. Professor, School of Aeronautics and Astronautics, Dalian Univ. of Technology, Dalian 116024, China.