Prior to that, he was on the faculty of the Department of Computer Science, Hofstra University from September 2008 - August 2011. He obtained his second Ph.D. degree in Computer Science and Engineering from the Department of Computer Science and Engineering, University of Texas at Arlington in May 2008, and his second Master's degree in Computer Science from the Department of Computer Science and Engineering, Southern Methodist University in December 2004. Also, he obtained his first Ph.D. and Master's degrees in Computer Science from the Department of Computer Science, Faculty of Sciences of Tunis in December 1996 and July 1992, respectively.