Professor of Mathematics, University of California, Berkeley

Professor of Computer Engineering, Shahed University

Department of Mathematics, University of Washington

Professor of Mathematics, Universitat Politècnica de Catalunya

Matemáticas, Universidad Nacional Sede Bogotá

Universidad Pedagógica y Tecnológica de Colombia

Department of Mathematics, Faculty of Science, University of Kurdistan, Sanandaj, Iran.

Faculty of Mathematical Sciences, Shahrood University of Technology.

Blekinge Institute of Technology & The University of Skövde

Postdoctoral Research Fellow, University of Tasmania