Office:   3050 Sience Hall East
Phone:   973-720-2574
Email:   zelekem@wpunj.edu
Office Hours:   Tuesdays and Thursdays 11:00am-12:15pm

Department: Mathematics
Position: Professor of Mathematics
Area Specialization: Enumerative Combinatorics

• Research Publications
  1. On Generalization of Motzkin Numbers using k-Trees (with M. Jani), Ars Combinatoria, 89, 287 – 297 (2008).
  2. A Bijective Proof of a Tennis Ball Problem (with M. Jani), Bulletin of Inst. Of Combinat. and its Appl., 41, 89 - 95 (2004).
  3. Catalan Identities and k-trees, Congressus Numerantium, 165, 39 - 49 (2003).
  4. Enumeration of K-Trees and Applications (with M. Jani & R.G. Rieper), Annals of Combinatorics 6,  375-382 (2002).
  5. Skew Diagrams and Ordered Trees (with R.G. Rieper), Advances in Applied Mathematics 27, 671-681 (2001).
  6. Valleyless Sequences (with R.G. Rieper), Congressus Numerantium 145, 33-42 (2000).
  7. On Disjoint Covering Systems with Precisely One Repeated Modulus (with J. Simpson), Advances in Applied Mathematics 23, 322-332 (1999).
  8. Examples of Noninjectivity for the Combinatorial Radon Transform, Journal of Difference Equations and Applications 5, 319 - 322 (1998).
  9. On Injectivity of the combinatorial Radon transform of order 5 (with T. Amdeberhan), Journal Computational and Applied Mathematics 83, 251-255 (1997).
• Selected Conference Presentations
  1. Mathematics Colloquium, Addis Ababa University, Addis Ababa, Ethiopia, February 2011.
  2. From A = B to Z = 60, Rutgers University, Piscataway, NJ, May 2010.
  3. 3^rd Annual South American Conference on  Algebra, Number Theory & Combinatorics, Universidad Industrial de Santander, Bucaramanga, Colombia, July 2008.
  4. Algebra Seminar, Universidad de Antioquia, Medellin, Colombia, July 2008.
  5. Mathematics Colloquium, Colgate University, Hamilton, NY, November 2007.
  6. 6^th International Conference on Lattice Path Combinatorics, Eastern Tennessee University, Johnstown, TN, July 2007.
  7. Experimental Mathematics Seminar, Rutgers University, Piscataway, NJ, March 2006.
  8. 37th Southeastern International Conference on Combinatorics, Graph Theory and Computing, Florida Atlantic University, Boca Raton, FL, March 2006.
  9. The 2005 INTEGERS Conference, University of West Georgia, Carrollton, GA, October 2005.
  10. International Conference on Paths, Permutations and Trees, Nankai University, Tianjin, P.R. China, February 2004.
  11. Joint Mathematics Meetings, Contributed Papers, Baltimore, MD, January 2003.
  12. 966^th AMS Meeting, Stevens Institute of Technology, Hoboken, NJ, April 2001.
  13. 9^th Annual Faculty-Student Scholarship Day, William Paterson University, Wayne, NJ, October 2000.
  14. 9^th Quadrennial International Conference on Graph Theory, Combinatorics and Applications, Western Michigan University, Kalamazoo, MI, June 2000.
  15. Mathematics Colloquium, Howard University, Washington, D.C., October 1999.
  16. AMS Eastern Sectional Meeting, State University of New York, Buffalo, NY, April 1999.
• Awards and Fellowships
  1. US Fulbright Scholar, Addis Ababa University, August 2010 – June 2011.
  2. Distinguished Teaching Award, Temple University, April 1997.