| DATE: | Wednesday, October 25th |
| TIME: | 12:00 PM - 1:00 PM |
| PLACE: | McConnell 320 |
| TITLE: | Non-Regular Square Bipartite Designs |
| SPEAKER: | Caterina De Simone, Istituto di Analidi dei Sistemi ed Informatica National Council of Research, Rome |
A square bipartite design is a pair of square 0-1 matrices A
and B satisfying the following matrix equation:
(A^T)B= lambda J + diag (d)
where J is a matrix filled with all ones, lambda is a positive
integer, and d is a vector. We give a characterization of a class of
non-regular square bipartite designs; our result generalize some
earlier results of De Bruijn and Erdos, Lehman, and Gasparyan.
Joint with Grigor Gasparyan and Paolo Nobili.