In this paper we study the sequence (ci)0id for a distance-regular graph. In particular we show that if d 2j and cj = c > 1 then c2j > c holds. Using this we give improveme...
Abstract The wide diameter of a graph is an important parameter to measure faulttolerance of interconnection network. This paper proves that for any two vertices in de Bruijn undir...
We prove results on the size of weakly and strongly separating set systems and matrices, and on cross-intersecting systems. As a consequence, we improve on a result of Katona and ...
Scale free graphs have attracted attention as their non-uniform structure that can be used as a model for many social networks including the WWW and the Internet. In this paper, w...