Given a simple connected graph Î“ and a subset of its vertices C, the pseudodistance-regularity around C generalizes, for not necessarily regular graphs, the notion of completely regular code. Up toâ€¦ (More)

Distance-regular graphs are a key concept in Algebraic Combinatorics and have given rise to several generalizations, such as association schemes. Motivated by spectral and other algebraicâ€¦ (More)

The future airspace system is being defined by several initiatives. SESAR in Europe and NextGen in the USA are working towards the modernization of ATM procedures. The foreseen integration ofâ€¦ (More)

The Spectral Excess Theorem provides a quasi-spectral characterization for a (regular) graph Î“ with d+1 different eigenvalues to be distance-regular graph, in terms of the mean (d-1)-excess of itsâ€¦ (More)