With a dependency grammar, this study provides a unified method for calculating the syntactic complexity in linear and hierarchical dimensions. Two metrics, mean dependency distance (MDD) and mean hierarchical distance (MHD), one for each dimension, are adopted. Some results from the Czech-English dependency treebank are revealed: (1) Positive asymmetries in the distributions of the two metrics...

We introduce the concept of distance mean-regular graph, which can be seen as a generalization of both vertex-transitive and distance-regular graphs. A graph Γ = (V,E) with diameter D is distance meanregular when, for given u ∈ V , the averages of the intersection numbers ai(u, v), bi(u, v), and ci(u, v) (defined as usual), computed over all vertices v at distance i = 0, 1, . . . , D from u, do...

In this paper we study the average distance in weighted graphs. More precisely, we consider assignments of families of non-negative weights to the edges. The aim is to maximise (minimise, respectively) the average distance in the resulting weighted graph. Two variants of the problem are considered depending on whether the collection of weights is fixed or not. The main results of this paper are...