Betweenness centrality is a distance-based invariant of graphs. In this paper, we use lexicographic product to compute betweenness centrality of some important classes of graphs. Finally, we pose some open problems related to this topic.

Computers can help dialectologists to make full use of the information they have acquired: the basic dimensions of dialectal reaserch can be enlarged and its possible outcomes can become more sophisticated. In this paper, we show how a dialectal database, DBT-ALT, containing the data collected for the Atlante Lessicale Toscano ‘Lexical Atlas of Tuscany’ can be used as the starting point for the...

The purpose of this note is to compute the probability of logrolling for three different probabilistic cultures. The primary finding is that the restriction of preferences to be in accord with the condition of separable preferences creates enough additional structure among voters’ preference rankings to create an increase in the likelihood that a Condorcet winner will exist with both IC and IAC...

This paper describes a method for planning with rich qualitative, temporally extended preferences (QTEPs) using lookahead heuristics inspired by those employed in state-of-the-art classical planners. Key to our approach is a transformation of the planning domain into an equivalent but simplified planning domain. First, compound preference formulae are transformed into simpler, equivalent prefer...

An identifying code in a graph is a set of vertices which intersects all the symmetric differences between pairs of neighbourhoods of vertices. Not all graphs have identifying codes; those that do are referred to as twin-free. In this paper, we design an algorithm that finds an identifying code in a twin-free graph on n vertices in O(n) binary operations, and returns a failure if the graph is n...