A bull is a graph obtained by adding a pendant vertex at two vertices of a triangle. Here we present polynomial-time combinatorial algorithms for the optimal weighted coloring and weighted clique problems in bull-free perfect graphs. The algorithms are based on a structural analysis and decomposition of bull-free perfect graphs.

Structural change is important driver of productivity. Existing decompositions structural rely heavily on the share weights firms. Ideally, one would need a complete census all firms to calculate weights. However, empirical data are often less than ideal. Another limitation that existing switch from industry another mixed with startups and bankrupt To address both these limitations, we develop ...

The paper summarises the ambient vibration-based assessment of an historic suspension footbridge, dating back to 1928. The footbridge is characterised by the timber floor system supported by two couples of cables, that were recently replaced. After the retrofit, the actual structural behaviour of the bridge were assessed by experimental and theoretical methods. The field tests included geometri...