Perfect graphs constitute a well-studied graph class with a rich structure, reflected by many characterizations w.r.t different concepts. Perfect graphs are, e.g., characterized as precisely those graphs G where the stable set polytope STAB(G) coincides with the clique constraint stable set polytope QSTAB(G). For all imperfect graphs STAB(G) ⊂ QSTAB(G) holds and, therefore, it is natural to mea...

Given a graph G and a non-negative integer weight or demand xv for each node v, a colouring of the pair (G, x) is an assignment to each node v of a set of xv colours such that adjacent nodes receive disjoint sets of colours. We are interested in such colourings when the maximum demand xv is large. An application where such colouring problems arise is in the design of cellular radio communicatio...

Construction and assembling process of shell structures has caused main problems. In these structures, there is no possibility for the integrated construction due to their large shell extent and they are built using a number of welded curved panel parts; hence, some geometrical imperfections emerge. Most of these imperfections are caused by the process of welding, transportation, inappropriate ...

The paper investigates the effects of international trade in goods and capital movement on the productivity distribution and industry-wide productivity when countries are heterogeneous in the quality of their financial institutions. In autarky, firm heterogeneity in their productivities arises in countries with poor financial institutions, while all firms adopt a high-productivity technology in...