This paper presents an experimental study of imperfection insensitive composite wavy cylindrical shells subject to axial compression. A fabrication technique for making cylindrical shells with intricate shape of cross-sections has been developed. A photogrammetry technique to measure the geometric imperfections has also been developed. The behavior of the wavy shells under axial compression was...

Geometric imperfection, known as a detrimental effect on the buckling load of cylindrical shells, has a new role under the emerging trend of using buckling for smart purposes. Eigenshape-based geometries were designed on the shell surface with the aim of tailoring the postbuckling response. Fourteen seeded geometric imperfection (SGI) cylinders were fabricated using polymer-based 3D printing, a...

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...

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...

BACKGROUND Ongoing molecular processes in a cell could target microsatellites, a kind of repetitive DNA, owing to length variations and motif imperfection. Mutational mechanisms underlying such kind of genetic variations have been extensively investigated in diverse organisms. However, obscure impact of ploidization, an evolutionary process of genome content duplication prevails mostly in plant...