An α-approximation algorithm is an algorithm guaranteed to output a solution that is within an α ratio of the optimal solution. We are interested in the following question: Given an NP-hard optimization problem, what is the best approximation guarantee that any polynomial time algorithm could achieve? We mostly focus on studying the approximability of two classes of NP-hard problems: Constraint...

The antiviral activity profile of the uterus and fetal membranes from bovine placenta, induced by the Newcastle disease virus (NDV) throughout gestation, was investigated. Explants of the endometrium and caruncles were collected from the uterus, and amniochorion, allantochorion and cotyledons, from fetal placenta. Tissue cultures were induced with ~6.0 hemagglutinating units (HU) of NDV. Supern...

Throughout this section, G = (V,E) is a multi-graph. A cut of G is a bipartition (S, S̄) of the vertex set of G. The capacity of a cut is the number of edges having one endpoint on both sides of the cut. A min-cut is a cut of minimum capacity. A minimum cut can be computed with the help of maxflow computations. For some vertex s and every other vertex t, one computes the minimum cut separating s...

Cut-elimination is usually presented as a set of local proof reduction steps together with a terminating strategy thus showing the existence of cut-free proofs for all provable sequents. Viewing cut-elimination as a transformation of mathematical proofs, not only the existence but also the structure and content of the cut-free proofs deserves investigation. In this paper we use proof skeletons ...

acres, and you enjoy a variety of activities on your land: watching wildlife, hiking, hunting, picking berries, picnicking or taking photos of wildlife and wildflowers. You delight in the beauty and solitude that comes with owning a woodland. You warm yourself in late fall and winter by cutting a little firewood, and you wouldn’t mind making a little extra cash, though managing your woodland fo...

we introduce some new concepts of topological spaces which say α − separable topologicalspace and o-topological group, α − first axiom, α − second axiom, and we find some relations betweenthem with some applications in normed spaces.