This is a preview. Log in through your library . Abstract The Tree QAP is a special case of the Quadratic Assignment Problem (QAP) where the nonzero flows form a tree. No condition is required for the ...

This is a preview. Log in through your library . Abstract An optimum rectilinear Steiner tree for a set A of points in the plane is a tree which interconnects A using horizontal and vertical lines of ...

A problem that began with a bug has increased the risk of danger during thunderstorms.“We have the dead ash trees that are very, very fragile,” said certified arborist Tim Back.The emerald ash borer ...