We investigate here the computational complexity of three natural problems in directed acyclic graphs. We prove their NP Completeness and consider their restrictions to linear orde...
We have implemented a set of computational physics codes on a network of IBM RS/6000 workstations used as a distributed parallel computer. We compare the performance of the codes ...
We completely characterise the computational complexity of the list homomorphism problem for graphs in combinatorial and algebraic terms: for every graph H the problem is either N...