The quadratic traveling salesman problem asks for a tour of min-imal costs where the costs are associated with each two arcs that are traversedin succession. This structure arises, e. g., if the succession of two arcs representsthe costs of loading processes in transport networks or a switch between dif-ferent technologies in communication networks. Based on a quadratic integer<...

Branch-and-bound and branch-and-cut use search trees to identify optimal solutions to combinatorial optimization problems. In this paper, we introduce an iterative search strategy which we refer to as cut-and-solve and prove optimality and termination for this method. This search is different from traditional tree search as there is no branching. At each node in the search path, a relaxed probl...

We generalize the tree doubling and Christofides algorithm to parameterized approximations for ATSP. The parameters we consider respective generalizations are upper bounded by number of asymmetric distances, which yields algorithms efficiently compute good also moderately TSP instances. As generalization algorithm, derive a 2.5-approximation, where parameter is size vertex cover subgraph induce...

Processor speed and memory capacity are increasing several times faster than disk speed. This disparity suggests that disk I/O performance will become an important bottleneck. Methods are needed for using disks more efficiently. Past analysis of disk scheduling algorithms has largely been experimental and little attempt has been made to develop algorithms with provable performance guarantees. W...

The ATSP polytope can be expressed by asymmetric polynomial size linear program. Introduction In his seminal work [1], M. Yannakakis proved that the Traveling Salesman problem (TSP) polytope cannot be expressed by symmetric polynomial size linear program, where symmetry means that the polytope is an invariant under vertex relabeling. The question about the size of asymmetric linear programs was...