We consider a project scheduling problem where the precedence constraints graph is an out-tree. The processing times can be compressed by using additional resources, which causes cost and simultaneously reduces the processing times of jobs. The objective is to minimize the sum of total lateness...

When scheduling a round robin tournament (RRT) a Home-Away-Pattern (HAP) set defines for each team i and each period p whether i plays at home or away in p. So far the complexity of the decision problem whether a RRT can be arranged based on a given HAP set or not is open. We give a necessary...

A single round robin tournament (RRT) consists of a set T of n teams (n even) and a set P of n - 1 periods. The teams have to be scheduled such that each team plays exactly once against each other team and such that each team plays exactly once per period. In order to establish fairness among...

In general scheduling a sports league is a difficult combinatorial optimization problem. We study some variants of round robin tournaments and analyze the relationship with the planar three index assignment problem. The complexity of scheduling a round robin tournaments is settled by a reduction...

Generally speaking in sports competition a number of teams play against each other over a period of time according to a certain scheme. The round robin scheme is very popular in many team sports like soccer and basketball. In this paper we study several basic variants of round robin tournaments....

The 0-1 knapsack problem with a single continuous variable (KPC) is a natural extension of the binary knapsack problem (KP), where the capacity is not any longer fixed but can be extended which is expressed by a continuous variable. This variable might be unbounded or restricted by a lower or...