BACKGROUND AND OBJECTIVES There exists gross disparity in national deceased donor kidney transplant availability and practice: waiting times exceed 6 years in some regions, but some patients receive kidneys before they require dialysis. This study aimed to quantify and characterize preemptive deceased donor kidney transplant recipients and compare their outcomes with patients transplanted short...

We investigate the problem of on-line scheduling two-machine open shops with the objective of minimizing the makespan. Jobs arrive independently over time, and the existence of a job is not known until its arrival. In the clairvoyant on-line model, the processing requirement of every job becomes fully known at the arrival of the job, while in the non-clairvoyant on-line model, this processing r...

We consider a 2-class, single-server, preemptive priority queueing model in which the high-priority customers form a classical M/M/1 queue, while the low-priority customers form the so-called Israeli Queue with at most N different groups and unlimited-size batch service. We provide an extensive probabilistic analysis and calculate key performance measures. Special cases are analyzed and numeric...

Many approximation results for single machine scheduling problems rely on the conversion of preemptive schedules into (preemptive or non-preemptive) solutions. The initial preemptive schedule is usually an optimal solution to a combinatorial relaxation or a linear programming relaxation of the scheduling problem under consideration. It therefore provides a lower bound on the optimal objective f...

The scheduling of tasks within a parallel program onto the underlying available processors has been studied for some time. To date, solutions to this problem generally assume that communication only occurs at the start or end of each parallel task, i.e., the child task can only start its execution when all its parent tasks complete and have sent data to it. This is termed \non-preemptive task s...