The rate of arteriovenous fistula (AVF) placement continues to rise and AVF failure is a major complication. The main cause of AVF failure is stenosis leading to thrombosis. Although the detection of early stenosis with preemptive correction prior to thrombosis seems to be a plausible option to prevent access failure, there is much debate, on the basis of studies of surveillance with arterioven...

The main risk factors for cytomegalovirus (CMV) disease in recipients of allogeneic stem cell transplants (SCT) are recipient CMV seropositivity and acute graft-versus-host disease. Currently, two antiviral strategies, prophylactic or preemptive antiviral treatment, are used for prevention of CMV disease. Preemptive treatment is most favorable when short-term (14-day) treatment is applied. Seve...

Shanthikumar [10] studied the priority M/G/1 queue with server vacations and found that the difference between the waiting time distribution under the non-preemptive priority and that under the preemptive-resume priority is independent of the vacation policy. We extend this interesting property i) to the generalized vacations which includes the two vacation policies considered by Shanthikumar, ...

We consider an equilibrium M/M/1 queue in which customers arrive at a random position, both for the preemptive and non-preemptive cases. The Laplace-Stieltjes transforms of their sojourn time distributions are derived and in the latter case it is verified that the result is that of an M/M/1 queue where the server chooses the next task to serve at random.

In this paper, we analyze a discrete-time preemptive repeat priority queue with resampling. High-priority packets have preemptive repeat priority, and interrupted low-priority packets are subjected to independent retransmission attempts. Both classes contain packets with generally distributed transmission times. We show that the use of generating functions is beneficial for analyzing the system...

Times is a modelling and schedulability analysis tool for embedded real-time systems, developed at Uppsala University in 2001. It is appropriate for systems that can be described as a set of preemptive or non-preemptive tasks which are triggered periodically or sporadically by time or external events. It provides a graphical interface for editing and simulation, and an engine for schedulability...

In this paper we consider a non-product form queueing model of a multiprocessor operating system. In order to improve upon model solution time over a discrete-event simulation and a Markov chain based approach, we propose an extension to the shadow technique to allow for any mixture of preemptive and non preemptive priority scheduling strategy combined with class switching. This new technique c...

We summarize the first major effort to use analytics for preemptive maintenance and repair of an electrical distribution network. This is a large-scale multi-year effort between scientists and students at Columbia and MIT and engineers from Con Edison, which operates the world’s oldest and largest underground electrical system. Con Edison’s preemptive maintenance programs are less than a decade...

BACKGROUND Recent evidence suggests that preemptive use of an intra-aortic balloon pump (IABP) is associated with better outcomes in high-risk patients undergoing cardiac surgery. This retrospective study compares preemptive (planned) use of the IABP to emergency (unplanned) use in a regional cardiothoracic center. METHODS All patients who required an IABP from February 2003 to June 2006 were...

Due to their potential to deliver increased performance over single-core processors, multi-core processors have become mainstream in processor design. Computation-intensive real-time systems must exploit intra-task parallelism to take full advantage of multi-core processing. However, existing results in real-time scheduling of parallel tasks focus on restrictive task models such as the synchron...