For a scheduling problem on parallel machines, the power of preemption is defined as the ratio of the makespan of an optimal non-preemptive schedule over the makespan of an optimal preemptive schedule. For m uniform parallel machines, we give the necessary and sufficient conditions under which the global bound of 2 − 1/m is tight. If the makespan of the optimal preemptive schedule is defined by...

In this paper, we study the Minimum Sum Set Coloring (MSSC) problem which consists in assigning a set of x(v) positive integers to each vertex v of a graph so that the intersection of sets assigned to adjacent vertices is empty and the sum of the assigned set of numbers to each vertex of the graph is minimum. The MSSC problem occurs in two versions: nonpreemptive and preemptive. We show that th...

Although theoretical results have been established regarding the utility of preemptive scheduling in reducing average job turnaround time, job suspension/restart is not much used in practice at supercomputer centres for parallel job scheduling. A number of questions remain unanswered regarding the practical utility of preemptive scheduling. We explore this issue through a simulation based study...

Mediastinal nerve stimulation (MNS) reproducibly evokes atrial fibrillation (AF) by excessive and heterogeneous activation of intrinsic cardiac (IC) neurons. This study evaluated whether preemptive vagus nerve stimulation (VNS) impacts MNS-induced evoked changes in IC neural network activity to thereby alter susceptibility to AF. IC neuronal activity in the right atrial ganglionated plexus was ...

OBJECTIVE To examine the evidence of preemptive use of gabapentin in abdominal hysterectomy. DATA SOURCES We conducted an electronic based search using the following databases: PubMed, EMBASE, Ovid MEDLINE, ClinicalTrials.gov, and Cochrane Central Register of Controlled Trials. The following medical subject heading terms, keywords, and their combinations were used: "postoperative pain, hyster...

We present constant approximative policies for preemptive stochastic scheduling. We derive policies with a guaranteed performance ratio of 2 for scheduling jobs with release dates on identical parallel machines subject to minimizing the sum of weighted completion times. Our policies as well as their analysis apply also to the recently introduced more general model of stochastic online schedulin...

Whether preemptive analgesic interventions are more effective than conventional regimens in managing acute postoperative pain remains controversial. We systematically searched for randomized controlled trials that specifically compared preoperative analgesic interventions with similar postoperative analgesic interventions via the same route. The retrieved reports were stratified according to fi...

Parallel Data processing has emerged to be one of the killer applications for Infrastructure-as-a-Service (IaaS) clouds. One of an IaaS cloud’s key feature is the provisioning of compute resources on demand. The computer resources available in the cloud are highly dynamic and possibly heterogeneous. Nephele is the first data processing framework to explicitly exploit the dynamic resource alloca...

group. There were no significant differences in the 24-hr changes in GFR or serum cortisol level, This study showed that perioperative administration of meloxicam reduced unfayorable postoperative changes in the cardiovascular system without influencing renal function. KEy woRDs: canine, cardiovascular parameters, meloxicam, preemptive analgesia, telemetry system, J. vlet, Med, Sci. 69(9): 939-...

BACKGROUND Invasive candidiasis is the third most common bloodstream infection in the intensive care unit (ICU) and is associated with morbidity and mortality. Prophylaxis and preemptive therapy are attractive strategies for this setting. METHODS We conducted a multicenter, randomized, double-blind, placebo-controlled trial of caspofungin as antifungal prophylaxis in 222 adults who were in th...