t is the purpose of this paper to contribute to the discussion initiated bywachter about the parallelism between principal component (pc) and atypological grade of membership (gom) analysis. the author testedempirically the close relationship between both analysis in a lowdimensional framework comprising up to nine dichotomous variables and twotypologies. our contribution to the subject is also...

Background: Violent patients constitute 10% of all psychiatric admissions. Treatment options and clinical practice interventions vary across the globe and no survey of practice in a Middle Eastern setting exists. Surveying treatments in Lebanon will show treatment interventions used in this part of the world and, most importantly, provide the treatment options that could potentially be used for...

For a GI/GI/1 queue, we show that the average sojourn time under the (blind) Randomized Multilevel Feedback algorithm is no worse than that under the Shortest Remaining Processing Time algorithm times a logarithmic function of the system load. Moreover, it is verified that this bound is tight in heavy traffic, up to a constant multiplicative factor. We obtain this result by combining techniques...

We study a system of several identical servers in parallel, where a routing decision must be made immediately on a job’s arrival. Jobs arrive according to a Poisson process, with their processing times following a discrete distribution with finite support. The processing time of a job is known on arrival and may be used in the routing decision. We propose a policy consisting of multi-layered ro...

This paper studies online job scheduling on multiprocessors and, in particular, investigates the algorithms SRPT and SJF for minimizing total stretch, where the stretch of a job is its flow time (response time) divided by its processing time. SRPT is perhaps the most well-studied algorithm for minimizing total flow time or stretch. This paper gives the first resource augmentation analysis of th...

We study cyclic polling models with exhaustive service at each queue under a variety of non-FCFS (first-come–first-served) local service orders, namely last-come–first-served with and without preemption, random-order-of-service, processor sharing, the multiclass priority scheduling with and without preemption, shortest-job-first, and the shortest remaining processing time policy. For each of th...

This paper uses trace-driven simulation to study the unfairness properties of Web server scheduling strategies, such as Processor Sharing (PS) and Shortest Remaining Processing Time (SRPT). We use a general-purpose probe-based sampling approach to estimate the mean and variance of the job response time for different job sizes, for arbitrary arrival processes and service time distributions. The ...

This paper uses a probe-based sampling approach to study the behavioural properties of Web server scheduling strategies, such as Processor Sharing (PS) and Shortest Remaining Processing Time (SRPT). The approach is general purpose, in that it can be used to estimate the mean and variance of the job response time, for arbitrary arrival processes, scheduling policies, and service time distributio...

The scheduling problem of robotic material handlers in flexible manufacturing systems (FMSs) is NP-hard. This paper proposes a state-dependent algorithm for the FMS robot scheduling problem in make-to-order (MTO) environments for mass customization (MC). A mathematical model of the problem is formulated. A computational study of the proposed algorithm is performed. The algorithm is compared to ...