The diiusion approximation is proved for a class of queueing networks, known as re-entrant lines, under a rst-buuer-rst-served (FBFS) service discipline. The diiusion limit for the workload process is a semi-martingale reeecting Brownian motion on a nonnegative orthant. This approximation has recently been used by Dai, Yeh and Zhou (1994) in estimating the performance measures of the re-entrant...

This paper presents an extended classification for non-permutation flowshops. The versatile options which occur with the possibility of resequencing jobs within the line are considered. The literature review shows that no classification exists which considers extensively this type of flowshop.

In this paper, we address the problem of two-machine flowshop scheduling problem with sequence independent setup times to minimize the total completion time. We propose five new polynomial lower bounds. Computational results based on randomly generated data show that our proposed lower bounds consistently outperform those of the literature.

We analyze industrial espionage in the context of entry deterrence. We consider a monopoly incumbent, who may expand capacity to deter entry, and a potential entrant who owns an inaccurate Intelligence System. The Intelligence System generates a noisy signal on incumbent's actions and the potential entrant decides whether to enter based on this signal. If the precision of the Intelligence Syste...

We propose an approximate approach for estimating the performance measures of the re-entrant line with single-jobmachines and batch machines based on the mean value analysis (MVA) technique.Multi-class jobs are assumed to be processed in predetermined routings, in which some processes may utilize the same machines in the re-entrant fashion. The performance measures of interest are the steady-st...

This paper represents linkage network of queues consisting of biserial and parallel servers linked to a common server in series with a flowshop scheduling system consisting of two machines. The significant transportation time of the jobs from one machine to another is also considered. Further, the completion time of jobs/customers (waiting time + service time) in the queue network is the set...

This paper analyzes preemptive patenting in a two-stage real options game where an incumbent firm competes with a potential entrant firm for the patent of a substitute product in a product market with profit flow uncertainty. The incumbent suffers loss of monopoly in the product market if the entrant acquires the patent of a substitute product and later commercializes the product. Our patent-in...

The mechanism of action of diphenylhydantoin (DPH) on re-entrant ventricular arrhythmias (RVA) was studied in dogs 3-7 days following ligation of the anterior descending coronary artery utilizing direct recordings of the re-entrant pathway (RP) from the epicardial surface of the infarction zone (IZ). DPH in a therapeutic dose consistently prolonged refractoriness of potentially RP in the IZ. Th...

Programmed electrical stimulation of the heart uncovered unusual findings in four patients suffering from supraventricular tachyeardias. They included 1) two supraventricular tachyeardias of different location and frequency in the same patient, 2) increase in rate of a re-entrant atrioventricular (A-V) nodal tachycardia followed by the development of 2-to-1 A-V block, 3) a "gap" in A-V conducti...