In this paper we demonstrate how tree-like processes can be used to analyze a general class of priority queues with three service classes, creating a new methodology to study priority queues. The key result is that the operation of a 3-class priority queue can be mimicked by means of an alternate system that is composed of a single stack and queue. The evolution of this alternate system is redu...

The genome of MM1 (40,248 bp), a temperate bacteriophage from the Spain(23F)-1 multiresistant epidemic clone of Streptococcus pneumoniae, is organized in 53 open reading frames (ORFs) and in at least five functional clusters. Bioinformatic and N-terminal amino acid sequence analyses enabled the assignment of possible functions to 26 ORFs. Analyses comparing the MM1 genome with those of other ba...

This paper presents an analytical model that evaluates the blocking probability of each service class in optical burst-switching networks. The model is applicable to systems with arbitrary burst length distributions and arbitrary-sized QoS header offsets. Thus, unlike previous models, it is applicable to the design and study of networks with a wide range of traffic characteristics, including sy...

Due to resource sharing among tasks, priority inversion can occur during prioritydriven preemptive scheduling. In this work, we investigate solutions to the priority inversion problem in a real-time database environment where two-phase locking is employed for concurrency control. We examine two basic schemes for addressing the priority inversion problem, one based on priority inheritance and th...

Modern Infrastructure Protection Systems (IPSs) tend to be geographically distributed as well as Internet based. Geographic distribution has the goal of increasing fault tolerance as well survivability (e.g. against attacks of various kinds). Usage of a public communication infrastructure like Internet has the goal of decreasing costs as well as easying system deployment. During an emergency, c...

We analyze a priority queueing system with congestion control based on thresholds. A priority queue with a triple of thresholds consisting of an abatement threshold, an onset threshold and a discard threshold was investigated by San-qi Li. We extend Li's model to a priority queue with N triples of thresholds and obtain the stationary probabilities of queue length by using the Embedded Markov ch...

The inheritance of material across the star and planet formation process is traced by deuterium fractionation. We report here first detection doubly deuterated methanol towards pre-stellar cores. study fractionation methanol, CH$_{3}$OH, two starless derive a D/H ratio 0.8-1.9$\%$ with CH$_{2}$DOH in cores H-MM1 L694-2, consistent measurements more evolved Class 0/I objects comet 67P/Churyumov-...

An admission control algorithm for a multimedia server is responsible for determining if a new request can be accepted without violating the QoS requirements of the existing requests in the system. Most admission control algorithms treat every request uniformly and hence optimize the system performance by maximizing the number of admitted and served requests. In practice, requests might have di...