This paper studies a control problem for the multiclass G/G/1 queue for a risk-sensitive cost of the form n logE exp ∑ i ciX n i (T ), where ci > 0 and T > 0 are constants, X n i denotes the class-i queue length process, and the number of arrivals and service completions per unit time are of order n. The main result is the asymptotic optimality, as n → ∞, of a priority policy, provided that ci ...

One hundred twenty-two members (experts) of the Society for Risk Analysis completed a mailed questionnaire and 150 nonexperts completed a similar questionnaire on the World Wide Web. Questions asked included those about priorities on personal and government action for risk reduction, badness of the risk, number of people affected, worry, and probabilities for self and others. Individual differe...

this research was undertaken to evaluate and determine the risk of gas fluids and leakage of persian gulf star refinery on the environment in bandar abbas. through collection and compilation of research findings, we attempted to identify and work on factors leading to environmental risks. the risk factors were identified by hazop team and the risk score was calculated by multiplying the probabi...

Including threats in spatial conservation prioritization helps identify areas for conservation actions where biodiversity is at imminent risk of extinction. At the global level, an important limitation when identifying spatial priorities for conservation actions is the lack of information on the spatial distribution of threats. Here, we identify spatial conservation priorities under three promi...

prevention of medication errors in neonatal intensive care units (nicus) is of paramount importance due to age-specific and physiological conditions of neonates. this study aimed to evaluate the risk of medication prescription and administration via failure mode and effects analysis (fmea), which was carried out at the research and medical teaching center of imam reza hospital in mashhad, iran....

We investigated the photonic packet switch architecture that enables a high node throughput and provides priority services. Previously, we proposed PBSO (partial buffer sharing with overwriting) method that enables prioritized buffer management to control an optical buffer [1]. The PBSO method is based on a single queue and its complexity is O p , where p is the number of priority classes. PBSO...

This paper provides the first exact analysis of a preemptive M/M/c queue with two priority classes having different service rates. To perform our analysis, we introduce a new technique to reduce the 2-dimensionally (2D) infinite Markov Chain (MC), representing the two class state space, into a 1-dimensionally (1D) infinite MC, from which the Generating Function (GF) of the number of low-priorit...

We investigate a photonic packet switch architecture that enables a high node throughput and provides priority services. We describe PBSO (partial buffer sharing with overwriting) method that allows control of an optical fiber-delay-line buffer by prioritized buffer management under conditions of synchronous arrival of fixed length optical packets at a packet switch. The PBSO method is based on...

This paper describes a novel cost-driven disk scheduling algorithm for environments consisting of multi-priority requests. An example application is a video-on-demand system that provides high and low quality services, termed priority 2 and 1, respectively. Customers ordering a high quality (priority 2) service pay a higher fee and are assigned a higher priority by the underlying system. Our pr...