Study Objective: Significant variation in emergency department patient arrival rates necessitates the adjustment of staffing patterns to optimize the timely care of patients. This study evaluates the effectiveness of a queueing model in identifying provider staffing patterns to reduce the fraction of patients who leave without being seen.
Objective: To examine the relationship between ambulance diversions and the incidence of myocardial infarction deaths in New York City. Methods: We obtained data for 1999 and 2000 on all 9,743 deaths due to myocardial infarction in New York City, as well as periods of diversion status for 58 New York City area hospitals operating under a central ambulance dispatch by the New York City Fire Department. Negative binomial regressions were used to model the percentage increase in myocardial infarction deaths associated with diversion status.
Traditional explanations for high rates of indirect trade have focused on the role of specialized agents in processing and distribution. We provide an alternative explanation based on the differential ability to evade tariffs from some trade entrepôts. Using data on exports to mainland China, we find that the fraction of goods that are routed through Hong Kong (rather than sent directly) is positively correlated with the Chinese tariff rates, both in the cross section and in differences, even though there is no legal tax advantage to sending goods via Hong Kong.
We consider a call center model with m input flows and r pools of agents; the m-vector [lamda] of instantaneous arrival rates is allowed to be time dependent and to vary stochastically. Seeking to optimize the trade-off between personnel costs and abandonment penalties, we develop and illustrate a practical method for sizing the r agent pools. Using stochastic fluid models, this method reduces the staffing problem to a multidimensional newsvendor problem, which can be solved numerically by a combination of linear programming and Monte Carlo simulation.
Motivated by applications in telephone call centers, we consider a service system model with m customer classes and r server pools. The model is one with doubly stochastic arrivals, which means that the m-vector λ of instantaneous arrival rates is allowed to vary both temporally and stochastically.
Revenue management (RM) refers to the collection of strategies and tactics firms use to scientifically manage demand for their products and services. It has gained attention recently as one of the most successful application areas of operations research (OR). The practice has grown from its origins as a relatively obscure practice among a handful of major airlines in the postderegulation era in the United States (circa 1978) to its status today as a mainstream business practice with a growing list of industry users, ranging fromWalt Disney Resorts to National Car Rental.
In this paper, we investigate the equilibrium behavior of decentralized supply chains with competing retailers under demand uncertainty. We also design contractual arrangements between the parties that allow the decentralized chain to perform as well as a centralized one.
This paper conducts a probabilistic analysis of an important class of heuristics for multi-item capacitated lot sizing problems.
This article pursues a statistical study of the Hough transform, the celebrated computer vision algorithm used to detect the presence of lines in a noisy image. We first study asymptotic properties of the Hough transform estimator, whose objective is to find the line that "best" fits a set of planar points. In particular, we establish strong consistency and rates of convergence, and characterize the limiting distribution of the Hough transform estimator.