METHODS FOR SOLVING NONLINEAR EQUATIONS USED IN EVALUATING EMERGENCY VEHICLE BUSY PROBABILITIES

• 成果类型: Article
• 署名作者: GOLDBERG, J; SZIDAROVSZKY, F
• 刊物名称: OPERATIONS RESEARCH
• ISSN/ISSBN: 0030-364X
• DOI: 10.1287/opre.39.6.903
• 发表日期: 1991
• 页码: 903-916
• 关键词: Health care; ambulance service; EVALUATING BUSY PROBABILITIES; mathematics; Fixed points; FIXED POINT METHODS FOR NONLINEAR EQUATIONS; queues; approximations; NONLINEAR EQUATION APPROXIMATION MODELS

摘要

In this paper we present two iterative methods for solving a model to evaluate busy probabilities for Emergency Medical Service (EMS) vehicles. The model considers location dependent service times and is an alternative to the mean service calibration method; a procedure, used with the Hypercube Model, to accommodate travel times and location-dependent service times. We use monotonicity arguments to prove that one iterative method always converges to a solution. A large computational experiment suggests that both methods work satisfactorily in EMS systems with low ambulance busy probabilities and the method that always converges to a solution performs significantly better in EMS systems with high busy probabilities.