多列模糊排队的隶属函数求解方法

应用α-截集的定义和Zadeh的扩展原理,将到达率和服务率均为模糊数的多列模糊排队问题转化为传统的多列排队问题.用一组参数规划来分别描述系统特征值的上限和下限,并且对其隶属函数进行求解.实例分析了某医院内科门诊的2列模糊排队系统.其中,患者的平均到达率和医生的平均服务率均用梯形模糊数来表示.通过对不同α水平的数值计算,求解出患者在门诊中平均逗留时间的隶属函数.这种方法能为医院的管理决策提供更丰富的信息.

A Solution to Membership Function of Multiple-Server Fuzzy Queues

The definition of a-cut and Zadeh's extension principle are applied to transforming multiple-server fuzzy queues, of which the arrival rate and service rate are both fuzzy numbers, into conventional multiple-server queues. Then, the system eigenvalues are described separately by programming a set of parameters to solve upper and lower bounds of the relevant membership function. For instance, there is a 2-server fuzzy queues system of outpatients in a hospital, in which the average arrival rate and service rate are both regarded as trapezoidal fuzzy numbers. With a numerical computation of different α levels, the membership function of the average staying time for all the outpatients can thus be solved. This method can provide more abundant information for managerial decision-making in hospitals.