Class Qsys_gigk_approx_cosmetatos

java.lang.Object
jline.api.qsys.Qsys_gigk_approx_cosmetatos

public final class Qsys_gigk_approx_cosmetatos extends Object
  • Method Summary

    Modifier and Type
    Method
    Description
    qsys_gigk_approx_cosmetatos(double lambda, double mu, double ca2, double cs2, int k)
    GI/G/k approximation by interpolation of the M/M/k, M/D/k and D/M/k queues (Cosmetatos 1982; Page 1982): Wq = [ca2*cs2 + ca2*(1-cs2)*phi1/2 + (1-ca2)*cs2*phi3/2]*Wq(M/M/k), where phi1 and phi3 are the Cosmetatos (1975) correction factors for M/D/k and D/M/k, with the safeguards of Whitt (1993).

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
  • Method Details

    • qsys_gigk_approx_cosmetatos

      public static HashMap<String,Object> qsys_gigk_approx_cosmetatos(double lambda, double mu, double ca2, double cs2, int k)
      GI/G/k approximation by interpolation of the M/M/k, M/D/k and D/M/k queues (Cosmetatos 1982; Page 1982): Wq = [ca2*cs2 + ca2*(1-cs2)*phi1/2 + (1-ca2)*cs2*phi3/2]*Wq(M/M/k), where phi1 and phi3 are the Cosmetatos (1975) correction factors for M/D/k and D/M/k, with the safeguards of Whitt (1993). The D/D/k corner has Wq=0. The interpolation requires ca2<=1 and cs2<=1; outside this region the Lee-Longton scaling Wq = ((ca2+cs2)/2)*Wq(M/M/k) is used.

      References: Cosmetatos, G.P. (1975). Approximate explicit formulae for the average queueing time in the processes (M/D/r) and (D/M/r). INFOR 13, 328-331. Page, E. (1982). Tables of waiting times for M/M/n, M/D/n and D/M/n and their use to give approximate waiting times in more general queues. J. Opl. Res. Soc. 33, 453-473.

      Parameters:
      lambda - arrival rate
      mu - service rate per server
      ca2 - squared coefficient of variation of inter-arrival time
      cs2 - squared coefficient of variation of service time
      k - number of servers
      Returns:
      HashMap containing L, W, Q, U