Package jline.api.sum

Class Sum_closed

java.lang.Object
jline.api.sum.Sum_closed

public class Sum_closed extends Object
Summation method (SUM) for closed queueing networks, including the extended SUM (ESUM) node functions for non-product-form networks with generally distributed service times. The method expresses the mean queue length of each station as a function of its throughput, Ki = fi(lambdai), and solves the population constraint sum_i Ki = K. Single-class models are solved by bisection on the system throughput (Bolch et al., Sec. 9.2.1); multiclass models by Gauss-Seidel sweeps of per-class bisections on the population constraints, a robust alternative to the successive substitution of Sec. 9.2.2. Node functions: - Product-form stations (scv=1, or insensitive disciplines PS/LCFS-PR, for which the caller must pass scv=1): Eq. (9.15)/(9.19). - FCFS stations with general service (scv!=1): ESUM corrections, Eq. (10.88) for -/G/1 and Eq. (10.89) for -/G/m, with ai=(1+scv_i)/2 and Erlang-C waiting probability P_mi. - Infinite-server stations (mi=Inf) and think times Z: Ki = lambdai*Li. Reference: G. Bolch, S. Greiner, H. de Meer, K.S. Trivedi, Queueing Networks and Markov Chains, 2nd ed., Wiley, 2006, Secs. 9.2 and 10.1.4.4.
  • Constructor Details

    • Sum_closed

      public Sum_closed()
  • Method Details

    • sum_closed

      public static Sum_closed.Result sum_closed(Matrix L, Matrix N, Matrix Z, Matrix mi, Matrix scv, double tol, int maxiter)
      Summation method for closed queueing networks.
      Parameters:
      L - MxR service demand matrix, L(i,r) = e(i,r)/mu(i,r)
      N - 1xR population vector
      Z - 1xR think times (aggregated as a delay term)
      mi - Mx1 number of servers (Double.POSITIVE_INFINITY for IS)
      scv - MxR squared coefficient of variation of service times
      tol - convergence tolerance (e.g. 1e-6)
      maxiter - maximum number of iterations (e.g. 10000)
      Returns:
      throughputs, queue lengths, utilizations, residence times