Class Pfqn_chow

java.lang.Object
jline.api.pfqn.mva.Pfqn_chow

public final class Pfqn_chow extends Object
Chow Second Approximation (SA) approximate MVA.

W.-M. Chow, "Approximations for large scale closed queueing networks", Perform. Eval. 3(1), 1983. The arrival-instant queue length is written exactly as

 A_k^(c)(N) = Q_k(N - 1_c) = Q_k(N) (1 + theta_ck),
 theta_ck   = [Q_k(N - 1_c) - Q_k(N)] / Q_k(N),
 

and the theta-terms are estimated ONCE, off the Bard LCP solution, before the fixed point is run. Two estimators are given: the BACKWARD one uses Qhat(N - 1_c), the FORWARD one Qhat(N + 1_c). Chow reports the forward form to be the more accurate of the two, so it is the default here. Setting every theta to zero recovers Pfqn_lcp.