Evaluating dependability metrics of critical systems: Monte ... - iaria
Evaluating dependability metrics of critical systems: Monte ... - iaria
Evaluating dependability metrics of critical systems: Monte ... - iaria
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Work-normalized properties<br />
Variance is not all, generation time is important (figure <strong>of</strong> merit).<br />
Let σ 2 n(ǫ) and t n (ǫ) be the variance and generation time t n (ǫ) for a<br />
sample <strong>of</strong> size n.<br />
When t n (ǫ) is strongly dependent on ǫ, any behavior is possible:<br />
increasing or decreasing to 0 as ǫ → 0.<br />
Work-normalized versions <strong>of</strong> the above properties:<br />
◮ The estimator verifies work-normalized relative variance if<br />
σ 2 n(ǫ)t n (ǫ)<br />
µ 2 (ǫ)<br />
is upper-bounded whatever the rarity, and is therefore a<br />
work-normalized version <strong>of</strong> the bounded relative error property.<br />
◮ The estimator verifies work-normalized asymptotic optimality if<br />
ln t n (ǫ) + lnσ<br />
lim<br />
n(ǫ)<br />
2 = 2.<br />
ǫ→0 lnµ(ǫ)<br />
G. Rubino (INRIA) <strong>Monte</strong> Carlo DEPEND 2010 34 / 72