“…If (ζ⋅ω n ) i is the product of ζ and ω n values of the i-th dominant pole at test run r, then the selected function admits the following form: g r (ζ,ω n ) = (ζ⋅ω n ) 1 + (ζ⋅ω n ) 2 + (ζ⋅ω n ) 3 (5) In other words, for each fish sample a vector X u (see subsection II.C) including the values g r (ζ,ω n ), with r=1,…,20 is formed. If the fish 0_1 is considered as freshness benchmark, then its corresponding vector X f , is compared with each one of all other vectors X u (corresponding each time to the fish samples 0_2, 3_1, 3_2, 6_1, 6_2 and 6_3) by means of the KS test (3). As shown in results of Table I, the correct hypothesis is selected at α=0.001 risk level for all fish samples tested.…”