Exact packing measure of linear Cantor sets

Let K be the attractor of a linear iterated function system Sjx = ρjx+bj (j = 1,..., m) on the real line satisfying the open set condition (where the open set is an interval). It is well known that the packing dimension of K is equal to α, the unique positive solution y of the equation ∑m j=1 ρ y j = 1; and the α–dimensional packing measure Pα(K) is finite and positive. Denote by µ the unique self–similar measure for the IF