A method of assisting delivery of useful services that contribute to improvement of people’s standard of living. Rf is a C5-C30 perfluoroalkyl group containing at least one ether bond, Q is a polyether group consisting of an ethylene glycol andor propylene glycol polymer chain, R is H or C1-C4 alkyl, X is a divalent linking group exclusive of oxygen, Y is a divalent linking group, p is an integer of at least 3, and 0<n<3. Reference wave generators generate reference waves.