“…The two major approaches taken for analysis of forced periodic operations (Guardabassi et al, 1974;Sterman and Ydstie, 1990a) are: (1) the Hamilton-Jacobi approach based on the maximum principle (Bailey and Horn, 1971;Bailey, 1973;Guardabassi et al, 1974;Ma ezoni, 1974;Noldus, 1977) or relaxed steady state analysis (Bailey and Horn, 1971;Bailey, 1973) suitable for high forcing frequencies, and (2) a frequency-domain approach using * Tel. : +1-312-567-3044; fax: +1-312-567-8874.…”