“…Yoon, Yang, and Kang (2002) presented an adaptive backstepping state feedback controller, and shown stability of the proposed scheme. Multi-model adaptive control schemes have been also developed and evaluated for nonlinear pH neutralization processes (Boling, Seborg, & Hespanha, 2007;Dougherty & Cooper, 2003;Galan, Romagnoli, & Palazoglu, 2004;Pishvaie & Shahrokhi, 2000). Several other adaptive nonlinear pH controllers have been proposed in the relevant literature (Gustafsson & Waller, 1983;Jutilia, 1983;Li & Biegler, 1990;Pajunen, 1985;Panish & Brosilow, 1988;Williams, Rhinehart, & Riggs, 1990).…”