RÉSUMÉ
A slow time-delay assumption restricts the application of control approaches for numerous systems which are constantly affected by multiple uncertainties, including parameters, control coefficients, and the asymmetric dead-zone input. This work presents a new adaptive method for a class of high-order nonlinear delayed systems by removing the so-called slow time-delay assumption and multiple uncertainties. Remarkably, with a novel Lyapunov-Razumikhin (L-R) function and a direct fuzzy adaptive regulation scheme, a memoryless adaptive feedback controller is skillfully constructed to guarantee that the output tracks the given reference signal while keeping the boundedness of all closed-system signals. Finally, the presented scheme is applied to control a single-link robot system.
RÉSUMÉ
The inhibitory effect of smallanthaditerpenic acids A, B, C and D previously isolated from leaves of Smallanthus sonchifolius (yacon) on alpha-glucosidase were examined and their IC50 were determined to be 0.48 mg/mL, 0.59 mg/mL, 1.00 mg/mL, and 1.17 mg/mL respectively. In addition, a rapid, reliable RP-HPLC method for the analysis of chlorogenic acid, caffeic acid, and smallanthaditerpenic acids A and C in yacon leaves was established, and the variation in their contents in leaves from plants cultivated in different places and collected at different times of the year were compared. The established analytical method for determining smallanthaditerpenic acids A and C, chlorogenic acid and caffeic acid presented good results and could be used as a method for the quality control of S. sonchifolius leaves.
