Symmetries of trigonometric integrable two-dimensional statistical face models are considered. The corresponding symmetry operators on the Hilbert space of states of the quantum version of these models define a weak $*$-Hopf algebra isomorphic to the Ocneanu double triangle algebra.
"Quantum symmetries of face models and the double triangle algebra." Adv. Theor. Math. Phys. 10 (1) 49 - 75, January 2006.