Abstract
An optimal control problem governed by the first bi-harmonic equation with the integral constraint for the state and its spectral approximations based on a mixed formulation are investigated. The optimality conditions of the exact and the discrete optimal control systems are derived. The a priori error estimates of high order spectral accuracy are obtained. Furthermore, a simple and efficient iterative algorithm is proposed to solve mixed discrete system. Some numerical examples are performed to verify the theoretical results.
Acknowledgements
We wish to express our thanks to referees for their useful suggestion and comments. Research supported partially by National Natural Science Foundation of China under the grant 11071080, Program of Shanghai Subject Chief Scientist, No. 09XD1401600, Fundamental Research Funds for the Central Universities of China and Shanghai Leading Academic Discipline Project: B407.