IMPROVED COORDINATION IN NONHIERARCHIC SYSTEM OPTIMIZATION

An improved coordination procedure for the optimization of nonhierarchic systems by decomposition into reduced subspaces is presented. A subspace coordination procedure based on sequential global approximation is extended to include second-order information. This second-order global approximation is formed using information obtained during subspace optimizations. The use of second-order information in the coordination procedure results in improved convergence for nonhierarchic system optimization as compared with the authors' earlier studies using a first-order coordination procedure. The same objective function and cumulative constraints are imposed at each subspace. Nonlocal functions are approximated at the subspaces using global sensitivities. The method optimizes subspace problems concurrently, allowing for parallel processing. Following each sequence of concurrent subspace optimizations, a second-order approximation of the global problem is formed using design data accumulated during the subspace optimizations. The solution of the global approximation problem is used as the starting point for subsequent subspace optimizations in an iterative solution procedure.