Patent ID: 7319943

Claim:
An optimum design method comprising: a first solution determining step of solving an optimization problem of a first evaluation function for a state variable vector with a design variable vector being as a parameter; and a second solution determining step of solving an optimization problem of a second evaluation function for the design variable vector and the state variable vector obtained in the first solution determining step, wherein the second solution determining step includes: a gradient vector computing step of computing a gradient vector of the second evaluation function for the design variable vector; a first coefficient computing step of computing a first coefficient based on a value of a norm of the gradient vector; a search vector computing step of computing a search vector based on the first coefficient; a second coefficient computing step of computing a second coefficient; and a design variable vector updating step of updating the design variable vector based on the second coefficient, the second coefficient computing step including the first solution determining step, the first solution determining step being executed as an iterative method based on the gradient vector, and the state variable vector being not initialized during iteration.