Enhanced methods of feasible directions for engineering design problems

After the advantages of methods of feasible directions in an engineering design environment are pointed out, several modifications to the classical scheme are proposed, aimed at improving computational efficiency while preserving convergence properties.First, an abstract algorithm model is set up and a set of sufficient conditions to ensure convergence is given. Several modifications are proposed, inspired by difficulties arising in an engineering design environment, and it is shown that the resulting algorithms satisfy the sufficient conditions just mentioned. An integrated-circuit bipolar operational amplifier is optimized in order to show the improvement in computation efficiency that the proposed enhancements can provide.This research was supported by the National Science Foundation, Grant No. ECS-82-04452 and by a grant from the Semiconductor Division of the Harris Corporation. The authors wish to thank K.H. Fan, for making numerous useful remarks and for carrying out the numerical experiments, and an anonymous reviewer for pointing out important flaws in an early version of the paper.