The foot is an essential part of the components prosthesis. Therefore, selected materials’ mechanical properties, cost, and weight must be considered when manufacturing prosthetic foot. This study studied properties materials used for feet. material chosen Carbon Fiber, Glass fiber, hybrid composite material. aims to simulate find optimal selection feet by assuming boundary conditions, reaction...

Krause et al. [2008] has an indirect proof that F ′ is not submodular. They give an example that shows the greedy algorithm can do arbitrarily bad when maximizing F ′ under a cardinality constraint. If F ′ were submodular the greedy algorithm would give a (1 − 1/e) approximation for maximizing under a cardinality constraint. We give a direct proof that F ′ is not submodular for completeness. In...