An optimal Kriging surrogate model based on a 5-fold cross-validation method and improved artificial fish swarm optimization is developed for improving the aerodynamic optimization efficiency of a high-speed train running in the open air. The developed optimal Kriging model is compared with the original Kriging model in two test sample points. and the prediction errors are all reduced... https://www.pomyslnaszycie.com/rivet-sweat-charcoal-on-sale/