�?�?t ε l ρ l v l + �?�?ε l ρ l v l v l = ε l �?�?τ l + ε l ρ l g �?ε l �?p �?β v l �?v s To make sure machine learning algorithms are each effective and generalizable, K-fold cross-validation was https://medium.com/@vertechs/the-critical-role-of-fluid-rheology-in-modern-oilfield-operations-a-look-through-the-lens-of-202bf6aa8de3