evonorm
**EvoNorm** is a **family of normalization-activation layers discovered by automated search** — using evolutionary algorithms to find novel combinations of normalization and activation operations that outperform hand-designed ones like BN-ReLU or GN-ReLU.
**How Was EvoNorm Discovered?**
- **Search Space**: Primitive operations (mean, variance, sigmoid, multiplication, max, etc.) combined in computation graphs.
- **Objective**: Maximize validation accuracy on ImageNet with various architectures.
- **Results**: EvoNorm-B0 (batch-dependent, replaces BN-ReLU), EvoNorm-S0 (batch-independent, replaces GN-ReLU).
- **Paper**: Liu et al. (2020).
**Why It Matters**
- **Beyond Hand-Design**: Demonstrates that automated search can discover normalization layers humans haven't considered.
- **Performance**: EvoNorm-S0 matches BatchNorm+ReLU accuracy while being batch-independent.
- **Joint Design**: Searches normalization and activation together, finding synergies that separate design misses.
**EvoNorm** is **evolved normalization** — normalization-activation layers discovered by evolution rather than human intuition.