diff --git a/model/activation.py b/model/activation.py
new file mode 100644
index 0000000..b710494
--- /dev/null
+++ b/model/activation.py
@@ -0,0 +1,8 @@
+# -*- Encoding: utf-8 -*-
+
+import keras.ops as K
+
+def sublinear(x):
+    return x / (1 + K.sqrt(K.sqrt(K.abs(x))))
+
+# EOF