Internal change

PiperOrigin-RevId: 443158595

official/vision/configs/experiments/retinanet/coco_spinenet49_mobile_tpu.yaml

 # --experiment_type=retinanet_mobile_coco
+# COCO mAP: 27.6
 runtime:
   distribution_strategy: 'tpu'
   mixed_precision_dtype: 'bfloat16'
@@ -26,7 +27,7 @@ task:
     max_level: 7
     min_level: 3
     norm_activation:
-      activation: 'swish'
+      activation: 'hard_swish'
       norm_epsilon: 0.001
       norm_momentum: 0.99
       use_sync_bn: true

official/vision/configs/experiments/retinanet/coco_spinenet49s_mobile_tpu.yaml

 # --experiment_type=retinanet_mobile_coco
+# COCO mAP: 23.5
 runtime:
   distribution_strategy: 'tpu'
   mixed_precision_dtype: 'bfloat16'
@@ -26,7 +27,7 @@ task:
     max_level: 7
     min_level: 3
     norm_activation:
-      activation: 'swish'
+      activation: 'hard_swish'
       norm_epsilon: 0.001
       norm_momentum: 0.99
       use_sync_bn: true

official/vision/configs/experiments/retinanet/coco_spinenet49xs_mobile_tpu.yaml

 # --experiment_type=retinanet_mobile_coco
+# COCO mAP: 16.8
 runtime:
   distribution_strategy: 'tpu'
   mixed_precision_dtype: 'bfloat16'
@@ -26,7 +27,7 @@ task:
     max_level: 7
     min_level: 3
     norm_activation:
-      activation: 'swish'
+      activation: 'hard_swish'
       norm_epsilon: 0.001
       norm_momentum: 0.99
       use_sync_bn: true

official/vision/modeling/backbones/spinenet_mobile.py

@@ -243,6 +243,7 @@ class SpineNetMobile(tf.keras.Model):
         in_filters=in_filters,
         out_filters=out_filters,
         strides=strides,
+        se_gating_activation='hard_sigmoid',
         se_ratio=se_ratio,
         expand_ratio=expand_ratio,
         stochastic_depth_drop_rate=stochastic_depth_drop_rate,