use he init when using relu activations

mlair/model_modules/fully_connected_networks.py

@@ -67,7 +67,8 @@ class FCN(AbstractModelClass):
                    "sigmoid": partial(keras.layers.Activation, "sigmoid"),
                    "linear": partial(keras.layers.Activation, "linear"),
                    "selu": partial(keras.layers.Activation, "selu")}
-    _initializer = {"selu": keras.initializers.lecun_normal()}
+    _initializer = {"tanh": "glorot_uniform", "sigmoid": "glorot_uniform", "linear": "glorot_uniform",
+                    "relu": keras.initializers.he_normal(), "selu": keras.initializers.lecun_normal()}
     _optimizer = {"adam": keras.optimizers.adam, "sgd": keras.optimizers.SGD}
     _regularizer = {"l1": keras.regularizers.l1, "l2": keras.regularizers.l2, "l1_l2": keras.regularizers.l1_l2}
     _requirements = ["lr", "beta_1", "beta_2", "epsilon", "decay", "amsgrad", "momentum", "nesterov", "l1", "l2"]