Table 4 Hyperparameters details.

From: Advancing skin cancer diagnosis with deep learning and attention mechanisms

Hyperparameter

Value

Description/range

Learning Rate

0.001

Optimizer learning rate, chosen through grid search over [0.0001, 0.001, 0.01]

Batch Size

32

Batch size used during training, selected from [16, 32, 64] based on memory constraints

Epochs

50

Number of epochs, selected based on convergence time and model performance

Optimizer

Adam

Adam optimizer was selected for its adaptive learning rate properties. We also experimented with RMSProp and SGD, but Adam outperformed them in terms of training stability and final accuracy.

Dropout Rate

0.5

Dropout is used to regularize the model and prevent overfitting. Tested values in [0.3, 0.5, 0.7].

Weight Decay (L2 Reg.)

0.0001

L2 regularization to avoid overfitting, set after grid search across [0, 0.0001, 0.001]

Activation Function

ReLU

The ReLU activation function, found to be effective for this segmentation task after comparisons with Leaky ReLU, Sigmoid, and Tanh.

Loss Function

Dice Loss

Dice loss was used for its ability to handle imbalanced data and penalize incorrect segmentation of lesion boundaries.

Input Image Size

224 × 224

Input image size, chosen based on available computational resources and the nature of the dataset.

Number of Filters (Conv.)

64

Number of convolutional filters, chosen for a balance between model complexity and performance.

Pooling Size

2 × 2

Standard 2 × 2 pooling was used to reduce spatial dimensions while retaining important features.