Table 2 Optimal hyperparameter values for each machine learning model.

From: Accurate modeling and simulation of the effect of bacterial growth on the pH of culture media using artificial intelligence approaches

Model

Key Hyperparameters

Optimal Values

AdaBoost

Number of base estimators

15

Learning rate

1

RF

Max depth

21

Number of trees (n_estimators)

100 (default)

Max features

sqrt (default)

DT

Max depth

3.34

ANN

First hidden layer neurons

25

Second hidden layer neurons

17

Transfer functions

Hyperbolic Tangent Sigmoid (tansig-hidden layers), Linear activation function (purelin- output layer)

LSSVM

Kernel

RBF

Regularization parameter (γ)

1213

Kernel width (σ²)

0.77

1D-CNN

Convolutional layers

2

Pooling layers

1

Fully connected layers

1

Activation function

Rectified Linear Unit (ReLU)

Learning rate

0.001

Epochs

100 (default)

Batch size

16 (assumed)

EL

Combined models

SVM, DT, KNN with C = 120, gamma = 0.02, epsilon = 0.001

SVM settings

RBF used as the Kernel function, distance = Euclidean

KNN settings

k = 9, distance = Euclidean

Combination method

Averaging