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Enhanced Skill Optimization Algorithm and Stacked Long Short-Term Memory with Sech Activation Function for Gastrointestinal Disease Cover

Enhanced Skill Optimization Algorithm and Stacked Long Short-Term Memory with Sech Activation Function for Gastrointestinal Disease

Open Access
|May 2026

Figures & Tables

Figure 1:

Workflow of proposed methodology. AHE, adaptive histogram equalization; ESOA, enhanced skill optimization algorithm; Stacked LSTM-SAF, stacked long short-term memory with Sech activation function.

Figure 2:

Sample original and preprocessed image.

Figure 3:

Workflow of the ESOA method. ESOA, enhanced skill optimization algorithm.

Figure 4:

Structure of the stacked LSTM. Stacked LSTM, stacked long short-term memory.

Figure 5:

Sample images of actual and predicted labels (A) Kvasir-V1 (B) Kvasir-V2 dataset.

Figure 6:

Evaluation of confusion matrix for Stacked LSTM-SAF (A) Kvasir-V1, (B) Kvasir-V2, (C) HyperKvasir. Stacked LSTM-SAF, stacked long short-term memory with Sech activation function.

Figure 7:

Evaluation of RoC curve for Stacked LSTM-SAF: (A) Kvasir-V1, (B) Kvasir-V2, (C) HyperKvasir. ROC, receiver operating characteristics; Stacked LSTM-SAF, stacked long short-term memory with Sech activation function.

Figure 8:

Analysis of standard deviation for the proposed method: (A) Kvasir-V1, (B) Kvasir-V2, (C) HyperKvasir.

Performance analysis of different feature selection methods

MethodsAccuracy (%)Precision (%)Recall (%)F1-score (%)Specificity (%)
Kvasir-V1
OOA94.1794.5493.9294.2392.67
COA96.6695.1595.3895.2794.38
BES97.3795.1296.3095.7194.79
SOA97.9996.5397.9897.2596.95
ESOA99.6099.2098.7198.9699.88

Kvasir-V2

OOA94.2694.6593.3394.6593.33
COA95.5895.2194.6795.2194.67
BES97.5195.1896.8495.1896.84
SOA97.5197.1896.8497.1896.84
ESOA99.8899.6197.1299.6197.12

HyperKvasir

OOA94.3294.7893.8594.1192.91
COA96.2895.4295.1695.2994.63
BES97.1495.8896.4196.1495.37
SOA97.9296.7197.6597.1896.82
ESOA99.7499.3398.9599.1499.61

Performance analysis of different classification methods

MethodsAccuracy (%)Precision (%)Recall (%)F1-score (%)
Kvasir-V1
RNN89.4490.5188.9091.42
GRU93.8094.0393.5992.14
LSTM96.0495.9994.8894.66
Stacked-LSTM99.6098.7199.8899.20

Kvasir-V2

RNN90.5690.5091.2792.95
GRU94.0793.1092.0094.56
LSTM97.4996.4095.5595.61
Stacked-LSTM99.8897.9397.1299.61

HyperKvasir

RNN89.8890.6589.4491.12
GRU93.9294.2193.7892.83
LSTM96.3896.1095.2195.68
Stacked-LSTM99.7498.9599.3399.14

Performance analysis of computational complexity across datasets

MethodsDatasetsMemory consumption (MB)Training time (s)Inference time (s)
RNNKvasir-V127.1237.9536.74
GRU 23.0532.5830.84
LSTM 8.6730.5826.59
Stacked-LSTM-SAF 6.722.549.58

RNNKvasir-V227.4838.6237.12
GRU 22.8735.1231.04
LSTM 9.0231.2827.11
Stacked-LSTM-SAF 6.582.739.92

RNNHyperKvasir30.4842.6940.98
GRU 27.4625.9622.02
LSTM 21.6919.7817.36
Stacked-LSTM-SAF 8.465.8011.96

Comparative analysis of existing methods on Kvasir-V1 and V2 datasets

MethodsDatasetsAccuracy (%)Precision (%)Recall (%)F1-score (%)
LPNet [17]Kvasir-V193.5593.5593.5593.55
VGG16 kernle RBF [19]Kvasir-V296.64979797
SK-Net [20]Kvasir-V198.45N/A96.60N/A
Kvasir-V297.83N/AN/AN/A
Star-GAN + InceptionNet-V3 [21]Kvasir-V294.96N/A94.9394.93
CapsNet [22]Kvasir-V293.40N/AN/AN/A
Proposed ESOA with Stacked LSTM-SAFKvasir-V199.6098.7199.8899.20
Kvasir-V299.8897.9397.1299.61

Cross-dataset validation results: Trained on Kvasir-V1 and tested on Kvasir-V2

MethodsAccuracy (%)Precision (%)Recall (%)F1-score (%)
RNN87.3588.2086.5087.34
GRU91.1292.0590.5091.27
LSTM94.5095.1093.8094.44
Stacked LSTM-SAF97.2596.8096.0096.39

Performance analysis of different activation functions

MethodsAccuracy (%)Precision (%)Recall (%)F1-score (%)T-test from p-valuesCI (%)
Kvasir-V1
Stacked LSTM-ReLU94.9793.4792.6093.630.03286.18
Stacked LSTM-Tanh95.4693.2894.3095.040.03087.63
Stacked LSTM-Sigmoid97.0396.9695.4396.010.02989.06
Stacked LSTM-sech99.5098.7199.8899.200.02694.12

Kvasir-V2

Stacked LSTM-ReLU93.5592.5392.6791.760.03489.60
Stacked LSTM-Tanh96.6295.7196.0097.260.03090.17
Stacked LSTM-Sigmoid97.4595.5094.1896.650.02891.78
Stacked LSTM-sech99.8897.9397.1299.610.02494.36

HyperKvasir

Stacked LSTM-ReLU94.7693.6292.8993.450.03687.15
Stacked LSTM-Tanh95.8494.7195.2595.070.03489.36
Stacked LSTM-Sigmoid97.2896.6495.8196.220.03191.58
Stacked LSTM-Sech99.7498.9599.3399.140.02994.85
Language: English
Submitted on: Aug 7, 2025
Published on: May 28, 2026
In partnership with: Paradigm Publishing Services
Publication frequency: 1 issue per year

© 2026 Janagama Srividya, Harikrishna Bommala, published by Macquarie University, Australia
This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

Volume 19 (2026): Issue 1 (January 2026)