[go: up one dir, main page]
More Web Proxy on the site http://driver.im/
You seem to have javascript disabled. Please note that many of the page functionalities won't work as expected without javascript enabled.
 
 
Sign in to use this feature.

Years

Between: -

Subjects

remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline

Journals

remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline

Article Types

Countries / Regions

remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline

Search Results (564)

Search Parameters:
Keywords = hybrid feature selection method

Order results
Result details
Results per page
Select all
Export citation of selected articles as:
39 pages, 3054 KiB  
Review
Applications of Machine Learning in Food Safety and HACCP Monitoring of Animal-Source Foods
by Panagiota-Kyriaki Revelou, Efstathia Tsakali, Anthimia Batrinou and Irini F. Strati
Foods 2025, 14(6), 922; https://doi.org/10.3390/foods14060922 (registering DOI) - 8 Mar 2025
Viewed by 20
Abstract
Integrating advanced computing techniques into food safety management has attracted significant attention recently. Machine learning (ML) algorithms offer innovative solutions for Hazard Analysis Critical Control Point (HACCP) monitoring by providing advanced data analysis capabilities and have proven to be powerful tools for assessing [...] Read more.
Integrating advanced computing techniques into food safety management has attracted significant attention recently. Machine learning (ML) algorithms offer innovative solutions for Hazard Analysis Critical Control Point (HACCP) monitoring by providing advanced data analysis capabilities and have proven to be powerful tools for assessing the safety of Animal-Source Foods (ASFs). Studies that link ML with HACCP monitoring in ASFs are limited. The present review provides an overview of ML, feature extraction, and selection algorithms employed for food safety. Several non-destructive techniques are presented, including spectroscopic methods, smartphone-based sensors, paper chromogenic arrays, machine vision, and hyperspectral imaging combined with ML algorithms. Prospects include enhancing predictive models for food safety with the development of hybrid Artificial Intelligence (AI) models and the automation of quality control processes using AI-driven computer vision, which could revolutionize food safety inspections. However, handling conceivable inclinations in AI models is vital to guaranteeing reasonable and exact hazard assessments in an assortment of nourishment generation settings. Moreover, moving forward, the interpretability of ML models will make them more straightforward and dependable. Conclusively, applying ML algorithms allows real-time monitoring and predictive analytics and can significantly reduce the risks associated with ASF consumption. Full article
(This article belongs to the Special Issue Artificial Intelligence (AI) and Machine Learning for Foods)
Show Figures

Figure 1

Figure 1
<p>GNB algorithm. GNB classifier models two Gaussian distributions corresponding to the labeled groups in the dataset. The decision boundary is established at the location where the probability densities of the two groups are equal. Adapted from Shyrokykh et al. [<a href="#B55-foods-14-00922" class="html-bibr">55</a>].</p>
Full article ">Figure 2
<p>KNN algorithm with <span class="html-italic">K</span> = 1 (<b>a</b>) and <span class="html-italic">K</span> = 20 (<b>b</b>). The KNN generalizes for larger <span class="html-italic">K</span> values, while it tends to overfit for small numbers of neighbors. Adapted from Kramer [<a href="#B56-foods-14-00922" class="html-bibr">56</a>].</p>
Full article ">Figure 3
<p>LDA establishes a linear boundary that separates the groups, effectively dividing the space between the centroids of these groups. Adapted from Adams [<a href="#B66-foods-14-00922" class="html-bibr">66</a>].</p>
Full article ">Figure 4
<p>Linear SVM model. Adapted from Ahmetoglou and Das [<a href="#B67-foods-14-00922" class="html-bibr">67</a>].</p>
Full article ">Figure 5
<p>Random Forest model. Adapted from Yang et al. [<a href="#B72-foods-14-00922" class="html-bibr">72</a>].</p>
Full article ">Figure 6
<p>Structure of a DT. Adapted from Chiu et al. [<a href="#B79-foods-14-00922" class="html-bibr">79</a>].</p>
Full article ">Figure 7
<p>XGBoost model. From Jiang et al. [<a href="#B83-foods-14-00922" class="html-bibr">83</a>].</p>
Full article ">Figure 8
<p>Auto-encoder. It has a symmetric structure with an encoding and a decoding phase. In the encoding phase, there is a compressed representation of the data, and in the decoding phase, the original input is reconstructed. From Zuo et al. [<a href="#B18-foods-14-00922" class="html-bibr">18</a>].</p>
Full article ">Figure 9
<p>The NIR device (<b>left</b>). An example of spectrum measurement on fish (<b>right</b>). From Ninh et al. [<a href="#B58-foods-14-00922" class="html-bibr">58</a>].</p>
Full article ">
21 pages, 8910 KiB  
Article
An Improved Fault Diagnosis Method for Rolling Bearing Based on Relief-F and Optimized Random Forests Algorithm
by Yueyi Yang, Jiabo Zhai, Haiquan Wang, Xiaobin Xu, Yabo Hu and Jinxia Wen
Machines 2025, 13(3), 183; https://doi.org/10.3390/machines13030183 - 25 Feb 2025
Viewed by 142
Abstract
Rolling Bearings are important supporting components of rotating machines in industrial processes; the faults of rolling bearings will cause the deterioration of the operation conditions of rotating machines. How to effectively extract the fault features and identify the fault modes of rolling bearings [...] Read more.
Rolling Bearings are important supporting components of rotating machines in industrial processes; the faults of rolling bearings will cause the deterioration of the operation conditions of rotating machines. How to effectively extract the fault features and identify the fault modes of rolling bearings quickly and accurately has become a key issue for the safe operation of rotating machines. In this paper, a novel hybrid fault diagnosis method of an optimized random forests classifier for rolling bearings is proposed. Firstly, the original vibration signals are decomposed by recursive variational mode decomposition (RVMD), and the typical time–frequency domain features are extracted from decomposed signals at different scales. The Relief-F ranking method is utilized to assess the quality of time–frequency domain features, and the top-ranked features with high weight gain are selected for identifying the fault modes. Then, an improved bee colony algorithm is proposed based on the simulated binary crossover criterion, which is used to optimize the key parameters of random forests (RF). Finally, several experiments are conducted on the Case Western Reserve University bearing dataset and the dataset collected from our rolling bearing fault testbed. The experimental results show that the proposed method can accurately identify bearing faults and outperform other state-of-the-art methods. Full article
Show Figures

Figure 1

Figure 1
<p>Overall flow chart of the proposed fault diagnosis method.</p>
Full article ">Figure 2
<p>Flow chart of SBX-ABC-RF.</p>
Full article ">Figure 3
<p>Bearing test rig of Western reserve university.</p>
Full article ">Figure 4
<p>Our developed real testbed.</p>
Full article ">Figure 5
<p>Fault components in our testbed: (<b>a</b>) Inner-ring fault, (<b>b</b>) Outer-ring fault, (<b>c</b>) Inner-ring and outer-ring fault, (<b>d</b>) Rolling ball fault, (<b>e</b>) Rolling cage fault.</p>
Full article ">Figure 6
<p>Fault components in our test rig: (<b>a</b>) Normal condition, (<b>b</b>) Rolling cage fault, (<b>c</b>) Rolling ball fault, (<b>d</b>) Inner-ring fault, (<b>e</b>) Outer-ring fault, (<b>f</b>) Both Inner-ring and outer-ring fault.</p>
Full article ">Figure 6 Cont.
<p>Fault components in our test rig: (<b>a</b>) Normal condition, (<b>b</b>) Rolling cage fault, (<b>c</b>) Rolling ball fault, (<b>d</b>) Inner-ring fault, (<b>e</b>) Outer-ring fault, (<b>f</b>) Both Inner-ring and outer-ring fault.</p>
Full article ">Figure 7
<p>The RVMD decomposition signals in fault modes F1 and F4. (<b>a</b>) Decomposition signals in fault mode F1. (<b>b</b>) Decomposition signals in fault mode F4.</p>
Full article ">Figure 8
<p>Feature selection results. (<b>a</b>) Weight value of all features in case 1, (<b>b</b>) Classification results of different number of the features in case 1.</p>
Full article ">Figure 9
<p>Classification effectiveness of the different features in Case 1. (<b>a</b>) Frequency domain feature C<sub>20</sub>. (<b>b</b>) Time domain feature C<sub>29</sub>.</p>
Full article ">Figure 10
<p>The optimized performance of SBX-ABC in Case 1. (<b>a</b>) The population of the swarm is 50. (<b>b</b>) The population of the swarm is 100.</p>
Full article ">Figure 11
<p>Classification results under different optimized algorithms in Case 1. (<b>a</b>) ABC-RF. (<b>b</b>) SBX-ABC-RF.</p>
Full article ">Figure 12
<p>RVMD decomposition signals in Case 2. (<b>a</b>) Rolling cage fault. (<b>b</b>) Rolling ball fault.</p>
Full article ">Figure 13
<p>Feature selection results. (<b>a</b>) The weight value of 203 features in case 2, (<b>b</b>) Classification results of different numbers of the features in case 2.</p>
Full article ">Figure 14
<p>Classification effectiveness of the different features in case 2. (<b>a</b>) Frequency domain feature C<sub>26</sub>. (<b>b</b>) Time domain feature C<sub>1</sub>.</p>
Full article ">Figure 15
<p>The optimized performance of SBX-ABC. (<b>a</b>) The population of the swarm is 50. (<b>b</b>) The population of the swarm is 100.</p>
Full article ">Figure 16
<p>Classification results under different optimized algorithms in Case 2. (<b>a</b>) ABC-RF. (<b>b</b>) SBX-ABC-RF.</p>
Full article ">
71 pages, 26964 KiB  
Article
Machine Learning Approaches for Fault Detection in Internal Combustion Engines: A Review and Experimental Investigation
by A. Srinivaas, N. R. Sakthivel and Binoy B. Nair
Informatics 2025, 12(1), 25; https://doi.org/10.3390/informatics12010025 - 21 Feb 2025
Viewed by 501
Abstract
Fault diagnostics in internal combustion engines (ICEs) is vital for optimal operation and avoiding costly breakdowns. This paper reviews methodologies for ICE fault detection, including model-based and data-driven approaches. The former uses physical models of engine components to diagnose defects, while the latter [...] Read more.
Fault diagnostics in internal combustion engines (ICEs) is vital for optimal operation and avoiding costly breakdowns. This paper reviews methodologies for ICE fault detection, including model-based and data-driven approaches. The former uses physical models of engine components to diagnose defects, while the latter employs statistical analysis of sensor data to identify patterns indicating faults. Various methods for ICE fault identification, such as vibration analysis, thermography, acoustic analysis, and optical approaches, are reviewed. This paper also explores the latest approaches for detecting ICE faults. It highlights the challenges in the diagnostic process and ways to enhance result accuracy and reliability. This paper concludes with a review of the progress in fault identification in ICE components and prospects, highlighted by an experimental investigation using 16 machine learning algorithms with seven feature selection techniques under three load conditions to detect faults in a four-cylinder ICE. Additionally, this study incorporates advanced deep learning techniques, including a deep neural network (DNN), a one-dimensional convolutional neural network (1D-CNN), Transformer and a hybrid Transformer and DNN model which demonstrate superior performance in fault detection compared to traditional machine learning methods. Full article
(This article belongs to the Section Machine Learning)
Show Figures

Figure 1

Figure 1
<p>Function block diagram of air–fuel ratio fault-tolerant system of ICEs.</p>
Full article ">Figure 2
<p>Function block diagram of piston fault diagnosis system of ICEs.</p>
Full article ">Figure 3
<p>Valve fault diagnosis process of ICEs.</p>
Full article ">Figure 4
<p>Functional block diagram of bearing fault diagnosis of ICEs.</p>
Full article ">Figure 5
<p>Sensor fault diagnosis of ICEs.</p>
Full article ">Figure 6
<p>Ignition fault diagnosis in ICEs.</p>
Full article ">Figure 7
<p>Injection fault diagnosis of ICEs.</p>
Full article ">Figure 8
<p>Hybrid fault diagnosis of ICEs.</p>
Full article ">Figure 9
<p>Engine load classifiers based on ANN.</p>
Full article ">Figure 10
<p>Other researchers’ unique research contributions in the fault diagnosis of ICEs [<a href="#B17-informatics-12-00025" class="html-bibr">17</a>,<a href="#B23-informatics-12-00025" class="html-bibr">23</a>,<a href="#B33-informatics-12-00025" class="html-bibr">33</a>,<a href="#B50-informatics-12-00025" class="html-bibr">50</a>,<a href="#B57-informatics-12-00025" class="html-bibr">57</a>,<a href="#B59-informatics-12-00025" class="html-bibr">59</a>,<a href="#B65-informatics-12-00025" class="html-bibr">65</a>,<a href="#B80-informatics-12-00025" class="html-bibr">80</a>,<a href="#B81-informatics-12-00025" class="html-bibr">81</a>,<a href="#B82-informatics-12-00025" class="html-bibr">82</a>,<a href="#B83-informatics-12-00025" class="html-bibr">83</a>].</p>
Full article ">Figure 11
<p>Engine experimental setup. (<b>a</b>) A—Computer for Acquiring Data, B—NI Data Acquisition (DAQ) Hardware, C—Ambassador Four Cylinder Engine, D—Engine Electric Dynamometer, E—Eclectic Loadcell for the controlling of the 0, 15, and 30% load, F—Cylinder Cutoff switch for each cylinder, (<b>b</b>) G—Tri-accelerometer (Vibration) Sensor in the middle of the Engine Head position, H—Microphone.</p>
Full article ">Figure 12
<p>Methodology workflow for machine learning-based vibration analysis and classification of a 4-cylinder Ambassador engine cylinder cutoff fault diagnosis.</p>
Full article ">Figure 13
<p>Tri-accelerometer signal graph: (<b>a</b>) 0% load condition, (<b>b</b>) 15% load condition, (<b>c</b>) 30% load condition vs. normal, first, second, third, fourth cylinder cutoff condition.</p>
Full article ">Figure 14
<p>Proposed DNN architecture: (<b>a</b>) neural network diagram representation [<a href="#B130-informatics-12-00025" class="html-bibr">130</a>], (<b>b</b>) neural network block diagram representation.</p>
Full article ">Figure 15
<p>Proposed 1D-CNN architecture diagram [<a href="#B130-informatics-12-00025" class="html-bibr">130</a>].</p>
Full article ">Figure 16
<p>Proposed transformer architecture: (<b>a</b>) complete architecture block diagram representation, (<b>b</b>) detailed transformer architecture [<a href="#B131-informatics-12-00025" class="html-bibr">131</a>].</p>
Full article ">Figure 17
<p>Proposed hybrid Transformer-DNN architecture block diagram representation.</p>
Full article ">Figure 18
<p>Proposed hybrid DNN model architecture neural network diagram representation [<a href="#B130-informatics-12-00025" class="html-bibr">130</a>].</p>
Full article ">Figure 19
<p>Confusion matrix.</p>
Full article ">Figure 20
<p>Accuracy heatmap for three load conditions: (<b>a</b>) 0%, (<b>b</b>) 15%, and (<b>c</b>) 30% with 16 classifiers and 7 feature selection techniques.</p>
Full article ">Figure 21
<p>Total cost heatmap for three load conditions: (<b>a</b>) 0%, (<b>b</b>) 15%, and (<b>c</b>) 30% with 16 classifiers and 7 feature selection techniques.</p>
Full article ">Figure 22
<p>Feature extraction F1 score for 0% load condition: (<b>a</b>) ANOVA, (<b>b</b>) Chi2, (<b>c</b>) Kruskal–Wallis, (<b>d</b>) MRMR, (<b>e</b>) PCA, (<b>f</b>) ReliefF, (<b>g</b>) RAW.</p>
Full article ">Figure 23
<p>Feature extraction F1 score for 15% load condition: (<b>a</b>) ANOVA, (<b>b</b>) Chi2, (<b>c</b>) Kruskal–Wallis, (<b>d</b>) MRMR, (<b>e</b>) PCA, (<b>f</b>) ReliefF, (<b>g</b>) RAW.</p>
Full article ">Figure 24
<p>Feature extraction F1 score for 30% load condition: (<b>a</b>) ANOVA, (<b>b</b>) Chi2, (<b>c</b>) Kruskal–Wallis, (<b>d</b>) MRMR, (<b>e</b>) PCA, (<b>f</b>) ReliefF, (<b>g</b>) RAW.</p>
Full article ">Figure 25
<p>Heatmap plot with 0% load condition for (<b>a</b>) ANOVA, (<b>b</b>) CHi2, (<b>c</b>) Kruskal–Wallis, (<b>d</b>) MRMR, (<b>e</b>) PCA, (<b>f</b>) ReliefF, (<b>g</b>) RAW.</p>
Full article ">Figure 25 Cont.
<p>Heatmap plot with 0% load condition for (<b>a</b>) ANOVA, (<b>b</b>) CHi2, (<b>c</b>) Kruskal–Wallis, (<b>d</b>) MRMR, (<b>e</b>) PCA, (<b>f</b>) ReliefF, (<b>g</b>) RAW.</p>
Full article ">Figure 26
<p>Heatmap plot with 15% load condition for (<b>a</b>) ANOVA, (<b>b</b>) CHi2, (<b>c</b>) Kruskal–Wallis, (<b>d</b>) MRMR, (<b>e</b>) PCA, (<b>f</b>) ReliefF, (<b>g</b>) RAW.</p>
Full article ">Figure 26 Cont.
<p>Heatmap plot with 15% load condition for (<b>a</b>) ANOVA, (<b>b</b>) CHi2, (<b>c</b>) Kruskal–Wallis, (<b>d</b>) MRMR, (<b>e</b>) PCA, (<b>f</b>) ReliefF, (<b>g</b>) RAW.</p>
Full article ">Figure 27
<p>Heatmap plot with 30% load condition for (<b>a</b>) ANOVA, (<b>b</b>) CHi2, (<b>c</b>) Kruskal–Wallis, (<b>d</b>) MRMR, (<b>e</b>) PCA, (<b>f</b>) ReliefF, (<b>g</b>) RAW.</p>
Full article ">Figure 27 Cont.
<p>Heatmap plot with 30% load condition for (<b>a</b>) ANOVA, (<b>b</b>) CHi2, (<b>c</b>) Kruskal–Wallis, (<b>d</b>) MRMR, (<b>e</b>) PCA, (<b>f</b>) ReliefF, (<b>g</b>) RAW.</p>
Full article ">Figure 28
<p>Confusion matrix of DNN architecture: (<b>a</b>) Zero percent load, (<b>b</b>) 15% load, (<b>c</b>) 30% load.</p>
Full article ">Figure 29
<p>Confusion matrix of 1D-CNN architecture: (<b>a</b>) Zero percent load, (<b>b</b>) 15% load, (<b>c</b>) 30% load.</p>
Full article ">Figure 30
<p>Confusion matrix of Transformer architecture: (<b>a</b>) Zero percent load, (<b>b</b>) 15% load, (<b>c</b>) 30% load.</p>
Full article ">Figure 31
<p>Accuracy vs. load plot for the proposed Transformer architecture.</p>
Full article ">Figure 32
<p>Confusion matrix of hybrid Transformer +DNN architecture: (<b>a</b>) Zero percent load, (<b>b</b>) 15% load, (<b>c</b>) 30% load.</p>
Full article ">Figure 33
<p>Accuracy vs. load plot for the proposed hybrid Transformer +DNN architecture.</p>
Full article ">Figure A1
<p>Feature extraction from the RAW sensor data.</p>
Full article ">Figure A2
<p>F1 Score Heatmap plot with 0% load condition for (<b>a</b>) ANOVA, (<b>b</b>) CHi2, (<b>c</b>) Kruskal–Wallis, (<b>d</b>) MRMR, (<b>e</b>) PCA, (<b>f</b>) ReliefF, (<b>g</b>) RAW.</p>
Full article ">Figure A2 Cont.
<p>F1 Score Heatmap plot with 0% load condition for (<b>a</b>) ANOVA, (<b>b</b>) CHi2, (<b>c</b>) Kruskal–Wallis, (<b>d</b>) MRMR, (<b>e</b>) PCA, (<b>f</b>) ReliefF, (<b>g</b>) RAW.</p>
Full article ">Figure A3
<p>F1 Score Heatmap plot with 15% load condition for (<b>a</b>) ANOVA, (<b>b</b>) CHi2, (<b>c</b>) Kruskal–Wallis, (<b>d</b>) MRMR, (<b>e</b>) PCA, (<b>f</b>) ReliefF, (<b>g</b>) RAW.</p>
Full article ">Figure A3 Cont.
<p>F1 Score Heatmap plot with 15% load condition for (<b>a</b>) ANOVA, (<b>b</b>) CHi2, (<b>c</b>) Kruskal–Wallis, (<b>d</b>) MRMR, (<b>e</b>) PCA, (<b>f</b>) ReliefF, (<b>g</b>) RAW.</p>
Full article ">Figure A4
<p>F1 Score Heatmap plot with 30% load condition for (<b>a</b>) ANOVA, (<b>b</b>) CHi2, (<b>c</b>) Kruskal–Wallis, (<b>d</b>) MRMR, (<b>e</b>) PCA, (<b>f</b>) ReliefF, (<b>g</b>) RAW.</p>
Full article ">Figure A4 Cont.
<p>F1 Score Heatmap plot with 30% load condition for (<b>a</b>) ANOVA, (<b>b</b>) CHi2, (<b>c</b>) Kruskal–Wallis, (<b>d</b>) MRMR, (<b>e</b>) PCA, (<b>f</b>) ReliefF, (<b>g</b>) RAW.</p>
Full article ">
32 pages, 3577 KiB  
Article
Design, Synthesis, and Antiproliferative Activity of Novel Indole/1,2,4-Triazole Hybrids as Tubulin Polymerization Inhibitors
by Esraa Mahmoud, Dalia Abdelhamid, Anber F. Mohammed, Zainab M. Almarhoon, Stefan Bräse, Bahaa G. M. Youssif, Alaa M. Hayallah and Mohamad Abdel-Aziz
Pharmaceuticals 2025, 18(2), 275; https://doi.org/10.3390/ph18020275 - 19 Feb 2025
Viewed by 213
Abstract
Background/Objectives: New indole/1,2,4-triazole hybrids were synthesized and tested for antiproliferative activity against the NCI 60 cell line as tubulin polymerization inhibitors. Methods: All final compounds, 6aj and 7aj were evaluated at a single concentration of 10 µM against a [...] Read more.
Background/Objectives: New indole/1,2,4-triazole hybrids were synthesized and tested for antiproliferative activity against the NCI 60 cell line as tubulin polymerization inhibitors. Methods: All final compounds, 6aj and 7aj were evaluated at a single concentration of 10 µM against a panel of sixty cancer cell lines. Results: Compounds 7aj, featuring the NO-releasing oxime moiety, exhibited superior anticancer activity to their precursor ketones 6aj across all tested cancer cell lines. Compounds 6h, 7h, 7i, and 7j were chosen for five-dose evaluations against a comprehensive array of 60 human tumor cell lines. The data showed that all tested compounds had significant anticancer activity throughout the nine tumor subpanels studied, with selectivity ratios ranging from 0.52 to 2.29 at the GI50 level. Compounds 7h and 7j showed substantial anticancer effectiveness against most cell lines across nine subpanels, with GI50 values ranging from 1.85 to 5.76 µM and 2.45 to 5.23 µM. Compounds 6h, 7h, 7i, and 7j were assessed for their inhibitory effects on tubulin polymerization. Conclusions: The results showed that compound 7i, an oxime-based derivative, was the most effective at blocking tubulin, with an IC50 value of 3.03 ± 0.11 µM. This was compared to the standard drug CA-4, which had an IC50 value of 8.33 ± 0.29 µM. Additionally, cell cycle analysis and apoptosis assays were performed for compound 7i. Molecular computational investigations have been performed to examine the binding mode of the most effective compounds to the target enzyme. Full article
(This article belongs to the Section Medicinal Chemistry)
Show Figures

Figure 1

Figure 1
<p>Structure of CA-4 (<b>I</b>), isoCA-4 (<b>II</b>), and compounds <b>III</b> and <b>IV</b>.</p>
Full article ">Figure 2
<p>Structure of oxime-based binding tubulin compounds <b>V</b> and <b>VI</b>.</p>
Full article ">Figure 3
<p>Structures of new targets <b>6a</b>–<b>j</b> and <b>7a</b>–<b>j</b>.</p>
Full article ">Figure 4
<p>Cell cycle analysis of <b>7i</b> in MDA-MB 231 cell line.</p>
Full article ">Figure 5
<p>Results for apoptosis induction assay of <b>7i</b>.</p>
Full article ">Figure 6
<p>Results for cell cycle analysis and apoptosis induction of <b>7i</b>.</p>
Full article ">Figure 7
<p>Ligplots at α/β-tubulin colchicine binding site: (<b>A</b>) 3D-docked model of CA-4 (dark yellow) showing the protein lipophilicity surface (purple: hydrophilic, white: neutral, and green: lipophilic), (cyan for α chain residues and brown for β chain residues), and (<b>B</b>) 2D-docked model of CA-4.</p>
Full article ">Figure 8
<p>Ligplots at α/β-tubulin colchicine binding site: (<b>A</b>) a 3D-docked model of compound <b>7i</b> (grey) showing the protein lipophilicity surface (purple: hydrophilic, white: neutral, and green: lipophilic), (cyan for α chain residues and brown for β chain residues), and (<b>B</b>) a 2D-docked model of <b>7i</b>.</p>
Full article ">Figure 9
<p>Ligplots at α/β-tubulin colchicine binding site: (<b>A</b>) 3D-docked model of compound <b>6h</b> (dark yellow) showing the protein lipophilicity surface (purple: hydrophilic, white: neutral, and green: lipophilic), (cyan for α chain residues and brown for β chain residues), and (<b>B</b>) 2D-docked model of <b>6h</b>.</p>
Full article ">Scheme 1
<p>Synthesis of target compounds <b>6a</b>–<b>j</b> and <b>7a</b>–<b>j</b>.</p>
Full article ">
32 pages, 124914 KiB  
Article
CNN–Transformer Hybrid Architecture for Underwater Sonar Image Segmentation
by Juan Lei, Huigang Wang, Zelin Lei, Jiayuan Li and Shaowei Rong
Remote Sens. 2025, 17(4), 707; https://doi.org/10.3390/rs17040707 - 19 Feb 2025
Viewed by 284
Abstract
The salient object detection (SOD) of forward-looking sonar images plays a crucial role in underwater detection and rescue tasks. However, the existing SOD algorithms find it difficult to effectively extract salient features and spatial structure information from images with scarce semantic information, uneven [...] Read more.
The salient object detection (SOD) of forward-looking sonar images plays a crucial role in underwater detection and rescue tasks. However, the existing SOD algorithms find it difficult to effectively extract salient features and spatial structure information from images with scarce semantic information, uneven intensity distribution, and high noise. Convolutional neural networks (CNNs) have strong local feature extraction capabilities, but they are easily constrained by the receptive field and lack the ability to model long-range dependencies. Transformers, with their powerful self-attention mechanism, are capable of modeling the global features of a target, but they tend to lose a significant amount of local detail. Mamba effectively models long-range dependencies in long sequence inputs through a selection mechanism, offering a novel approach to capturing long-range correlations between pixels. However, since the saliency of image pixels does not exhibit sequential dependencies, this somewhat limits Mamba’s ability to fully capture global contextual information during the forward pass. Inspired by multimodal feature fusion learning, we propose a hybrid CNN–Transformer–Mamba architecture, termed FLSSNet. FLSSNet is built upon a CNN and Transformer backbone network, integrating four core submodules to address various technical challenges: (1) The asymmetric dual encoder–decoder (ADED) is capable of simultaneously extracting features from different modalities and systematically modeling both local contextual information and global spatial structure. (2) The Transformer feature converter (TFC) module optimizes the multimodal feature fusion process through feature transformation and channel compression. (3) The long-range correlation attention (LRCA) module enhances CNN’s ability to model long-range dependencies through the collaborative use of convolutional kernels, selective sequential scanning, and attention mechanisms, while effectively suppressing noise interference. (4) The recursive contour refinement (RCR) model refines edge contour information through a layer-by-layer recursive mechanism, achieving greater precision in boundary details. The experimental results show that FLSSNet exhibits outstanding competitiveness among 25 state-of-the-art SOD methods, achieving MAE and Eξ values of 0.04 and 0.973, respectively. Full article
(This article belongs to the Special Issue Ocean Remote Sensing Based on Radar, Sonar and Optical Techniques)
Show Figures

Figure 1

Figure 1
<p>Examples of FLS images containing various noise sources. The red region indicates the ground truth of the salient target, the purple region represents areas with intensity inconsistency, the blue region indicates multipath noise, and the yellow region represents shadow noise.</p>
Full article ">Figure 2
<p>The overall structure of the proposed FLSSNet. The method employs a two-stage strategy: the first stage utilizes an asymmetric dual encoder–decoder structure for saliency feature extraction, while the second stage further refines the feature maps using the recursive refine module. In the first stage, the image is input into two encoders to obtain feature information from different modalities. Simultaneously, the Transformer feature converter module is used to transform and compress information from these modalities. Next, the long-range correlation attention module integrates multi-level features and reduces feature redundancy. Finally, the recursive refine module is employed to further enhance the precision of feature prediction.</p>
Full article ">Figure 3
<p>The overall structure of the proposed Transformer feature converter (TFC) module. The TFC module mainly consists of the residual channel attention module (RCAM) and the multi-scale dual self-attention mechanism module. MHSA stands for multi-head attention mechanism.</p>
Full article ">Figure 4
<p>The overall structure of the proposed long-range correlation attention (LRCA) module. The LRCA module primarily consists of a multi-directional convolution module (MDC) and omnidirectional selective scan module (OSSM), an attention module.</p>
Full article ">Figure 5
<p>The overall structure of the proposed recursive block (<b>a</b>) and recursive contour extraction (RECM) module (<b>b</b>). <span class="html-italic">N</span> denotes the number of RECMs, and <span class="html-italic">m</span> represents the sequence number of recursive blocks in the hierarchy of RCR.</p>
Full article ">Figure 6
<p>Contains different types of samples. (<b>a</b>) Bottle; (<b>b</b>) can; (<b>c</b>) tire; (<b>d</b>) chain; (<b>e</b>) hook; (<b>f</b>) standing bottle; (<b>g</b>) drink carton; (<b>h</b>) shampoo bottle; (<b>i</b>) valve; (<b>j</b>) propeller; (<b>k</b>) wall.</p>
Full article ">Figure 7
<p>Examples of noise in FLS images are shown. The red areas indicate the ground truth. The blue areas represent small targets that are easily lost due to spatial positioning. The yellow areas show shadow noise caused by occlusions. The cyan areas depict scattering noise caused by sound waves encountering suspended particles, bubbles, and other media. The purple areas illustrate pseudo-target noise caused by reflection noise from water waves.</p>
Full article ">Figure 8
<p>The comparison between FLSSNet and its comparison model on the PR curve (<b>a</b>) and F-measure curve (<b>b</b>). Please zoom in to view.</p>
Full article ">Figure 9
<p>Visual display of FLSSNet and comparison models. The red box indicates significant differences.</p>
Full article ">Figure 10
<p>Visualization results of side outputs at different levels of the recursive block.</p>
Full article ">Figure 11
<p>(<b>a</b>,<b>b</b>) Quantitative comparison of the variant models within the CNN–Transformer hybrid backbone architecture in the PR (precision–recall) and F-measure curves.</p>
Full article ">Figure 12
<p>Visualization results of variant models in CNN–Transformer hybrid backbone architecture.</p>
Full article ">Figure 13
<p>The visualization results of a single module in a pure CNN backbone architecture.</p>
Full article ">Figure 14
<p>Visualization of ablation experiments using MDC and OSSM in CNN–Transformer hybrid architecture and pure CNN architecture.</p>
Full article ">Figure 15
<p>In different levels of RCR, the visualization results of <math display="inline"><semantics> <msubsup> <mi>X</mi> <mrow> <mo>(</mo> <mi>n</mi> <mo>−</mo> <mn>1</mn> <mo>)</mo> </mrow> <mi>l</mi> </msubsup> </semantics></math> and <math display="inline"><semantics> <msubsup> <mi>X</mi> <mrow> <mo>(</mo> <mi>n</mi> <mo>−</mo> <mn>1</mn> <mo>)</mo> </mrow> <mi>c</mi> </msubsup> </semantics></math> in the second layer of RCEM are presented. Here, <math display="inline"><semantics> <mrow> <mo>(</mo> <mi>s</mi> <mn>1</mn> <mo>,</mo> <mi>s</mi> <mn>2</mn> <mo>,</mo> <mo>…</mo> <mo>,</mo> <mi>s</mi> <mn>5</mn> <mo>)</mo> </mrow> </semantics></math> represent the hierarchical sequence of RCEM, while <span class="html-italic">L</span> and <span class="html-italic">C</span>, respectively, denote the specific visualization results of <math display="inline"><semantics> <msubsup> <mi>X</mi> <mrow> <mo>(</mo> <mi>n</mi> <mo>−</mo> <mn>1</mn> <mo>)</mo> </mrow> <mi>l</mi> </msubsup> </semantics></math> and <math display="inline"><semantics> <msubsup> <mi>X</mi> <mrow> <mo>(</mo> <mi>n</mi> <mo>−</mo> <mn>1</mn> <mo>)</mo> </mrow> <mi>c</mi> </msubsup> </semantics></math>.</p>
Full article ">
25 pages, 836 KiB  
Article
Hybrid Random Feature Selection and Recurrent Neural Network for Diabetes Prediction
by Oyebayo Ridwan Olaniran, Aliu Omotayo Sikiru, Jeza Allohibi, Abdulmajeed Atiah Alharbi and Nada MohammedSaeed Alharbi
Mathematics 2025, 13(4), 628; https://doi.org/10.3390/math13040628 - 14 Feb 2025
Viewed by 418
Abstract
This paper proposes a novel two-stage ensemble framework combining Long Short-Term Memory (LSTM) and Bidirectional LSTM (BiLSTM) with randomized feature selection to enhance diabetes prediction accuracy and calibration. The method first trains multiple LSTM/BiLSTM base models on dynamically sampled feature subsets to promote [...] Read more.
This paper proposes a novel two-stage ensemble framework combining Long Short-Term Memory (LSTM) and Bidirectional LSTM (BiLSTM) with randomized feature selection to enhance diabetes prediction accuracy and calibration. The method first trains multiple LSTM/BiLSTM base models on dynamically sampled feature subsets to promote diversity, followed by a meta-learner that integrates predictions into a final robust output. A systematic simulation study conducted reveals that feature selection proportion critically impacts generalization: mid-range values (0.5–0.8 for LSTM; 0.6–0.8 for BiLSTM) optimize performance, while values close to 1 induce overfitting. Furthermore, real-life data evaluation on three benchmark datasets—Pima Indian Diabetes, Diabetic Retinopathy Debrecen, and Early Stage Diabetes Risk Prediction—revealed that the framework achieves state-of-the-art results, surpassing conventional (random forest, support vector machine) and recent hybrid frameworks with an accuracy of up to 100%, AUC of 99.1–100%, and superior calibration (Brier score: 0.006–0.023). Notably, the BiLSTM variant consistently outperforms unidirectional LSTM in the proposed framework, particularly in sensitivity (98.4% vs. 97.0% on retinopathy data), highlighting its strength in capturing temporal dependencies. Full article
(This article belongs to the Section D1: Probability and Statistics)
Show Figures

Figure 1

Figure 1
<p>Flowchart showing the diagnostic process of RFLSTM and RFBiLSTM.</p>
Full article ">Figure 2
<p>Training and validation loss trajectories of RFLSTM across varying <math display="inline"><semantics> <mi>η</mi> </semantics></math> (proportion of predictors).</p>
Full article ">Figure 3
<p>Training and validation loss trajectories of RFBiLSTM across varying <math display="inline"><semantics> <mi>η</mi> </semantics></math> (proportion of predictors).</p>
Full article ">Figure 4
<p>Receiver Operating Characteristic (ROC) curves of the various methods for the Pima Indian dataset. (Note the AUC value shown on the plot corresponds to the AUC from one of the ten iterations).</p>
Full article ">Figure 5
<p>Receiver Operating Characteristic (ROC) curves of the various methods for the Diabetic Retinopathy Debrecen Dataset. (Note the AUC value shown on the plot corresponds to the AUC from one of the ten iterations).</p>
Full article ">Figure 6
<p>Receiver Operating Characteristic (ROC) curves of the various methods for the Early Stage Diabetes Risk dataset. (Note the AUC value shown on the plot corresponds to the AUC from one of the ten iterations).</p>
Full article ">
18 pages, 576 KiB  
Review
Autism Data Classification Using AI Algorithms with Rules: Focused Review
by Abdulhamid Alsbakhi, Fadi Thabtah and Joan Lu
Bioengineering 2025, 12(2), 160; https://doi.org/10.3390/bioengineering12020160 - 7 Feb 2025
Viewed by 758
Abstract
Autism Spectrum Disorder (ASD) presents challenges in early screening due to its varied nature and sophisticated early signs. From a machine-learning (ML) perspective, the primary challenges include the need for large, diverse datasets, managing the variability in ASD symptoms, providing easy-to-understand models, and [...] Read more.
Autism Spectrum Disorder (ASD) presents challenges in early screening due to its varied nature and sophisticated early signs. From a machine-learning (ML) perspective, the primary challenges include the need for large, diverse datasets, managing the variability in ASD symptoms, providing easy-to-understand models, and ensuring ASD predictive models that can be employed across different populations. Interpretable or explainable classification algorithms, like rule-based or decision tree, play a crucial role in dealing with some of these issues by offering classification models that can be exploited by clinicians. These models offer transparency in decision-making, allowing clinicians to understand reasons behind diagnostic decisions, which is critical for trust and adoption in medical settings. In addition, interpretable classification algorithms facilitate the identification of important behavioural features and patterns associated with ASD, enabling more accurate and explainable diagnoses. However, there is a scarcity of review papers focusing on interpretable classifiers for ASD detection from a behavioural perspective. Thereby this research aimed to conduct a recent review on rule-based classification research works in order to provide added value by consolidating current research, identifying gaps, and guiding future studies. Our research would enhance the understanding of these techniques, based on data used to generate models and obtain performance by trying to highlight early detection and intervention ways for ASD. Integrating advanced AI methods like deep learning with rule-based classifiers can improve model interpretability, exploration, and accuracy in ASD-detection applications. While this hybrid approach has feature selection relevant features that can be detected in an efficient manner, rule-based classifiers can provide clinicians with transparent explanations for model decisions. This hybrid approach is critical in clinical applications like ASD, where model content is as crucial as achieving high classification accuracy. Full article
(This article belongs to the Section Biosignal Processing)
Show Figures

Figure 1

Figure 1
<p>Rule-based classification-model taxonomy.</p>
Full article ">Figure 2
<p>Steps needed to develop an ASD classification system.</p>
Full article ">
24 pages, 6584 KiB  
Article
Machine Learning Framework for Hybrid Clad Characteristics Modeling in Metal Additive Manufacturing
by Sina Tayebati and Kyu Taek Cho
J. Manuf. Mater. Process. 2025, 9(2), 49; https://doi.org/10.3390/jmmp9020049 - 5 Feb 2025
Viewed by 563
Abstract
Metal additive manufacturing (MAM) has advanced significantly, yet accurately predicting clad characteristics from processing parameters remains challenging due to process complexity and data scarcity. This study introduces a novel hybrid machine learning (ML) framework that integrates validated multi-physics computational fluid dynamics simulations with [...] Read more.
Metal additive manufacturing (MAM) has advanced significantly, yet accurately predicting clad characteristics from processing parameters remains challenging due to process complexity and data scarcity. This study introduces a novel hybrid machine learning (ML) framework that integrates validated multi-physics computational fluid dynamics simulations with experimental data, enabling prediction of clad characteristics unattainable through conventional methods alone. Our approach uniquely incorporates physics-aware features, such as volumetric energy density and linear mass density, enhancing process understanding and model transferability. We comprehensively benchmark ML models across traditional, ensemble, and neural network categories, analyzing their computational complexity through Big O notation and evaluating both classification and regression performance in predicting clad geometries and process maps. The framework demonstrates superior prediction accuracy with sub-second inference latency, overcoming limitations of purely experimental or simulation-based methods. The trained models generate processing maps with 0.95 AUC (Area Under Curve) accuracy that directly guide MAM parameter selection, bridging the gap between theoretical modeling and practical process control. By integrating physics-based simulations with ML techniques and physics-aware features, our approach achieves an R2 of 0.985 for clad geometry prediction and improved generalization over traditional methods, establishing a new standard for MAM process modeling. This research advances both theoretical understanding and practical implementation of MAM processes through a comprehensive, physics-aware machine learning approach. Full article
(This article belongs to the Special Issue Large-Scale Metal Additive Manufacturing)
Show Figures

Figure 1

Figure 1
<p>Schematic of the DED process and the clad characteristics.</p>
Full article ">Figure 2
<p>Hybrid data, ML models, and task implementation in our framework.</p>
Full article ">Figure 3
<p>Distribution of clad features in our dataset, (<b>a</b>) “width” distribution, (<b>b</b>) “height” distribution, (<b>c</b>) “depth” distribution, (<b>d</b>) occurrence of clad quality labels.</p>
Full article ">Figure 4
<p>Diagram of boundary conditions.</p>
Full article ">Figure 5
<p>Comparison of experimental and modeling results: (<b>a</b>) comparison of clad height from experiment and modeling results; (<b>b</b>) comparison of dilution from experiment and modeling results.</p>
Full article ">Figure 6
<p>Feature distribution comparison between modeling and experimental datasets for key process parameters i.e., (<b>a</b>) volumetric energy density <math display="inline"><semantics> <mrow> <mfenced separators="|"> <mrow> <mstyle scriptlevel="0" displaystyle="true"> <mfrac> <mrow> <mi mathvariant="normal">J</mi> </mrow> <mrow> <msup> <mrow> <mi mathvariant="normal">m</mi> <mi mathvariant="normal">m</mi> </mrow> <mrow> <mn>3</mn> </mrow> </msup> </mrow> </mfrac> </mstyle> </mrow> </mfenced> </mrow> </semantics></math>, (<b>b</b>) linear mass density <math display="inline"><semantics> <mrow> <mfenced separators="|"> <mrow> <mstyle scriptlevel="0" displaystyle="true"> <mfrac> <mrow> <mi mathvariant="normal">g</mi> </mrow> <mrow> <mi mathvariant="normal">m</mi> <mi mathvariant="normal">m</mi> </mrow> </mfrac> </mstyle> </mrow> </mfenced> </mrow> </semantics></math>, (<b>c</b>) laser power (<math display="inline"><semantics> <mrow> <mi mathvariant="normal">W</mi> </mrow> </semantics></math>), (<b>d</b>) laser scanning speed <math display="inline"><semantics> <mrow> <mfenced separators="|"> <mrow> <mstyle scriptlevel="0" displaystyle="true"> <mfrac> <mrow> <mi mathvariant="normal">m</mi> <mi mathvariant="normal">m</mi> </mrow> <mrow> <mi mathvariant="normal">s</mi> </mrow> </mfrac> </mstyle> </mrow> </mfenced> </mrow> </semantics></math>.</p>
Full article ">Figure 7
<p>Benchmark performance comparison for predicting geometrical characteristics of the single clad: (<b>a</b>,<b>b</b>) width prediction accuracy and MAE results, (<b>c</b>,<b>d</b>) height prediction accuracy and MAE results, (<b>e</b>,<b>f</b>) depth prediction accuracy and MAE results.</p>
Full article ">Figure 8
<p>Predicted clad geometry plotted against the actual ground truth geometry values: (<b>a</b>) width prediction using ‘Gradient Boosting’, (<b>b</b>) height prediction using ‘Gradient Boosting’, (<b>c</b>) depth prediction using ‘Gradient Boosting’.</p>
Full article ">Figure 9
<p>Printability maps constructed by the ML regression models on the test dataset, showing the effect of laser power and laser scanning velocity on single clad geometry features: (<b>a</b>) predicted width using Gradient Boosting Regression, (<b>b</b>) predicted height using Gradient Boosting Regression, (<b>c</b>) predicted depth using Gradient Boosting Regression.</p>
Full article ">Figure 10
<p>Benchmark performance comparison for predicting the class of the clad and process map: (<b>a</b>) accuracy results, (<b>b</b>) AUC-ROC results.</p>
Full article ">Figure 11
<p>ROC curves of the ML classifiers in predicting the class of the clad and process map.</p>
Full article ">Figure 12
<p>(<b>a</b>) Printability maps (classification boundaries) of our testing dataset based on laser power and laser scanning velocity for printing a single clad with desirable (20% <math display="inline"><semantics> <mrow> <mo>≤</mo> </mrow> </semantics></math> Dilution <math display="inline"><semantics> <mrow> <mo>≤</mo> <mtext> </mtext> <mn>50</mn> <mo>%</mo> </mrow> </semantics></math>) or undesirable (Dilution <math display="inline"><semantics> <mrow> <mo>≤</mo> </mrow> </semantics></math> 20% or Dilution <math display="inline"><semantics> <mrow> <mo>≥</mo> </mrow> </semantics></math> 50%) quality for neural network model. (<b>b</b>) Confusion matrix for clad classification based on neural network prediction.</p>
Full article ">Figure 13
<p>Feature importance analysis. (<b>a</b>) Feature importance for clad height prediction (<b>b</b>) Feature importance for clad width prediction (<b>c</b>) Feature importance for clad depth prediction (<b>d</b>) Feature importance for clad quality classification.</p>
Full article ">Figure 14
<p>Comparison of the time complexity of machine learning models using Big O notation.</p>
Full article ">
12 pages, 6129 KiB  
Article
Effect of OSEM Reconstruction Iteration Number and Monte Carlo Collimator Modeling on 166Ho Activity Quantification in SPECT/CT
by Rita Albergueiro, Vera Antunes and João Santos
Appl. Sci. 2025, 15(3), 1589; https://doi.org/10.3390/app15031589 - 5 Feb 2025
Viewed by 594
Abstract
Background: Accurate reconstruction and quantification in the post-therapy SPECT/CT imaging of 166Ho microspheres for hepatic malignancies is crucial for treatment evaluation. This present study aimed to explore the impact of the OSEM reconstruction parameters on SPECT/CT image features for dose distribution determination, [...] Read more.
Background: Accurate reconstruction and quantification in the post-therapy SPECT/CT imaging of 166Ho microspheres for hepatic malignancies is crucial for treatment evaluation. This present study aimed to explore the impact of the OSEM reconstruction parameters on SPECT/CT image features for dose distribution determination, using Hybrid Recon™ (Hermes Medical Solutions AB) and full Monte Carlo (MC) collimator modeling. Methods: Image quality and activity quantification were assessed through two acquisitions of the Jaszczak phantom using a Siemens Symbia Intevo Bold SPECT/CT system. The datasets were reconstructed using the OSEM method, with variations in the number of iterations for 15 and 8 subsets, both with and without full MC collimator modeling. Contrast recovery coefficient (QH), coefficient of variation (CV), contrast-to-noise ratio (CNR), calibration factor (CF), and activity recovery coefficient (ARC) were calculated and used to evaluate image quality and activity quantification. Results: Reconstructions with 5 iterations and 15 subsets, as well as 10 iterations and 8 subsets, were selected as the most suitable for 166Ho imaging, as they provided higher QH and ARCs. Incorporating full MC collimator modeling in both reconstructions led to significant improvements in image quality and activity recovery. The CFs remained consistent for a fixed value of 15 and 8 subsets, with values of (14.9 ± 0.5) cps/MBq and (14.6 ± 0.5) cps/MBq, respectively. However, when applying full collimator modeling, the CF values decreased to a range between 10.9 and 12.1 cps/MBq. Conclusions: For 166Ho SPECT/CT imaging, OSEM (with either 5 iterations and 15 subsets or 10 iterations and 8 subsets) combined with full MC collimator modeling yielded superior image quality and quantification results. Full article
(This article belongs to the Special Issue Bioinformatics in Healthcare to Prevent Cancer and Children Obesity)
Show Figures

Figure 1

Figure 1
<p>SPECT/CT images of the Jaszczak phantom. (<b>A</b>) Phantom setup for acquisition; (<b>B</b>) SPECT transaxial slice without background activity; (<b>C</b>) SPECT transaxial slice with background activity.</p>
Full article ">Figure 2
<p>Relationship between the contrast recovery coefficients and the number of iterations for all six spheres. Graph (<b>A</b>) shows data for a fixed value of 15 subsets, while Graph (<b>B</b>) shows data for a fixed value of 8 subsets.</p>
Full article ">Figure 3
<p>Coefficient of variation (%) as a function of the number of iterations for both fixed subset values.</p>
Full article ">Figure 4
<p>Phantom’s reconstructions: 1, 3, and 7 iterations with 15 subsets (<b>top</b> row) and 2, 6, and 14 iterations with 8 subsets (<b>bottom</b> row).</p>
Full article ">Figure 5
<p>CF (cps/MBq) as a function of the number of iterations for both fixed subset values and including full MC collimator modeling.</p>
Full article ">Figure 6
<p>Relationship between activity recovery coefficients and the number of iterations for all six spheres. Graph (<b>A</b>) shows data for a fixed value of 15 subsets, while Graph (<b>B</b>) shows data for a fixed value of 8 subsets.</p>
Full article ">Figure 7
<p>(<b>A</b>) Profile in red and yellow lines; (<b>B</b>) Phantom’s reconstruction of 5 iterations and 15 subsets; (<b>C</b>) Phantom’s reconstruction of 10 iterations and 8 subsets.</p>
Full article ">Figure 8
<p>Contrast recovery coefficients (graph <b>A</b>) and contrast-to-noise ratio (graph <b>B</b>) as a function of the sphere’s diameter for the selected reconstructions.</p>
Full article ">Figure 9
<p>Activity recovery coefficients as a function of the sphere’s volume for the selected reconstructions calculated using both methods (graph <b>A</b>—first method and graph <b>B</b>—second method).</p>
Full article ">
23 pages, 1112 KiB  
Article
STL-DCSInformer-ETS: A Hybrid Model for Medium- and Long-Term Sales Forecasting of Fast-Moving Consumer Goods
by Yecheng Ma, Lili He and Junhong Zheng
Appl. Sci. 2025, 15(3), 1516; https://doi.org/10.3390/app15031516 - 2 Feb 2025
Viewed by 524
Abstract
Accurately forecasting sales for fast-moving consumer goods (FMCG) remains a significant challenge due to the volatile and multi-faceted nature of sales data. Existing methods often struggle to capture intricate patterns driven by seasonal trends, external factors, and consumer behavior, hindering effective inventory management [...] Read more.
Accurately forecasting sales for fast-moving consumer goods (FMCG) remains a significant challenge due to the volatile and multi-faceted nature of sales data. Existing methods often struggle to capture intricate patterns driven by seasonal trends, external factors, and consumer behavior, hindering effective inventory management and strategic decision-making. To overcome these challenges, we propose STL-DCSInformer-ETS, a hybrid model that integrates three complementary components: STL decomposition, an enhanced DCSInformer model, and the ETS model. The model uses monthly sales data from a FMCG company, with key features including sales volume, product prices, promotional activities, and regulatory factors such as holidays, geographical information, consumer behavior, product factors, etc. STL decomposition partitions time-series data into trend, seasonal, and residual components, reducing data complexity and enabling more targeted forecasting. The enhanced DCSInformer employs dilated causal convolution and a multi-scale feature extraction mechanism to capture long-term dependencies and short-term variations effectively. Meanwhile, the ETS model specializes in modeling seasonal patterns, further refining forecasting precision. To further improve predictive performance, the Random Forest-based Recursive Feature Elimination (RF-RFE) method is applied to optimize feature selection. RF-RFE identifies key predictive factors from multiple dimensions, such as time, geography, and economy, which significantly influence forecasting accuracy. Through numerical experiments, the method demonstrates excellent performance by achieving a 35.9% reduction in Mean Squared Error and a 21.4% decrease in Mean Absolute Percentage Error, significantly outperforming traditional methods. Furthermore, the model effectively captures both medium- and long-term sales trends while addressing short-term fluctuations, leading to more accurate forecasting and improved decision-making for fast-moving consumer goods. This research provides new theoretical insights into hybrid forecasting models and practical solutions for optimizing inventory management and strategic planning in the FMCG industry. Full article
Show Figures

Figure 1

Figure 1
<p>STL-DCSInformer-ETS hybrid model.</p>
Full article ">Figure 2
<p>Informer model architecture diagram.</p>
Full article ">Figure 3
<p>The DCSInformer model architecture diagram, illustrating the various components of the model, including the Max Pooling, Multi-Head Attention, and Self-Attention mechanisms, which work together to process and capture features from the input time series (inputs <math display="inline"><semantics> <msub> <mi>X</mi> <mi>t</mi> </msub> </semantics></math>).</p>
Full article ">Figure 4
<p>An illustration of the Self-Attention mechanism.</p>
Full article ">Figure 5
<p>Dilated causal convolution.</p>
Full article ">Figure 6
<p>Monthly sales trend chart of different types.</p>
Full article ">Figure 7
<p>Monthly sales trend in different regions.</p>
Full article ">Figure 8
<p>Comparison of ablation and comparative experiment prediction results.</p>
Full article ">
15 pages, 1279 KiB  
Article
A Novel Hybrid Methodology Based on Transfer Learning, Machine Learning, and ReliefF for Chickpea Seed Variety Classification
by İbrahim Kılıç and Nesibe Yalçın
Appl. Sci. 2025, 15(3), 1334; https://doi.org/10.3390/app15031334 - 27 Jan 2025
Viewed by 713
Abstract
Seed quality is a critical factor in crop production. Therefore, seed classification is required to obtain high-quality seeds and to enhance agricultural sustainability and productivity. This study focuses on the varietal classification of chickpeas, an important source of protein and fiber. Chickpea seed [...] Read more.
Seed quality is a critical factor in crop production. Therefore, seed classification is required to obtain high-quality seeds and to enhance agricultural sustainability and productivity. This study focuses on the varietal classification of chickpeas, an important source of protein and fiber. Chickpea seed varieties can currently be identified by domain experts; their reliability and efficiency depend on the experience and skills of experts and are prone to human error. The design of classification models with high accuracy to assist in selection mechanisms is required for chickpea varieties. In this study, a novel hybrid methodology is proposed for the chickpea classification problem. This methodology combines three well-suited and robust components: feature extraction using three pre-trained models, feature selection with the ReliefF algorithm, and classification employing classical machine learning methods to enhance classification accuracy and efficiency. Various experiments have been conducted using the four hybrid models developed. Their performance has been compared in terms of accuracy, recall, F1-score, precision, and AUC. TL+SVM and TL+LDA outperformed the other models, with test accuracies of 94.4% and 94%, respectively. These results demonstrate the potential of a powerful model that will be beneficial as a component of computer vision systems in smart agriculture applications. Full article
(This article belongs to the Section Computing and Artificial Intelligence)
Show Figures

Figure 1

Figure 1
<p>Classification flowchart of chickpea varieties using the hybrid model.</p>
Full article ">Figure 2
<p>Certified chickpea varieties used in the study.</p>
Full article ">Figure 3
<p>Image capturing system for chickpea seeds [<a href="#B43-applsci-15-01334" class="html-bibr">43</a>].</p>
Full article ">Figure 4
<p>ROC curves and AUC values of all models: (<b>a</b>) training phase and (<b>b</b>) test phase.</p>
Full article ">
13 pages, 1206 KiB  
Article
Machine Learning-Based Spectral Analyses for Camellia japonica Cultivar Identification
by Pedro Miguel Rodrigues and Clara Sousa
Molecules 2025, 30(3), 546; https://doi.org/10.3390/molecules30030546 - 25 Jan 2025
Viewed by 533
Abstract
Camellia japonica is a plant species with high cultural and biological relevance. Besides being used as an ornamental plant species, C. japonica has relevant biological properties. Due to hybridization, thousands of cultivars are known, and their accurate identification is mandatory. Infrared spectroscopy is [...] Read more.
Camellia japonica is a plant species with high cultural and biological relevance. Besides being used as an ornamental plant species, C. japonica has relevant biological properties. Due to hybridization, thousands of cultivars are known, and their accurate identification is mandatory. Infrared spectroscopy is currently recognized as an accurate and rapid technique for species and/or subspecies identifications, including in plants. However, selecting proper analysis tools (spectra pre-processing, feature selection, and chemometric models) highly impacts the accuracy of such identifications. This study tests the impact of two distinct machine learning-based approaches for discriminating C. japonica cultivars using near-infrared (NIR) and Fourier transform infrared (FTIR) spectroscopies. Leaves infrared spectra (NIR—obtained in a previous study; FTIR—obtained herein) of 15 different C. japonica cultivars (38 plants) were modeled and analyzed via different machine learning-based approaches (Approach 1 and Approach 2), each combining a feature selection method plus a classifier application. Regarding Approach 1, NIR spectroscopy emerged as the most effective technique for predicting C. japonica cultivars, achieving 81.3% correct cultivar assignments. However, Approach 2 obtained the best results with FTIR spectroscopy data, achieving a perfect 100.0% accuracy in cultivar assignments. When comparing both approaches, Approach 2 also improved the results for NIR data, increasing the correct cultivar predictions by nearly 13%. The results obtained in this study highlight the importance of chemometric tools in analyzing infrared data. The choice of a specific data analysis approach significantly affects the accuracy of the technique. Moreover, the same approach can have varying impacts on different techniques. Therefore, it is not feasible to establish a universal data analysis approach, even for very similar datasets from comparable analytical techniques. Full article
Show Figures

Figure 1

Figure 1
<p><span class="html-italic">C. japonica</span> air-dried leaves FTIR-ATR spectra (mean spectra of each cultivar).</p>
Full article ">Figure 2
<p>Data analysis and prediction workflow. The Approach 1 workflow for NIR Data (Sousa et al. 2019) can be found at [<a href="#B5-molecules-30-00546" class="html-bibr">5</a>].</p>
Full article ">Figure 3
<p>The stratified k-fold strategy used for classifying data by ML models (Approach 2).</p>
Full article ">Figure 4
<p>Confusion matrices with prediction accuracy in percentage (%) of the discrimination processes per each approach and used data modality (NIR and FTIR-ATR). (<b>a</b>) Discrimination results obtained in Sousa et al. 2019 study date from [<a href="#B5-molecules-30-00546" class="html-bibr">5</a>]; (<b>b</b>) NIR—Approach 2: GaussianNB discrimination model (10-fold SCV); 13 PCA components of 710 frequency bins selected by FDR forward selection. (<b>c</b>) FTIR-ATR—Approach 1: PLSDA discrimination model [17 LVs; 1800–900 cm<sub>−1</sub>; pre-processing: SNV+SavGol(15,2,2)]. (<b>d</b>) FTIR—Approach 2: BaggingClassifier discrimination model (10-fold SCV); 7 PCA components of 640 frequency bins selected by FER forward selection. Ab—Albino botti; Ap—Alba plena; Algp—Augusto leal gouveia pinto; Bm—Bella milanese; Bp—Bella portuense; Ca—Camurça; Co—Colletti; Cb—Conde do bonfim; Dn—Duchesse de nassau; Ep—Etoile polaire; Fa—Fimbria alba; MI—Maria irene; Rb—Roi des belges; Smb—Saudade martins branco; S—Sophia.</p>
Full article ">Figure 4 Cont.
<p>Confusion matrices with prediction accuracy in percentage (%) of the discrimination processes per each approach and used data modality (NIR and FTIR-ATR). (<b>a</b>) Discrimination results obtained in Sousa et al. 2019 study date from [<a href="#B5-molecules-30-00546" class="html-bibr">5</a>]; (<b>b</b>) NIR—Approach 2: GaussianNB discrimination model (10-fold SCV); 13 PCA components of 710 frequency bins selected by FDR forward selection. (<b>c</b>) FTIR-ATR—Approach 1: PLSDA discrimination model [17 LVs; 1800–900 cm<sub>−1</sub>; pre-processing: SNV+SavGol(15,2,2)]. (<b>d</b>) FTIR—Approach 2: BaggingClassifier discrimination model (10-fold SCV); 7 PCA components of 640 frequency bins selected by FER forward selection. Ab—Albino botti; Ap—Alba plena; Algp—Augusto leal gouveia pinto; Bm—Bella milanese; Bp—Bella portuense; Ca—Camurça; Co—Colletti; Cb—Conde do bonfim; Dn—Duchesse de nassau; Ep—Etoile polaire; Fa—Fimbria alba; MI—Maria irene; Rb—Roi des belges; Smb—Saudade martins branco; S—Sophia.</p>
Full article ">Figure 5
<p>ROC curves of various applied approaches, highlighting the mean AUC. (<b>a</b>) ROC curve—discrimination results obtained in Sousa et al. 2019 study [<a href="#B5-molecules-30-00546" class="html-bibr">5</a>]. (<b>b</b>) ROC curve NIR—Approach 2. (<b>c</b>) ROC curve FTIR-ATR—Approach 1. (<b>d</b>) ROC curve FTIR-ATR—Approach 2.</p>
Full article ">
42 pages, 11529 KiB  
Article
A Novel Evolutionary Deep Learning Approach for PM2.5 Prediction Using Remote Sensing and Spatial–Temporal Data: A Case Study of Tehran
by Mehrdad Kaveh, Mohammad Saadi Mesgari and Masoud Kaveh
ISPRS Int. J. Geo-Inf. 2025, 14(2), 42; https://doi.org/10.3390/ijgi14020042 - 23 Jan 2025
Viewed by 625
Abstract
Forecasting particulate matter with a diameter of 2.5 μm (PM2.5) is critical due to its significant effects on both human health and the environment. While ground-based pollution measurement stations provide highly accurate PM2.5 data, their limited number and geographic coverage [...] Read more.
Forecasting particulate matter with a diameter of 2.5 μm (PM2.5) is critical due to its significant effects on both human health and the environment. While ground-based pollution measurement stations provide highly accurate PM2.5 data, their limited number and geographic coverage present significant challenges. Recently, the use of aerosol optical depth (AOD) has emerged as a viable alternative for estimating PM2.5 levels, offering a broader spatial coverage and higher resolution. Concurrently, long short-term memory (LSTM) models have shown considerable promise in enhancing air quality predictions, often outperforming other prediction techniques. To address these challenges, this study leverages geographic information systems (GIS), remote sensing (RS), and a hybrid LSTM architecture to predict PM2.5 concentrations. Training LSTM models, however, is an NP-hard problem, with gradient-based methods facing limitations such as getting trapped in local minima, high computational costs, and the need for continuous objective functions. To overcome these issues, we propose integrating the novel orchard algorithm (OA) with LSTM to optimize air pollution forecasting. This paper utilizes meteorological data, topographical features, PM2.5 pollution levels, and satellite imagery from the city of Tehran. Data preparation processes include noise reduction, spatial interpolation, and addressing missing data. The performance of the proposed OA-LSTM model is compared to five advanced machine learning (ML) algorithms. The proposed OA-LSTM model achieved the lowest root mean square error (RMSE) value of 3.01 µg/m3 and the highest coefficient of determination (R2) value of 0.88, underscoring its effectiveness compared to other models. This paper employs a binary OA method for sensitivity analysis, optimizing feature selection by minimizing prediction error while retaining critical predictors through a penalty-based objective function. The generated maps reveal higher PM2.5 concentrations in autumn and winter compared to spring and summer, with northern and central areas showing the highest pollution levels. Full article
Show Figures

Figure 1

Figure 1
<p>Workflow of the proposed model for PM<sub>2.5</sub> prediction.</p>
Full article ">Figure 2
<p>Overview of the study area: (<b>a</b>) global map highlighting Iran; (<b>b</b>) map of Tehran province indicating the study region; and (<b>c</b>) detailed map of Tehran city showing pollution and meteorological monitoring stations along with elevation data.</p>
Full article ">Figure 3
<p>Histogram and summary statistics of variables in the sample dataset (<span class="html-italic">S</span> = 8106).</p>
Full article ">Figure 4
<p>Time series of the refined PM<sub>2.5</sub> data.</p>
Full article ">Figure 5
<p>Time series of the AOD data: (<b>a</b>) raw data; (<b>b</b>) refined data.</p>
Full article ">Figure 6
<p>Time series of the refined ground-based meteorological data: (<b>a</b>) minimum temperature; (<b>b</b>) maximum temperature; (<b>c</b>) wind speed; (<b>d</b>) wind direction; (<b>e</b>) humidity; and (<b>f</b>) air pressure.</p>
Full article ">Figure 7
<p>Example of cutting operator in proposed OA.</p>
Full article ">Figure 8
<p>The chain-like structure of the standard LSTM.</p>
Full article ">Figure 9
<p>The structure of the proposed OA-LSTM.</p>
Full article ">Figure 10
<p>Example of the OA operators for optimizing LSTM weights and biases.</p>
Full article ">Figure 11
<p>Scatter plot of proposed: (<b>a</b>) OA-LSTM; (<b>b</b>) LSTM; (<b>c</b>) RNN; (<b>d</b>) DNN; (<b>e</b>) RF; and (<b>f</b>) SVM.</p>
Full article ">Figure 12
<p>The convergence trend of proposed models based on the RMSE metric.</p>
Full article ">Figure 13
<p>Spatial distribution of observed PM<sub>2.5</sub> concentrations in (<b>a</b>) August 2016 (Wednesday, summer) and (<b>b</b>) December 2016 (Friday, winter).</p>
Full article ">Figure 14
<p>Spatial distribution of estimated PM<sub>2.5</sub> concentrations in August 2016 (Wednesday, summer): (<b>a</b>) OA-LSTM; (<b>b</b>) LSTM; (<b>c</b>) RNN; (<b>d</b>) DNN; (<b>e</b>) RF; and (<b>f</b>) SVM.</p>
Full article ">
17 pages, 4218 KiB  
Article
Operational Robustness of Amino Acid Recognition via Transverse Tunnelling Current Across Metallic Graphene Nano-Ribbon Electrodes: The Pro-Ser Case
by Giuseppe Zollo
Computation 2025, 13(2), 22; https://doi.org/10.3390/computation13020022 - 21 Jan 2025
Viewed by 466
Abstract
Asymmetric cove-edged graphene nano-ribbons were employed as metallic electrodes in a hybrid gap device structure with zig-zag graphene nano-ribbons terminations for amino acid recognition and peptide sequencing. On a theoretical basis, amino acid recognition is attained by calculating, using the non equilibrium Green [...] Read more.
Asymmetric cove-edged graphene nano-ribbons were employed as metallic electrodes in a hybrid gap device structure with zig-zag graphene nano-ribbons terminations for amino acid recognition and peptide sequencing. On a theoretical basis, amino acid recognition is attained by calculating, using the non equilibrium Green function scheme based on density functional theory, the transversal tunnelling current flowing across the gap device during the peptide translocation through the device. The reliability and robustness of this sequencing method versus relevant operations parameters, such as the bias, the gap size, and small perturbations of the atomistic structures, are studied for the paradigmatic case of Pro-Ser model peptide. I evidence that the main features of the tunnelling signal, that allow the recognition, survive for all of the operational conditions explored. I also evidence a sort of geometrical selective sensitivity of the hybrid cove-edged graphene nano-ribbons versus the bias that should be carefully considered for recognition. Full article
(This article belongs to the Section Computational Chemistry)
Show Figures

Figure 1

Figure 1
<p>8AsCEZGNR−6ZGNR nanogap device. Top view (<b>upper</b> panel) and side view (<b>lower</b> panel). In blue and orange, respectively, the right positive and the left negative electrode regions. In the middle, the device region. The peptide is translocated across the nano-pore (side view) and the tunnelling current flowing across the gap is collected at the electrodes. Carbon, hydrogen, oxygen, and nitrogen atoms are, respectively, grey, white, red, and blue. The green arrow indicates the translocation direction of the peptide.</p>
Full article ">Figure 2
<p>Pro-Ser tunnelling currents obtained for relaxed configurations with different force threshold values.</p>
Full article ">Figure 3
<p>Grouped bond currents for two relevant configurations, namely <math display="inline"><semantics> <mrow> <msub> <mi>C</mi> <mi>α</mi> </msub> <msub> <mi>H</mi> <mrow> <mi>S</mi> <mi>e</mi> <mi>r</mi> </mrow> </msub> <mo>−</mo> <mn>1</mn> </mrow> </semantics></math> and <math display="inline"><semantics> <mrow> <msub> <mi>C</mi> <mi>α</mi> </msub> <msub> <mi>H</mi> <mrow> <mi>P</mi> <mi>r</mi> <mi>o</mi> </mrow> </msub> </mrow> </semantics></math>, relaxed with a force threshold of <math display="inline"><semantics> <mrow> <msub> <mi>f</mi> <mrow> <mi>t</mi> <mi>h</mi> <mi>r</mi> </mrow> </msub> <mo>=</mo> <mn>0.2</mn> </mrow> </semantics></math> eV/Å and <math display="inline"><semantics> <mrow> <msub> <mi>f</mi> <mrow> <mi>t</mi> <mi>h</mi> <mi>r</mi> </mrow> </msub> <mo>=</mo> <mn>0.2</mn> </mrow> </semantics></math> eV/Å (<b>a</b>). I report the corresponding atomistic configurations for <math display="inline"><semantics> <mrow> <msub> <mi>f</mi> <mrow> <mi>t</mi> <mi>h</mi> <mi>r</mi> </mrow> </msub> <mo>=</mo> <mn>0.2</mn> </mrow> </semantics></math> eV/Å (<b>b</b>,<b>d</b>) and for <math display="inline"><semantics> <mrow> <msub> <mi>f</mi> <mrow> <mi>t</mi> <mi>h</mi> <mi>r</mi> </mrow> </msub> <mo>=</mo> <mn>1.0</mn> </mrow> </semantics></math> eV/Å (<b>c</b>,<b>e</b>).</p>
Full article ">Figure 4
<p>Tunnelling current of Pro-Ser for gap size <math display="inline"><semantics> <mrow> <msub> <mi>d</mi> <mrow> <mi>g</mi> <mi>a</mi> <mi>p</mi> </mrow> </msub> <mo>=</mo> <mspace width="0.222222em"/> <mn>5</mn> <mspace width="3.33333pt"/> <mo>Å</mo> </mrow> </semantics></math>, force threshold tolerance <math display="inline"><semantics> <mrow> <msub> <mi>f</mi> <mrow> <mi>t</mi> <mi>o</mi> <mi>l</mi> </mrow> </msub> <mo>=</mo> <mspace width="0.277778em"/> <mn>0.2</mn> <mspace width="0.277778em"/> <mi>eV</mi> <mo>/</mo> <mo>Å</mo> </mrow> </semantics></math>, and with variable bias in the range (0.1 V <math display="inline"><semantics> <mrow> <mo>≤</mo> <msub> <mi>V</mi> <mrow> <mi>b</mi> <mi>i</mi> <mi>a</mi> <mi>s</mi> </mrow> </msub> <mo>≤</mo> <mn>1.0</mn> </mrow> </semantics></math> V). In the inset is shown a magnified view of the Pro signal for bias values (0.1 V <math display="inline"><semantics> <mrow> <mo>≤</mo> <msub> <mi>V</mi> <mrow> <mi>b</mi> <mi>i</mi> <mi>a</mi> <mi>s</mi> </mrow> </msub> <mo>≤</mo> <mn>0.5</mn> </mrow> </semantics></math> V) to better evidence its rise with the bias.</p>
Full article ">Figure 5
<p>Behaviour of the tunnelling current main peaks versus the bias in the range (0.1 V <math display="inline"><semantics> <mrow> <mo>≤</mo> <msub> <mi>V</mi> <mrow> <mi>b</mi> <mi>i</mi> <mi>a</mi> <mi>s</mi> </mrow> </msub> <mo>≤</mo> </mrow> </semantics></math> 1.0 V) for the Pro-Ser model peptide with gap size <math display="inline"><semantics> <mrow> <msub> <mi>d</mi> <mrow> <mi>g</mi> <mi>a</mi> <mi>p</mi> </mrow> </msub> <mo>=</mo> <mspace width="0.222222em"/> <mn>5</mn> <mspace width="3.33333pt"/> <mo>Å</mo> </mrow> </semantics></math>, force threshold tolerance <math display="inline"><semantics> <mrow> <msub> <mi>f</mi> <mrow> <mi>t</mi> <mi>o</mi> <mi>l</mi> </mrow> </msub> <mo>=</mo> <mspace width="0.277778em"/> <mn>0.2</mn> </mrow> </semantics></math> eV/Å.</p>
Full article ">Figure 6
<p>Grouped bond currents of the Pro-Ser current main peaks. Current is injected from the positive left electrode (<b>a</b>) and collected into the right negative electrode (<b>b</b>). The grouped bond currents are calculated for the reference bias of <math display="inline"><semantics> <mrow> <msub> <mi>V</mi> <mrow> <mi>b</mi> <mi>i</mi> <mi>a</mi> <mi>s</mi> </mrow> </msub> <mo>=</mo> <mn>1</mn> </mrow> </semantics></math> V and for the bias values corresponding to the maximum of the three main peaks, as shown in <a href="#computation-13-00022-f005" class="html-fig">Figure 5</a>. The gap size is <math display="inline"><semantics> <mrow> <msub> <mi>d</mi> <mrow> <mi>g</mi> <mi>a</mi> <mi>p</mi> </mrow> </msub> <mo>=</mo> <mspace width="0.222222em"/> <mn>5</mn> <mspace width="3.33333pt"/> <mo>Å</mo> </mrow> </semantics></math>, and the force threshold tolerance <math display="inline"><semantics> <mrow> <msub> <mi>f</mi> <mrow> <mi>t</mi> <mi>o</mi> <mi>l</mi> </mrow> </msub> <mo>=</mo> <mspace width="0.277778em"/> <mn>0.2</mn> </mrow> </semantics></math> eV/Å.</p>
Full article ">Figure 7
<p><math display="inline"><semantics> <mrow> <mi>S</mi> <msub> <mi>C</mi> <mrow> <mi>S</mi> <mi>e</mi> <mi>r</mi> </mrow> </msub> </mrow> </semantics></math> and <math display="inline"><semantics> <mrow> <mi>S</mi> <msub> <mi>C</mi> <mrow> <mi>P</mi> <mi>r</mi> <mi>o</mi> </mrow> </msub> </mrow> </semantics></math> contributions to the <math display="inline"><semantics> <mrow> <mi>C</mi> <mi>B</mi> <mi>S</mi> <msub> <mi>N</mi> <mrow> <mi>S</mi> <mi>e</mi> <mi>r</mi> </mrow> </msub> <mo>−</mo> <mn>1</mn> </mrow> </semantics></math> peak versus the bias. In the inset is shown the <math display="inline"><semantics> <mrow> <mi>C</mi> <mi>B</mi> <mi>S</mi> <msub> <mi>N</mi> <mrow> <mi>S</mi> <mi>e</mi> <mi>r</mi> </mrow> </msub> <mo>−</mo> <mn>1</mn> </mrow> </semantics></math> configuration, where the arrows indicate the side chains through which the tunnelling current flows.</p>
Full article ">Figure 8
<p>Projections of the transmission amplitude between molecular orbitals of the right (incoming electrons) and the left hybrid nano-ribbons in the device region for <math display="inline"><semantics> <mrow> <mi>C</mi> <mi>B</mi> <mi>S</mi> <msub> <mi>N</mi> <mrow> <mi>S</mi> <mi>e</mi> <mi>r</mi> </mrow> </msub> <mo>−</mo> <mn>1</mn> </mrow> </semantics></math> at <math display="inline"><semantics> <mrow> <msub> <mi>V</mi> <mrow> <mi>b</mi> <mi>i</mi> <mi>a</mi> <mi>s</mi> </mrow> </msub> <mo>=</mo> <mn>1</mn> </mrow> </semantics></math> V and the <math display="inline"><semantics> <mrow> <mi>C</mi> <mi>B</mi> <mi>S</mi> <msub> <mi>N</mi> <mrow> <mi>S</mi> <mi>e</mi> <mi>r</mi> </mrow> </msub> <mo>−</mo> <mn>1</mn> </mrow> </semantics></math>. In the inset are shown the left and right eigenchannels at <math display="inline"><semantics> <mrow> <mi>E</mi> <mo>=</mo> <mn>0.09</mn> </mrow> </semantics></math> eV, where the transmission has a maximum.</p>
Full article ">Figure 9
<p>Projections of the transmission amplitude between molecular orbitals of the right (incoming electrons) and the left hybrid nano-ribbons in the device region for <math display="inline"><semantics> <mrow> <mi>C</mi> <mi>B</mi> <mi>S</mi> <msub> <mi>N</mi> <mrow> <mi>S</mi> <mi>e</mi> <mi>r</mi> </mrow> </msub> <mo>−</mo> <mn>1</mn> </mrow> </semantics></math> at <math display="inline"><semantics> <mrow> <msub> <mi>V</mi> <mrow> <mi>b</mi> <mi>i</mi> <mi>a</mi> <mi>s</mi> </mrow> </msub> <mo>=</mo> <mn>0.4</mn> </mrow> </semantics></math> V. In the insets are shown the left and right eigenchannels at <math display="inline"><semantics> <mrow> <mi>E</mi> <mo>=</mo> <mn>0.106</mn> </mrow> </semantics></math> eV, where the transmission has a maximum.</p>
Full article ">Figure 10
<p>Pro-Ser tunnelling current for different gap sizes. The tunnelling current is in <math display="inline"><semantics> <mrow> <mi>f</mi> <mi>A</mi> </mrow> </semantics></math>, and the current is reported in logarithmic scale. The adopted force threshold and bias are, respectively, <math display="inline"><semantics> <mrow> <msub> <mi>f</mi> <mrow> <mi>t</mi> <mi>h</mi> <mi>r</mi> </mrow> </msub> <mo>=</mo> <mn>0.2</mn> </mrow> </semantics></math> eV/Å and <math display="inline"><semantics> <mrow> <msub> <mi>V</mi> <mrow> <mi>b</mi> <mi>i</mi> <mi>a</mi> <mi>s</mi> </mrow> </msub> <mo>=</mo> <mn>1</mn> </mrow> </semantics></math> V.</p>
Full article ">Figure 11
<p>Grouped bond current analysis injected from the right positive lead into the peptide for the <math display="inline"><semantics> <mrow> <msub> <mi>C</mi> <mi>α</mi> </msub> <msub> <mi>H</mi> <mrow> <mi>P</mi> <mi>r</mi> <mi>o</mi> </mrow> </msub> </mrow> </semantics></math> and <math display="inline"><semantics> <mrow> <mi>N</mi> <msub> <mi>H</mi> <mrow> <mi>S</mi> <mi>e</mi> <mi>r</mi> </mrow> </msub> </mrow> </semantics></math> configurations with a gap size of <math display="inline"><semantics> <mrow> <msub> <mi>d</mi> <mrow> <mi>g</mi> <mi>a</mi> <mi>p</mi> </mrow> </msub> <mo>=</mo> <mn>7</mn> <mspace width="0.277778em"/> <mo>Å</mo> </mrow> </semantics></math> and <math display="inline"><semantics> <mrow> <msub> <mi>V</mi> <mrow> <mi>b</mi> <mi>i</mi> <mi>a</mi> <mi>s</mi> </mrow> </msub> <mo>=</mo> <mn>1</mn> </mrow> </semantics></math> V, <math display="inline"><semantics> <mrow> <msub> <mi>f</mi> <mrow> <mi>t</mi> <mi>o</mi> <mi>l</mi> </mrow> </msub> <mo>=</mo> <mn>0.2</mn> </mrow> </semantics></math> eV/Å.</p>
Full article ">
24 pages, 3877 KiB  
Article
A Hybrid Approach for Sports Activity Recognition Using Key Body Descriptors and Hybrid Deep Learning Classifier
by Muhammad Tayyab, Sulaiman Abdullah Alateyah, Mohammed Alnusayri, Mohammed Alatiyyah, Dina Abdulaziz AlHammadi, Ahmad Jalal and Hui Liu
Sensors 2025, 25(2), 441; https://doi.org/10.3390/s25020441 - 13 Jan 2025
Viewed by 634
Abstract
This paper presents an approach for event recognition in sequential images using human body part features and their surrounding context. Key body points were approximated to track and monitor their presence in complex scenarios. Various feature descriptors, including MSER (Maximally Stable Extremal Regions), [...] Read more.
This paper presents an approach for event recognition in sequential images using human body part features and their surrounding context. Key body points were approximated to track and monitor their presence in complex scenarios. Various feature descriptors, including MSER (Maximally Stable Extremal Regions), SURF (Speeded-Up Robust Features), distance transform, and DOF (Degrees of Freedom), were applied to skeleton points, while BRIEF (Binary Robust Independent Elementary Features), HOG (Histogram of Oriented Gradients), FAST (Features from Accelerated Segment Test), and Optical Flow were used on silhouettes or full-body points to capture both geometric and motion-based features. Feature fusion was employed to enhance the discriminative power of the extracted data and the physical parameters calculated by different feature extraction techniques. The system utilized a hybrid CNN (Convolutional Neural Network) + RNN (Recurrent Neural Network) classifier for event recognition, with Grey Wolf Optimization (GWO) for feature selection. Experimental results showed significant accuracy, achieving 98.5% on the UCF-101 dataset and 99.2% on the YouTube dataset. Compared to state-of-the-art methods, our approach achieved better performance in event recognition. Full article
(This article belongs to the Section Intelligent Sensors)
Show Figures

Figure 1

Figure 1
<p>Proposed architecture for event classification.</p>
Full article ">Figure 2
<p>The pre-processing steps are as follows: (<b>a</b>) raw frame extracted from a video of Clean &amp; Jerk, (<b>b</b>) background noise removed, (<b>c</b>) sharpness reduced and edges smoothed, and (<b>d</b>) 3D image converted to 2D.</p>
Full article ">Figure 3
<p>Binary images of humans after silhouette extraction: (<b>a</b>) UCF-101; (<b>b</b>) YouTube, illustrations of human pose estimation by key points; (<b>c</b>) UCF-101; (<b>d</b>) YouTube.</p>
Full article ">Figure 4
<p>Example of SURF and those circles are showing the extracted keypoints: (<b>a</b>,<b>b</b>) UCF-101 and (<b>c</b>,<b>d</b>) YouTube.</p>
Full article ">Figure 5
<p>MSER point extraction and the green blocks are showing the stable regions: (<b>a</b>,<b>b</b>) UCF-101; (<b>c</b>,<b>d</b>) YouTube.</p>
Full article ">Figure 6
<p>Finding degree points and distances while blue color semi circles are showing the angle between joints: (<b>a</b>,<b>b</b>) UCF-101; (<b>c</b>,<b>d</b>) YouTube.</p>
Full article ">Figure 7
<p>Finding distance transform points and the color scheme is showing intensity: (<b>a</b>,<b>b</b>) UCF-101; (<b>c</b>,<b>d</b>) YouTube.</p>
Full article ">Figure 8
<p>BRIEF feature points: (<b>a</b>,<b>b</b>) UCF-101; (<b>c</b>,<b>d</b>) YouTube.</p>
Full article ">Figure 9
<p>ORB features extracted: (<b>a</b>,<b>b</b>) UCF-101; (<b>c</b>,<b>d</b>) YouTube.</p>
Full article ">Figure 10
<p>HOG gradient points: (<b>a</b>,<b>b</b>) UCF-101; (<b>c</b>,<b>d</b>) YouTube.</p>
Full article ">Figure 11
<p>FAST feature points: (<b>a</b>,<b>b</b>) UCF-101; (<b>c</b>,<b>d</b>) YouTube.</p>
Full article ">Figure 12
<p>Feature fusion graphical representation: (<b>a</b>) full-body points (silhouettes); (<b>b</b>) pose estimation points.</p>
Full article ">Figure 13
<p>Flow graph of Grey Wolf Optimization points.</p>
Full article ">Figure 14
<p>Exemplary structure of hybrid classifier.</p>
Full article ">Figure 15
<p>Failure cases of background removal during our experiments: (<b>a</b>) basketball dunk; (<b>b</b>) boxing.</p>
Full article ">
Back to TopTop