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Search Results (2,931)

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11 pages, 978 KiB  
Article
Estimating Progression-Free Survival in Patients with Primary High-Grade Glioma Using Machine Learning
by Agnieszka Kwiatkowska-Miernik, Piotr Gustaw Wasilewski, Bartosz Mruk, Katarzyna Sklinda, Maciej Bujko and Jerzy Walecki
J. Clin. Med. 2024, 13(20), 6172; https://doi.org/10.3390/jcm13206172 - 16 Oct 2024
Viewed by 314
Abstract
Background/Objectives: High-grade gliomas are the most common primary malignant brain tumors in adults. These neoplasms remain predominantly incurable due to the genetic diversity within each tumor, leading to varied responses to specific drug therapies. With the advent of new targeted and immune [...] Read more.
Background/Objectives: High-grade gliomas are the most common primary malignant brain tumors in adults. These neoplasms remain predominantly incurable due to the genetic diversity within each tumor, leading to varied responses to specific drug therapies. With the advent of new targeted and immune therapies, which have demonstrated promising outcomes in clinical trials, there is a growing need for image-based techniques to enable early prediction of treatment response. This study aimed to evaluate the potential of radiomics and artificial intelligence implementation in predicting progression-free survival (PFS) in patients with highest-grade glioma (CNS WHO 4) undergoing a standard treatment plan. Methods: In this retrospective study, prediction models were developed in a cohort of 51 patients with pathologically confirmed highest-grade glioma (CNS WHO 4) from the authors’ institution and the repository of the Cancer Imaging Archive (TCIA). Only patients with confirmed recurrence after complete tumor resection with adjuvant radiotherapy and chemotherapy with temozolomide were included. For each patient, 109 radiomic features of the tumor were obtained from a preoperative magnetic resonance imaging (MRI) examination. Four clinical features were added manually—sex, weight, age at the time of diagnosis, and the lobe of the brain where the tumor was located. The data label was the time to recurrence, which was determined based on follow-up MRI scans. Artificial intelligence algorithms were built to predict PFS in the training set (n = 75%) and then validate it in the test set (n = 25%). The performance of each model in both the training and test datasets was assessed using mean absolute percentage error (MAPE). Results: In the test set, the random forest model showed the highest predictive performance with 1-MAPE = 92.27% and a C-index of 0.9544. The decision tree, gradient booster, and artificial neural network models showed slightly lower effectiveness with 1-MAPE of 88.31%, 80.21%, and 91.29%, respectively. Conclusions: Four of the six models built gave satisfactory results. These results show that artificial intelligence models combined with radiomic features could be useful for predicting the progression-free survival of high-grade glioma patients. This could be beneficial for risk stratification of patients, enhancing the potential for personalized treatment plans and improving overall survival. Further investigation is necessary with an expanded sample size and external multicenter validation. Full article
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<p>Assuming that each small square represents a pixel, the morphological and first-order features of images (<b>A</b>,<b>B</b>) would be the same, but the images differ in texture.</p>
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<p>Study flowchart. (<b>a</b>) Magnetic resonance (MR) imaging; the study is based on contrast-enhanced T1—w images. (<b>b</b>) Identification of a region of interest (ROI) and semi-automatic image segmentation. (<b>c</b>) Normalization and radiomic feature extraction from the defined ROI; 109 radiomic features were obtained in the study. (<b>d</b>) Data preprocessing and analysis; five different machine learning (ML) models were trained on the received data (AI—artificial intelligence, DL—deep learning). (<b>e</b>) Results.</p>
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<p>Flowchart of the patient selection process.</p>
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<p>Glioma CNS WHO 4 in the left parietal lobe. T1-weighted image after administration of contrast agent; the blue color was used to mark the tumor segmented by the semi-automated method.</p>
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<p>Kaplan–Meier curve of PFS for patients in the study group.</p>
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<p>Performance of the five models for predicting the PFS presented using 1-MAPE.</p>
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<p>Kaplan–Meier curve of predicted PFS for the test set by the random forest model marked in blue and Kaplan–Meier curve of PFS for patients in the study group marked in orange.</p>
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24 pages, 4102 KiB  
Article
Plastic Constitutive Training Method for Steel Based on a Recurrent Neural Network
by Tianwei Wang, Yongping Yu, Haisong Luo and Zhigang Wang
Buildings 2024, 14(10), 3279; https://doi.org/10.3390/buildings14103279 - 16 Oct 2024
Viewed by 290
Abstract
The deep learning steel plastic constitutive model training method was studied based on the recurrent neural network (RNN) model to improve the allocative efficiency of the deep learning steel plastic constitutive model and promote its application in practical engineering. Two linear hardening constitutive [...] Read more.
The deep learning steel plastic constitutive model training method was studied based on the recurrent neural network (RNN) model to improve the allocative efficiency of the deep learning steel plastic constitutive model and promote its application in practical engineering. Two linear hardening constitutive datasets of steel were constructed using the Gaussian stochastic process. The RNN, long short-term memory (LSTM), and gated recurrent unit (GRU) were used as models for training. The effects of the data pre-processing method, neural network structure, and training method on the model training were analyzed. The prediction ability of the model for different scale series and the corresponding data demand were evaluated. The results show that LSTM and the GRU are more suitable for stress–strain prediction. The marginal effect of the stacked neural network depth and number gradually decreases, and the hysteresis curve can be accurately predicted by a two-layer RNN. The optimal structure of the two models is A50-100 and B150-150. The prediction accuracy of the models increased with the decrease in batch size and the increase in training batch, and the training time also increased significantly. The decay learning rate method could balance the prediction accuracy and training time, and the optimal initial learning rate, batch size, and training batch were 0.001, 60, and 100, respectively. The deep learning plastic constitutive model based on the optimal parameters can accurately predict the hysteresis curve of steel, and the prediction abilities of the GRU are 6.13, 6.7, and 3.3 times those of LSTM in short, medium, and long sequences, respectively. Full article
(This article belongs to the Special Issue Intelligent Design, Green Construction, and Innovation)
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<p>Traditional constitutive model construction and deep learning constitutive model construction flow.</p>
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<p>Linear hardening constitutive model: (<b>a</b>) linear isotropic hardening constitutive; (<b>b</b>) linear kinematic hardening constitutive.</p>
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<p>Original RNN structure.</p>
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<p>LSTM network structure.</p>
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<p>GRU network structure.</p>
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<p>Comparison of data pre-processing methods.</p>
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<p>The effect of the number of neurons on the model: (<b>a</b>) the effect on the model performance; (<b>b</b>) the effect on the training time.</p>
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<p>Influence of hidden layers on model performance: (<b>a</b>) influence on model performance; (<b>b</b>) influence on training time.</p>
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<p>Influence of neural network topology on model performance and training time: (<b>a</b>) influence on model performance; (<b>b</b>) influence on training time.</p>
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<p>Effects of training frequency and training batches on the model: (<b>a</b>) LSTM; (<b>b</b>) GRU.</p>
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<p>Influence of learning rate on the model: (<b>a</b>) LSTM; (<b>b</b>) GRU.</p>
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<p>Influence of learning rate on the number of iterations.</p>
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<p>Model prediction effects of different dataset sizes: (<b>a</b>–<b>g</b>) prediction curve of LSTM when the dataset size is 500–10,000; (<b>h</b>–<b>n</b>) prediction curve of GRU when the dataset size is 500–10,000.</p>
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<p>Model prediction effects of different dataset sizes: (<b>a</b>–<b>g</b>) prediction curve of LSTM when the dataset size is 500–10,000; (<b>h</b>–<b>n</b>) prediction curve of GRU when the dataset size is 500–10,000.</p>
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<p>Prediction capabilities of LSTM and GRU: (<b>a</b>) LSTM; (<b>b</b>) GRU.</p>
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<p>Prediction effect of the model: (<b>a</b>–<b>c</b>) linear isotropic constitutive hardening, and (<b>d</b>–<b>f</b>) linear kinematic constitutive hardening.</p>
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42 pages, 2931 KiB  
Review
Advances in Medical Image Segmentation: A Comprehensive Review of Traditional, Deep Learning and Hybrid Approaches
by Yan Xu, Rixiang Quan, Weiting Xu, Yi Huang, Xiaolong Chen and Fengyuan Liu
Bioengineering 2024, 11(10), 1034; https://doi.org/10.3390/bioengineering11101034 - 16 Oct 2024
Viewed by 364
Abstract
Medical image segmentation plays a critical role in accurate diagnosis and treatment planning, enabling precise analysis across a wide range of clinical tasks. This review begins by offering a comprehensive overview of traditional segmentation techniques, including thresholding, edge-based methods, region-based approaches, clustering, and [...] Read more.
Medical image segmentation plays a critical role in accurate diagnosis and treatment planning, enabling precise analysis across a wide range of clinical tasks. This review begins by offering a comprehensive overview of traditional segmentation techniques, including thresholding, edge-based methods, region-based approaches, clustering, and graph-based segmentation. While these methods are computationally efficient and interpretable, they often face significant challenges when applied to complex, noisy, or variable medical images. The central focus of this review is the transformative impact of deep learning on medical image segmentation. We delve into prominent deep learning architectures such as Convolutional Neural Networks (CNNs), Fully Convolutional Networks (FCNs), U-Net, Recurrent Neural Networks (RNNs), Adversarial Networks (GANs), and Autoencoders (AEs). Each architecture is analyzed in terms of its structural foundation and specific application to medical image segmentation, illustrating how these models have enhanced segmentation accuracy across various clinical contexts. Finally, the review examines the integration of deep learning with traditional segmentation methods, addressing the limitations of both approaches. These hybrid strategies offer improved segmentation performance, particularly in challenging scenarios involving weak edges, noise, or inconsistent intensities. By synthesizing recent advancements, this review provides a detailed resource for researchers and practitioners, offering valuable insights into the current landscape and future directions of medical image segmentation. Full article
(This article belongs to the Section Biosignal Processing)
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<p>Overview of traditional segmentation techniques in Session 2.</p>
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<p>Classification of clustering-based image segmentation methods.</p>
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<p>Hierarchical clustering dendrogram.</p>
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<p>Schematic representation of the relationship between image segmentation and graph partitioning. (<b>a</b>) Image; (<b>b</b>) graph; (<b>c</b>) graph partitioning; (<b>d</b>) image segmentation.</p>
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<p>Generic architecture of CNNs [<a href="#B93-bioengineering-11-01034" class="html-bibr">93</a>].</p>
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<p>The architecture of FCNs demonstrating the forward inference process that generates pixel-wise predictions and the backward learning process for updating weights during training.</p>
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<p>The structure of the U-Net [<a href="#B16-bioengineering-11-01034" class="html-bibr">16</a>].</p>
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<p>The structure of the GANs.</p>
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<p>A generic architecture of AEs.</p>
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23 pages, 1739 KiB  
Review
Utilising Artificial Intelligence to Predict Membrane Behaviour in Water Purification and Desalination
by Reza Shahouni, Mohsen Abbasi, Mahdieh Dibaj and Mohammad Akrami
Water 2024, 16(20), 2940; https://doi.org/10.3390/w16202940 (registering DOI) - 15 Oct 2024
Viewed by 348
Abstract
Water scarcity is a critical global issue, necessitating efficient water purification and desalination methods. Membrane separation methods are environmentally friendly and consume less energy, making them more economical compared to other desalination and purification methods. This survey explores the application of artificial intelligence [...] Read more.
Water scarcity is a critical global issue, necessitating efficient water purification and desalination methods. Membrane separation methods are environmentally friendly and consume less energy, making them more economical compared to other desalination and purification methods. This survey explores the application of artificial intelligence (AI) to predict membrane behaviour in water purification and desalination processes. Various AI platforms, including machine learning (ML) and artificial neural networks (ANNs), were utilised to model water flux, predict fouling behaviour, simulate micropollutant dynamics and optimise operational parameters. Specifically, models such as convolutional neural networks (CNNs), recurrent neural networks (RNNs) and support vector machines (SVMs) have demonstrated superior predictive capabilities in these applications. This review studies recent advancements, emphasising the superior predictive capabilities of AI models compared to traditional methods. Key findings include the development of AI models for various membrane separation techniques and the integration of AI concepts such as ML and ANNs to simulate membrane fouling, water flux and micropollutant behaviour, aiming to enhance wastewater treatment and optimise treatment and desalination processes. In conclusion, this review summarised the applications of AI in predicting the behaviour of membranes as well as their strengths, weaknesses and future directions of AI in membranes for water purification and desalination processes. Full article
(This article belongs to the Section Wastewater Treatment and Reuse)
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<p>AI algorithm in flux and fouling modelling in membranes.</p>
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<p>A basic ANN structure with commonly used inputs and outputs in membranes [<a href="#B69-water-16-02940" class="html-bibr">69</a>].</p>
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<p>The structure of ANN for predicting the water flux in membranes [<a href="#B100-water-16-02940" class="html-bibr">100</a>].</p>
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<p>Schematic diagram of the procedure of ML for predicting pollutants in membranes [<a href="#B108-water-16-02940" class="html-bibr">108</a>].</p>
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24 pages, 2131 KiB  
Article
Improving Text Classification in Agricultural Expert Systems with a Bidirectional Encoder Recurrent Convolutional Neural Network
by Xiaojuan Guo, Jianping Wang, Guohong Gao, Li Li, Junming Zhou and Yancui Li
Electronics 2024, 13(20), 4054; https://doi.org/10.3390/electronics13204054 (registering DOI) - 15 Oct 2024
Viewed by 357
Abstract
With the rapid development of internet and AI technologies, Agricultural Expert Systems (AESs) have become crucial for delivering technical support and decision-making in agricultural management. However, traditional natural language processing methods often struggle with specialized terminology and context, and they lack the adaptability [...] Read more.
With the rapid development of internet and AI technologies, Agricultural Expert Systems (AESs) have become crucial for delivering technical support and decision-making in agricultural management. However, traditional natural language processing methods often struggle with specialized terminology and context, and they lack the adaptability to handle complex text classifications. The diversity and evolving nature of agricultural texts make deep semantic understanding and integration of contextual knowledge especially challenging. To tackle these challenges, this paper introduces a Bidirectional Encoder Recurrent Convolutional Neural Network (AES-BERCNN) tailored for short-text classification in agricultural expert systems. We designed an Agricultural Text Encoder (ATE) with a six-layer transformer architecture to capture both preceding and following word information. A recursive convolutional neural network based on Gated Recurrent Units (GRUs) was also developed to merge contextual information and learn complex semantic features, which are then combined with the ATE output and refined through max-pooling to form the final feature representation. The AES-BERCNN model was tested on a self-constructed agricultural dataset, achieving an accuracy of 99.63% in text classification. Its generalization ability was further verified on the Tsinghua News dataset. Compared to other models such as TextCNN, DPCNN, BiLSTM, and BERT-based models, the AES-BERCNN shows clear advantages in agricultural text classification. This work provides precise and timely technical support for intelligent agricultural expert systems. Full article
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<p>Preprocessing and construction dataset.</p>
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<p>Structure of AES-BERCNN.</p>
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<p>Structure of ATE.</p>
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<p>Structure of the agricultural text classifier.</p>
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<p>The accuracy, loss, and time of comparative models on agricultural question training set: (<b>a</b>) accuracy comparison, (<b>b</b>) loss comparison, and (<b>c</b>) time comparison.</p>
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<p>Comparative model experimental results of precision, recall, and F1 on agricultural question test dataset: (<b>a</b>) precision comparison, (<b>b</b>) recall comparison, and (<b>c</b>) F1 comparison.</p>
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<p>Confusion matrix of classification effect of each model: (<b>a</b>) BiLSTM, (<b>b</b>) BiGRU, (<b>c</b>) TextCNN, (<b>d</b>) DPCNN, (<b>e</b>) BERT-TextCNN, (<b>f</b>) BERT-DPCNN, (<b>g</b>) BERT-BiLSTM, (<b>h</b>) BERT-BiGRU, (<b>i</b>) ATE-DPCNN, (<b>j</b>) ATE-TextCNN, (<b>k</b>) ATE-BiLSTM, (<b>l</b>) ATE-BiGRU, and (<b>m</b>) ATE-BERCNN.</p>
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<p>Confusion matrix of classification effect of each model: (<b>a</b>) BiLSTM, (<b>b</b>) BiGRU, (<b>c</b>) TextCNN, (<b>d</b>) DPCNN, (<b>e</b>) BERT-TextCNN, (<b>f</b>) BERT-DPCNN, (<b>g</b>) BERT-BiLSTM, (<b>h</b>) BERT-BiGRU, (<b>i</b>) ATE-DPCNN, (<b>j</b>) ATE-TextCNN, (<b>k</b>) ATE-BiLSTM, (<b>l</b>) ATE-BiGRU, and (<b>m</b>) ATE-BERCNN.</p>
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<p>The accuracy and loss of comparative models on Tsinghua training set: (<b>a</b>) accuracy comparison and (<b>b</b>) loss comparison.</p>
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18 pages, 5741 KiB  
Article
Advanced Predictive Structural Health Monitoring in High-Rise Buildings Using Recurrent Neural Networks
by Abbas Ghaffari, Yaser Shahbazi, Mohsen Mokhtari Kashavar, Mohammad Fotouhi and Siamak Pedrammehr
Buildings 2024, 14(10), 3261; https://doi.org/10.3390/buildings14103261 (registering DOI) - 15 Oct 2024
Viewed by 321
Abstract
This study proposes a machine learning (ML) model to predict the displacement response of high-rise structures under various vertical and lateral loading conditions. The study combined finite element analysis (FEA), parametric modeling, and a multi-objective genetic algorithm to create a robust and diverse [...] Read more.
This study proposes a machine learning (ML) model to predict the displacement response of high-rise structures under various vertical and lateral loading conditions. The study combined finite element analysis (FEA), parametric modeling, and a multi-objective genetic algorithm to create a robust and diverse dataset of loading scenarios for developing a predictive ML model. The ML model was trained using a recurrent neural network (RNN) with Long Short-Term Memory (LSTM) layers. The developed model demonstrated high accuracy in predicting time series of vertical, lateral (X), and lateral (Y) displacements. The training and testing results showed Mean Squared Errors (MSE) of 0.1796 and 0.0033, respectively, with R2 values of 0.8416 and 0.9939. The model’s predictions differed by only 0.93% from the actual vertical displacement values and by 4.55% and 7.35% for lateral displacements in the Y and X directions, respectively. The results demonstrate the model’s high accuracy and generalization ability, making it a valuable tool for structural health monitoring (SHM) in high-rise buildings. This research highlights the potential of ML to provide real-time displacement predictions under various load conditions, offering practical applications for ensuring the structural integrity and safety of high-rise buildings, particularly in high-risk seismic areas. Full article
(This article belongs to the Special Issue Autonomous Strategies for Structural Health Monitoring)
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<p>The high-rise structure modeled in Grasshopper and karamba3D: (<b>a</b>) top; (<b>b</b>) perspective; (<b>c</b>) right; and (<b>d</b>) front view.</p>
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<p>Flowchart of developed definition in grasshopper and karamba3D for data generation.</p>
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<p>Flowchart of the proposed framework to predict structure displacements.</p>
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<p>Loss charts of the developed ML model over 500 epochs: (<b>a</b>) training; and (<b>b</b>) validation.</p>
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<p>Residual values plotted for (<b>a</b>) training; and (<b>b</b>) test data for vertical displacement.</p>
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<p>Residual values plotted for (<b>a</b>) training; and (<b>b</b>) test data for lateral (X) displacement.</p>
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<p>Residual values plotted for (<b>a</b>) training; and (<b>b</b>) test data for lateral (Y) displacement.</p>
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<p>Residual values plotted for (<b>a</b>) training; and (<b>b</b>) test data for lateral (Y) displacement.</p>
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<p>The actual and predicted (<b>a</b>) vertical; (<b>b</b>) lateral (X); and (<b>c</b>) lateral (Y) displacement values.</p>
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<p>Actual vs. predicted displacement values over the entire structure height in each floor in X direction for six test cases: (<b>a</b>) actual vs. predicted values; (<b>b</b>) actual values; and (<b>c</b>) predicted values. Each colored line in the figures represents a test case.</p>
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<p>Actual vs. predicted displacement values over the entire structure height in each floor in Y direction for six test cases: (<b>a</b>) actual vs. predicted values; (<b>b</b>) actual values; and (<b>c</b>) predicted values. Each colored line in the figures represents a test case.</p>
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25 pages, 830 KiB  
Review
Current Status and Challenges and Future Trends of Deep Learning-Based Intrusion Detection Models
by Yuqiang Wu, Bailin Zou and Yifei Cao
J. Imaging 2024, 10(10), 254; https://doi.org/10.3390/jimaging10100254 - 14 Oct 2024
Viewed by 686
Abstract
With the advancement of deep learning (DL) technology, DL-based intrusion detection models have emerged as a focal point of research within the domain of cybersecurity. This paper provides an overview of the datasets frequently utilized in the research. This article presents an overview [...] Read more.
With the advancement of deep learning (DL) technology, DL-based intrusion detection models have emerged as a focal point of research within the domain of cybersecurity. This paper provides an overview of the datasets frequently utilized in the research. This article presents an overview of the widely utilized datasets in the research, establishing a basis for future investigation and analysis. The text subsequently summarizes the prevalent data preprocessing methods and feature engineering techniques utilized in intrusion detection. Following this, it provides a review of seven deep learning-based intrusion detection models, namely, deep autoencoders, deep belief networks, deep neural networks, convolutional neural networks, recurrent neural networks, generative adversarial networks, and transformers. Each model is examined from various dimensions, highlighting their unique architectures and applications within the context of cybersecurity. Furthermore, this paper broadens its scope to include intrusion detection techniques facilitated by the following two large-scale predictive models: the BERT series and the GPT series. These models, leveraging the power of transformers and attention mechanisms, have demonstrated remarkable capabilities in understanding and processing sequential data. In light of these findings, this paper concludes with a prospective outlook on future research directions. Four key areas have been identified for further research. By addressing these issues and advancing research in the aforementioned areas, this paper envisions a future in which DL-based intrusion detection systems are not only more accurate and efficient but also better aligned with the dynamic and evolving landscape of cybersecurity threats. Full article
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<p>Common types of network intrusions.</p>
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<p>Architecture of a TF-IDM.</p>
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22 pages, 2200 KiB  
Article
Intra- and Interpatient ECG Heartbeat Classification Based on Multimodal Convolutional Neural Networks with an Adaptive Attention Mechanism
by Ítalo Flexa Di Paolo and Adriana Rosa Garcez Castro
Appl. Sci. 2024, 14(20), 9307; https://doi.org/10.3390/app14209307 - 12 Oct 2024
Viewed by 474
Abstract
Echocardiography (ECG) is a noninvasive technology that is widely used for recording heartbeats and diagnosing cardiac arrhythmias. However, interpreting ECG signals is challenging and may require substantial time from medical specialists. The evolution of technology and artificial intelligence has led to advances in [...] Read more.
Echocardiography (ECG) is a noninvasive technology that is widely used for recording heartbeats and diagnosing cardiac arrhythmias. However, interpreting ECG signals is challenging and may require substantial time from medical specialists. The evolution of technology and artificial intelligence has led to advances in the study and development of automatic arrhythmia classification systems to aid in medical diagnoses. Within this context, this paper introduces a framework for classifying cardiac arrhythmias on the basis of a multimodal convolutional neural network (CNN) with an adaptive attention mechanism. ECG signal segments are transformed into images via the Hilbert space-filling curve (HSFC) and recurrence plot (RP) techniques. The framework is developed and evaluated using the MIT-BIH public database in alignment with AAMI guidelines (ANSI/AAMI EC57). The evaluations accounted for interpatient and intrapatient paradigms, considering variations in the input structure related to the number of ECG leads (lead MLII and V1 + MLII). The results indicate that the framework is competitive with those in state-of-the-art studies, particularly for two ECG leads. The accuracy, precision, sensitivity, specificity and F1 score are 98.48%, 94.15%, 80.23%, 96.34% and 81.91%, respectively, for the interpatient paradigm and 99.70%, 98.01%, 97.26%, 99.28% and 97.64%, respectively, for the intrapatient paradigm. Full article
(This article belongs to the Section Computing and Artificial Intelligence)
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<p>Sign of a normal heartbeat.</p>
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<p>Overview of the proposed CNN-AM structure.</p>
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<p>Transformation of ECG segments (classes N, S and V) into RGB rainbow images via the HSFC and RP techniques.</p>
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<p>Classifier with an attention mechanism.</p>
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<p>Three optimized N-class segments.</p>
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27 pages, 920 KiB  
Article
AI-Generated Spam Review Detection Framework with Deep Learning Algorithms and Natural Language Processing
by Mudasir Ahmad Wani, Mohammed ElAffendi and Kashish Ara Shakil
Computers 2024, 13(10), 264; https://doi.org/10.3390/computers13100264 - 12 Oct 2024
Viewed by 349
Abstract
Spam reviews pose a significant challenge to the integrity of online platforms, misleading consumers and undermining the credibility of genuine feedback. This paper introduces an innovative AI-generated spam review detection framework that leverages Deep Learning algorithms and Natural Language Processing (NLP) techniques to [...] Read more.
Spam reviews pose a significant challenge to the integrity of online platforms, misleading consumers and undermining the credibility of genuine feedback. This paper introduces an innovative AI-generated spam review detection framework that leverages Deep Learning algorithms and Natural Language Processing (NLP) techniques to identify and mitigate spam reviews effectively. Our framework utilizes multiple Deep Learning models, including Convolutional Neural Networks (CNNs), Long Short-Term Memory (LSTM) networks, Gated Recurrent Unit (GRU), and Bidirectional LSTM (BiLSTM), to capture intricate patterns in textual data. The system processes and analyzes large volumes of review content to detect deceptive patterns by utilizing advanced NLP and text embedding techniques such as One-Hot Encoding, Word2Vec, and Term Frequency-Inverse Document Frequency (TF-IDF). By combining three embedding techniques with four Deep Learning algorithms, a total of twelve exhaustive experiments were conducted to detect AI-generated spam reviews. The experimental results demonstrate that our approach outperforms the traditional machine learning models, offering a robust solution for ensuring the authenticity of online reviews. Among the models evaluated, those employing Word2Vec embeddings, particularly the BiLSTM_Word2Vec model, exhibited the strongest performance. The BiLSTM model with Word2Vec achieved the highest performance, with an exceptional accuracy of 98.46%, a precision of 0.98, a recall of 0.97, and an F1-score of 0.98, reflecting a near-perfect balance between precision and recall. Its high F2-score (0.9810) and F0.5-score (0.9857) further highlight its effectiveness in accurately detecting AI-generated spam while minimizing false positives, making it the most reliable option for this task. Similarly, the Word2Vec-based LSTM model also performed exceptionally well, with an accuracy of 97.58%, a precision of 0.97, a recall of 0.96, and an F1-score of 0.97. The CNN model with Word2Vec similarly delivered strong results, achieving an accuracy of 97.61%, a precision of 0.97, a recall of 0.96, and an F1-score of 0.97. This study is unique in its focus on detecting spam reviews specifically generated by AI-based tools rather than solely detecting spam reviews or AI-generated text. This research contributes to the field of spam detection by offering a scalable, efficient, and accurate framework that can be integrated into various online platforms, enhancing user trust and the decision-making processes. Full article
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<p>Detailed data collection procedure.</p>
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<p>Generating AI-based spam/fake reviews based on human-authored samples.</p>
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<p>Check for the working of GPT Module.</p>
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<p>Data preparation and preprocessing with NLTK toolkit.</p>
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<p>Experimental setup and configuration.</p>
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<p>Performance of selected Deep Learning models on TF-IDF representation.</p>
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<p>Performance of selected Deep Learning models on Word2Vec feature representation.</p>
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<p>Performance of selected Deep Learning models on One-Hot Encoding.</p>
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<p>The radar plot showing proposed approaches. Particularly, Word2Vec-based BiLSTM outperformed the existing methods.</p>
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<p>Heptagon: seven ways to prevent abuse and ensure ethical use of AI-generated reviews.</p>
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18 pages, 3339 KiB  
Article
Prediction of Rock Bursts Based on Microseismic Energy Change: Application of Bayesian Optimization–Long Short-Term Memory Combined Model
by Xing Fu, Shiwei Chen and Tuo Zhang
Appl. Sci. 2024, 14(20), 9277; https://doi.org/10.3390/app14209277 - 11 Oct 2024
Viewed by 506
Abstract
The prediction of rock bursts is of paramount importance in ensuring the safety of coal mine production. In order to enhance the precision of rock burst prediction, this paper utilizes a working face of the Gengcun Coal Mine as a case study. The [...] Read more.
The prediction of rock bursts is of paramount importance in ensuring the safety of coal mine production. In order to enhance the precision of rock burst prediction, this paper utilizes a working face of the Gengcun Coal Mine as a case study. The paper employs a three-year microseismic monitoring data set from the working face and employs a sensitivity analysis to identify three monitoring indicators with a higher correlation with rock bursts: daily total energy, daily maximum energy, and daily frequency. Three subsets are created from the 10-day monitoring data: daily frequency, daily maximum energy, and daily total energy. The impact risk score of the next day is assessed as the sample label by the expert assessment system. Sample input and sample label define the data set. The long short-term memory (LSTM) neural network is employed to extract the features of time series. The Bayesian optimization algorithm is introduced to optimize the model, and the Bayesian optimization–long short-term memory (BO-LSTM) combination model is established. The prediction effect of the BO-LSTM model is compared with that of the gated recurrent unit (GRU) and the convolutional neural network (1DCNN). The results demonstrate that the BO-LSTM combined model has a practical application value because the four evaluation indexes of the model are mean absolute error (MAE), mean absolute percentage error (MAPE), variance accounted for (VAF), and mean squared error (MSE) of 0.026272, 0.226405, 0.870296, and 0.001102, respectively. These values are better than those of the other two single models. The rock explosion prediction model can make use of the research findings as a guide. Full article
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<p>Rock burst prediction flowchart.</p>
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<p>LSTM network structure.</p>
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<p>GRU unit structure diagram.</p>
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<p>Correlation charts: (<b>a</b>) Pearson correlation charts; (<b>b</b>) Spearman charts diagram.</p>
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<p>Microseismic monitoring data: (<b>a</b>) the daily maximum energy value of the first 10 days at time t; (<b>b</b>) the daily total energy value of the first 10 days before the time of t; (<b>c</b>) the daily maximum frequency of the first 10 days at time t.</p>
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<p>BO-LSTM model impact hazard prediction results.</p>
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<p>GRU model impact hazard prediction results.</p>
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<p>1DCNN model impact hazard prediction results.</p>
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<p>BO-LSTM microseismic data prediction results: (<b>a</b>) daily maximum energy prediction results; (<b>b</b>) daily total energy prediction results; (<b>c</b>) daily frequency prediction results.</p>
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<p>The far–near field monitoring and early warning system for rock bursts.</p>
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<p>Gengcun Coal Mine microseismic measuring point layout diagram.</p>
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14 pages, 2474 KiB  
Article
Exploiting Temporal Features in Calculating Automated Morphological Properties of Spiky Nanoparticles Using Deep Learning
by Muhammad Aasim Rafique
Sensors 2024, 24(20), 6541; https://doi.org/10.3390/s24206541 - 10 Oct 2024
Viewed by 260
Abstract
Object segmentation in images is typically spatial and focuses on the spatial coherence of pixels. Nanoparticles in electron microscopy images are also segmented frame by frame, with subsequent morphological analysis. However, morphological analysis is inherently sequential, and a temporal regularity is evident in [...] Read more.
Object segmentation in images is typically spatial and focuses on the spatial coherence of pixels. Nanoparticles in electron microscopy images are also segmented frame by frame, with subsequent morphological analysis. However, morphological analysis is inherently sequential, and a temporal regularity is evident in the process. In this study, we extend the spatially focused morphological analysis by incorporating a fusion of hard and soft inductive bias from sequential machine learning techniques to account for temporal relationships. Previously, spiky Au nanoparticles (Au-SNPs) in electron microscopy images were analyzed, and their morphological properties were automatically generated using a hourglass convolutional neural network architecture. In this study, recurrent layers are integrated to capture the natural, sequential growth of the particles. The network is trained with a spike-focused loss function. Continuous segmentation of the images explores the regressive relationships among natural growth features, generating morphological statistics of the nanoparticles. This study comprehensively evaluates the proposed approach by comparing the results of segmentation and morphological properties analysis, demonstrating its superiority over earlier methods. Full article
(This article belongs to the Special Issue Nanotechnology Applications in Sensors Development)
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<p>(<b>a</b>,<b>b</b>) depict the hard and soft inductive bias, where the CNN shown in (<b>a</b>) shows the spatial coherence, and the LSTM node in (<b>b</b>) depicts the temporal cohesion. (<b>a</b>) Hard inductive bias of CNN. (<b>b</b>) Temporal cohesion with an LSTM node.</p>
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<p>The proposed architecture of deep neural networks for segmentation. ⊕ denotes the concatenation of the features among various layers. The arrow points the direction of the features.</p>
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<p>The sample of images for Au-SNP growth monitored in TEM images. The top row shows the images for frame no. 1123, 1156, and 1180 (left to right), and the bottom row depicts the ground truth.</p>
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<p>(<b>a</b>,<b>b</b>) depict the identified shape and the area of a Au-SNP during its growth. (<b>a</b>) Shape. (<b>b</b>) Number of spikes.</p>
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<p>(<b>a</b>) shows the masked particle after segmenting the image, (<b>b</b>) shows the spike count graph. (<b>a</b>) Masked particle. (<b>b</b>) Spike count.</p>
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<p>The qualitative results of segmentation from various techniques. Row (<b>a</b>) is the original image of the particle, row (<b>b</b>) shows segmentation results of the MaskRCNN, row (<b>c</b>) shows segmentation results of conventional techniques used in [<a href="#B9-sensors-24-06541" class="html-bibr">9</a>], row (<b>d</b>) shows the results of [<a href="#B18-sensors-24-06541" class="html-bibr">18</a>], and row (<b>e</b>) shows results generated by our proposed technique.</p>
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16 pages, 8258 KiB  
Article
Multi-Source Fusion Deformation-Monitoring Accuracy Calibration Method Based on a Normal Distribution Transform–Convolutional Neural Network–Self Attention Network
by Xuezhu Lin, Bo Zhang, Lili Guo, Wentao Zhang, Jing Sun, Yue Liu and Shihan Chao
Photonics 2024, 11(10), 953; https://doi.org/10.3390/photonics11100953 - 10 Oct 2024
Viewed by 405
Abstract
In multi-source fusion deformation-monitoring methods that utilize fiber Bragg grating (FBG) data and other data types, the lack of FBG constraint points in edge regions often results in inaccuracies in fusion results, thereby impacting the overall deformation-monitoring accuracy. This study proposes a multi-source [...] Read more.
In multi-source fusion deformation-monitoring methods that utilize fiber Bragg grating (FBG) data and other data types, the lack of FBG constraint points in edge regions often results in inaccuracies in fusion results, thereby impacting the overall deformation-monitoring accuracy. This study proposes a multi-source fusion deformation-monitoring calibration method and develops a calibration model that integrates vision and FBG multi-source fusion data. The core of this model is a normal distribution transform (NDT)–convolutional neural network (CNN)–self-attention (SA) calibration network. This network enhances continuity between points in point clouds using the NDT module, thereby reducing outliers at the edges of the fusion results. Experimental validation shows that this method reduces the absolute error to below 0.2 mm between multi-source fusion calibration results and high-precision measured point clouds, with a confidence interval of 99%. The NDT-CNN-SA network offers significant advantages, with a performance improvement of 36.57% over the CNN network, 14.39% over the CNN–gated recurrent unit (GRU)–convolutional block attention module (CBAM) network, and 9.54% over the CNN–long short term memory (LSTM)–SA network, thereby demonstrating its superior generalization, accuracy, and robustness. This calibration method provides smoother and accurate structural deformation data, supports real-time deformation monitoring, and reduces the impact of assembly deviation on product quality and performance. Full article
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<p>Multi-source fusion deformation-monitoring accuracy calibration model.</p>
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<p>Normal distribution transform module.</p>
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<p>CNN point-cloud feature extraction module.</p>
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<p>Self-attention mechanism module.</p>
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<p>NDT-CNN-SA network architecture.</p>
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<p>Data−acquisition experimental environment.</p>
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<p>Calibration network training performance results: (<b>a</b>) decrease in loss during iterations and (<b>b</b>) deviation statistics for the validation data calibrated under different datasets.</p>
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<p>Calibrated network module ablation experimental training comparison results: (<b>a</b>) comparison of the loss drop in the test set; (<b>b</b>) comparison of the RMSE decline in the test set.</p>
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<p>Plot of the deviation of ablation experiment network calibration results compared to labeled data: (<b>a</b>) CNN calibration results vs. the labeled data; (<b>b</b>) NDT-CNN calibration results vs. the labeled data; (<b>c</b>) CNN-SA calibration results vs. the labeled data; and (<b>d</b>) NDT-CNN-SA calibration results vs. the labeled data.</p>
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<p>Calibration network comparison experiment training results: (<b>a</b>) comparison of loss drop in the test set and (<b>b</b>) comparison of RMSE decline in the test set.</p>
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<p>Plot comparing the deviation of the calibration results from the experimental networks to the labeled data: (<b>a</b>) CNN-GRU-CBAM calibration results vs. the labeled data; (<b>b</b>) CNN-LSTM-SA calibration results vs. the labeled data; (<b>c</b>) NDT-CNN-SA calibration results vs. the labeled data; (<b>d</b>) deviation value statistics for the experimental network calibration validation set results.</p>
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<p>Plot comparing the deviation of the calibration results from the experimental networks to the labeled data: (<b>a</b>) CNN-GRU-CBAM calibration results vs. the labeled data; (<b>b</b>) CNN-LSTM-SA calibration results vs. the labeled data; (<b>c</b>) NDT-CNN-SA calibration results vs. the labeled data; (<b>d</b>) deviation value statistics for the experimental network calibration validation set results.</p>
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20 pages, 6441 KiB  
Article
A Performance Comparison Study on Climate Prediction in Weifang City Using Different Deep Learning Models
by Qingchun Guo, Zhenfang He, Zhaosheng Wang, Shuaisen Qiao, Jingshu Zhu and Jiaxin Chen
Water 2024, 16(19), 2870; https://doi.org/10.3390/w16192870 - 9 Oct 2024
Viewed by 669
Abstract
Climate change affects the water cycle, water resource management, and sustainable socio-economic development. In order to accurately predict climate change in Weifang City, China, this study utilizes multiple data-driven deep learning models. The climate data for 73 years include monthly average air temperature [...] Read more.
Climate change affects the water cycle, water resource management, and sustainable socio-economic development. In order to accurately predict climate change in Weifang City, China, this study utilizes multiple data-driven deep learning models. The climate data for 73 years include monthly average air temperature (MAAT), monthly average minimum air temperature (MAMINAT), monthly average maximum air temperature (MAMAXAT), and monthly total precipitation (MP). The different deep learning models include artificial neural network (ANN), recurrent NN (RNN), gate recurrent unit (GRU), long short-term memory neural network (LSTM), deep convolutional NN (CNN), hybrid CNN-GRU, hybrid CNN-LSTM, and hybrid CNN-LSTM-GRU. The CNN-LSTM-GRU for MAAT prediction is the best-performing model compared to other deep learning models with the highest correlation coefficient (R = 0.9879) and lowest root mean square error (RMSE = 1.5347) and mean absolute error (MAE = 1.1830). These results indicate that The hybrid CNN-LSTM-GRU method is a suitable climate prediction model. This deep learning method can also be used for surface water modeling. Climate prediction will help with flood control and water resource management. Full article
(This article belongs to the Section Water and Climate Change)
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<p>Location Map of Weifang city.</p>
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<p>Original data on monthly climate change in Weifang city from 1951 to 2023. (<b>a</b>) change of monthly average minimum atmospheric temperature, (<b>b</b>) change of monthly average minimum atmospheric temperature, (<b>c</b>) change of monthly average maximum atmospheric temperature, (<b>d</b>) change of monthly precipitation.</p>
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<p>CNN-LSTM-GRU model.</p>
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<p>The flowchart of this study.</p>
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<p>Annual climate change in Weifang from 1951 to 2023. (<b>a</b>) annual change of average minimum air temperature, average minimum air temperature, and average maximum atmospheric temperature; (<b>b</b>) annual change of precipitation.</p>
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<p>Periodic change of monthly climate in Weifang city. (<b>a</b>) periodic change of monthly average minimum atmospheric temperature (MAAT), (<b>b</b>) periodic change of monthly average minimum atmospheric temperature (MAMINAT), (<b>c</b>) periodic change of monthly average maximum atmospheric temperature (MAMAXAT), (<b>d</b>) periodic change of monthly precipitation.</p>
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<p>The prediction results of monthly average air temperature (MAAT) in Weifang from September 2016 to December 2023. (<b>a</b>) Plot, (<b>b</b>) Scatterplot.</p>
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<p>Comparison of observed and predicted MAAT values for each model. (<b>a</b>) results of ANN, (<b>b</b>) results of RNN, (<b>c</b>) results of CNN, (<b>d</b>) results of GRU, (<b>e</b>) results of LSTM, (<b>f</b>) results of CNN-GRU, (<b>g</b>) results of CNN-LSTM, (<b>h</b>) results of CNN-LSTM-GRU.</p>
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<p>The prediction results of monthly average minimum air temperature (MAMINAT) in Weifang from September 2016 to December 2023. (<b>a</b>) Plot, (<b>b</b>) Scatterplot.</p>
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<p>Comparison of observed and predicted MAMINAT values for each model. (<b>a</b>) results of ANN, (<b>b</b>) results of RNN, (<b>c</b>) results of CNN, (<b>d</b>) results of GRU, (<b>e</b>) results of LSTM, (<b>f</b>) results of CNN-GRU, (<b>g</b>) results of CNN-LSTM, (<b>h</b>) results of CNN-LSTM-GRU.</p>
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<p>The prediction results of monthly average maximum air temperature (MAMAXAT) in Weifang from September 2016 to December 2023. (<b>a</b>) Plot, (<b>b</b>) Scatterplot.</p>
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<p>Comparison of observed and predicted MAMAXAT values for each model. (<b>a</b>) results of ANN, (<b>b</b>) results of RNN, (<b>c</b>) results of CNN, (<b>d</b>) results of GRU, (<b>e</b>) results of LSTM, (<b>f</b>) results of CNN-GRU, (<b>g</b>) results of CNN-LSTM, (<b>h</b>) results of CNN-LSTM-GRU.</p>
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<p>The prediction results of monthly precipitation in Weifang City from September 2016 to December 2023. (<b>a</b>) Predicted results, (<b>b</b>) Scatter plots.</p>
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<p>Comparison of observed and predicted precipitation values for each model. (<b>a</b>) results of ANN, (<b>b</b>) results of RNN, (<b>c</b>) results of CNN, (<b>d</b>) results of GRU, (<b>e</b>) results of LSTM, (<b>f</b>) results of CNN-GRU, (<b>g</b>) results of CNN-LSTM, (<b>h</b>) results of CNN-LSTM-GRU.</p>
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49 pages, 9488 KiB  
Article
Intelligent Method of Identifying the Nonlinear Dynamic Model for Helicopter Turboshaft Engines
by Serhii Vladov, Arkadiusz Banasik, Anatoliy Sachenko, Wojciech M. Kempa, Valerii Sokurenko, Oleksandr Muzychuk, Piotr Pikiewicz, Agnieszka Molga and Victoria Vysotska
Sensors 2024, 24(19), 6488; https://doi.org/10.3390/s24196488 - 9 Oct 2024
Viewed by 535
Abstract
This research focused on the helicopter turboshaft engine dynamic model, identifying task solving in unsteady and transient modes (engine starting and acceleration) based on sensor data. It is known that about 85% of helicopter turboshaft engines operate in steady-state modes, while only around [...] Read more.
This research focused on the helicopter turboshaft engine dynamic model, identifying task solving in unsteady and transient modes (engine starting and acceleration) based on sensor data. It is known that about 85% of helicopter turboshaft engines operate in steady-state modes, while only around 15% operate in unsteady and transient modes. Therefore, developing dynamic multi-mode models that account for engine behavior during these modes is a critical scientific and practical task. The dynamic model for starting and acceleration modes has been further developed using on-board parameters recorded by sensors (gas-generator rotor r.p.m., free turbine rotor speed, gas temperature in front of the compressor turbine, fuel consumption) to achieve a 99.88% accuracy in identifying the dynamics of these parameters. An improved Elman recurrent neural network with dynamic stack memory was introduced, enhancing the robustness and increasing the performance by 2.7 times compared to traditional Elman networks. A theorem was proposed and proven, demonstrating that the total execution time for N Push and Pop operations in the dynamic stack memory does not exceed a certain value O(N). The training algorithm for the Elman network was improved using time delay considerations and Butterworth filter preprocessing, reducing the loss function from 2.5 to 0.12% over 120 epochs. The gradient diagram showed a decrease over time, indicating the model’s approach to the minimum loss function, with optimal settings ensuring the stable training. Full article
(This article belongs to the Section Intelligent Sensors)
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<p>Diagrams of changes in the helicopter turboshaft engine parameters (using for example, the TV3-117 engine) at starting mode: (<b>a</b>) fuel consumption, (<b>b</b>) gas-generator rotor r.p.m., (<b>c</b>) free turbine rotor speed, (<b>d</b>) gas temperature in front of the compressor turbine (author’s research).</p>
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<p>Diagram of changes in the helicopter turboshaft engine’s (using for example, the TV3-117 engine) gas temperature in front of the compressor turbine after applying the low-frequency filtering procedure at starting mode (author’s research).</p>
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<p>The dependency diagrams of the helicopter turboshaft engine parameters: (<b>a</b>) fuel consumption, (<b>b</b>) gas-generator rotor r.p.m. (author’s research).</p>
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<p>The statistical characteristics of the helicopter turboshaft engine parameters (author’s research).</p>
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<p>Implementation diagram of a memory layer for a modified Elman neural network with dynamic stack memory ([<a href="#B76-sensors-24-06488" class="html-bibr">76</a>], p. 134, URL: <a href="https://swsys.ru/index.php?page=article&amp;id=3910&amp;lang=.docs" target="_blank">https://swsys.ru/index.php?page=article&amp;id=3910&amp;lang=.docs</a> (accessed on 28 June 2024)).</p>
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<p>Modified Elman neural network with dynamic stack memory as a helicopter TE dynamic model (author’s research).</p>
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<p>The TV3-117 turboshaft engine parameters’ dynamics time series using digitized oscillograms. (<b>Black curve</b>) Gas-generator rotor r.p.m; (<b>Blue curve</b>) free turbine rotor speed; (<b>Orange curve</b>) gas temperature in front of the compressor turbine (author’s research).</p>
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<p>Cluster analysis results: (<b>a</b>) training set, (<b>b</b>) test set (author’s research).</p>
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<p>Diagram of the helicopter turboshaft engines parameters (using the TV3-117 engine as an example) after the low-frequency filtering procedure with an eighth-order Butterworth filter: (<b>a</b>): gas-generator rotor r.p.m; (<b>b</b>) free turbine rotor speed; (<b>c</b>) gas temperature in front of the compressor turbine (author’s research).</p>
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<p>Diagrams of the spectral characteristics of the helicopter turboshaft engine parameters (using the TV3-117 engine as an example): (<b>a</b>) gas-generator rotor r.p.m., (<b>b</b>) free turbine rotor speed, (<b>c</b>) gas temperature in front of the compressor turbine (author’s research).</p>
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<p>Scheme of the training sample loading of the helicopter turboshaft engine’s thermogas-dynamic parameters and the processing of experimental data by the proposed algorithm (author’s research).</p>
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<p>Diagrams of the transient processes of the helicopter turboshaft engine parameters at starting mode (using the TV3-117 engine as an example): (<b>a</b>) gas-generator rotor r.p.m., (<b>b</b>) free turbine rotor speed, (<b>c</b>) gas temperature in front of the compressor turbine (author’s research).</p>
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<p>Diagrams of the difference between the simulated and experimental processes of the helicopter turboshaft engine at starting mode (using the TV3-117 engine as an example): (<b>a</b>) gas-generator rotor r.p.m., (<b>b</b>) free turbine rotor speed, (<b>c</b>) gas temperature in front of the compressor turbine (author’s research).</p>
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<p>Diagrams of the transient processes of the helicopter turboshaft engine parameters at acceleration mode (using the TV3-117 engine as an example): (<b>a</b>) gas-generator rotor r.p.m., (<b>b</b>) free turbine rotor speed, (<b>c</b>) gas temperature in front of the compressor turbine (author’s research).</p>
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<p>Diagrams of the difference between the simulated and experimental processes of the helicopter turboshaft engine at acceleration mode (using the TV3-117 engine as an example): (<b>a</b>) gas-generator rotor r.p.m., (<b>b</b>) free turbine rotor speed, (<b>c</b>) gas temperature in front of the compressor turbine (author’s research).</p>
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<p>Diagram of the influence of epoch number passed the mean square error (author’s research).</p>
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<p>Diagram of accuracy metric (author’s research).</p>
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<p>Diagram of loss function (author’s research).</p>
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<p>Diagram of changes in loss function gradients (author’s research).</p>
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<p>Diagrams of the distribution surfaces <span class="html-italic">U</span><sub>1</sub>(<span class="html-italic">k</span>) (<b>a</b>), <span class="html-italic">U</span><sub>2</sub>(<span class="html-italic">k</span>) (<b>b</b>), and <span class="html-italic">U</span><sub>3</sub>(<span class="html-italic">k</span>) (<b>c</b>) (author’s research).</p>
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<p>The resulting k-fold cross-validation diagrams (author’s research).</p>
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<p>The AUC-ROC curves. (<b>a</b>) Proposed modified Elman neural network with dynamic stack memory; (<b>b</b>) traditional Elman neural network developed in [<a href="#B34-sensors-24-06488" class="html-bibr">34</a>,<a href="#B66-sensors-24-06488" class="html-bibr">66</a>]; (<b>c</b>) cubic spline interpolation (author’s research).</p>
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24 pages, 4151 KiB  
Article
Optimizing Plant Disease Classification with Hybrid Convolutional Neural Network–Recurrent Neural Network and Liquid Time-Constant Network
by An Thanh Le, Masoud Shakiba, Iman Ardekani and Waleed H. Abdulla
Appl. Sci. 2024, 14(19), 9118; https://doi.org/10.3390/app14199118 - 9 Oct 2024
Viewed by 731
Abstract
This paper addresses the practical challenge of detecting tomato plant diseases using a hybrid lightweight model that combines a Convolutional Neural Network (CNN) and Recurrent Neural Network (RNN). Traditional image classification models demand substantial computational resources, limiting their practicality. This study aimed to [...] Read more.
This paper addresses the practical challenge of detecting tomato plant diseases using a hybrid lightweight model that combines a Convolutional Neural Network (CNN) and Recurrent Neural Network (RNN). Traditional image classification models demand substantial computational resources, limiting their practicality. This study aimed to develop a model that can be easily implemented on low-cost IoT devices while maintaining high accuracy with real-world images. The methodology leverages a CNN for extracting high-level image features and an RNN for capturing temporal relationships, thereby enhancing model performance. The proposed model incorporates a Closed-form Continuous-time Neural Network, a lightweight variant of liquid time-constant networks, and integrates Neural Circuit Policy to capture long-term dependencies in image patterns, reducing overfitting. Augmentation techniques such as random rotation and brightness adjustments were applied to the training data to improve generalization. The results demonstrate that the hybrid models outperform their single pre-trained CNN counterparts in both accuracy and computational cost, achieving a 97.15% accuracy on the test set with the proposed model, compared to around 94% for state-of-the-art pre-trained models. This study provides evidence of the effectiveness of hybrid CNN-RNN models in improving accuracy without increasing computational cost and highlights the potential of liquid neural networks in such applications. Full article
(This article belongs to the Special Issue Multimedia Signal Processing: Theory, Methods, and Applications)
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<p>On-site image processing for real-time tomato plant disease detection: the optimized CNN-RNN model deployed on IoT devices processes images locally, eliminating the need for cloud servers and enabling rapid feedback to user devices for timely intervention.</p>
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<p>Images of tomato leaves with the ten different diseases.</p>
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<p>Class distribution of tomato leaf diseases dataset from Kaggle, highlighting data imbalance. All the data classes are listed as (a) Bacterial spot; (b) Early blight; (c) Late blight; (d) Leaf Mold; (e) Septoria leaf spot; (f) Spider mites; (g) Target spot; (h) Tomato yellow leaf; (i) Tomato mosaic virus; (j) Healthy, and (k) Powdery mildew.</p>
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<p>Structure of a typical convolutional neural network.</p>
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<p>Application of transfer learning on ImageNet.</p>
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<p>Proposed architecture for a hybrid CNN-RNN model that efficiently captures temporal and spatial relationships in images using pre-trained CNN and advanced neural network components CfC and NCP.</p>
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<p>Model performance heatmap for learning rate and batch size combinations.</p>
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<p>Model implementation process from image input processing to final validation for each training epoch.</p>
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<p>ROC curves of the proposed model show the performance of the model across various disease classes with corresponding AUC values.</p>
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<p>Training and validation accuracy comparison between 5 models over 50 epochs.</p>
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<p>Comparison of training accuracy and loss between augmented and non-augmented datasets.</p>
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<p>Comparison of metrics between non-augmented and augmented models on the test dataset.</p>
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<p>Comparison of test accuracy and model complexity across different models: (a) VGG-16; (b) MobileNetV2; (c) MobileNetV2-LSTM; (d) MobileNetV2-CfC; (e) MobileNetV2-CfC-NCP; (f) MobileNetV2-CfC-NCP (Augmentation).</p>
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