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Search Results (1,211)

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21 pages, 3912 KiB  
Article
Advancing Healthcare: Intelligent Speech Technology for Transcription, Disease Diagnosis, and Interactive Control of Medical Equipment in Smart Hospitals
by Ahmed Elhadad, Safwat Hamad, Noha Elfiky, Fulayjan Alanazi, Ahmed I. Taloba and Rasha M. Abd El-Aziz
AI 2024, 5(4), 2497-2517; https://doi.org/10.3390/ai5040121 - 26 Nov 2024
Abstract
Intelligent Speech Technology (IST) is revolutionizing healthcare by enhancing transcription accuracy, disease diagnosis, and medical equipment control in smart hospital environments. This study introduces an innovative approach employing federated learning with Multi-Layer Perceptron (MLP) and Gated Recurrent Unit (GRU) neural networks to improve [...] Read more.
Intelligent Speech Technology (IST) is revolutionizing healthcare by enhancing transcription accuracy, disease diagnosis, and medical equipment control in smart hospital environments. This study introduces an innovative approach employing federated learning with Multi-Layer Perceptron (MLP) and Gated Recurrent Unit (GRU) neural networks to improve IST performance. Leveraging the “Medical Speech, Transcription, and Intent” dataset from Kaggle, comprising a variety of speech recordings and corresponding medical symptom labels, noise reduction was applied using a Wiener filter to improve audio quality. Feature extraction through MLP and sequence classification with GRU highlighted the model’s robustness and capacity for detailed medical understanding. The federated learning framework enabled collaborative model training across multiple hospital sites, preserving patient privacy by avoiding raw data exchange. This distributed approach allowed the model to learn from diverse, real-world data while ensuring compliance with strict data protection standards. Through rigorous five-fold cross-validation, the proposed Fed MLP-GRU model demonstrated an accuracy of 98.6%, with consistently high sensitivity and specificity, highlighting its reliable generalization across multiple test conditions. In real-time applications, the model effectively performed medical transcription, provided symptom-based diagnostic insights, and facilitated hands-free control of healthcare equipment, reducing contamination risks and enhancing workflow efficiency. These findings indicate that IST, powered by federated neural networks, can significantly improve healthcare delivery, accuracy in patient diagnosis, and operational efficiency in clinical settings. This research underscores the transformative potential of federated learning and advanced neural networks for addressing pressing challenges in modern healthcare and setting the stage for future innovations in intelligent medical technology. Full article
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<p>Proposed Fed MLP GRU Methodology for Intelligent Speech Technology in Smart Hospitals.</p>
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<p>Architecture of MLP.</p>
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<p>Architecture of GRU.</p>
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<p>Architecture of Federated Learning.</p>
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<p>Comparison of Training and Validation Accuracies Across Different Neural Network Models.</p>
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<p>Training and Testing Loss Curves. (<b>A</b>) Scenario A. (<b>B</b>) Scenario B. (<b>C</b>) Scenario C. (<b>D</b>) Federated: The federated model’s performance.</p>
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<p>ROC Curves for FED LSTM Model across Different Sample Sizes.</p>
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<p>Model Performance Convergence across Different Datasets and Thresholds.</p>
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<p>Performance Evaluation for Different Methods.</p>
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24 pages, 4239 KiB  
Article
Exploring rounD Dataset for Domain Generalization in Autonomous Vehicle Trajectory Prediction
by Zikai Zhang
Sensors 2024, 24(23), 7538; https://doi.org/10.3390/s24237538 - 26 Nov 2024
Viewed by 45
Abstract
This paper analyzes the rounD dataset to advance motion forecasting algorithms for autonomous vehicles navigating complex roundabout environments. We develop a trajectory prediction framework inspired by Gated Recurrent Unit (GRU) networks and graph-based modules to effectively model vehicle interactions. Our primary objective is [...] Read more.
This paper analyzes the rounD dataset to advance motion forecasting algorithms for autonomous vehicles navigating complex roundabout environments. We develop a trajectory prediction framework inspired by Gated Recurrent Unit (GRU) networks and graph-based modules to effectively model vehicle interactions. Our primary objective is to evaluate the generalizability of the proposed model across diverse training and testing datasets. Through extensive experiments, we investigate how varying data distributions—such as different road configurations and recording times—impact the model’s prediction accuracy and robustness. This study provides key insights into the challenges of domain generalization in autonomous vehicle trajectory prediction. Full article
(This article belongs to the Special Issue Applications of Machine Learning in Automotive Engineering)
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<p>All four roundabout types in the rounD dataset. Here, roundabout type 0 is denoted as the background image from recording file 0 and so are roundabout types 1, 2 and 9.</p>
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<p>Class distribution of agents, categorized into ‘Majority’ (<span style="color: #FF0000">car</span>), ‘Medium’ (truck, van, trailer), and ‘Minority’ (<span style="color:#FF8C00">motorcycle, bicycle, bus, pedestrian</span>).</p>
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<p>Time distribution of recordings, divided into morning, <span style="color:#FF8C00">noon</span>, and <span style="color: #00FF00">afternoon</span> categories, highlighting variations in driving behaviors.</p>
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<p>Comparison of morning and afternoon driving behaviors: wider velocity and acceleration ranges are observed in the morning, indicating more aggressive, stop-and-go driving. Noon and afternoon driving shows higher velocities but more consistent, relaxed acceleration patterns.</p>
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<p>Velocity and acceleration comparison of road agents and VRUs: road agents (e.g., car, truck, van, motorcycle, bus) exhibit a much wider range than VRUs. Both velocity and acceleration show similar trends, indicating their comparable impact in motion forecasting.</p>
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<p>Correlation matrix heatmap: darker colors and lighter colors indicate larger positive and smaller negative correlations between indicators. Notable relationships include connections between xCenter, yCenter, xVelocity, and yVelocity, as well as between velocity and acceleration (<span style="color: #FF0000">noted in red rectangles</span>). These findings suggest potential redundancy and highlight areas for feature extraction or dimensional reduction.</p>
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<p>Pie chart analysis: cars dominate across all scenarios (over 75%) according to all recordings. Missing classes (some classes cannot be observed in a certain roundabout type) and VRUs, like trailers, bicycles, and pedestrians, are present in low percentages.</p>
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<p>Acceleration and deceleration frequencies vary across recordings in the roundabout scenario, with deceleration generally being more common. Different trends are observed (<span style="color: #FF0000">marked in red</span>), such as roundabout type 2’s unique pattern, roundabout type 1’s emphasis on specific acceleration ranges, and roundabout type 9’s tendency for constant speed.</p>
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<p>Overall architecture of the backbone trajectory prediction model used in our paper. Three main modules are included: data input, graph convolution model, and trajectory prediction model. Details of each model can be found in <a href="#sensors-24-07538-f010" class="html-fig">Figure 10</a> and <a href="#sensors-24-07538-f011" class="html-fig">Figure 11</a>.</p>
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<p>Details of the graph convolution model. The model is based on a Graph Convolution Network (GCN) structure. The input layer represents the initial node features (<span style="color:#FF8C00">source node</span>, neighboring node), which are passed through multiple hidden layers, each applying a graph convolution operation followed by a sigmoid activation function. The hidden layers capture the relationships between nodes by iteratively aggregating neighboring node information. The output layer provides the final representation of the node features after transformation through the network.</p>
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<p>Details of the trajectory prediction model. A Gated Recurrent Unit (GRU) is utilized to capture the hidden information within the sequential input trajectories. The GRU architecture consists of reset and update gates, which control the flow of information. The reset gate <math display="inline"><semantics> <msub> <mi>R</mi> <mi>t</mi> </msub> </semantics></math> determines how much of the previous hidden state <math display="inline"><semantics> <msub> <mi>H</mi> <mrow> <mi>t</mi> <mo>−</mo> <mn>1</mn> </mrow> </msub> </semantics></math> to forget, while the update gate <math display="inline"><semantics> <msub> <mi>Z</mi> <mi>t</mi> </msub> </semantics></math> balances between the previous hidden state and the candidate hidden state <math display="inline"><semantics> <msub> <mi>H</mi> <mi>t</mi> </msub> </semantics></math>, calculated using a tanh activation function. By combining the previous state and new information, the GRU captures dependencies without the need for separate cell states, as in LSTMs. In our paper, two Gated Recurrent Units are used.</p>
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<p>Illustration of the transformation from a global coordinate system to a localized coordinate system.</p>
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<p>Visualized Prediction Results: (<span style="color:#FF8C00">target</span>, neighboring agents). … and <span style="color:#FFFF00">…</span> are the trajectory history and labels of all road agents. ▽ are the predicted trajectories of the <span style="color:#FF8C00">targets</span> in model 0. × represents model 1, and + and ★ represent model 2 and model 9, respectively.</p>
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20 pages, 5375 KiB  
Article
PM2.5 Time Series Imputation with Moving Averages, Smoothing, and Linear Interpolation
by Anibal Flores, Hugo Tito-Chura, Osmar Cuentas-Toledo, Victor Yana-Mamani and Deymor Centty-Villafuerte
Computers 2024, 13(12), 312; https://doi.org/10.3390/computers13120312 - 26 Nov 2024
Viewed by 127
Abstract
In this work, a novel model for hourly PM2.5 time series imputation is proposed for the estimation of missing values in different gap sizes, including 1, 3, 6, 12, and 24 h. The proposed model is based on statistical techniques such as moving [...] Read more.
In this work, a novel model for hourly PM2.5 time series imputation is proposed for the estimation of missing values in different gap sizes, including 1, 3, 6, 12, and 24 h. The proposed model is based on statistical techniques such as moving averages, linear interpolation smoothing, and linear interpolation. For the experimentation stage, two datasets were selected in Ilo City in southern Peru. Also, five benchmark models were implemented to compare the proposed model results; the benchmark models include exponential weighted moving average (EWMA), autoregressive integrated moving average (ARIMA), long short-term memory (LSTM), gated recurrent unit (GRU), and bidirectional GRU (BiGRU). The results show that, in terms of average MAPEs, the proposed model outperforms the best deep learning model (GRU) between 26.61% and 90.69%, and the best statistical model (ARIMA) between 2.33% and 6.67%. So, the proposed model is a good alternative for the estimation of missing values in PM2.5 time series. Full article
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<p>Location of the environmental monitoring stations in Ilo City, Peru.</p>
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<p>The 24−day correlation of Pacocha station.</p>
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<p>The 24−day correlation of Pardo station.</p>
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<p>Two days were considered to impute missing values.</p>
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<p>The 72 estimated hours with the moving average equation for gaps of 24 h.</p>
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<p>The 72 estimated hours with the moving average and linear interpolation smoothing for gaps of 24 h.</p>
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<p>The 72 estimated hours for gaps of 24 h using LANN.</p>
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<p>The 72 estimated hours for gaps of 24 h with the proposed model.</p>
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<p>Imputations of 144 h for 24 h gaps using GRU, ARIMA, and the proposed model for Pacocha Station.</p>
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<p>Imputations of 144 h for 24 h gaps using GRU, ARIMA, and the proposed model for Pardo Station.</p>
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<p>How the benchmark models work in this study. (<b>a</b>) Statistical models and (<b>b</b>) deep learning models. NA is the not available or missing value.</p>
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19 pages, 2511 KiB  
Article
TS-GRU: A Stock Gated Recurrent Unit Model Driven via Neuro-Inspired Computation
by Yuanfang Zhang and Heinz D. Fill
Electronics 2024, 13(23), 4659; https://doi.org/10.3390/electronics13234659 - 26 Nov 2024
Viewed by 135
Abstract
Existing risk measurement methods often fail to fully consider the impact of climatic conditions on stock market risk, making it difficult to capture dynamic patterns and long-term dependencies. To address these issues, we propose the TS-GRU method: this approach utilizes a temporal convolutional [...] Read more.
Existing risk measurement methods often fail to fully consider the impact of climatic conditions on stock market risk, making it difficult to capture dynamic patterns and long-term dependencies. To address these issues, we propose the TS-GRU method: this approach utilizes a temporal convolutional network (TCN) to extract underlying features from historical data, capturing key characteristics of time series data. Subsequently, a gated recurrent unit (GRU) model is employed to capture dynamic patterns and long-term dependencies within the stock market. Finally, the TS-GRU model is optimized using the Sparrow algorithm based on collective behavior, iteratively evaluating and refining model parameters to obtain improved solutions. Experimental results demonstrate the effectiveness of the TS-GRU method in providing accurate risk assessment and forecasting. This comprehensive approach takes into account carbon finance, climate change, and environmental factors, offering valuable insights to investors to help them to understand and manage investment risks in the ever-changing stock market. Full article
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<p>Architecture of the proposed TS-GRU model. The TS-GRU model optimizes data flow by integrating climate and stock data. First, the input includes climate (such as temperature and humidity) and stock (such as opening price and closing price) data. After preprocessing and feature engineering, it enters the GRU model training phase. The model uses Sparrow algorithm optimization to learn time series patterns and dependencies and outputs prediction results and decision support to help understand and respond to market and climate change. This process combines deep learning technology and algorithm optimization to improve prediction accuracy and application effect.</p>
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<p>Diagram illustrating the TCN principle.</p>
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<p>A schematic diagram of the principle of GRU.</p>
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<p>A schematic diagram of the principle of Sparrow search algorithm.</p>
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<p>Comparison of indicators across various methods and datasets.</p>
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<p>Comparison of indicators across various methods and datasets.</p>
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<p>Experiments on the removal of the TCN module conducted on various datasets.</p>
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<p>Testing the performance of the GRU module through ablation experiments on various datasets.</p>
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22 pages, 5592 KiB  
Article
Multi-Factor Prediction of Water Inflow from the Working Face Based on an Improved SSA-RG-MHA Model
by Yingying Ding, Shangxian Yin, Zhenxue Dai, Huiqing Lian and Changsen Bu
Water 2024, 16(23), 3390; https://doi.org/10.3390/w16233390 - 25 Nov 2024
Viewed by 257
Abstract
The accurate prediction of mine water inflow is very important for mine design and safe production. The existing forecasting methods based on single factors are often less accurate and stable. Multi-factor data-driven models play a key role in predicting water inflow without taking [...] Read more.
The accurate prediction of mine water inflow is very important for mine design and safe production. The existing forecasting methods based on single factors are often less accurate and stable. Multi-factor data-driven models play a key role in predicting water inflow without taking physical changes into account. Therefore, a multi-factor prediction method based on an improved SSA-RG-MHA model is introduced in this study. The model uses two sets of data related to water inflow as the input to improve prediction accuracy and stability. The model first applies a residual network (ResNet) to mitigate the problems of disappearing gradients and explosions. Gated Recurrent Units (GRUs) are then used to learn the characteristics of long-term sequence data. The model combines ResNet and GRU into a new network architecture and incorporates a multiple attention (MHA) mechanism to focus on information at different time scales. Finally, the optimized sparrow search algorithm (SSA) is used to optimize the network parameters to improve the global search ability and avoid local optimization. The mine water inflow is affected by many factors, among which the water level and microseismic energy data are particularly important. Therefore, these data types are selected as the key variables of mine water inflow prediction. The experimental results show that the improved SSA-RG-MHA model significantly reduces the prediction error: the mean absolute error (MAE), root mean square error (RMSE), and mean absolute percentage error (MAPE) were reduced to 4.42 m3/h, 7.17 m3/h, and 5%, respectively. The multi-factor water inflow prediction method is more stable and reliable than single-factor models as it comprehensively considers the factors affecting the water inflow of the working face. Compared with other multi-factor models, this model exhibits higher prediction accuracy and robustness, providing a basis for mine water hazard monitoring and early warning. Full article
(This article belongs to the Special Issue Engineering Hydrogeology Research Related to Mining Activities)
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<p>Flow chart of the SSSA-RG-MHA model.</p>
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<p>Combined with residual network structure.</p>
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<p>Structural unit of the Gated Recurrent Unit.</p>
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<p>A basic diagram of the multi-head attention mechanism.</p>
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<p>The generating process of Q, K, and V matrix.</p>
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<p>Flowchart of SSSA.</p>
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<p>Structure of the RG-MHA model.</p>
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<p>The position of the 207 working face.</p>
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<p>Relationships of microseismic energy, water level, and mine water inflow.</p>
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<p>The relationship between data and models.</p>
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<p>Optimization algorithm comparison results.</p>
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<p>Predicted results of various models.</p>
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<p>Comparison of water inflow forecast.</p>
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19 pages, 7556 KiB  
Article
Deep Learning-Enhanced Autoencoder for Multi-Carrier Wireless Systems
by Md Abdul Aziz, Md Habibur Rahman, Rana Tabassum, Mohammad Abrar Shakil Sejan, Myung-Sun Baek and Hyoung-Kyu Song
Mathematics 2024, 12(23), 3685; https://doi.org/10.3390/math12233685 - 24 Nov 2024
Viewed by 423
Abstract
In a multi-carrier (MC) system, the transmitted data are split across several sub-carriers as a crucial approach for achieving high data rates, reliability, and spectral efficiency. Deep learning (DL) enhances MC systems by improving signal representation, leading to more efficient data transmission and [...] Read more.
In a multi-carrier (MC) system, the transmitted data are split across several sub-carriers as a crucial approach for achieving high data rates, reliability, and spectral efficiency. Deep learning (DL) enhances MC systems by improving signal representation, leading to more efficient data transmission and reduced bit error rates. In this paper, we propose an MC system supported by DL for operation on fading channels. Deep neural networks are utilized to model the modulation block, while a gated recurrent unit (GRU) network is used to model the demodulation blocks, acting as the encoder and decoder within an autoencoder (AE) architecture. The proposed scheme, known as MC-AE, differs from existing AE-based systems by directly processing channel state information and the received signal in a fully data-driven way, unlike traditional methods that rely on channel equalizers. This approach enables MC-AE to improve diversity and coding gains in fading channels by simultaneously optimizing the encoder and decoder. In this experiment, we evaluated the performance of the proposed model under both perfect and imperfect channel conditions and compared it with other models. Additionally, we assessed the performance of the MC-AE system against index modulation-based MC systems. The results demonstrate that the GRU-based MC-AE system outperforms the others. Full article
24 pages, 1917 KiB  
Article
Recurrent Neural Network (RNN)-Based Approach to Predict Mean Flow Stress in Industrial Rolling
by Alexey G. Zinyagin, Alexander V. Muntin, Vadim S. Tynchenko, Pavel I. Zhikharev, Nikita R. Borisenko and Ivan Malashin
Metals 2024, 14(12), 1329; https://doi.org/10.3390/met14121329 - 24 Nov 2024
Viewed by 271
Abstract
This study addresses the usage of data from industrial plate mills to calculate the mean flow stress of different steel grades. Accurate flow stress values may optimize rolling technology, but the existing literature often provides coefficients like those in the Hensel–Spittel equation for [...] Read more.
This study addresses the usage of data from industrial plate mills to calculate the mean flow stress of different steel grades. Accurate flow stress values may optimize rolling technology, but the existing literature often provides coefficients like those in the Hensel–Spittel equation for a limited number of steel grades, whereas in modern production, the chemical composition may vary by thickness, customer requirements, and economic factors, making it necessary to conduct costly and labor-intensive laboratory studies. This research demonstrates that leveraging data from industrial rolling mills and employing machine learning (ML) methods can predict material rheological behavior without extensive laboratory research. Two modeling approaches are employed: Gated Recurrent Unit (GRU) and Long Short-Term Memory (LSTM) architectures. The model comprising one GRU layer and two fully connected layers, each containing 32 neurons, yields the best performance, achieving a Root Mean Squared Error (RMSE) of 7.5 MPa for the predicted flow stress of three steel grades in the validation set. Full article
(This article belongs to the Special Issue Machine Learning Models in Metals)
25 pages, 4564 KiB  
Article
Harnessing Deep Learning and Snow Cover Data for Enhanced Runoff Prediction in Snow-Dominated Watersheds
by Rana Muhammad Adnan, Wang Mo, Ozgur Kisi, Salim Heddam, Ahmed Mohammed Sami Al-Janabi and Mohammad Zounemat-Kermani
Atmosphere 2024, 15(12), 1407; https://doi.org/10.3390/atmos15121407 - 22 Nov 2024
Viewed by 306
Abstract
Predicting streamflow is essential for managing water resources, especially in basins and watersheds where snowmelt plays a major role in river discharge. This study evaluates the advanced deep learning models for accurate monthly and peak streamflow forecasting in the Gilgit River Basin. The [...] Read more.
Predicting streamflow is essential for managing water resources, especially in basins and watersheds where snowmelt plays a major role in river discharge. This study evaluates the advanced deep learning models for accurate monthly and peak streamflow forecasting in the Gilgit River Basin. The models utilized were LSTM, BiLSTM, GRU, CNN, and their hybrid combinations (CNN-LSTM, CNN-BiLSTM, CNN-GRU, and CNN-BiGRU). Our research measured the model’s accuracy through root mean square error (RMSE), mean absolute error (MAE), Nash–Sutcliffe efficiency (NSE), and the coefficient of determination (R2). The findings indicated that the hybrid models, especially CNN-BiGRU and CNN-BiLSTM, achieved much better performance than traditional models like LSTM and GRU. For instance, CNN-BiGRU achieved the lowest RMSE (71.6 in training and 95.7 in testing) and the highest R2 (0.962 in training and 0.929 in testing). A novel aspect of this research was the integration of MODIS-derived snow-covered area (SCA) data, which enhanced model accuracy substantially. When SCA data were included, the CNN-BiLSTM model’s RMSE improved from 83.6 to 71.6 during training and from 108.6 to 95.7 during testing. In peak streamflow prediction, CNN-BiGRU outperformed other models with the lowest absolute error (108.4), followed by CNN-BiLSTM (144.1). This study’s results reinforce the notion that combining CNN’s spatial feature extraction capabilities with the temporal dependencies captured by LSTM or GRU significantly enhances model accuracy. The demonstrated improvements in prediction accuracy, especially for extreme events, highlight the potential for these models to support more informed decision-making in flood risk management and water allocation. Full article
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<p>Location map of the study area.</p>
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<p>The long short-term memory (LSTM) architecture.</p>
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<p>The bidirectional long short-term memory (LSTM).</p>
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<p>The gated recurrent unit (GRU).</p>
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<p>Bidirectional gated recurrent unit (Bi-GRU).</p>
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<p>Blocks diagram of convolutional neural network (CNN)-based LSTM, BiLSTM, GRU, and Bi-GRU deep learning.</p>
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<p>Scatterplots of the observed and predicted streamflow by different models in the test period using the best input combination.</p>
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<p>Scatterplots of the observed and predicted streamflow by different models in the test period using the best input combination.</p>
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<p>Taylor diagrams of the predicted streamflow by different models in the test period using the best input combination.</p>
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<p>Violin charts of the predicted streamflow by different models in the test period using the best input combination.</p>
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13 pages, 3389 KiB  
Article
Dynamic Prediction of Proton-Exchange Membrane Fuel Cell Degradation Based on Gated Recurrent Unit and Grey Wolf Optimization
by Xiangdong Wang, Zerong Huang, Daxing Zhang, Haoyu Yuan, Bingzi Cai, Hanlin Liu, Chunsheng Wang, Yuan Cao, Xinyao Zhou and Yaolin Dong
Energies 2024, 17(23), 5855; https://doi.org/10.3390/en17235855 - 22 Nov 2024
Viewed by 244
Abstract
This paper addresses the challenge of degradation prediction in proton-exchange membrane fuel cells (PEMFCs). Traditional methods often struggle to balance accuracy and complexity, particularly under dynamic operational conditions. To overcome these limitations, this study proposes a data-driven approach based on the gated recurrent [...] Read more.
This paper addresses the challenge of degradation prediction in proton-exchange membrane fuel cells (PEMFCs). Traditional methods often struggle to balance accuracy and complexity, particularly under dynamic operational conditions. To overcome these limitations, this study proposes a data-driven approach based on the gated recurrent unit (GRU) neural network, optimized by the grey wolf optimizer (GWO). The integration of the GWO automates the hyperparameter tuning process, enhancing the predictive performance of the GRU network. The proposed GWO-GRU method was validated utilizing actual PEMFC data under dynamic load conditions. The results demonstrate that the GWO-GRU method achieves superior accuracy compared to other standard methods. The method offers a practical solution for online PEMFC degradation prediction, providing stable and accurate forecasting for PEMFC systems in dynamic environments. Full article
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<p>PEMFC durability test. (<b>a</b>) Test bench in FCLAB. (<b>b</b>) Constant and dynamic currents in the two experiments.</p>
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<p>Degradation voltage profiles under constant and dynamic load conditions.</p>
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<p>Raw voltage data and processed voltage data under dynamic load conditions.</p>
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<p>Architecture of GRU cells.</p>
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<p>Searching for prey versus attacking prey, (<b>a</b>) searching, (<b>b</b>) attacking.</p>
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<p>GWO-GRU schematic diagram.</p>
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<p>Prediction results under different methods and training lengths. (<b>a</b>) Fifty percent training length. (<b>b</b>) Sixty percent training length. (<b>c</b>) Seventy percent training length. (<b>d</b>) Eighty percent training length.</p>
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<p>Absolute percentage error results under different methods and training lengths. (<b>a</b>) Fifty percent training length. (<b>b</b>) Sixty percent training length. (<b>c</b>) Seventy percent training length. (<b>d</b>) Eighty percent training length.</p>
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25 pages, 4861 KiB  
Article
Short-Term Traffic Flow Forecasting Based on a Novel Combined Model
by Lu Liu, Caihong Li, Yi Yang and Jianzhou Wang
Sustainability 2024, 16(23), 10216; https://doi.org/10.3390/su162310216 - 22 Nov 2024
Viewed by 462
Abstract
To improve the forecasting accuracy of traffic flow, this paper proposes a traffic flow forecasting algorithm based on Principal Component Analysis (PCA) and Complete Ensemble Empirical Mode Decomposition with Adaptive Noise (CEEMDAN) for data processing. The Grey Wolf Optimizer (GWO) algorithm is used [...] Read more.
To improve the forecasting accuracy of traffic flow, this paper proposes a traffic flow forecasting algorithm based on Principal Component Analysis (PCA) and Complete Ensemble Empirical Mode Decomposition with Adaptive Noise (CEEMDAN) for data processing. The Grey Wolf Optimizer (GWO) algorithm is used to optimize the weights of a combined model called the GWO-PC-CGLX model, which consists of the Convolutional Neural Network (CNN), Gated Recurrent Unit (GRU), Long Short-Term Memory (LSTM), and Extreme Gradient Boosting (XGBoost). Initially, PCA and CEEMDAN are used to reduce the dimensionality and noise in the air quality index (AQI) data and traffic flow data. The smoothed data are then input into the CNN, GRU, LSTM, and XGboost models for forecasting. To improve the forecasting accuracy, the GWO algorithm is used to find the optimal weight combination of the four single models. Taking the data from Jiayuguan and Lanzhou in Gansu Province as an example, compared with the actual data, the values of the evaluation indicator R2 (Coefficient of Determination) reached 0.9452 and 0.9769, respectively, which are superior to those of the comparison models. The research results not only improve the accuracy of traffic flow forecasting but also provide effective support for the construction of intelligent transportation systems and sustainable traffic management. Full article
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<p>CNN diagram.</p>
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<p>LSTM network diagram.</p>
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<p>GRU network diagram.</p>
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<p>The image depicts a grey wolf attacking and searching for prey: (<b>a</b>) When <math display="inline"><semantics> <mrow> <mfenced close="|" open="|"> <mi>A</mi> </mfenced> <mo>&lt;</mo> <mn>1</mn> </mrow> </semantics></math>, the wolf approaches the prey; (<b>b</b>) When <math display="inline"><semantics> <mrow> <mfenced close="|" open="|"> <mi>A</mi> </mfenced> <mo>&gt;</mo> <mn>1</mn> </mrow> </semantics></math>, the wolf moves away from the prey.</p>
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<p>The illustration diagram for the grey wolf position update.</p>
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<p>The flowchart for the GWO-PC-CGXL combined model.</p>
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<p>Research areas in Jiayuguan and Lanzhou, Gansu Province.</p>
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20 pages, 4043 KiB  
Article
Short-Term Wind Power Forecasting Based on OMNIC and Adaptive Fractional Order Generalized Pareto Motion Model
by Fan Cai, Dongdong Chen, Yuesong Jiang and Tongbo Zhu
Energies 2024, 17(23), 5848; https://doi.org/10.3390/en17235848 - 22 Nov 2024
Viewed by 302
Abstract
With the rapid development of renewable energy, accurately forecasting wind power is crucial for the stable operation of power systems and effective energy management. This paper proposes a short-term wind power forecasting method based on the Orthogonalized Maximal Information Coefficient (OMNIC) combined with [...] Read more.
With the rapid development of renewable energy, accurately forecasting wind power is crucial for the stable operation of power systems and effective energy management. This paper proposes a short-term wind power forecasting method based on the Orthogonalized Maximal Information Coefficient (OMNIC) combined with an Adaptive fractional Generalized Pareto motion (fGPm) model. The method quantifies the influence of meteorological factors on wind power prediction and identifies the optimal set and number of influencing factors. The model accounts for long-range dependence (LRD) in time series data and constructs an uncertainty model using the properties and parameters of the fractional generalized Pareto distribution (GPD), significantly improving prediction accuracy under nonlinear conditions. The proposed approach was validated using a real dataset from a wind farm in northwest China and compared with other models such as Convolutional Neural Network-Long Short-Term Memory (CNN-LSTM) and Convolutional Neural Network-Gated Recurrent Unit (CNN-GRU). Results show that the adaptive fGPm model reduces RMSE by 0.448 MW and 0.466 MW, MAPE by 6.936% and 9.702%, and achieves an average R2 of 0.9826 compared to CNN-GRU and CNN-LSTM. The improvement is due to the dynamic adjustment to data trends and effective use of LRD features. This method provides practical value in improving wind power prediction accuracy and addressing grid integration and regulation challenges. Full article
(This article belongs to the Section A3: Wind, Wave and Tidal Energy)
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<p>PDF of GPD with Different Shape Parameters.</p>
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<p>PDF of GPD with Different Scale Parameters.</p>
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<p>Simulation sequences of the fGPm model under different conditions (<b>a</b>) <span class="html-italic">H</span> = 0.85, <math display="inline"><semantics> <mrow> <mi>α</mi> <mo>=</mo> <mn>1.1</mn> </mrow> </semantics></math>; (<b>b</b>) <span class="html-italic">H</span> = 0.85, <math display="inline"><semantics> <mrow> <mi>α</mi> <mo>=</mo> <mn>1.4</mn> </mrow> </semantics></math>; (<b>c</b>) <span class="html-italic">H</span> = 0.85, <math display="inline"><semantics> <mrow> <mi>α</mi> <mo>=</mo> <mn>1.7</mn> </mrow> </semantics></math>; (<b>d</b>) <span class="html-italic">H</span> = 0.85, <math display="inline"><semantics> <mrow> <mi>α</mi> <mo>=</mo> <mn>2</mn> </mrow> </semantics></math>. Time representation in the figure is specified as time steps, where each time step represents the simulated sequence count.</p>
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<p>Original Wind Power Data.</p>
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<p>Wind farm power generation forecasting model framework.</p>
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<p>Winter Wind Power Forecasting Results for Wind Turbine Generators; (<b>a</b>) predicting 12 steps; (<b>b</b>) predicting 24 steps; (<b>c</b>) predicting 36 steps; (<b>d</b>) predicting 48 steps.</p>
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<p>Summer Wind Power Forecasting Results for Wind Turbine Generators; (<b>a</b>) predicting 12 steps; (<b>b</b>) predicting 24 steps; (<b>c</b>) predicting 36 steps; (<b>d</b>) predicting 48 steps.</p>
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<p>Comparison of Prediction Curves from Different Models in Winter. (<b>a</b>) 6 h (<b>b</b>) 12 h (<b>c</b>) 18 h (<b>d</b>) 24 h.</p>
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<p>Comparison of Prediction Curves from Different Models in Summer. (<b>a</b>) 6 h (<b>b</b>) 12 h (<b>c</b>) 18 h (<b>d</b>) 24 h.</p>
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28 pages, 3823 KiB  
Article
Optimizing Renewable Energy Systems Placement Through Advanced Deep Learning and Evolutionary Algorithms
by Konstantinos Stergiou and Theodoros Karakasidis
Appl. Sci. 2024, 14(23), 10795; https://doi.org/10.3390/app142310795 - 21 Nov 2024
Viewed by 361
Abstract
As the world shifts towards a low-carbon economy, the strategic deployment of renewable energy sources (RESs) is critical for maximizing energy output and ensuring sustainability. This study introduces GREENIA, a novel artificial intelligence (AI)-powered framework for optimizing RES placement that holistically integrates machine [...] Read more.
As the world shifts towards a low-carbon economy, the strategic deployment of renewable energy sources (RESs) is critical for maximizing energy output and ensuring sustainability. This study introduces GREENIA, a novel artificial intelligence (AI)-powered framework for optimizing RES placement that holistically integrates machine learning (gated recurrent unit neural networks with swish activation functions and attention layers), evolutionary optimization algorithms (Jaya), and Shapley additive explanations (SHAPs). A key innovation of GREENIA is its ability to provide natural language explanations (NLEs), enabling transparent and interpretable insights for both technical and non-technical stakeholders. Applied in Greece, the framework addresses the challenges posed by the interplay of meteorological factors from 10 different meteorological stations across the country. Validation against real-world data demonstrates improved prediction accuracy using metrics like root mean squared error (RMSE), mean absolute error (MAE), and mean absolute percentage error (MAPE). SHAP analysis enhances transparency by identifying key meteorological influences, such as temperature and humidity, while NLE translates these insights into actionable recommendations in natural language, improving accessibility for energy planners and policymakers. The resulting strategic plan offers precise, intelligent, and interpretable recommendations for deploying RES technologies, ensuring maximum efficiency and sustainability. This approach not only advances renewable energy optimization but also equips stakeholders with practical tools for guiding the strategic deployment of RES across diverse regions, contributing to sustainable energy management. Full article
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<p>GREENIA high-level architecture.</p>
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<p>Map of meteorological stations across Greece.</p>
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<p>Histogram of the input features dataset. (Different colors correspond to different features).</p>
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<p>Histogram for the output feature.</p>
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<p>GRU with attention layer (Swish activation function).</p>
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<p>Training vs validation loss curve.</p>
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<p>Main model results.</p>
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<p>Daily forecasting through AR mechanism.</p>
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<p>Optimization results for the forecasted energy.</p>
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33 pages, 8595 KiB  
Article
A Secure IIoT Environment That Integrates AI-Driven Real-Time Short-Term Active and Reactive Load Forecasting with Anomaly Detection: A Real-World Application
by Md. Ibne Joha, Md Minhazur Rahman, Md Shahriar Nazim and Yeong Min Jang
Sensors 2024, 24(23), 7440; https://doi.org/10.3390/s24237440 - 21 Nov 2024
Viewed by 283
Abstract
The Industrial Internet of Things (IIoT) revolutionizes both industrial and residential operations by integrating AI (artificial intelligence)-driven analytics with real-time monitoring, optimizing energy usage, and significantly enhancing energy efficiency. This study proposes a secure IIoT framework that simultaneously predicts both active and reactive [...] Read more.
The Industrial Internet of Things (IIoT) revolutionizes both industrial and residential operations by integrating AI (artificial intelligence)-driven analytics with real-time monitoring, optimizing energy usage, and significantly enhancing energy efficiency. This study proposes a secure IIoT framework that simultaneously predicts both active and reactive loads while also incorporating anomaly detection. The system is optimized for real-time deployment on an edge server, such as a single-board computer (SBC), as well as on a cloud or centralized server. It ensures secure and reliable industrial operations by integrating smart data acquisition systems with real-time monitoring, control, and protective measures. We propose a Temporal Convolutional Networks-Gated Recurrent Unit-Attention (TCN-GRU-Attention) model to predict both active and reactive loads, which demonstrates superior performance compared to other conventional models. The performance metrics for active load forecasting are 0.0183 Mean Squared Error (MSE), 0.1022 Mean Absolute Error (MAE), and 0.1354 Root Mean Squared Error (RMSE), while for reactive load forecasting, the metrics are 0.0202 (MSE), 0.1077 (MAE), and 0.1422 (RMSE). Furthermore, we introduce an optimized Isolation Forest model for anomaly detection that considers the transient conditions of appliances when identifying irregular behavior. The model demonstrates very promising performance, with the average performance metrics for all appliances using this Isolation Forest model being 95% for Precision, 98% for Recall, 96% for F1 Score, and nearly 100% for Accuracy. To secure the entire system, Transport Layer Security (TLS) and Secure Sockets Layer (SSL) security protocols are employed, along with hash-encoded encrypted credentials for enhanced protection. Full article
(This article belongs to the Section Internet of Things)
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<p>Proposed system architecture.</p>
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<p>Proposed architecture for the edge IIoT layer.</p>
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<p>Proposed architecture for the cloud IIoT layer.</p>
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<p>A comprehensive workflow for developing a load forecasting AI model.</p>
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<p>A comprehensive workflow for developing an anomaly detection AI model.</p>
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<p>(<b>a</b>) illustrates the overall model architecture, while (<b>b</b>) shows the arrangement of the TCN and GRU layers.</p>
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<p>A single TCN block architecture.</p>
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<p>The architecture of a single GRU layer.</p>
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<p>A detailed process for securing an MQTT broker.</p>
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<p>A comprehensive process for securing the Node-RED server.</p>
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<p>Configuration of the edge IIoT layer.</p>
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<p>Configuration of the cloud or centralized IIoT layer.</p>
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<p>Visual representation of a historical active and reactive power consumption dataset.</p>
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<p>Actual versus predicted active power using the TCN-GRU-attention model.</p>
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<p>Actual versus predicted reactive power using the TCN-GRU-attention model.</p>
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<p>Detected anomalies in the mini PC power consumption data.</p>
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<p>Detected anomalies in the PC power consumption data.</p>
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<p>Detected anomalies in the monitor power consumption data.</p>
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<p>Detected anomalies in the refrigerator power consumption data.</p>
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<p>Detected anomalies in overall total power (Home 01) consumption data.</p>
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<p>MQTT broker security verification.</p>
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<p>Anomaly detection alert notification.</p>
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<p>Cloud IIoT layer interface.</p>
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<p>Edge computing on the Jetson Nano board.</p>
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29 pages, 8399 KiB  
Article
Automatic Modulation Recognition Based on Multimodal Information Processing: A New Approach and Application
by Wenna Zhang, Kailiang Xue, Aiqin Yao and Yunqiang Sun
Electronics 2024, 13(22), 4568; https://doi.org/10.3390/electronics13224568 - 20 Nov 2024
Viewed by 372
Abstract
Automatic modulation recognition (AMR) has wide applications in the fields of wireless communications, radar systems, and intelligent sensor networks. The existing deep learning-based modulation recognition models often focus on temporal features while overlooking the interrelations and spatio-temporal relationships among different types of signals. [...] Read more.
Automatic modulation recognition (AMR) has wide applications in the fields of wireless communications, radar systems, and intelligent sensor networks. The existing deep learning-based modulation recognition models often focus on temporal features while overlooking the interrelations and spatio-temporal relationships among different types of signals. To overcome these limitations, a hybrid neural network based on a multimodal parallel structure, called the multimodal parallel hybrid neural network (MPHNN), is proposed to improve the recognition accuracy. The algorithm first preprocesses the data by parallelly processing the multimodal forms of the modulated signals before inputting them into the network. Subsequently, by combining Convolutional Neural Networks (CNN) and Bidirectional Gated Recurrent Unit (Bi-GRU) models, the CNN is used to extract spatial features of the received signals, while the Bi-GRU transmits previous state information of the time series to the current state to capture temporal features. Finally, the Convolutional Block Attention Module (CBAM) and Multi-Head Self-Attention (MHSA) are introduced as two attention mechanisms to handle the temporal and spatial correlations of the signals through an attention fusion mechanism, achieving the calibration of the signal feature maps. The effectiveness of this method is validated using various datasets, with the experimental results demonstrating that the proposed approach can fully utilize the information of multimodal signals. The experimental results show that the recognition accuracy of MPHNN on multiple datasets reaches 93.1%, and it has lower computational complexity and fewer parameters than other models. Full article
(This article belongs to the Section Artificial Intelligence)
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<p>Visualization of instantaneous amplitude, instantaneous phase, instantaneous frequency, and IQ time-domain plots for 11 modulation modes.</p>
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<p>Overall architecture of the MPHNN.</p>
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<p>Structure of CBAM.</p>
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<p>Working mechanism of the CBAM.</p>
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<p>Structure of the Multi-Head Self-Attention (MHSA) module.</p>
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<p>Scaled dot-product attention.</p>
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<p>Structure of attention fusion mechanism.</p>
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<p>Bi-GRU information flow transfer diagram.</p>
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<p>Changes during training: (<b>a</b>) accuracy and (<b>b</b>) loss values.</p>
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<p>Recognition accuracy of the dataset RadioML2016.10A on several models.</p>
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<p>Confusion matrix at an SNR of 18 dB for (<b>a</b>) 1D-CNN, (<b>b</b>) 2D-CNN, (<b>c</b>) CLDNN, (<b>d</b>) DenseNet, (<b>e</b>) LSTM, (<b>f</b>) ResNet, and (<b>g</b>) proposed model.</p>
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<p>Confusion matrix at full SNR: (<b>a</b>) 1D-CNN, (<b>b</b>) 2D-CNN, (<b>c</b>) CLDNN, (<b>d</b>) DenseNet, (<b>e</b>) LSTM, (<b>f</b>) ResNet, and (<b>g</b>) proposed model.</p>
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<p>Recognition accuracy for each modulated signal in the range of −20~18 db for all seven methods. (<b>a</b>) The recognition accuracy of each modulated signal using 1D-CNN. (<b>b</b>) The recognition accuracy of each modulated signal using 2D-CNN. (<b>c</b>) The recognition accuracy of CLDNN for each modulated signal. (<b>d</b>) The recognition accuracy of each modulated signal using DenseNet. (<b>e</b>) The recognition accuracy of each modulated signal using LSTM. (<b>f</b>) The recognition accuracy of each modulated signal using ResNET. (<b>g</b>) The recognition accuracy of the proposed model in this paper for each modulated signal.</p>
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<p>Recognition accuracy for each modulated signal in the range of −20~18 db for all seven methods. (<b>a</b>) The recognition accuracy of each modulated signal using 1D-CNN. (<b>b</b>) The recognition accuracy of each modulated signal using 2D-CNN. (<b>c</b>) The recognition accuracy of CLDNN for each modulated signal. (<b>d</b>) The recognition accuracy of each modulated signal using DenseNet. (<b>e</b>) The recognition accuracy of each modulated signal using LSTM. (<b>f</b>) The recognition accuracy of each modulated signal using ResNET. (<b>g</b>) The recognition accuracy of the proposed model in this paper for each modulated signal.</p>
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<p>Recognition accuracy for each modulated signal in the range of −20~18 db for all seven methods. (<b>a</b>) The recognition accuracy of each modulated signal using 1D-CNN. (<b>b</b>) The recognition accuracy of each modulated signal using 2D-CNN. (<b>c</b>) The recognition accuracy of CLDNN for each modulated signal. (<b>d</b>) The recognition accuracy of each modulated signal using DenseNet. (<b>e</b>) The recognition accuracy of each modulated signal using LSTM. (<b>f</b>) The recognition accuracy of each modulated signal using ResNET. (<b>g</b>) The recognition accuracy of the proposed model in this paper for each modulated signal.</p>
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<p>Recognition accuracy for each modulated signal in the range of −20~18 db for all seven methods. (<b>a</b>) The recognition accuracy of each modulated signal using 1D-CNN. (<b>b</b>) The recognition accuracy of each modulated signal using 2D-CNN. (<b>c</b>) The recognition accuracy of CLDNN for each modulated signal. (<b>d</b>) The recognition accuracy of each modulated signal using DenseNet. (<b>e</b>) The recognition accuracy of each modulated signal using LSTM. (<b>f</b>) The recognition accuracy of each modulated signal using ResNET. (<b>g</b>) The recognition accuracy of the proposed model in this paper for each modulated signal.</p>
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<p>Validation on other datasets: (<b>a</b>) RadioML2016.10B and (<b>b</b>) RadioML2018.01A-sample.</p>
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20 pages, 7227 KiB  
Article
A Physics-Guided Machine Learning Model for Predicting Viscoelasticity of Solids at Large Deformation
by Bao Qin and Zheng Zhong
Polymers 2024, 16(22), 3222; https://doi.org/10.3390/polym16223222 - 20 Nov 2024
Viewed by 317
Abstract
Physics-guided machine learning (PGML) methods are emerging as valuable tools for modelling the constitutive relations of solids due to their ability to integrate both data and physical knowledge. While various PGML approaches have successfully modeled time-independent elasticity and plasticity, viscoelasticity remains less addressed [...] Read more.
Physics-guided machine learning (PGML) methods are emerging as valuable tools for modelling the constitutive relations of solids due to their ability to integrate both data and physical knowledge. While various PGML approaches have successfully modeled time-independent elasticity and plasticity, viscoelasticity remains less addressed due to its dependence on both time and loading paths. Moreover, many existing methods require large datasets from experiments or physics-based simulations to effectively predict constitutive relations, and they may struggle to model viscoelasticity accurately when experimental data are scarce. This paper aims to develop a physics-guided recurrent neural network (RNN) model to predict the viscoelastic behavior of solids at large deformations with limited experimental data. The proposed model, based on a combination of gated recurrent units (GRU) and feedforward neural networks (FNN), utilizes both time and stretch (or strain) sequences as inputs, allowing it to predict stress dependent on time and loading paths. Additionally, the paper introduces a physics-guided initialization approach for GRU–FNN parameters, using numerical stress–stretch data from the generalized Maxwell model for viscoelastic VHB polymers. This initialization is performed prior to training with experimental data, helping to overcome challenges associated with data scarcity. Full article
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<p>The generalized Maxwell model for solids under large deformation. It is assumed to be equivalent to an equilibrium spring with a deformation gradient <span class="html-italic"><b>F</b></span>, and <span class="html-italic">n</span> parallel Maxwell element, each characterized by an elastic deformation gradient <math display="inline"><semantics> <msubsup> <mi mathvariant="bold-italic">F</mi> <mi mathvariant="bold-italic">i</mi> <mi mathvariant="bold-italic">e</mi> </msubsup> </semantics></math> and a viscous deformation gradient <math display="inline"><semantics> <msubsup> <mi mathvariant="bold-italic">F</mi> <mi mathvariant="bold-italic">i</mi> <mi mathvariant="bold-italic">v</mi> </msubsup> </semantics></math> (1 ≤ <span class="html-italic">i</span> ≤ <span class="html-italic">n</span>).</p>
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<p>The fitting stress–stretch curves between theoretical model and experimental data.</p>
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<p>Theoretical stress–stretch curves at different stretching rates.</p>
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<p>(<b>a</b>) GRU–FNN architecture; (<b>b</b>) details of GRU; (<b>c</b>) details of FNN.</p>
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<p>Evolution of the loss during training and testing with respect to epochs.</p>
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<p>The comparison of the stress–strain curves from the training data and the model’s prediction after 5000 epochs.</p>
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<p>The comparison of the stress–strain curves from testing data and model’s prediction after 5000 epochs.</p>
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<p>Evolution of loss with respect to epochs during training and testing at 273 K.</p>
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<p>The comparison of the stress–stretch curves from the experimental data and the model’s prediction at 273 K after 5300 epochs.</p>
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<p>Evolution of the loss with respect to epochs during training and testing at 273 K.</p>
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<p>The comparison of the stress–strain curves from the experimental data and the model’s prediction at 273 K.</p>
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<p>Evolution of loss with respect to epochs during training and testing at 313 K.</p>
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<p>The comparison of the stress–strain curves from the experimental data and the model’s prediction at 313 K.</p>
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<p>Evolution of loss with respect to epochs during training and testing at 333 K.</p>
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<p>The comparison of the stress–strain curves from the experimental data and the model’s prediction at 333 K.</p>
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<p>The comparison of the stress–strain curves from the model’s prediction at 273 K and the experimental data with (<b>a</b>) 0.5% noise and (<b>b</b>) 1.0% noise.</p>
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