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Search Results (1,637)

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27 pages, 1643 KiB  
Article
Sea Horse Optimization–Deep Neural Network: A Medication Adherence Monitoring System Based on Hand Gesture Recognition
by Palanisamy Amirthalingam, Yasser Alatawi, Narmatha Chellamani, Manimurugan Shanmuganathan, Mostafa A. Sayed Ali, Saleh Fahad Alqifari, Vasudevan Mani, Muralikrishnan Dhanasekaran, Abdulelah Saeed Alqahtani, Majed Falah Alanazi and Ahmed Aljabri
Sensors 2024, 24(16), 5224; https://doi.org/10.3390/s24165224 - 12 Aug 2024
Abstract
Medication adherence is an essential aspect of healthcare for patients and is important for achieving medical objectives. However, the lack of standard techniques for measuring adherence is a global concern, making it challenging to accurately monitor and measure patient medication regimens. The use [...] Read more.
Medication adherence is an essential aspect of healthcare for patients and is important for achieving medical objectives. However, the lack of standard techniques for measuring adherence is a global concern, making it challenging to accurately monitor and measure patient medication regimens. The use of sensor technology for medication adherence monitoring has received much attention lately since it makes it possible to continuously observe patients’ medication adherence behavior. Sensor devices or smart wearables utilize state-of-the-art machine learning (ML) methods to analyze intricate data patterns and provide predictions accurately. The key aim of this work is to develop a sensor-based hand gesture recognition model to predict medication activities. In this research, a smart sensor device-based hand gesture prediction model is developed to recognize medication intake activities. The device includes a tri-axial gyroscope, geometric, and accelerometer sensors to sense and gather data from hand gestures. A smartphone application gathers hand gesture data from the sensor device, which is then stored in the cloud database in a .csv format. These data are collected, processed, and classified to recognize the medication intake activity using the proposed novel neural network model called Sea Horse Optimization–Deep Neural Network (SHO-DNN). The SHO technique is implemented to update the biases and weights and the number of hidden layers in the DNN model. By updating these parameters, the DNN model is improved in classifying the samples of hand gestures to identify the medication activities. The research model demonstrates impressive performance, with an accuracy of 98.59%, sensitivity of 97.82%, precision of 98.69%, and an F1 score of 98.48%. Hence, the proposed model outperformed the most available models in all the aforementioned aspects. The results indicate that this model is a promising approach for medication adherence monitoring in healthcare applications, instilling confidence in its effectiveness. Full article
13 pages, 2797 KiB  
Article
A Novel Radial Basis and Sigmoid Neural Network Combination to Solve the Human Immunodeficiency Virus System in Cancer Patients
by Zulqurnain Sabir, Sahar Dirani, Sara Bou Saleh, Mohamad Khaled Mabsout and Adnène Arbi
Mathematics 2024, 12(16), 2490; https://doi.org/10.3390/math12162490 - 12 Aug 2024
Abstract
The purpose of this work is to design a novel process based on the deep neural network (DNN) process to solve the dynamical human immunodeficiency virus (HIV-1) infection system in cancer patients (HIV-1-ISCP). The dual hidden layer neural network structure using the combination [...] Read more.
The purpose of this work is to design a novel process based on the deep neural network (DNN) process to solve the dynamical human immunodeficiency virus (HIV-1) infection system in cancer patients (HIV-1-ISCP). The dual hidden layer neural network structure using the combination of a radial basis and sigmoid function with twenty and forty neurons is presented for the solution of the nonlinear HIV-1-ISCP. The mathematical form of the model is divided into three classes named cancer population cells (T), healthy cells (H), and infected HIV (I) cells. The validity of the designed novel scheme is proven through the comparison of the results. The optimization is performed using a competent scale conjugate gradient procedure, the correctness of the proposed numerical approach is observed through the reference results, and negligible values of the absolute error are around 10−3 to 10−4. The database numerical solutions are achieved from the Runge–Kutta numerical scheme, and are used further to reduce the mean square error by taking 72% of the data for training, while 14% of the data is taken for testing and substantiations. To authenticate the credibility of this novel procedure, graphical plots using different performances are derived. Full article
(This article belongs to the Special Issue Numerical Analysis and Modeling)
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<p>A process of the DNN based on two hidden layers for solving the nonlinear HIV-1-ISCP model.</p>
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<p>A trained neural network for the nonlinear dynamics based on the HIV-1-ISCP. (<b>a</b>) A trained neural network for case 1; (<b>b</b>) atrained neural network for case 2; (<b>c</b>) atrained neural network for case 3.</p>
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<p>MSE and gradient values for solving the nonlinear HIV-1-ISCP. (<b>a</b>) MSE values for 1st Case; (<b>b</b>) MSE values for 2nd Case; (<b>c</b>) MSE values for 3rd Case; (<b>d</b>) Gradient for 1st case; (<b>e</b>) Gradient for 2nd case; (<b>f</b>) Gradient for 3rd case.</p>
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<p>MSE and gradient values for solving the nonlinear HIV-1-ISCP. (<b>a</b>) MSE values for 1st Case; (<b>b</b>) MSE values for 2nd Case; (<b>c</b>) MSE values for 3rd Case; (<b>d</b>) Gradient for 1st case; (<b>e</b>) Gradient for 2nd case; (<b>f</b>) Gradient for 3rd case.</p>
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<p>Function fitness for solving the nonlinear HIV-1-ISCP. (<b>a</b>) Func. Fit (1); (<b>b</b>) Func. Fit (2); (<b>c</b>) Func. Fit (3).</p>
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<p>Error values for solving the nonlinear HIV-1-ISCP. (<b>a</b>) Error values for case 1; (<b>b</b>) Error values for case 2; (<b>c</b>) Error values for case 3.</p>
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<p>Regression for solving the nonlinear HIV-1-ISCP. (<b>a</b>) Regression values for case 1; (<b>b</b>) Regression values for case 2; (<b>c</b>) Regression values for case 3.</p>
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<p>Results for each case of the nonlinear HIV-1-ISCP. (<b>a</b>) Results forcase 1; (<b>b</b>) Results for case 2; (<b>c</b>) Results for case 3.</p>
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25 pages, 7790 KiB  
Article
Mix-VIO: A Visual Inertial Odometry Based on a Hybrid Tracking Strategy
by Huayu Yuan, Ke Han and Boyang Lou
Sensors 2024, 24(16), 5218; https://doi.org/10.3390/s24165218 - 12 Aug 2024
Abstract
In this paper, we proposed Mix-VIO, a monocular and binocular visual-inertial odometry, to address the issue where conventional visual front-end tracking often fails under dynamic lighting and image blur conditions. Mix-VIO adopts a hybrid tracking approach, combining traditional handcrafted tracking techniques with Deep [...] Read more.
In this paper, we proposed Mix-VIO, a monocular and binocular visual-inertial odometry, to address the issue where conventional visual front-end tracking often fails under dynamic lighting and image blur conditions. Mix-VIO adopts a hybrid tracking approach, combining traditional handcrafted tracking techniques with Deep Neural Network (DNN)-based feature extraction and matching pipelines. The system employs deep learning methods for rapid feature point detection, while integrating traditional optical flow methods and deep learning-based sparse feature matching methods to enhance front-end tracking performance under rapid camera motion and environmental illumination changes. In the back-end, we utilize sliding window and bundle adjustment (BA) techniques for local map optimization and pose estimation. We conduct extensive experimental validations of the hybrid feature extraction and matching methods, demonstrating the system’s capability to maintain optimal tracking results under illumination changes and image blur. Full article
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<p>(<b>a</b>,<b>b</b>) show adjacent images from the EuRoc dataset [<a href="#B12-sensors-24-05218" class="html-bibr">12</a>], where noticeable blurring occurs between images. (<b>c</b>,<b>d</b>) display adjacent images from the UMA-VI dataset [<a href="#B13-sensors-24-05218" class="html-bibr">13</a>], highlighting significant changes in lighting between the two images. Blue indicates fewer tracking instances, representing initial feature point, while red indicates frequent successful feature matches due to multiple trackings. Points with rings illustrate results obtained through traditional feature extraction and optical flow matching; the inner circle radius represents the suppression radius for SP features, and the outer circle radius for traditional features, thus dispersing the feature points. The green arrows point to the positions of the points in the previous frame from current frame. Points without rings represent SP features, with 1024 features extracted in the image. It can be observed that in (<b>a</b>,<b>b</b>), despite the blurring, optical flow matching still matches many feature points, but SP + LG largely fails. In (<b>c</b>,<b>d</b>), due to drastic illumination changes, optical flow matching fails, but SP + LG still successfully matches many feature points. The traditional approach and deep learning approach complement each other, achieving better tracking results.</p>
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<p>Mix-VIO system overview.</p>
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<p>Mixed-up feature-tracking pipeline overview.</p>
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<p>Superpoint network architecture.</p>
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<p>Lightglue network using Superpoint as the input.</p>
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<p>The process of point tracking and the hybrid feature-tracking strategy. The red-colored points represent points where optical flow tracking fails; green points represent Superpoint features which are matched using Lightglue; blue points represent points tracked by optical flow. It is noteworthy that yellow Superpoint points, although unmatched, are added to the system if the number of feature points does not reach the threshold, serving as a basis for feature matching in the next frame.</p>
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<p>Sequences (Machine House, MH) and collection equipment in EuRoc dataset.</p>
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<p>Comparison of SP + LG (<b>a</b>,<b>b</b>) and GFT+optical flow (<b>c</b>,<b>d</b>) methods under image blur caused by fast camera movement speed. To distinguish between the two, connect the points matched by the optical flow method with lines and represent the SP points with hollow circles.</p>
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<p>Comparison of another set of SP+LG (<b>a</b>,<b>b</b>) and GFT + optical flow (<b>c</b>,<b>d</b>) methods under image blur caused by rapid camera movement.</p>
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<p>Sequences (ill-change) in UMA-VI dataset. We selected some representative images, and in the actual sequence, several images are kept in low-light conditions. From left to right, the lighting in each row gradually dims and then is turned back on.</p>
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<p>Comparison of another set of SP + LG (<b>a</b>,<b>b</b>) and GFT + optical flow (<b>c</b>,<b>d</b>) methods under illumination variations caused by the lighting change. Even if completely dark images are skipped, the optical flow method still cannot track the results of the previous and subsequent frames, which will cause the VIO system to fail.</p>
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<p>Comparison of another set of SP + LG (<b>a</b>,<b>b</b>) and GFT + optical flow (<b>c</b>,<b>d</b>) methods under illumination variation caused by the lighting change in the UMA-VI dataset. Although it is no longer possible to clearly distinguish the contour, the SP + LG-based method can still achieve good tracking results.</p>
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14 pages, 1992 KiB  
Article
Solvation Enthalpies and Free Energies for Organic Solvents through a Dense Neural Network: A Generalized-Born Approach
by Sergei F. Vyboishchikov
Liquids 2024, 4(3), 525-538; https://doi.org/10.3390/liquids4030030 (registering DOI) - 12 Aug 2024
Viewed by 89
Abstract
A dense artificial neural network, ESE-ΔH-DNN, with two hidden layers for calculating both solvation free energies ΔG°solv and enthalpies ΔH°solv for neutral solutes in organic solvents is proposed. The input features are generalized-Born-type monatomic and pair electrostatic [...] Read more.
A dense artificial neural network, ESE-ΔH-DNN, with two hidden layers for calculating both solvation free energies ΔG°solv and enthalpies ΔH°solv for neutral solutes in organic solvents is proposed. The input features are generalized-Born-type monatomic and pair electrostatic terms, the molecular volume, and atomic surface areas of the solute, as well as five easily available properties of the solvent. ESE-ΔH-DNN is quite accurate for ΔG°solv, with an RMSE (root mean square error) below 0.6 kcal/mol and an MAE (mean absolute error) well below 0.4 kcal/mol. It performs particularly well for alkane, aromatic, ester, and ketone solvents. ESE-ΔH-DNN also exhibits a fairly good accuracy for ΔH°solv prediction, with an RMSE below 1 kcal/mol and an MAE of about 0.6 kcal/mol. Full article
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<p>DNN architecture used in the present work. The first row (various colors) denotes the original 56 input features. The dimensionality reduction is achieved via a 56 × 40 linear transformation. The second row (40 red circles) represents the DNN input layer (40 linear combinations of the 56 initial features). The following blue circles denote two hidden layers (14 and 6 neurons, respectively). The green circles at the bottom are neurons in the output layer, corresponding to Δ<span class="html-italic">G</span>°<sub>solv</sub> and Δ<span class="html-italic">H</span>°<sub>solv</sub>.</p>
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<p>Solvation free energies (in kcal/mol) calculated by ESE-ΔH-DNN: (<b>a</b>) the entire testing set (922 entries); (<b>b</b>) amide solvents (56 entries); (<b>c</b>) alkane solvents (245 entries); (<b>d</b>) aromatic solvents (81 entries) versus reference values. Red points denote outliers with a deviation greater than 1 kcal/mol. The slanting line represents the identity line.</p>
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<p>Solvation enthalpies (in kcal/mol) calculated by ESE-ΔH-DNN: (<b>a</b>) the entire testing set (1036 entries); (<b>b</b>) amide solvents (39 entries) versus reference values. Red points denote outliers with a deviation greater than 1 kcal/mol. The slanting line represents the identity line.</p>
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15 pages, 5540 KiB  
Article
Mobile Network Coverage Prediction Using Multi-Modal Model Based on Deep Neural Networks and Semantic Segmentation
by Sheng Zeng, Yuhang Ji, Weiwei Chen, Liping Yan and Xiang Zhao
Sensors 2024, 24(16), 5178; https://doi.org/10.3390/s24165178 - 10 Aug 2024
Viewed by 356
Abstract
A coverage prediction model helps network operators find coverage gaps, plan base station locations, evaluate quality of service, and build radio maps for spectrum sharing, interference management, localization, etc. Existing coverage prediction models rely on the height and transmission power of the base [...] Read more.
A coverage prediction model helps network operators find coverage gaps, plan base station locations, evaluate quality of service, and build radio maps for spectrum sharing, interference management, localization, etc. Existing coverage prediction models rely on the height and transmission power of the base station, or the assistance of a path loss model. All of these increase the complexity of large-scale coverage predictions. In this paper, we propose a multi-modal model, DNN-SS, which combines a DNN (deep neural network) and SS (semantic segmentation) to perform coverage prediction for mobile networks. Firstly, DNN-SS filters the samples with a geospatial-temporal moving average filter algorithm, and then uses a DNN to extract numerical features. Secondly, a pre-trained model is used to perform semantic segmentation of satellite images of the measurement area. Thirdly, a DNN is used to extract features from the results after semantic segmentation to form environmental features. Finally, the prediction model is trained on the dataset consisting of numerical features and environmental features. The experimental results on campus show that for random location prediction, the model achieves a RMSE (Root Mean Square Error) of 1.97 dB and a MAE (Mean Absolute Error) of 1.41 dB, which is an improvement of 10.86% and 10.2%, respectively, compared with existing models. For the prediction of a test area, the RMSE and MAE of the model are 4.32 dB and 3.45 dB, respectively, and the RMSE is only 0.22 dB lower than that of existing models. However, the DNN-SS model does not need the height, transmission power, and antenna gain of the base station, or a path loss model, which makes it more suitable for large-scale coverage prediction. Full article
(This article belongs to the Special Issue Advanced Microwave Sensors and Their Applications in Measurement)
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<p>Satellite map of the experimental area. Blue indicates measurement points, with denser blue indicating more measurement points. The yellow area served as validation data for the test area case.</p>
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<p>The architecture of DNN-SS.</p>
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<p>The fluctuation of the RSRPs around the measurement points (60 measurement points).</p>
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<p>The effect of the geospatial-temporal moving average filter (1000 samples).</p>
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<p>Semantic segmentation of the satellite image (one of the 16 sub-images): (<b>a</b>) satellite image. (<b>b</b>) The result of semantic segmentation by pre-training based on OCRNet.</p>
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<p>Box plot of real and predicted RSRPs at random locations.</p>
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<p>Histogram of real and predicted RSRPs at random locations.</p>
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<p>Comparison between real and predicted RSRPs (100 samples).</p>
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<p>Comparison of RMSE and MAE at random locations.</p>
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<p>Histogram of real and predicted RSRPs at test area.</p>
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<p>Comparison of RMSE and MAE at test area.</p>
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25 pages, 3302 KiB  
Article
Multi-Class Intrusion Detection Based on Transformer for IoT Networks Using CIC-IoT-2023 Dataset
by Shu-Ming Tseng, Yan-Qi Wang and Yung-Chung Wang
Future Internet 2024, 16(8), 284; https://doi.org/10.3390/fi16080284 - 8 Aug 2024
Viewed by 432
Abstract
This study uses deep learning methods to explore the Internet of Things (IoT) network intrusion detection method based on the CIC-IoT-2023 dataset. This dataset contains extensive data on real-life IoT environments. Based on this, this study proposes an effective intrusion detection method. Apply [...] Read more.
This study uses deep learning methods to explore the Internet of Things (IoT) network intrusion detection method based on the CIC-IoT-2023 dataset. This dataset contains extensive data on real-life IoT environments. Based on this, this study proposes an effective intrusion detection method. Apply seven deep learning models, including Transformer, to analyze network traffic characteristics and identify abnormal behavior and potential intrusions through binary and multivariate classifications. Compared with other papers, we not only use a Transformer model, but we also consider the model’s performance in the multi-class classification. Although the accuracy of the Transformer model used in the binary classification is lower than that of DNN and CNN + LSTM hybrid models, it achieves better results in the multi-class classification. The accuracy of binary classification of our model is 0.74% higher than that of papers that also use Transformer on TON-IOT. In the multi-class classification, our best-performing model combination is Transformer, which reaches 99.40% accuracy. Its accuracy is 3.8%, 0.65%, and 0.29% higher than the 95.60%, 98.75%, and 99.11% figures recorded in papers using the same dataset, respectively. Full article
(This article belongs to the Special Issue IoT Security: Threat Detection, Analysis and Defense)
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<p>Architecture diagram of this paper.</p>
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<p>Distribution of converted labels containing benign traffic.</p>
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<p>(<b>a</b>) Architecture diagram of DNN, (<b>b</b>) architecture diagram of RNN, (<b>c</b>) architecture diagram of CNN, (<b>d</b>) architecture diagram of LSTM, (<b>e</b>) architecture diagram of CNN + RNN, and (<b>f</b>) architecture diagram of CNN + LSTM.</p>
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<p>(<b>a</b>) Architecture diagram of DNN, (<b>b</b>) architecture diagram of RNN, (<b>c</b>) architecture diagram of CNN, (<b>d</b>) architecture diagram of LSTM, (<b>e</b>) architecture diagram of CNN + RNN, and (<b>f</b>) architecture diagram of CNN + LSTM.</p>
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<p>Transformer encoder architecture diagram.</p>
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<p>The schematic diagram of finding one of the outputs <math display="inline"><semantics> <mrow> <msub> <mi mathvariant="bold-italic">b</mi> <mn mathvariant="bold">1</mn> </msub> </mrow> </semantics></math>.</p>
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<p>(<b>a</b>) The schematic diagram of finding one of the output <math display="inline"><semantics> <mrow> <msup> <mi mathvariant="bold-italic">b</mi> <mrow> <mn mathvariant="bold">1</mn> <mo>,</mo> <mn mathvariant="bold">1</mn> </mrow> </msup> </mrow> </semantics></math>; (<b>b</b>) the schematic diagram of finding one of the output <math display="inline"><semantics> <mrow> <msup> <mi mathvariant="bold-italic">b</mi> <mrow> <mn mathvariant="bold">1</mn> <mo>,</mo> <mn mathvariant="bold">2</mn> </mrow> </msup> </mrow> </semantics></math>; and (<b>c</b>) the schematic diagram of adding two results.</p>
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<p>(<b>a</b>) The schematic diagram of finding one of the output <math display="inline"><semantics> <mrow> <msup> <mi mathvariant="bold-italic">b</mi> <mrow> <mn mathvariant="bold">1</mn> <mo>,</mo> <mn mathvariant="bold">1</mn> </mrow> </msup> </mrow> </semantics></math>; (<b>b</b>) the schematic diagram of finding one of the output <math display="inline"><semantics> <mrow> <msup> <mi mathvariant="bold-italic">b</mi> <mrow> <mn mathvariant="bold">1</mn> <mo>,</mo> <mn mathvariant="bold">2</mn> </mrow> </msup> </mrow> </semantics></math>; and (<b>c</b>) the schematic diagram of adding two results.</p>
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<p>Accuracy figure of DNN with (layer = 3, Node = 768, multi-class).</p>
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<p>Accuracy figure of RNN (with layer = 3, node = 768, multi-class classification).</p>
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<p>Accuracy figure of CNN (with layer = 3, node = 768, multi-class classification).</p>
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<p>Accuracy figure of LSTM (with layer = 3, node = 768, multi-class classification).</p>
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<p>Accuracy figure of CNN + RNN (with layer = 3, node = 768, multi-class classification).</p>
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<p>Accuracy figure of CNN + LSTM (with layer = 3, node = 768, multi-class classification).</p>
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<p>Accuracy figure of Transformer (with Dense Dimension = 2048, Number of Heads = 1, Number of Layers = 1, multi-class classification).</p>
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17 pages, 8415 KiB  
Article
Quantitative Prediction and Analysis of Rattle Index Using DNN on Sound Quality of Synthetic Sources with Gaussian Noise
by Jaehyeon Nam, Seokbeom Kim and Dongshin Ko
Sensors 2024, 24(16), 5128; https://doi.org/10.3390/s24165128 - 8 Aug 2024
Viewed by 219
Abstract
This study researched the prediction of the BSR noise evaluation quantitative index, Loudness N10, for sound sources with noise using statistics and machine learning. A total of 1170 data points was obtained from 130 automotive seats measured at 9-point positions, with Gaussian noise [...] Read more.
This study researched the prediction of the BSR noise evaluation quantitative index, Loudness N10, for sound sources with noise using statistics and machine learning. A total of 1170 data points was obtained from 130 automotive seats measured at 9-point positions, with Gaussian noise integrated to construct synthetic sound data. Ten physical quantities related to sound quality and sound pressure were used and defined as dB and fluctuation strength, considering statistical characteristics and Loudness N10. BSR quantitative index prediction was performed using regression analysis with K-fold cross-validation, DNN in hold-out, and DNN in K-fold cross-validation. The DNN in the K-fold cross-validation model demonstrated relatively superior prediction accuracy, especially when the data quantity was relatively small. The results demonstrate that applying machine learning to BSR prediction allows for the prediction of quantitative indicators without complex formulas and that specific physical quantities can be easily estimated even with noise. Full article
(This article belongs to the Section Physical Sensors)
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<p>Flow diagram of prediction method for Loudness N10.</p>
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<p>Experimental setup: (<b>a</b>) sensor position; (<b>b</b>) test equipment.</p>
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<p>Characteristics of added noise in raw data: (<b>a</b>) time domain; (<b>b</b>) frequency domain.</p>
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<p>Comparison of correlation coefficient.</p>
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<p>Schematic of K-fold cross-validation.</p>
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<p>Structure of traditional DNN model.</p>
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<p>Prediction error by linear regression.</p>
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<p>Prediction error by nonlinear regression.</p>
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<p>Prediction error by DNN using hold out.</p>
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<p>Prediction error by DNN using K-fold cross-validation.</p>
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<p>Comparing the performance of each model.</p>
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<p>Results of the experiment: (<b>a</b>) loss: (<b>b</b>) root mean square.</p>
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27 pages, 6668 KiB  
Article
Multi-Objectives Optimization of Plastic Injection Molding Process Parameters Based on Numerical DNN-GA-MCS Strategy
by Feng Guo, Dosuck Han and Naksoo Kim
Polymers 2024, 16(16), 2247; https://doi.org/10.3390/polym16162247 - 7 Aug 2024
Viewed by 350
Abstract
An intelligent optimization technique has been presented to enhance the multiple structural performance of PA6-20CF carbon fiber-reinforced polymer (CFRP) plastic injection molding (PIM) products. This approach integrates a deep neural network (DNN), Non-dominated Sorting Genetic Algorithm II (NSGA-II), and Monte Carlo simulation (MCS), [...] Read more.
An intelligent optimization technique has been presented to enhance the multiple structural performance of PA6-20CF carbon fiber-reinforced polymer (CFRP) plastic injection molding (PIM) products. This approach integrates a deep neural network (DNN), Non-dominated Sorting Genetic Algorithm II (NSGA-II), and Monte Carlo simulation (MCS), collectively referred to as the DNN-GA-MCS strategy. The main objective is to ascertain complex process parameters while elucidating the intrinsic relationships between processing methods and material properties. To realize this, a numerical study on the PIM structural performance of an automotive front engine hood panel was conducted, considering fiber orientation tensor (FOT), warpage, and equivalent plastic strain (PEEQ). The mold temperature, melt temperature, packing pressure, packing time, injection time, cooling temperature, and cooling time were employed as design variables. Subsequently, multiple objective optimizations of the molding process parameters were employed by GA. The utilization of Z-score normalization metrics provided a robust framework for evaluating the comprehensive objective function. The numerical target response in PIM is extremely intricate, but the stability offered by the DNN-GA-MCS strategy ensures precision for accurate results. The enhancement effect of global and local multi-objectives on the molded polymer–metal hybrid (PMH) front hood panel was verified, and the numerical results showed that this strategy can quickly and accurately select the optimal process parameter settings. Compared with the training set mean value, the objectives were increased by 8.63%, 6.61%, and 9.75%, respectively. Compared to the full AA 5083 hood panel scenario, our design reduces weight by 16.67%, and achievements of 92.54%, 93.75%, and 106.85% were obtained in lateral, longitudinal, and torsional strain energy, respectively. In summary, our proposed methodology demonstrates considerable potential in improving the, highlighting its significant impact on the optimization of structural performance. Full article
(This article belongs to the Special Issue Manufacturing of Polymer-Matrix Composites)
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<p>Numerical simulations implementation process of mapping operation flow in the Helius module for advanced material exchange.</p>
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<p>(<b>a</b>) PA6-20CF specimen samples manufactured by PIM, (<b>b</b>) schematic diagram of specimen samples with various fiber directions (<span class="html-italic">θ</span>) from the PIM samples (X as loading axis), (<b>c</b>) fiber arrangement and fiber orientation tensor (<span class="html-italic">θ</span>) in the sample of 0°, 45°, and 90°, (<b>d</b>) dimensions of ASTM-D 638-02a-IV type sample and slicing positions of tensile specimens from the plate. Reproduced from [<a href="#B5-polymers-16-02247" class="html-bibr">5</a>], MDPI, 2023.</p>
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<p>Numerical and experimental curves of PA6-20CF ASTM-D638 tensile specimens. Reproduced from [<a href="#B5-polymers-16-02247" class="html-bibr">5</a>], MDPI, 2023.</p>
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<p>Tensile engineering stress–engineering strain curves of PA6-20CF ASTM-D638 tensile specimens of fiber orientation tensor (<span class="html-italic">θ</span>) as (<b>a</b>) 0°, (<b>b</b>) 45°, and (<b>c</b>) 90°. Reproduced from [<a href="#B5-polymers-16-02247" class="html-bibr">5</a>], MDPI, 2023.</p>
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<p>Schematic diagram of assembly FEA model with car front hood panel, main parts’ measured dimensions, and injection molding process parameter LHD sampling scheme.</p>
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<p>The boundary conditions used for evaluation are (<b>a</b>) lateral stiffness, (<b>b</b>) transversal stiffness, and (<b>c</b>) torsional stiffness.</p>
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<p>Definition of objective functions for evaluation in an example case of (<b>a</b>) fiber orientation tensor, (<b>b</b>) warpage, and (<b>c</b>) equivalent plastic strain (PEEQ).</p>
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<p>Schematic diagram of injection molding process parameter optimization process.</p>
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<p>(<b>a</b>) Schematic diagram of injection molding process parameter DNN structure modeling and (<b>b</b>) K-fold cross-validation array. We used K-fold cross-validation to ensure database consistency before training and prevent overfitting. In the K-fold cross-validation process, the dataset is divided into k groups and then trained or validated according to predetermined distribution standards.</p>
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<p>The DNN validation results revealed a close correlation between predicted values and true values, as well as the relationship between approximation error and R-squared. Sub-figures show the training dataset (<b>a</b>–<b>c</b>) for FOT, warpage, and PEEQ and the test dataset (<b>d</b>–<b>f</b>) for FOT, warpage, and PEEQ. In these sub-figures, the circles represent the predicted mean of the DNN model, the error bars represent the standard deviation proving the reliability of the DNN model predictions, and the bar distribution represents the identification of collected data falling inside the range, demonstrating the setting reliability of the DNN model.</p>
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<p>Schematic diagram of NSGA-II workflow.</p>
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<p>Workflow of Monte Carlo simulation.</p>
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<p>Approximate RSM model for the melt temperature, mold temperature, packing pressure, and cooling time variables with structural performances, depicting the response relationship across FOT, warpage, and PEEQ. (<b>a</b>)–(<b>i</b>) Distinct variables for each structural performance. Each sub-figure shows a unique relationship, describing the diversifications within DNN models under deliberation.</p>
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<p>The Pareto optimal set contains multiple optimal responses with (<b>a</b>) 3D view design space section, (<b>b</b>) front-view section, (<b>c</b>) top-view section, and (<b>d</b>) side-view section.</p>
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<p>Pareto chart of types of the frequencies for various molding process parameters of multi-objectives of (<b>a</b>) fiber orientation tensor (FOT), (<b>b</b>) warpage, and (<b>c</b>) equivalent plastic strain (PEEQ).</p>
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<p>Comparison of PA6-20CF PMH and AA 5083 material case numerical optimization results of equivalent plastic strain (PEEQ) distribution with three boundary conditions of (<b>a</b>) lateral, (<b>b</b>) transverse, and (<b>c</b>) torsion.</p>
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<p>After-mapping local stiffness results of the multi-boundary conditions for (<b>a</b>) lateral, (<b>b</b>) transverse, and (<b>c</b>) torsion.</p>
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<p>Numerical optimization results of PA6-20CF PMH case and AA 5083 case of (<b>a</b>) comparison of strain energy values under lateral, transverse, and torsional conditions and (<b>b</b>) comparison of total strain energy value and weight value.</p>
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18 pages, 5562 KiB  
Article
A Stock Market Decision-Making Framework Based on CMR-DQN
by Xun Chen, Qin Wang, Chao Hu and Chengqi Wang
Appl. Sci. 2024, 14(16), 6881; https://doi.org/10.3390/app14166881 - 6 Aug 2024
Viewed by 624
Abstract
In the dynamic and uncertain stock market, precise forecasting and decision-making are crucial for profitability. Traditional deep neural networks (DNN) often struggle with capturing long-term dependencies and multi-scale features in complex financial time series data. To address these challenges, we introduce CMR-DQN, an [...] Read more.
In the dynamic and uncertain stock market, precise forecasting and decision-making are crucial for profitability. Traditional deep neural networks (DNN) often struggle with capturing long-term dependencies and multi-scale features in complex financial time series data. To address these challenges, we introduce CMR-DQN, an innovative framework that integrates discrete wavelet transform (DWT) for multi-scale data analysis, temporal convolutional network (TCN) for extracting deep temporal features, and a GRU–LSTM–Attention mechanism to enhance the model’s focus and memory. Additionally, CMR-DQN employs the Rainbow DQN reinforcement learning strategy to learn optimal trading strategies in a simulated environment. CMR-DQN significantly improved the total return rate on six selected stocks, with increases ranging from 20.37% to 55.32%. It also demonstrated substantial improvements over the baseline model in terms of Sharpe ratio and maximum drawdown, indicating increased excess returns per unit of total risk and reduced investment risk. These results underscore the efficiency and effectiveness of CMR-DQN in handling multi-scale time series data and optimizing stock market decisions. Full article
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<p>The architecture of CMR-DQN framework.</p>
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<p>The structural diagram of DWT-TCN.</p>
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<p>Working diagram of Rainbow DQN.</p>
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<p>Dueling architecture network.</p>
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<p>The accumulation of rewards and the variation trend of the loss function during the training process of the CMR-DQN model on six datasets.</p>
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<p>Results of Different Models on Six Datasets.</p>
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19 pages, 10406 KiB  
Article
A Data-Driven DNN Model to Predict the Ultimate Strength of a Ship’s Bottom Structure
by Im-jun Ban, Chaeog Lim, Gi-yong Kim, Seo-young Choi and Sung-chul Shin
J. Mar. Sci. Eng. 2024, 12(8), 1328; https://doi.org/10.3390/jmse12081328 - 6 Aug 2024
Viewed by 287
Abstract
Plates and curved plates are essential components in ship construction. In the design stage, the methods used to evaluate the ultimate strength required to confirm the structural safety of plates include prediction through analytical methods, finite-element analysis (FEA), and empirical formulas. However, with [...] Read more.
Plates and curved plates are essential components in ship construction. In the design stage, the methods used to evaluate the ultimate strength required to confirm the structural safety of plates include prediction through analytical methods, finite-element analysis (FEA), and empirical formulas. However, with nonlinear buckling, the results of the empirical formula and the FEA differ for small flank angles (1~9). As a result, the prediction of the nonlinear ultimate strength of flank angle (1~9) plates still requires significant computation time and cost. To compensate for this, this study performed an ultimate strength prediction method utilizing a deep neural network together with the 4050 curved plate analysis. In addition, this paper presents the analysis results of the nonlinear finite-element method and the geometric shape and ratio of curved plates as training data. Based on the results of this study, designers can more efficiently design appropriate curved plate members by considering the ultimate strength. Full article
(This article belongs to the Special Issue Data-Driven Methods for Marine Structures)
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<p>Overall configuration of the research paper.</p>
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<p>Schematic view of the curved plate.</p>
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<p>Curved plate scenario selection study.</p>
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<p>Mesh convergence study result.</p>
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<p>Applied boundary condition of the curved plate.</p>
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<p>Validation of the ultimate strength of the curved plate [<a href="#B15-jmse-12-01328" class="html-bibr">15</a>].</p>
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<p>Effect of slenderness ratio on analysis results.</p>
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<p>Effect of initial deflection on analysis results.</p>
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<p>Result of the curved plate with secondary buckling.</p>
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<p>Composition of the DNN model.</p>
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<p>Normalization results of features.</p>
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<p>MSE result according to the activation functions.</p>
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<p>Schematic function of ReLU.</p>
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<p>Deep learning model training result.</p>
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<p>Ultimate strength prediction result of deep learning model (all test data).</p>
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<p>Effect of ultimate strength on secondary buckling.</p>
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<p>Ultimate strength prediction result of deep learning model (secondary buckling test data).</p>
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<p>Ultimate strength prediction result of deep learning model (unlearned data).</p>
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17 pages, 6918 KiB  
Article
Real-Time Calculation of CO2 Conversion in Radio-Frequency Discharges under Martian Pressure by Introducing Deep Neural Network
by Ruiyao Li, Xucheng Wang and Yuantao Zhang
Appl. Sci. 2024, 14(16), 6855; https://doi.org/10.3390/app14166855 - 6 Aug 2024
Viewed by 420
Abstract
In recent years, the in situ resource utilization of CO2 in the Martian atmosphere by low-temperature plasma technology has garnered significant attention. However, numerical simulation is extremely time-consuming for modeling the complex CO2 plasma, involving tens of species and hundreds of [...] Read more.
In recent years, the in situ resource utilization of CO2 in the Martian atmosphere by low-temperature plasma technology has garnered significant attention. However, numerical simulation is extremely time-consuming for modeling the complex CO2 plasma, involving tens of species and hundreds of reactions, especially under Martian pressure. In this study, a deep neural network (DNN) with multiple hidden layers is introduced to investigate the CO2 conversion in radio-frequency (RF) discharges at a given power density under Martian pressure in almost real time. After training on the dataset obtained from the fluid model or experimental measurements, the DNN shows the ability to accurately and efficiently predict the various discharge characteristics and plasma chemistry of RF CO2 discharge even in seconds. Compared with conventional fluid models, the computational efficiency of the DNN is improved by nearly 106 times; thus, a real-time calculation of RF CO2 discharge can almost be achieved. The DNN can provide an enormous amount of data to enhance the simulation results due to the very high computational efficiency. The numerical data also suggest that the CO2 conversion increases with driving frequency at a fixed power density. This study shows the ability of the DNN-based approach to investigate CO2 conversion in RF discharges for various applications, providing a promising tool for the modeling of complex non-thermal plasmas. Full article
(This article belongs to the Section Applied Physics General)
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<p>Schematic diagram of DNN-assisted RF <math display="inline"><semantics> <mrow> <msub> <mi>CO</mi> <mn>2</mn> </msub> </mrow> </semantics></math> discharge modeling method.</p>
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<p>Temporal evolutions of current density and voltage predicted by the DNN in RF <math display="inline"><semantics> <msub> <mi>CO</mi> <mn>2</mn> </msub> </semantics></math> discharge with a comparison of the results obtained from the fluid simulation. Red dotted line: the predicted current density; green dotted line: the predicted voltage.</p>
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<p>Spatial distributions of time-averaged positive charge density, negative charge density, and electric field predicted by the DNN with a comparison of the results obtained from the fluid simulation.</p>
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<p>Spatial distributions of time-average charged particle density predicted by the DNN with a comparison of the results obtained from the fluid simulation.</p>
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<p>Spatial distributions of time-average vibrationally excited <math display="inline"><semantics> <msub> <mi>CO</mi> <mn>2</mn> </msub> </semantics></math> density predicted by the DNN with a comparison of the results obtained from the fluid simulation.</p>
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<p>RMS current density and RMS voltage predicted by the DNN as a function of the driving frequency at a given power density of 60 W/cm<sup>2</sup>.</p>
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<p>Spatial distributions of the time-averaged electric field predicted by the DNN for various driving frequencies at a given power density of 60 W/cm<sup>2</sup>.</p>
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<p>Spatial distributions of the time-averaged electron density predicted by the DNN for various driving frequencies at a given power density of 60 W/cm<sup>2</sup>.</p>
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<p>Spatial distributions of the time-averaged electron temperature predicted by the DNN for various driving frequencies at a given power density of 60 W/cm<sup>2</sup>.</p>
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<p>Spatial distributions of the time-averaged densities of the asymmetric stretching mode of <math display="inline"><semantics> <msub> <mi>CO</mi> <mn>2</mn> </msub> </semantics></math> molecules ((<b>a</b>) <math display="inline"><semantics> <mrow> <msub> <mi>CO</mi> <mn>2</mn> </msub> <msub> <mi mathvariant="normal">v</mi> <mn>1</mn> </msub> </mrow> </semantics></math>, (<b>b</b>) <math display="inline"><semantics> <mrow> <msub> <mi>CO</mi> <mn>2</mn> </msub> <msub> <mi mathvariant="normal">v</mi> <mn>2</mn> </msub> </mrow> </semantics></math>, (<b>c</b>) <math display="inline"><semantics> <mrow> <msub> <mi>CO</mi> <mn>2</mn> </msub> <msub> <mi mathvariant="normal">v</mi> <mn>3</mn> </msub> </mrow> </semantics></math>, (<b>d</b>) <math display="inline"><semantics> <mrow> <msub> <mi>CO</mi> <mn>2</mn> </msub> <msub> <mi mathvariant="normal">v</mi> <mn>4</mn> </msub> </mrow> </semantics></math>, (<b>e</b>) <math display="inline"><semantics> <mrow> <msub> <mi>CO</mi> <mn>2</mn> </msub> <msub> <mi mathvariant="normal">v</mi> <mn>5</mn> </msub> </mrow> </semantics></math>, (<b>f</b>) <math display="inline"><semantics> <mrow> <msub> <mi>CO</mi> <mn>2</mn> </msub> <msub> <mi mathvariant="normal">v</mi> <mn>6</mn> </msub> </mrow> </semantics></math>, (<b>g</b>) <math display="inline"><semantics> <mrow> <msub> <mi>CO</mi> <mn>2</mn> </msub> <msub> <mi mathvariant="normal">v</mi> <mn>7</mn> </msub> </mrow> </semantics></math>, and (<b>h</b>) <math display="inline"><semantics> <mrow> <msub> <mi>CO</mi> <mn>2</mn> </msub> <msub> <mi mathvariant="normal">v</mi> <mn>8</mn> </msub> </mrow> </semantics></math>) predicted by the DNN as a function of the driving frequency at a given power density of 60 W/cm<sup>2</sup>.</p>
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<p>Spatial distributions of the time-averaged (<b>a</b>) CO density and (<b>b</b>) <math display="inline"><semantics> <msub> <mi mathvariant="normal">O</mi> <mn>2</mn> </msub> </semantics></math> density predicted by the DNN as a function of the driving frequency at a given power density of 60 W/cm<sup>2</sup>.</p>
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<p>The <math display="inline"><semantics> <msub> <mi>CO</mi> <mn>2</mn> </msub> </semantics></math> conversion predicted by the DNN as a function of the driving frequency at a given power density of 60 W/cm<sup>2</sup>.</p>
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<p>Spatial distributions of the time-averaged electric field predicted by the DNN for various power densities at a driving frequency of 13.56 MHz.</p>
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<p>Spatial distributions of the time-averaged (<b>a</b>) CO density and (<b>b</b>) <math display="inline"><semantics> <msub> <mi mathvariant="normal">O</mi> <mn>2</mn> </msub> </semantics></math> density predicted by the DNN as a function of the power density at a given driving frequency of 13.56 MHz.</p>
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<p>The <math display="inline"><semantics> <msub> <mi>CO</mi> <mn>2</mn> </msub> </semantics></math> conversion predicted by the DNN as a function of the power density at a given driving frequency of 13.56 MHz.</p>
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14 pages, 6608 KiB  
Article
An Efficient Motion Adjustment Method for a Dual-Arm Transfer Robot Based on a Two-Level Neural Network and a Greedy Algorithm
by Mengqian Chen, Qiming Liu, Kai Wang, Zhiqiang Yang and Shijie Guo
Electronics 2024, 13(15), 3090; https://doi.org/10.3390/electronics13153090 - 5 Aug 2024
Viewed by 365
Abstract
As the manipulation object of a patient transfer robot is a human, which can be considered a complex and time-varying system, motion adjustment of a patient transfer robot is inevitable and essential for ensuring patient safety and comfort. This paper proposes a motion [...] Read more.
As the manipulation object of a patient transfer robot is a human, which can be considered a complex and time-varying system, motion adjustment of a patient transfer robot is inevitable and essential for ensuring patient safety and comfort. This paper proposes a motion adjustment method based on a two-level deep neural network (DNN) and a greedy algorithm. First, a dataset including information about human posture and contact forces is collected by experiment. Then, the DNN, which is used to estimate contact force, is established and trained with the collected datasets. Furthermore, the adjustment is conducted by comparing the estimated contact force of the next state and the real contact force of the current state by a greedy algorithm. To assess the validity, first, we employed the DNN to estimate contact force and obtained the accuracy and speed of 84% and 30 ms, respectively (implemented with an affordable processing unit). Then, we applied the greedy algorithm to a dual-arm transfer robot and found that the motion adjustment could reduce the contact force and improve human comfort efficiently; these validated the effectiveness of our proposal and provided a new approach to adjust the posture of the care receiver for improving their comfort through reducing the contact force between human and robot. Full article
(This article belongs to the Special Issue Applications of Artificial Intelligence in Mechanical Engineering)
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<p>Operational steps of a patient transfer robot.</p>
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<p>Structure of the developed network.</p>
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<p>Function of the encoder.</p>
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<p>Structure of the first level subnetwork. <b><span class="html-italic">S</span></b> is the heatmap 1, <b>L</b> is the vector field, <b><span class="html-italic">S</span></b>′ is the heatmap 2, C: X-Y represents a convolutional layer, which includes X convolutional kernels with the size of Y × Y, and P:N is a maxpooling layer, where N is the stride of filter.</p>
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<p>Structure of the second level subnetwork. <b>F</b>, <b>F</b>′, <b>Z</b>, and <b>Z</b>′ are feature maps, <b>N</b> is the number of iterations.</p>
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<p>Structure of the multi-head attention module.</p>
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<p>Flowchart for lifting state adjustment. A represents a virtual action set; a is an action in the action set A; s is the current lifting state, and s_ is the next lifting state, which is generated from s and a through a real human-machine system; S_ is the next virtual lifting state set. The virtual human-machine system functions to generate the next virtual lifting state set based on s and an A. While the real human-machine system functions to generate the real next lifting state based on s and a, DNN is the proposed neural network, and <span class="html-italic">Min</span>() is a minimized function, which is capable of choosing a minimum value from an array. <span class="html-italic">F</span> is the virtual contact force set, while <span class="html-italic">f</span> is the real contact force. Arrow in dash functions as updating.</p>
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<p>Sequences of generating the virtual lifting state.</p>
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<p>Platform for data collection.</p>
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<p>Markers for data collection.</p>
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<p>Lifting state adjustment for data collection.</p>
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<p>Typical examples of the CFPR dataset. The first column shows the position of human joints and the lifting points, the second column indicates the weight of the subjects, and the last column depicts the contact force on thigh and back of the experimenters.</p>
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<p>Examples of lifting state adjustment. (<b>a</b>) the lifting state before adjustment; (<b>b</b>) the lifting state after adjustment.</p>
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18 pages, 4076 KiB  
Article
Deep Ensemble Learning-Based Sensor for Flotation Froth Image Recognition
by Xiaojun Zhou and Yiping He
Sensors 2024, 24(15), 5048; https://doi.org/10.3390/s24155048 - 4 Aug 2024
Viewed by 377
Abstract
Froth flotation is a widespread and important method for mineral separation, significantly influencing the purity and quality of extracted minerals. Traditionally, workers need to control chemical dosages by observing the visual characteristics of flotation froth, but this requires considerable experience and operational skills. [...] Read more.
Froth flotation is a widespread and important method for mineral separation, significantly influencing the purity and quality of extracted minerals. Traditionally, workers need to control chemical dosages by observing the visual characteristics of flotation froth, but this requires considerable experience and operational skills. This paper designs a deep ensemble learning-based sensor for flotation froth image recognition to monitor actual flotation froth working conditions, so as to assist operators in facilitating chemical dosage adjustments and achieve the industrial goals of promoting concentrate grade and mineral recovery. In our approach, training and validation data on flotation froth images are partitioned in K-fold cross validation, and deep neural network (DNN) based learners are generated through pre-trained DNN models in image-enhanced training data, in order to improve their generalization and robustness. Then, a membership function utilizing the performance information of the DNN-based learners during the validation is proposed to improve the recognition accuracy of the DNN-based learners. Subsequently, a technique for order preference by similarity to an ideal solution (TOPSIS) based on the F1 score is proposed to select the most probable working condition of flotation froth images through a decision matrix composed of the DNN-based learners’ predictions via a membership function, which is adopted to optimize the combination process of deep ensemble learning. The effectiveness and superiority of the designed sensor are verified in a real industrial gold–antimony froth flotation application. Full article
(This article belongs to the Special Issue Deep Learning Technology and Image Sensing: 2nd Edition)
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<p>Combination methods based on meta-classifiers.</p>
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<p>Combination methods based on voting.</p>
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<p>Combination methods based on aggregation rules.</p>
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<p>Scheme of flotation froth image recognition in our deep ensemble learning-based sensor.</p>
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<p>The flowchart of our deep ensemble learning method for flotation froth image recognition.</p>
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<p>Partitioning of training, validation, and testing sets.</p>
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<p>Flotation froth under eight different working conditions.</p>
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<p>Accuracy in base learners in flotation froth image recognition task.</p>
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<p>Confusion matrix of our method.</p>
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<p>Accuracy of classical ensemble learning.</p>
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<p>Accuracy of different combination methods on testing data.</p>
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<p>Accuracy of base learners using membership function or not.</p>
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<p>Accuracy of different combination methods on testing data under image interference.</p>
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25 pages, 4586 KiB  
Article
Prediction of Boiling Heat Transfer Coefficient for Micro-Fin Using Mini-Channel
by Tomihiro Kinjo, Yuichi Sei, Niccolo Giannetti, Kiyoshi Saito and Koji Enoki
Appl. Sci. 2024, 14(15), 6777; https://doi.org/10.3390/app14156777 - 2 Aug 2024
Viewed by 332
Abstract
The prediction of the heat transfer coefficient commonly relies on the development of new empirical prediction equations when operating conditions and refrigerants change from the existing equations. Creating new prediction equations is expensive and time-consuming; therefore, recent attention has been given to machine [...] Read more.
The prediction of the heat transfer coefficient commonly relies on the development of new empirical prediction equations when operating conditions and refrigerants change from the existing equations. Creating new prediction equations is expensive and time-consuming; therefore, recent attention has been given to machine learning approaches. However, machine learning requires a large amount of data, and insufficient data can result in inadequate accuracy and applicability. This study showed that using mini-channel data as highly relevant data for the micro-fin heat transfer coefficient yields high prediction accuracy, even when the experimental dataset of interest is limited. In the proposed method, we added dimensionless numbers assumed to significantly influence heat transfer coefficients calculated from experimental data to the training dataset. This allowed efficient learning of the characteristics of thin liquid films present in mini-channels and micro-fins. By combining distinctive physical mechanisms related to heat transfer coefficients with DNN/GPR/Fine-tuning, the proposed method can predict 96.7% of the data points within ±30% deviation. In addition, it has been confirmed that the dryout quality and post-dryout heat transfer coefficients were predicted with high accuracy. Additionally, we utilized visualization techniques to investigate the contents of the black-box machine learning models. Full article
(This article belongs to the Section Energy Science and Technology)
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<p>Images of boiling by thin liquid films in mini-channels and micro-fins.</p>
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<p>Calculation process of node.</p>
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<p>Overall structure of deep neural networks.</p>
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<p>Distribution of the mini-channel database: (<b>a</b>) saturation pressure, (<b>b</b>) heat flux, (<b>c</b>) mass flux, (<b>d</b>) quality, (<b>e</b>) work fluids.</p>
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<p>Distribution of the micro-fin database: (<b>a</b>) saturation pressure, (<b>b</b>) heat flux, (<b>c</b>) mass flux, (<b>d</b>) quality, (<b>e</b>) work fluids.</p>
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<p>Pre-training and Fine-tuning, with consideration of physical mechanisms (Case 3, Present).</p>
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<p>Prediction using micro-fins and consideration of physical mechanisms (Case 3, Present).</p>
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<p>Overview of the Proposed Method Incorporating Dimensionless Numbers.</p>
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<p>Model structure of training phase using pre-training and fine-tuning, with consideration of physical mechanisms (Case 3, Present).</p>
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<p>Comparison of predictions and experimental data: (<b>a</b>) Results of DNN (Case 1); (<b>b</b>) Results of DNN + GPR (Case 2); (<b>c</b>) Results of fine-tuning and consideration of physical mechanisms (Case 3).</p>
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<p>Variance (uncertainty) vs. mean squared error.</p>
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<p>Impact on model output (for micro-fin vs. mini-channel data).</p>
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<p>Impact on Case 3 model output (pre-training vs. fine-tuning and consideration of physical mechanisms).</p>
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<p>Comparison of predictions and experimental data (mini-channel data &gt; micro-fin data): (<b>a</b>) Results of DNN (Case 1); (<b>b</b>) Results of DNN + GPR (Case 2); (<b>c</b>) Results of fine-tuning and consideration of physical mechanisms (Case 3).</p>
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<p>Comparison of prediction (open) and experimental (closed) heat transfer coefficients.</p>
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20 pages, 4456 KiB  
Article
Predicting the Characteristics of High-Speed Serial Links Based on a Deep Neural Network (DNN)—Transformer Cascaded Model
by Liyin Wu, Jingyang Zhou, Haining Jiang, Xi Yang, Yongzheng Zhan and Yinhang Zhang
Electronics 2024, 13(15), 3064; https://doi.org/10.3390/electronics13153064 - 2 Aug 2024
Viewed by 393
Abstract
The design level of channel physical characteristics has a crucial influence on the transmission quality of high-speed serial links. However, channel design requires a complex simulation and verification process. In this paper, a cascade neural network model constructed of a Deep Neural Network [...] Read more.
The design level of channel physical characteristics has a crucial influence on the transmission quality of high-speed serial links. However, channel design requires a complex simulation and verification process. In this paper, a cascade neural network model constructed of a Deep Neural Network (DNN) and a Transformer is proposed. This model takes physical features as inputs and imports a Single-Bit Response (SBR) as a connection, which is enhanced through predicting frequency characteristics and equalizer parameters. At the same time, signal integrity (SI) analysis and link optimization are achieved by predicting eye diagrams and channel operating margins (COMs). Additionally, Bayesian optimization based on the Gaussian process (GP) is employed for hyperparameter optimization (HPO). The results show that the DNN–Transformer cascaded model achieves high-precision predictions of multiple metrics in performance prediction and optimization, and the maximum relative error of the test-set results is less than 2% under the equalizer architecture of a 3-taps TX FFE, an RX CTLE with dual DC gain, and a 12-taps RX DFE, which is more powerful than other deep learning models in terms of prediction ability. Full article
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<p>Common structure of a SerDes circuit.</p>
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<p>(<b>a</b>) FD. (<b>b</b>) TD. Illustration of two different simulation methods for detecting SI.</p>
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<p>A typical COM model.</p>
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<p>COM calculation process.</p>
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<p>Channel fabrication and simulation process.</p>
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<p>The structure of the M-P neuron model.</p>
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<p>The structure of this study’s DNN.</p>
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<p>The structure of our Transformer for regression tasks.</p>
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<p>The structure of the cascaded model.</p>
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<p>Comparison of predicted and actual values for (<b>a</b>) IL and (<b>b</b>) RL.</p>
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<p>Relative errors of eye diagrams for test set channels in the two modulation formats.</p>
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<p>True and predicted results for (<b>a</b>) the SBR before equalization and (<b>b</b>) the SBR after equalization for 3-taps FFE + CTLE + 12-taps DFE test set channels (ID: 3).</p>
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<p>Relative error and COM values for PAM4 coding (ID: 1–40) in the standard equalizer configuration.</p>
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<p>Comparison of predicted and actual equalizer parameter results.</p>
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