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

Years

Between: -

Subjects

remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline

Journals

remove_circle_outline
remove_circle_outline
remove_circle_outline

Article Types

Countries / Regions

remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline

Search Results (550)

Search Parameters:
Keywords = whale optimization algorithm

Order results
Result details
Results per page
Select all
Export citation of selected articles as:
24 pages, 9598 KiB  
Article
Discharge Voltage Prediction Model of Batteries in Different Degradation States Based on IWOA-ATCN
by Jingwei Yang, Yitong Chen, Qiang Huang, Guilong Wu, Lin Liu, Zhimin Yang and Yu Huang
Processes 2025, 13(1), 46; https://doi.org/10.3390/pr13010046 (registering DOI) - 28 Dec 2024
Viewed by 202
Abstract
As a key technology for future decarbonization, storage batteries are widely used in areas such as electric vehicles and power systems. However, battery aging inevitably limits their broader application. To address the low accuracy in predicting discharge voltage under different aging states, this [...] Read more.
As a key technology for future decarbonization, storage batteries are widely used in areas such as electric vehicles and power systems. However, battery aging inevitably limits their broader application. To address the low accuracy in predicting discharge voltage under different aging states, this paper proposes the IWOA-ATCN method based on a TCN model with a sliding window mechanism. First, the improved whale optimization algorithm (IWOA) is employed to optimize the hyperparameters in the TCN model, including window size and sliding step, to obtain the optimal sample structure. Then, the temporal attention mechanism is introduced into the TCN model to accurately capture the temporal correlation of discharge voltage, thereby improving the prediction accuracy of long time series data. Finally, the model is tested on the NASA dataset with an RMSE of 0.0072, MAE of 0.0046, and R2 of 0.9984. The test results on the PL Sample dataset showed RMSE of 0.0081, MAE of 0.0040, and R2 of 0.9983. It is indicated that the prediction accuracy and stability of the IWOA-ATCN model are higher than other models, such as BP, RNN, and LSTM. Full article
Show Figures

Figure 1

Figure 1
<p>(<b>a</b>) Random initialization location map; (<b>b</b>) tent initialization location map.</p>
Full article ">Figure 2
<p>The dilated causal convolution structure.</p>
Full article ">Figure 3
<p>The network architecture diagram of ATCN model. The discharge curve of the battery serves as the input, which passes through eight layers of TCN modules, with each TCN layer employing the ReLU activation function to enhance nonlinearity. The first and last layers utilize residual connections. The features processed by the fifth TCN layer are then fed into a temporal attention layer, where attention weights are generated using the Tanh activation function and SoftMax operation. Finally, these weights are multiplied with the fifth TCN layer outputs to form the input of the next TCN layer. Among them, black dots represent the TCN layers, and blocks of different colors represent network layers with different functions.</p>
Full article ">Figure 4
<p>IWOA-ATCN model. (<b>a</b>) The Tent mapping, nonlinear convergence factor and inertia weight are introduced to improve the WOA algorithm for optimizing the window size and sliding step size. (<b>b</b>) The optimized hyperparameters and ATCN models are used for voltage prediction. Among them, black dots represent the TCN layers, and blocks of different colors represent net-work layers with different functions (<b>c</b>) The voltage prediction accuracy is validated by the publicly available dataset and evaluations. Different colors represent different degrees of degradation of the battery.</p>
Full article ">Figure 5
<p>Discharge voltage curves of different batteries in the NASA dataset. Relative Time indicates that the initial time of each voltage curve is set to 0, and the end time is the relative discharge time. The change in color indicates the relative length of discharge, that is, the degree of aging state of the corresponding battery. The colour of the curve from yellow to green indicates that the relative discharge duration is from long to short, which means that the aging state of the battery is aggravated.</p>
Full article ">Figure 6
<p>Discharge voltage curves of different batteries in the PL Sample dataset, in which ‘Relative Time’ indicates that the initial time of each voltage curve is unified to 0, and the end duration is the relative discharge time. The change in color represents the magnitude of the relative discharge time, which corresponds to the degree of aging of the respective battery. The colour of the curve goes from green to purple to blue indicating that the relative discharge duration goes from long to short, implying an aggravated state of aging of the battery.</p>
Full article ">Figure 7
<p>Fitness curves of various algorithms at 50-D.</p>
Full article ">Figure 8
<p>Bar chart of time consumption for various algorithms at 50-D. In the chart, the x-axis represents the different algorithms, the y-axis represents the 6 benchmark test functions, and the z-axis represents the duration of consumption (in seconds).</p>
Full article ">Figure 9
<p>Fitness values and their corresponding parameter changes for different numbers of whales in the NASA dataset. Among them, (<b>a</b>) shows the variation of the fitness curves with the number of iterations for different numbers of whales, while (<b>b</b>–<b>d</b>) represent the parameter changes when the number of whales is 5, 10, and 15, respectively.</p>
Full article ">Figure 10
<p>Visualization of the prediction results of each model on the NASA dataset. Each subfigure corresponds to a model and includes different aging states of the battery. ‘T-1’ represents the true value curve for aging state 1, while ‘P-1’ indicates the predicted value curve for the same state.</p>
Full article ">Figure 11
<p>Visualization of the prediction results of each model on the PL Sample dataset. Each subfigure corresponds to a model and includes different aging states of the battery. ‘T-1’ represents the true value curve for aging state 1, while ‘P-1’ indicates the predicted value curve for the same state.</p>
Full article ">
18 pages, 3176 KiB  
Article
Flow Control of Flow Boiling Experimental System by Whale Optimization Algorithm (WOA) Improved Single Neuron PID
by Yan Li, Miao Qian, Daojing Dai, Weitao Wu, Le Liu, Haonan Zhou and Zhong Xiang
Actuators 2025, 14(1), 5; https://doi.org/10.3390/act14010005 - 27 Dec 2024
Viewed by 157
Abstract
In the present study, to address the issue of flow rate instability in the flow boiling experimental system, a flow rate adaptive control system is developed using a single-neuron PID adaptive algorithm, enhanced with the whale optimization algorithm (WOA) for parameter tuning. A [...] Read more.
In the present study, to address the issue of flow rate instability in the flow boiling experimental system, a flow rate adaptive control system is developed using a single-neuron PID adaptive algorithm, enhanced with the whale optimization algorithm (WOA) for parameter tuning. A recursive least-squares online identification method is integrated to adapt to varying operating conditions. The simulation results demonstrate that in step response the WOA-improved single-neuron PID significantly mitigates the overshoot, with a mere 0.31% overshoot observed, marking a reduction of 98.27% compared to the traditional PID control. The output curve of the WOA-improved single-neuron PID closely aligns with the sinusoidal signal, exhibiting an average absolute error of 0.120, which is lower than that of the traditional PID (0.209) and fuzzy PID (0.296). The WOA-improved single-neuron PID (1.01 s) exhibited a faster return to a stable state compared to the traditional PID (2.46 s) and fuzzy PID (1.28 s). Finally, the effectiveness of the algorithm is validated through practical application. The results demonstrate that, compared to traditional PID and single-neuron PID algorithms, the WOA-improved single-neuron PID algorithm achieves an average flow stability of 9.9848 with a standard error of 0.0914394. It exhibits superior performance, including faster rise and settling times, and higher stability. Full article
Show Figures

Figure 1

Figure 1
<p>Flow boiling experimental system.</p>
Full article ">Figure 2
<p>(<b>a</b>) The system flow step response; (<b>b</b>) fitness of identification flow model at 1000 rpm speed, (<b>c</b>) fitness of identification flow model at 1500 rpm speed, and (<b>d</b>) fitness of identification flow model at 2000 rpm speed model fitness.</p>
Full article ">Figure 3
<p>Flow response at motor speed of 1000 rpm under case 1 and case 2.</p>
Full article ">Figure 4
<p>Single-neuron PID control block diagram.</p>
Full article ">Figure 5
<p>WOA improved single-neuron PID control block diagram.</p>
Full article ">Figure 6
<p>Step response simulation of three control algorithms.</p>
Full article ">Figure 7
<p>(<b>a</b>) Sine signal response and (<b>b</b>) absolute error of sine signal response.</p>
Full article ">Figure 8
<p>Anti-interference ability test of three algorithms.</p>
Full article ">Figure 9
<p>System online identification simulation.</p>
Full article ">Figure 10
<p>Physical system.</p>
Full article ">Figure 11
<p>(<b>a</b>) Step response of identification system and actual system and (<b>b</b>) the control effect of three control algorithms on system flow.</p>
Full article ">
20 pages, 9510 KiB  
Article
Generalized Type-2 Fuzzy Approach for Parameter Adaptation in the Whale Optimization Algorithm
by Leticia Amador-Angulo, Oscar Castillo, Patricia Melin and Zong Woo Geem
Mathematics 2024, 12(24), 4031; https://doi.org/10.3390/math12244031 - 22 Dec 2024
Viewed by 521
Abstract
An enhanced whale optimization algorithm (WOA) through the implementation of a generalized type-2 fuzzy logic system (GT2FLS) is outlined. The initial idea is to improve the efficacy of the original WOA using a GT2FLS to find the optimal values of the [...] Read more.
An enhanced whale optimization algorithm (WOA) through the implementation of a generalized type-2 fuzzy logic system (GT2FLS) is outlined. The initial idea is to improve the efficacy of the original WOA using a GT2FLS to find the optimal values of the r1 and r2 parameters of the WOA, for the case of optimizing mathematical functions. In the WOA algorithm, r1 is a variable that affects the new position of the whale in the search space, in this case, affecting the exploration, and r2 is a variable that has an effect on finding the local optima, which is an important factor for the exploration. The efficiency of a fuzzy WOA with a GT2FLS (FWOA-GT2FLS) is highlighted by presenting the excellent results of the case study of the benchmark function optimization. A relevant analysis and comparison with a bio-inspired algorithm based on artificial bees is also presented. Statistical tests and comparisons with other bio-inspired algorithms and the initial WOA, with type-1 FLS (FWOA-T1FLS) and interval type-2 FLS (FWOA-IT2FLS), are presented. For each of the methodologies, the metric for evaluation is the average of the minimum squared errors. Full article
Show Figures

Figure 1

Figure 1
<p>Visualization of the idea for the fuzzy WOA–GT2FLS.</p>
Full article ">Figure 2
<p>Visual representation of a GT2MF.</p>
Full article ">Figure 3
<p>FOU of a GT2MF.</p>
Full article ">Figure 4
<p>General structure of a GT2FLS.</p>
Full article ">Figure 5
<p>Example of an <math display="inline"><semantics> <mo>∝</mo> </semantics></math>-plane.</p>
Full article ">Figure 6
<p>Proposed structure of the GT2FLS.</p>
Full article ">Figure 7
<p>Graphical illustration of the ScaleTriScaleGaussT2MF.</p>
Full article ">Figure 8
<p>Representation of the surface of the output for <math display="inline"><semantics> <mrow> <mover accent="true"> <mrow> <msub> <mi>r</mi> <mn>1</mn> </msub> </mrow> <mo stretchy="true">→</mo> </mover> </mrow> </semantics></math>.</p>
Full article ">Figure 9
<p>Fuzzy rules of the GT2FLS.</p>
Full article ">Figure 10
<p>Plots of the functions: (<b>a</b>) Sphere, Griewangk; (<b>b</b>) Rastringin, Shewefel; (<b>c</b>) Sum of Different Power, Zakharov; (<b>d</b>) Dixon and Price, Levy; (<b>e</b>) Sum Squares and Rotated Hyper-Ellipsoid.</p>
Full article ">Figure 10 Cont.
<p>Plots of the functions: (<b>a</b>) Sphere, Griewangk; (<b>b</b>) Rastringin, Shewefel; (<b>c</b>) Sum of Different Power, Zakharov; (<b>d</b>) Dixon and Price, Levy; (<b>e</b>) Sum Squares and Rotated Hyper-Ellipsoid.</p>
Full article ">Figure 11
<p>Behavior of the Levy function with 500 dimensions.</p>
Full article ">
20 pages, 8699 KiB  
Article
Detection and Identification of Coating Defects in Lithium Battery Electrodes Based on Improved BT-SVM
by Xianju Wang, Shanhui Liu, Xuyang Kou, Yu Jiao and Yinfeng Li
Coatings 2024, 14(12), 1592; https://doi.org/10.3390/coatings14121592 - 19 Dec 2024
Viewed by 344
Abstract
Aiming to address the problems of uneven brightness and small defects of low contrast on the surface of lithium battery electrode (LBE) coatings, this study proposes a method for detection and identification of coatings defects in LBEs based on an improved Binary Tree [...] Read more.
Aiming to address the problems of uneven brightness and small defects of low contrast on the surface of lithium battery electrode (LBE) coatings, this study proposes a method for detection and identification of coatings defects in LBEs based on an improved Binary Tree Support Vector Machine (BT-SVM). Firstly, adaptive Gamma correction is applied to enhance an image, and an improved Canny algorithm combined with morphological processing is used to accurately detect the defect regions. Secondly, the shape and grayscale features of the defects are extracted from the connected defect areas, and these features are then fused and normalized. Finally, a BT-SVM multi-class classification model is constructed, with the Whale Optimization Algorithm (WOA) employed to assist in hyperparameter tuning. The experimental results show that the proposed method can effectively detect and identify five common types of defects in the coating of LBEs, including scratches, bubbles, metal leakage, particles, and decarbonization, with an average detection accuracy of 94.4% and an average detection time of less than 0.2 s, meeting the real-time detection requirements for online defect inspection. After Whale Optimization, the BT-SVM defect recognition model achieves an average recognition accuracy of 98.7%, significantly enhancing the performance of current defect detection technologies for LBE coatings. Full article
Show Figures

Figure 1

Figure 1
<p>Manufacturing process of LBEs.</p>
Full article ">Figure 2
<p>Defect detection and identification process.</p>
Full article ">Figure 3
<p>Gamma correction curve image.</p>
Full article ">Figure 4
<p>Enhancement effect images of the defect images. (<b>a1</b>–<b>a5</b>) Original images of the coating defects; and (<b>b1</b>–<b>b5</b>) enhanced images based on the improved Gamma correction.</p>
Full article ">Figure 5
<p>Flowchart of the defect segmentation process.</p>
Full article ">Figure 6
<p>Effect image of defect segmentation. (<b>a1</b>–<b>a5</b>) Enhanced defect images; (<b>b1</b>–<b>b5</b>) defect segmentation based on the improved Canny algorithm; and (<b>c1</b>–<b>c5</b>) defect region filling based on morphological closing operations.</p>
Full article ">Figure 7
<p>Defect contour marking. (<b>a1</b>,<b>a2</b>) Scratch defect marking and positioning and (<b>b1</b>,<b>b2</b>) decarbonization defect marking and positioning.</p>
Full article ">Figure 8
<p>Flowchart of defect classification based on BT-SVM.</p>
Full article ">Figure 9
<p>BT-SVM classification diagram. (<b>a</b>) The cycle of binary classification and (<b>b</b>) accumulated classification errors.</p>
Full article ">Figure 10
<p>Schematic diagram of hybrid-structure BT-SVM construction. (<b>a</b>) Initial sample data; (<b>b</b>) searching for extreme centroids; (<b>c</b>) hyperplane segmentation; and (<b>d</b>) SVM classification decision.</p>
Full article ">Figure 11
<p>Schematic diagram of WOA-optimized BT-SVM classification model.</p>
Full article ">Figure 12
<p>Comparison of various segmentation methods used on coating defect images.</p>
Full article ">Figure 13
<p>Defect classification confusion matrix.</p>
Full article ">Figure 14
<p>Evaluation of defect classification results.</p>
Full article ">Figure 15
<p>Comparison of defect classification accuracies using different classification methods.</p>
Full article ">Figure 16
<p>Comparison of classification accuracy for various defects.</p>
Full article ">Figure 17
<p>Comparison of average classification accuracy of defects.</p>
Full article ">
19 pages, 6911 KiB  
Article
Prediction of Water-Richness Zoning of Weathered Bedrock Based on Whale Optimisation Algorithm and Random Forest
by Enke Hou, Qianlong Li, Lei Yang, Meng Bi, Yan Li and Yangyang He
Water 2024, 16(24), 3655; https://doi.org/10.3390/w16243655 - 18 Dec 2024
Viewed by 332
Abstract
To effectively predict the water richness of weathered bedrock aquifers, the West First Plate area of the Hongliulin coal mine was taken as the study area, and 42 sets of pumping test borehole data from the weathered bedrock in the study area were [...] Read more.
To effectively predict the water richness of weathered bedrock aquifers, the West First Plate area of the Hongliulin coal mine was taken as the study area, and 42 sets of pumping test borehole data from the weathered bedrock in the study area were used as training and testing samples. A total of five indicators related to the water richness of weathered bedrock, namely, the aquifer thickness, sand–base ratio, core take rate, degree of weathering, and lithological structure index, were selected. A prediction model for the water richness of weathered bedrock aquifers (WOA-RF) was subsequently proposed by combining the whale optimisation algorithm (WOA) and random forest (RF). This model can predict the water-richness level of weathered bedrock in an area with no pumping test data. The geological information from 98 sets of exploration boreholes in the study area was comprehensively used to achieve water-richness zoning of the weathered bedrock. The results indicated that the WOA is effective in optimising parameters and improving model performance. The accuracies of the optimal WOA-RF model in the training set and the test set were 93.1% and 92.3%, respectively. Compared with those of the single RF model, the accuracy, recall, and F1 value of the optimal WOA-RF model were increased by 11.3%, 18.2%, and 11%, respectively, and the differences before and after optimisation were obvious. A comparison and analysis of the predictive performance of each model revealed that the overall performance of the WOA-RF model was better than that of the other models. The weathered bedrock in the study area as a whole is weakly to moderately rich in water, and the predicted results are in good agreement with reality, which can provide a reference for future safe production in the West First Plate area. Full article
Show Figures

Figure 1

Figure 1
<p>A schematic of the location of the study area.</p>
Full article ">Figure 2
<p>Stratigraphic column and section in the study area.</p>
Full article ">Figure 3
<p>Maps of the main factors controlling the water richness of weathered bedrock in the study area. (<b>a</b>) The thickness of the weathered bedrock, (<b>b</b>) degree of weathering, (<b>c</b>) sand–base ratio, (<b>d</b>) core take rate, and (<b>e</b>) rock structure index.</p>
Full article ">Figure 4
<p>Flowchart of WOA-RF model.</p>
Full article ">Figure 5
<p>Confusion matrix.</p>
Full article ">Figure 6
<p>Fitness variation for different population sizes during the optimisation process.</p>
Full article ">Figure 7
<p>Confusion matrix for WOA-RF model: (<b>a</b>) training set confusion matrix and (<b>b</b>) test set confusion matrix.</p>
Full article ">Figure 8
<p>Radar chart of classification performance indicators for each model.</p>
Full article ">Figure 9
<p>Water-richness zones of weathered bedrock.</p>
Full article ">
30 pages, 41611 KiB  
Article
Step-Wise Parameter Adaptive FMD Incorporating Clustering Algorithm in Rolling Bearing Compound Fault Diagnosis
by Shuai Xu, Chao Zhang, Jing Zhang, Guiyi Liu, Yangbiao Wu and Bing Ouyang
Symmetry 2024, 16(12), 1675; https://doi.org/10.3390/sym16121675 - 18 Dec 2024
Viewed by 350
Abstract
Ideally, the vibration signal of a rolling bearing should be symmetrical. However, in practical operation, the vibration signals in both time and frequency domains often exhibit asymmetry due to factors such as load, speed, and wear. The relatively weak composite fault characteristics are [...] Read more.
Ideally, the vibration signal of a rolling bearing should be symmetrical. However, in practical operation, the vibration signals in both time and frequency domains often exhibit asymmetry due to factors such as load, speed, and wear. The relatively weak composite fault characteristics are easily masked. Although the Feature Modal Decomposition (FMD) method is outstanding in diagnosing composite faults in bearings, its effectiveness is easily constrained by parameter selection. To address this, this paper proposes a stepwise parameter adaptive FMD method combined with a clustering algorithm, specifically designed for diagnosing composite faults in rolling bearings. Firstly, this study employs the Density Peak Clustering algorithm to determine the number of modes n in the composite fault vibration signal. Subsequently, considering the signal spectral energy and modal characteristics, a new composite fault index is formulated, namely, the adaptive weighted frequency domain kurtosis-to-information entropy ratio, as the fitness function. The Whale Optimization Algorithm determines the filter length L and the number of segments K, thereby achieving step-wise signal decomposition. Through in-depth analysis of signal symmetry and asymmetry, simulation and experimental verification confirm the effectiveness of this method. Compared with four other index-optimized FMD methods and traditional techniques, this method significantly reduces the influence of parameters on FMD, is capable of separating the characteristic frequencies related to composite faults, and performs excellently in the diagnosis of composite faults in rolling bearings. Full article
(This article belongs to the Section Engineering and Materials)
Show Figures

Figure 1

Figure 1
<p>Filtering characteristics of FMD with different Hurst exponents: (<b>a</b>) <span class="html-italic">H</span> = 0.2; (<b>b</b>) <span class="html-italic">H</span> = 0.5; (<b>c</b>) <span class="html-italic">H</span> = 0.8; (<b>d</b>) <span class="html-italic">H</span> = 1.</p>
Full article ">Figure 2
<p>Filtering characteristics of FMD under different numbers of modes <span class="html-italic">n</span>: (<b>a</b>) <span class="html-italic">n</span> = 4; (<b>b</b>) <span class="html-italic">n</span> = 6.</p>
Full article ">Figure 3
<p>Filtering characteristics of FMD under different filter lengths <span class="html-italic">L</span>: (<b>a</b>) <span class="html-italic">L</span> = 60; (<b>b</b>) <span class="html-italic">L</span> = 40.</p>
Full article ">Figure 4
<p>Filtering characteristics of FMD under different numbers of segments <span class="html-italic">K</span>: (<b>a</b>) <span class="html-italic">K</span> = 10; (<b>b</b>) <span class="html-italic">K</span> = 7.</p>
Full article ">Figure 5
<p>The Robustness of Various Metrics under Different SNR: (<b>a</b>) Inner Race Fault; (<b>b</b>) Rolling Element Fault; (<b>c</b>) Outer Race Fault.</p>
Full article ">Figure 6
<p>Variation Rates under Different SNR: (<b>a</b>) Inner Race Fault Variation Rate; (<b>b</b>) Rolling Element Fault Variation Rate; (<b>c</b>) Outer Race Fault Variation Rate.</p>
Full article ">Figure 7
<p>Flowchart of composite fault diagnosis.</p>
Full article ">Figure 8
<p>Simulation signal processing results: (<b>a</b>) time-domain diagram of outer race fault; (<b>b</b>) time-domain diagram of inner race fault; (<b>c</b>) time-domain diagram of analog signal; (<b>d</b>) analog signal envelope diagram; (<b>e</b>) clustering renderings; (<b>f</b>) composite indicator iteration curve.</p>
Full article ">Figure 9
<p>Simulation signal decomposition: (<b>a</b>) Time-domain diagram of each IMF component; (<b>b</b>) Envelope plot of IMF components; (<b>c</b>) IMF1 envelope diagram; (<b>d</b>) IMF5 envelope diagram.</p>
Full article ">Figure 10
<p>Processing results of different indicators: (<b>a</b>) EE; (<b>b</b>) IE; (<b>c</b>) SE; (<b>d</b>) EnE.</p>
Full article ">Figure 11
<p>Results of different algorithms: (<b>a</b>) GWO; (<b>b</b>) PSO; (<b>c</b>) DE; (<b>d</b>) SSA.</p>
Full article ">Figure 12
<p>Comparison method processing results: (<b>a</b>) Simultaneous optimization of three parameters by WOA; (<b>b</b>) Time–Cost comparison.</p>
Full article ">Figure 13
<p>HZXT-DS-003 double-span rotor rolling bearing experimental bench and collection equipment.</p>
Full article ">Figure 14
<p>Experimental signal I processing results: (<b>a</b>) Time-domain diagram; (<b>b</b>) Envelope spectrum; (<b>c</b>) Clustering results; (<b>d</b>) Iterative curve.</p>
Full article ">Figure 15
<p>Experimental signal I decomposition: (<b>a</b>) Time-domain diagram of each IMF component; (<b>b</b>) Envelope plot of IMF components; (<b>c</b>) IMF time-domain diagram; (<b>d</b>) IMF envelope diagram.</p>
Full article ">Figure 16
<p>Comparison method processing results: (<b>a</b>) EE t; (<b>b</b>) IE; (<b>c</b>) SE; (<b>d</b>) EnE.</p>
Full article ">Figure 17
<p>Comparison method processing results: (<b>a</b>) GWO; (<b>b</b>) PSO; (<b>c</b>) DE; (<b>d</b>) SSA; (<b>e</b>) WOA optimizing three parameters simultaneously; (<b>f</b>) Time–cost comparison.</p>
Full article ">Figure 18
<p>Bearing data test bed, University of Paderborn, Germany.</p>
Full article ">Figure 19
<p>Experimental signal II processing results: (<b>a</b>) Time-domain diagram; (<b>b</b>) Envelope spectrum; (<b>c</b>) Clustering results; (<b>d</b>) Iterative curve.</p>
Full article ">Figure 20
<p>Experimental signal II decomposition: (<b>a</b>) Time-domain diagram of each IMF component; (<b>b</b>) Envelope plot of IMF components; (<b>c</b>) IMF1 envelope diagram; (<b>d</b>) IMF2 envelope diagram.</p>
Full article ">Figure 21
<p>Comparison method processing results: (<b>a</b>) EMD; (<b>b</b>) EEMD; (<b>c</b>) VMD; (<b>d</b>) EWT.</p>
Full article ">
29 pages, 8028 KiB  
Article
Developing a Hybrid Approach with Whale Optimization and Deep Convolutional Neural Networks for Enhancing Security in Smart Home Environments’ Sustainability Through IoT Devices
by Kavitha Ramaswami Jothi and Balamurugan Vaithiyanathan
Sustainability 2024, 16(24), 11040; https://doi.org/10.3390/su162411040 - 16 Dec 2024
Viewed by 472
Abstract
Even while living circumstances and construction techniques have generally improved, occupants of these spaces frequently feel unsatisfied with the sense of security they provide, which leads to looking for and eventually enacting ever-more-effective safety precautions. The continuous uncertainty that contemporary individuals experience, particularly [...] Read more.
Even while living circumstances and construction techniques have generally improved, occupants of these spaces frequently feel unsatisfied with the sense of security they provide, which leads to looking for and eventually enacting ever-more-effective safety precautions. The continuous uncertainty that contemporary individuals experience, particularly with regard to their protection in places like cities, prompted the field of computing to design smart devices that attempt to reduce threats and ultimately strengthen people’s sense of protection. Intelligent apps were developed to provide protection and make a residence a smart and safe home. The proliferation of technology for smart homes necessitates the implementation of rigorous safety precautions to protect users’ personal information and avoid illegal access. The importance of establishing cyber security has been recognized by academic and business institutions all around the globe. Providing reliable computation for the Internet of Things (IoT) is also crucial. A new method for enhancing safety in smart home environments’ sustainability using IoT devices is presented in this paper, combining the Whale Optimization Algorithm (WOA) with Deep Convolutional Neural Networks (DCNNs). WOA-DCNN hybridization seeks to enhance safety measures by efficiently identifying and averting possible attacks in real time. We show how effective the proposed approach is in defending smart home systems from a range of safety risks via in-depth testing and analysis. By providing a potential path for protecting smart home surroundings in a world that is growing more linked, this research advances the state of the art in IoT security. Full article
Show Figures

Figure 1

Figure 1
<p>Smart home system.</p>
Full article ">Figure 2
<p>Smart home environment.</p>
Full article ">Figure 3
<p>Proposed architecture of the smart home system.</p>
Full article ">Figure 4
<p>Demand-side load management strategies.</p>
Full article ">Figure 5
<p>Overall layout of smart home architecture.</p>
Full article ">Figure 6
<p>Humpback whale bubble-net feeding.</p>
Full article ">Figure 7
<p>Step-by-step procedure of the WOA.</p>
Full article ">Figure 8
<p>Smart home device registration.</p>
Full article ">Figure 9
<p>Smart home security based on WOA-DCNN.</p>
Full article ">Figure 10
<p>Intruder detection system architecture based on WOA-DCNN.</p>
Full article ">Figure 11
<p>Proposed system-trained confusion matrix of detecting smart home appliances from the intrusion detection system.</p>
Full article ">Figure 12
<p>Cloud federated authentication.</p>
Full article ">Figure 13
<p>(<b>a</b>) EED (<b>b</b>) Throughput of various scenarios.</p>
Full article ">Figure 14
<p>Comparison of proposed and existing systems.</p>
Full article ">Figure 14 Cont.
<p>Comparison of proposed and existing systems.</p>
Full article ">Figure 15
<p>Proposed system training and validation loss.</p>
Full article ">Figure 16
<p>Proposed system training and validation accuracy.</p>
Full article ">Figure 17
<p>QoE after 88 iterations with <math display="inline"><semantics> <mrow> <mi>α</mi> <mo>=</mo> <mn>20</mn> </mrow> </semantics></math>.</p>
Full article ">Figure 18
<p>QoE after 88 iterations with <math display="inline"><semantics> <mrow> <mi>α</mi> <mo>=</mo> <mn>15</mn> </mrow> </semantics></math>.</p>
Full article ">Figure 19
<p>QoE after 88 iterations with <math display="inline"><semantics> <mrow> <mi>α</mi> <mo>=</mo> <mn>10</mn> </mrow> </semantics></math>.</p>
Full article ">Figure 20
<p>Reliability analysis.</p>
Full article ">Figure 21
<p>Overall system stability.</p>
Full article ">Figure 22
<p>Message cost comparisons.</p>
Full article ">
24 pages, 3565 KiB  
Article
Two-Stage Energy Storage Allocation Considering Voltage Management and Loss Reduction Requirements in Unbalanced Distribution Networks
by Hu Cao, Lingling Ma, Guoying Liu, Zhijian Liu and Hang Dong
Energies 2024, 17(24), 6325; https://doi.org/10.3390/en17246325 - 15 Dec 2024
Viewed by 815
Abstract
The authors propose a two-stage sequential configuration method for energy storage systems to solve the problems of the heavy load, low voltage, and increased network loss caused by the large number of electric vehicle (EV) charging piles and distributed photovoltaic (PV) access in [...] Read more.
The authors propose a two-stage sequential configuration method for energy storage systems to solve the problems of the heavy load, low voltage, and increased network loss caused by the large number of electric vehicle (EV) charging piles and distributed photovoltaic (PV) access in urban, old and unbalanced distribution networks. At the stage of selecting the location of energy storage, a comprehensive power flow sensitivity variance (CPFSV) is defined to determine the location of the energy storage. At the energy storage capacity configuration stage, the energy storage capacity is optimized by considering the benefits of peak shaving and valley filling, energy storage costs, and distribution network voltage deviations. Finally, simulations are conducted using a modified IEEE-33-node system, and the results obtained using the improved beluga whale optimization algorithm show that the peak-to-valley difference of the system after the addition of energy storage decreased by 43.7% and 51.1% compared to the original system and the system with EV and PV resources added, respectively. The maximum CPFSV of the system decreased by 52% and 75.1%, respectively. In addition, the engineering value of this method is verified through a real-machine system with 199 nodes in a district of Kunming. Therefore, the energy storage configuration method proposed in this article can provide a reference for solving the outstanding problems caused by the large-scale access of EVs and PVs to the distribution network. Full article
(This article belongs to the Section D: Energy Storage and Application)
Show Figures

Figure 1

Figure 1
<p>Peak shaving and valley filling schematic of the DESS.</p>
Full article ">Figure 2
<p>Beluga whale behaviors.</p>
Full article ">Figure 3
<p>Flowchart of the TWBWO algorithm solving the DESS capacity optimization problem.</p>
Full article ">Figure 4
<p>Modified IEEE-33 node distribution network system.</p>
Full article ">Figure 5
<p>System operating parameters: (<b>a</b>) daily load curve and PV output prediction curve; and (<b>b</b>) daily load curve of electric vehicle charging piles and urban villages.</p>
Full article ">Figure 6
<p>Comprehensive power flow sensitivity variance (<math display="inline"><semantics> <mrow> <msup> <mi>χ</mi> <mn>2</mn> </msup> </mrow> </semantics></math>) of each node under Cases 1, 2, and 5: (<b>a</b>–<b>c</b>) correspond to the trend charts of A, B, and C phases, respectively.</p>
Full article ">Figure 6 Cont.
<p>Comprehensive power flow sensitivity variance (<math display="inline"><semantics> <mrow> <msup> <mi>χ</mi> <mn>2</mn> </msup> </mrow> </semantics></math>) of each node under Cases 1, 2, and 5: (<b>a</b>–<b>c</b>) correspond to the trend charts of A, B, and C phases, respectively.</p>
Full article ">Figure 7
<p>Distribution of the Pareto solutions for the different algorithms: (<b>a</b>) BWO algorithm; and (<b>b</b>) TWBWO algorithm.</p>
Full article ">Figure 8
<p>Convergence curves of the two algorithms.</p>
Full article ">Figure 9
<p>System daily load curve with different distributed energy resources.</p>
Full article ">Figure 10
<p>Charge and discharge curves of 3 sets of DESSs.</p>
Full article ">Figure 11
<p>Topological structure of the actual distribution network system with 199 nodes.</p>
Full article ">Figure 12
<p>Heat map of the CPFSV value of 199 nodes over time: (<b>a</b>–<b>c</b>) corresponding to working conditions 1, 2, and 3.</p>
Full article ">Figure 12 Cont.
<p>Heat map of the CPFSV value of 199 nodes over time: (<b>a</b>–<b>c</b>) corresponding to working conditions 1, 2, and 3.</p>
Full article ">Figure 13
<p>Load curves under three operating conditions.</p>
Full article ">Figure 14
<p>Contour map of the voltage per unit value at each node under two operating conditions: (<b>a</b>,<b>b</b>) corresponding to operating conditions 2 and 3.</p>
Full article ">
20 pages, 1823 KiB  
Article
Interline Power Flow Controller Allocation for Active Power Losses Enhancement Using Whale Optimization Algorithm
by Ahmed M. Alshannaq, Mohammed A. Haj-ahmed, Mais Aldwaik and Dia Abualnadi
Energies 2024, 17(24), 6318; https://doi.org/10.3390/en17246318 - 15 Dec 2024
Viewed by 420
Abstract
Transmission networks face continuous electrical and mechanical stresses due to increasing system challenges and power losses. Transmission networks require special focus and detailed studies each time a load or a generator emerges to the grid. The interline power flow controller (IPFC) is a [...] Read more.
Transmission networks face continuous electrical and mechanical stresses due to increasing system challenges and power losses. Transmission networks require special focus and detailed studies each time a load or a generator emerges to the grid. The interline power flow controller (IPFC) is a relatively new scheme that is implemented in the transmission network to improve transmission efficiency, decrease transmission losses, and enhance voltage profile. In this paper, the interline power flow controller’s impact on transmission network performance is investigated as it is implemented within the IEEE 5-bus, 14-bus, and IEEE 57-bus systems. In addition, the whale optimization algorithm (WOA) is used to optimize the interline power flow controller locations within the system to achieve optimal transmission system performance. WOA performance is also compared to genetic algorithm (GA) and particle swarm optimization (PSO) algorithms, and the superiority of the proposed WOA-based control is proved. The robustness of the optimized system against load variations is investigated and the results introduced affirm the capability of the interline power flow controller to enhance transmission network efficiency. Full article
(This article belongs to the Special Issue Energy Storage, Energy Conversion, and Multifunctional Materials 2024)
Show Figures

Figure 1

Figure 1
<p>Schematic diagram of IPFC connected to two transmission lines [<a href="#B27-energies-17-06318" class="html-bibr">27</a>].</p>
Full article ">Figure 2
<p>WOA flowchart for IPFC allocation.</p>
Full article ">Figure 3
<p>IEEE 14-bus system active power losses with and without using IPFC.</p>
Full article ">Figure 4
<p>IEEE 14-bus system active losses comparison between GA and WOA.</p>
Full article ">Figure 5
<p>IEEE 5-bus system voltage values with and without using IPFC.</p>
Full article ">Figure 6
<p>IEEE 5-bus system voltage values comparison between GA and WOA.</p>
Full article ">Figure 7
<p>Active power losses enhancement convergence of WOA versus population size.</p>
Full article ">
20 pages, 2833 KiB  
Article
An Advanced Whale Optimization Algorithm for Grayscale Image Enhancement
by Yibo Han, Pei Hu, Zihan Su, Lu Liu and John Panneerselvam
Biomimetics 2024, 9(12), 760; https://doi.org/10.3390/biomimetics9120760 - 14 Dec 2024
Viewed by 395
Abstract
Image enhancement is an important step in image processing to improve contrast and information quality. Intelligent enhancement algorithms are gaining popularity due to the limitations of traditional methods. This paper utilizes a transformation function to enhance the global and local information of grayscale [...] Read more.
Image enhancement is an important step in image processing to improve contrast and information quality. Intelligent enhancement algorithms are gaining popularity due to the limitations of traditional methods. This paper utilizes a transformation function to enhance the global and local information of grayscale images, but the parameters of this function can produce significant changes in the processed images. To address this, the whale optimization algorithm (WOA) is employed for parameter optimization. New equations are incorporated into WOA to improve its global optimization capability, and exemplars and advanced spiral updates improve the convergence of the algorithm. Its performance is validated on four different types of images. The algorithm not only outperforms comparison algorithms in the objective function but also excels in other image enhancement metrics, including peak signal-to-noise ratio (PSNR), feature similarity index (FSIM), structural similarity index (SSIM), and patch-based contrast quality index (PCQI). It is superior to the comparison algorithms in 11, 6, 11, 13, and 7 images in these metrics, respectively. The results demonstrate that the algorithm is suitable for image enhancement both subjectively and statistically. Full article
Show Figures

Figure 1

Figure 1
<p>The process of image enhancement.</p>
Full article ">Figure 2
<p>The values of A.</p>
Full article ">Figure 3
<p>The values of <math display="inline"><semantics> <mrow> <msup> <mi>e</mi> <mi>l</mi> </msup> <mo>·</mo> <mo form="prefix">cos</mo> <mrow> <mo>(</mo> <mn>2</mn> <mi>π</mi> <mi>l</mi> <mo>)</mo> </mrow> </mrow> </semantics></math>.</p>
Full article ">Figure 4
<p>The process of AWOA.</p>
Full article ">Figure 5
<p>The test images and their histograms.</p>
Full article ">Figure 6
<p>The test images and their histograms.</p>
Full article ">Figure 7
<p>Convergence cures.</p>
Full article ">Figure 8
<p>The enhanced images and their histograms.</p>
Full article ">Figure 9
<p>The enhanced images and their histograms.</p>
Full article ">
18 pages, 8161 KiB  
Article
A Significant Wave Height Prediction Method Based on Improved Temporal Convolutional Network and Attention Mechanism
by Ying Han, Jiaxin Tang, Hongyun Jia, Changming Dong and Ruihan Zhao
Electronics 2024, 13(24), 4879; https://doi.org/10.3390/electronics13244879 - 11 Dec 2024
Viewed by 393
Abstract
Wave prediction is crucial for ensuring the safety and disaster mitigation of coastal areas, helping to support marine economic activities. Currently, many deep learning models, such as the temporal convolutional network (TCN), have been applied to wave prediction. In this study, a prediction [...] Read more.
Wave prediction is crucial for ensuring the safety and disaster mitigation of coastal areas, helping to support marine economic activities. Currently, many deep learning models, such as the temporal convolutional network (TCN), have been applied to wave prediction. In this study, a prediction model based on improved TCN-Attention (ITCN-A) is proposed. This model incorporates improvements in two aspects. Firstly, to address the difficulty of calibrating hyperparameters in traditional TCN models, a whale optimization algorithm (WOA) has been introduced to achieve global optimization of hyperparameters. Secondly, we integrate dynamic ReLU to implement an adaptive activation function. The improved TCN is then combined with the attention mechanism to further enhance the extraction of long-term features of wave height. We conducted experiments using data from three buoy stations with varying water depths and geographical locations, covering prediction lead times ranging from 1 h to 24 h. The results demonstrate that the proposed integrated model reduces the RMSE of prediction by 12.1% and MAE by an 18.6% compared with the long short-term memory (LSTM) model. Consequently, this model effectively improves the accuracy of wave height predictions at different stations, verifying its effectiveness and general applicability. Full article
Show Figures

Figure 1

Figure 1
<p>Causal convolutional structure figure.</p>
Full article ">Figure 2
<p>Improved TCN block.</p>
Full article ">Figure 3
<p>Attention mechanism figure.</p>
Full article ">Figure 4
<p>Structure of proposed method.</p>
Full article ">Figure 5
<p>Selected buoy station location.</p>
Full article ">Figure 6
<p>Fitness value iteration curve.</p>
Full article ">Figure 7
<p>Prediction performance of different models at station 41008.</p>
Full article ">Figure 8
<p>Comparison of 1 h predicted values of different models at station 41008.</p>
Full article ">Figure 9
<p>Comparison of 3 h predicted values of different models at station 41008.</p>
Full article ">Figure 10
<p>Comparison of 6 h predicted values of different models at station 41008.</p>
Full article ">Figure 11
<p>Long-term predictive performance of different models.</p>
Full article ">Figure 12
<p>Scatter plot of station 42055’s prediction results.</p>
Full article ">Figure 13
<p>Scatter plot of station 46083’s prediction results.</p>
Full article ">
28 pages, 4709 KiB  
Article
Multipopulation Whale Optimization-Based Feature Selection Algorithm and Its Application in Human Fall Detection Using Inertial Measurement Unit Sensors
by Haolin Cao, Bingshuo Yan, Lin Dong and Xianfeng Yuan
Sensors 2024, 24(24), 7879; https://doi.org/10.3390/s24247879 - 10 Dec 2024
Viewed by 420
Abstract
Feature selection (FS) is a key process in many pattern-recognition tasks, which reduces dimensionality by eliminating redundant or irrelevant features. However, for complex high-dimensional issues, traditional FS methods cannot find the ideal feature combination. To overcome this disadvantage, this paper presents a multispiral [...] Read more.
Feature selection (FS) is a key process in many pattern-recognition tasks, which reduces dimensionality by eliminating redundant or irrelevant features. However, for complex high-dimensional issues, traditional FS methods cannot find the ideal feature combination. To overcome this disadvantage, this paper presents a multispiral whale optimization algorithm (MSWOA) for feature selection. First, an Adaptive Multipopulation merging Strategy (AMS) is presented, which uses exponential variation and individual location information to divide the population, thus avoiding the premature aggregation of subpopulations and increasing candidate feature subsets. Second, a Double Spiral updating Strategy (DSS) is devised to break out of search stagnations by discovering new individual positions continuously. Last, to facilitate the convergence speed, a Baleen neighborhood Exploitation Strategy (BES) which mimics the behavior of whale tentacles is proposed. The presented algorithm is thoroughly compared with six state-of-the-art meta-heuristic methods and six promising WOA-based algorithms on 20 UCI datasets. Experimental results indicate that the proposed method is superior to other well-known competitors in most cases. In addition, the proposed method is utilized to perform feature selection in human fall-detection tasks, and extensive real experimental results further illustrate the superior ability of the proposed method in addressing practical problems. Full article
(This article belongs to the Section Intelligent Sensors)
Show Figures

Figure 1

Figure 1
<p>Variation curve of the number of subpopulations.</p>
Full article ">Figure 2
<p>Particle spiral trajectory curve.</p>
Full article ">Figure 3
<p>Flowchart of MSWOA.</p>
Full article ">Figure 4
<p>Seven methods’ convergence curves on 17 datasets.</p>
Full article ">Figure 4 Cont.
<p>Seven methods’ convergence curves on 17 datasets.</p>
Full article ">Figure 5
<p>Flowchart of the fall detection system.</p>
Full article ">Figure 6
<p>The data collection details of the SFall dataset.</p>
Full article ">Figure 7
<p>Signal changes in acceleration, angular velocity, and angle for three types of activities.</p>
Full article ">
20 pages, 9020 KiB  
Article
Simulation and Prediction of Springback in Sheet Metal Bending Process Based on Embedded Control System
by Jinhan Xu, Jun Yan, Yan Huang and Dawei Ding
Sensors 2024, 24(23), 7863; https://doi.org/10.3390/s24237863 - 9 Dec 2024
Viewed by 577
Abstract
Amidst the accelerating pace of automation in sheet metal bending, the need for small-batch, multi-varietal, efficient, and adaptable production modalities has become increasingly pronounced. To address this need and to enhance the efficacy of the bending process, this study presents the design and [...] Read more.
Amidst the accelerating pace of automation in sheet metal bending, the need for small-batch, multi-varietal, efficient, and adaptable production modalities has become increasingly pronounced. To address this need and to enhance the efficacy of the bending process, this study presents the design and development of an embedded soft PLC (Programmable Logic Controller) rooted in the Codesys development platform and leveraging the ARM Cortex-A55 architecture. This controller employs the EtherCAT communication protocol to facilitate seamless and efficient interactions with fully electric servo-driven CNC (Computerized Numerical Control) bending machinery. To mitigate the challenge of bending springback errors, a finite element simulation model is constructed and refined through the application of ALE (Arbitrary Lagrangian-Eulerian) adaptive grid technology, thereby bolstering simulation precision. Subsequently, an enhanced WOA-BP (Whale Optimization Algorithm—Backpropagation) model, integrating Latin hypercube sampling and neural network techniques, is deployed to anticipate and counteract these springback errors. Experimental outcomes demonstrate that the proposed methodology effectively constrains the final forming angle deviation to within 0.3°, significantly enhancing the reliability and precision of the bending system. This achievement not only underscores the technical feasibility but also contributes to advancing the frontier of sheet metal bending automation. Full article
(This article belongs to the Section Industrial Sensors)
Show Figures

Figure 1

Figure 1
<p>Diagram of the bending machine and component description; 1—lower mold; 2—upper mold; 3—connecting rod structure; 4—rollerscrews; 5—backstop motor; 6—slider motor.</p>
Full article ">Figure 2
<p>Feedback control of the servomotor.</p>
Full article ">Figure 3
<p>Hardware framework of the bending machine control system.</p>
Full article ">Figure 4
<p>Structure of embedded soft PLC control system.</p>
Full article ">Figure 5
<p>A complete control diagram of embedded system for bending process.</p>
Full article ">Figure 6
<p>Schematic of traditional free bending process.</p>
Full article ">Figure 7
<p>Flowchart of finite element simulation of bending process.</p>
Full article ">Figure 8
<p>Simulation of the upper mold: (<b>a</b>) before unloading; (<b>b</b>) after unloading.</p>
Full article ">Figure 9
<p>Simulation using different grids: (<b>a</b>) not introducing ALE; (<b>b</b>) introducing ALE.</p>
Full article ">Figure 10
<p>Images of sheet metal parts captured using a Basler camera: (<b>a</b>) before unloading; (<b>b</b>) after unloading.</p>
Full article ">Figure 11
<p>Comparative results of different simulations of (<b>a</b>) forming angle; (<b>b</b>) springback angle.</p>
Full article ">Figure 12
<p>Effect of multiple factors on the springback angle: (<b>a</b>) plate thickness; (<b>b</b>) elastic modulus; (<b>c</b>) corner radius; (<b>d</b>) width of lower groove.</p>
Full article ">Figure 13
<p>Structure diagram of BP neural network.</p>
Full article ">Figure 14
<p>Simulations using BP neural network: (<b>a</b>) test and predicted values; (<b>b</b>) errors.</p>
Full article ">Figure 15
<p>Comparative results using (<b>a</b>) WOA-BP algorithm; (<b>b</b>) improved WOA-BP algorithm.</p>
Full article ">Figure 16
<p>Error comparison of springback angles using different prediction models.</p>
Full article ">Figure 17
<p>Error comparison of downward amount using different prediction models.</p>
Full article ">Figure 18
<p>Experimental configuration of the robot-assisted bending system.</p>
Full article ">Figure 19
<p>Bending process using the designed system and methods: (<b>a</b>) preparation for bending; (<b>b</b>) feeding; (<b>c</b>) slider down; (<b>d</b>) back stopper; (<b>e</b>) bending process; (<b>f</b>) backhaul.</p>
Full article ">
17 pages, 2114 KiB  
Article
Research on a Passenger Flow Prediction Model Based on BWO-TCLS-Self-Attention
by Sheng Liu, Lang Du, Ting Cao and Tong Zhang
Electronics 2024, 13(23), 4849; https://doi.org/10.3390/electronics13234849 - 9 Dec 2024
Viewed by 434
Abstract
In recent years, with the rapid development of the global demand and scale for deep underground space utilization, deep space has gradually transitioned from single-purpose uses such as underground transportation, civil defense, and commerce to a comprehensive, livable, and disaster-resistant underground ecosystem. This [...] Read more.
In recent years, with the rapid development of the global demand and scale for deep underground space utilization, deep space has gradually transitioned from single-purpose uses such as underground transportation, civil defense, and commerce to a comprehensive, livable, and disaster-resistant underground ecosystem. This shift has brought increasing attention to the safety of personnel flow in deep spaces. In addressing challenges in deep space passenger flow prediction, such as irregular flow patterns, surges in extreme conditions, large data dimensions, and redundant features complicating the model, this paper proposes a deep space passenger flow prediction model that integrates a Temporal Convolutional Network (TCN) and Long Short-Term Memory (LSTM) network. The model first employs a dual-layer LSTM network structure with a Dropout layer to capture complex temporal dynamics while preventing overfitting. Then, a Self-Attention mechanism and TCN network are introduced to reduce redundant feature data and enhance the model’s performance and speed. Finally, the Beluga Whale Optimization (BWO) algorithm is used to optimize hyperparameters, further improving the prediction accuracy of the network. Experimental results demonstrate that the BWO-TCLS-Self-Attention model proposed in this paper achieves an R2 value of 96.94%, with MAE and RMSE values of 118.464 and 218.118, respectively. Compared with some mainstream prediction models, the R2 value has increased, while both MAE and RMSE values have decreased, indicating its ability to accurately predict passenger flow in deep underground spaces. Full article
Show Figures

Figure 1

Figure 1
<p>Hyperparametric optimization process.</p>
Full article ">Figure 2
<p>SSA vs. BWO optimization process.</p>
Full article ">Figure 3
<p>Improved two-layer LSTM structure.</p>
Full article ">Figure 4
<p>TCN-LSTM-Self-Attention network structure.</p>
Full article ">Figure 5
<p>Passenger traffic for 31 days at one location.</p>
Full article ">Figure 6
<p>Loss values for different models.</p>
Full article ">Figure 7
<p>Line graphs of the results of multiple model passenger flow forecasts.</p>
Full article ">Figure 8
<p>Line graphs of the results of multiple models’ passenger flow forecasts.</p>
Full article ">
19 pages, 13813 KiB  
Article
Prediction of Anthocyanin Content in Purple-Leaf Lettuce Based on Spectral Features and Optimized Extreme Learning Machine Algorithm
by Chunhui Liu, Haiye Yu, Yucheng Liu, Lei Zhang, Dawei Li, Junhe Zhang, Xiaokai Li and Yuanyuan Sui
Agronomy 2024, 14(12), 2915; https://doi.org/10.3390/agronomy14122915 - 6 Dec 2024
Viewed by 402
Abstract
Monitoring anthocyanins is essential for assessing nutritional value and the growth status of plants. This study aimed to utilize hyperspectral technology to non-destructively monitor anthocyanin levels. Spectral data were preprocessed using standard normal variate (SNV) and first-derivative (FD) spectral processing. Feature wavelengths were [...] Read more.
Monitoring anthocyanins is essential for assessing nutritional value and the growth status of plants. This study aimed to utilize hyperspectral technology to non-destructively monitor anthocyanin levels. Spectral data were preprocessed using standard normal variate (SNV) and first-derivative (FD) spectral processing. Feature wavelengths were selected using uninformative variable elimination (UVE) and UVE combined with competitive adaptive reweighted sampling (UVE + CARS). The optimal two-band vegetation index (VI2) and three-band vegetation index (VI3) were then calculated. Finally, dung beetle optimization (DBO), subtraction-average-based optimization (SABO), and the whale optimization algorithm (WOA) optimized the extreme learning machine (ELM) for modeling. The results indicated the following: (1) For the feature band selection methods, the UVE-CARS-SNV-DBO-ELM model achieved an Rm2 of 0.8623, an RMSEm of 0.0098, an Rv2 of 0.8617, and an RMSEv of 0.0095, resulting in an RPD of 2.7192, further demonstrating that UVE-CARS enhances feature band extraction based on UVE and indicating a strong model performance. (2) For the vegetation index, VI3 showed a better predictive accuracy than VI2. The VI3-WOA-ELM model achieved an Rm2 of 0.8348, an RMSEm of 0.0109 mg/g, an Rv2 of 0.812, an RMSEv of 0.011 mg/g, and an RPD of 2.3323, demonstrating good performance. (3) For the optimization algorithms, the DBO, SABO, and WOA all performed well in optimizing the ELM model. The R2 of the DBO model increased by 5.8% to 27.82%, that of the SABO model by 2.92% to 26.84%, and that of the WOA model by 3.75% to 27.51%. These findings offer valuable insights for future anthocyanin monitoring using hyperspectral technology, highlighting the effectiveness of feature selection and optimization algorithms for accurate detection. Full article
(This article belongs to the Section Precision and Digital Agriculture)
Show Figures

Figure 1

Figure 1
<p>Schematic diagram of extreme learning machine.</p>
Full article ">Figure 2
<p>Average spectral curves of purple-leaf lettuce under different supplementary lighting plans.</p>
Full article ">Figure 3
<p>A flowchart of the methodology.</p>
Full article ">Figure 4
<p>Spectral preprocessing methods: raw spectra (Raw) (<b>a</b>), standard normal variate (SNV) (<b>b</b>), and first derivative (FD) (<b>c</b>).</p>
Full article ">Figure 5
<p>Variables selected by UVE + CARS method. (<b>a</b>) Preliminary feature wavelengths selected by UVE. (<b>b</b>) Feature wavelengths further selected by CARS. (<b>c</b>) Feature wavelengths after initial UVE screening. (<b>d</b>) Final feature wavelengths after UVE + CARS screening.</p>
Full article ">Figure 6
<p>Heatmaps of correlation coefficients between VI2 and anthocyanins. NARI (<b>a</b>), MGRVI (<b>b</b>), ARI (<b>c</b>), and OSAVI (<b>d</b>).</p>
Full article ">Figure 7
<p>Heatmaps of correlation coefficients between VI3 and anthocyanins. MARI (<b>a</b>), EVI (<b>b</b>), TVI (<b>c</b>), and PSRI (<b>d</b>).</p>
Full article ">Figure 8
<p>The optimal anthocyanin prediction model: UVE + SNV + CARS + DBO + ELM (<b>a</b>); the prediction errors of the test data (<b>b</b>).</p>
Full article ">Figure 9
<p>The accuracy parameters of the models. R<sub>m</sub><sup>2</sup> represents the training set’s R<sup>2</sup>, R<sub>v</sub><sup>2</sup> represents the test set’s R<sup>2</sup>, RPD represents the residual predictive deviation, RMSE<sub>m</sub> represents the root mean square error of the training set, and RMSE<sub>v</sub> represents the root mean square error of the test set.</p>
Full article ">Figure 10
<p>The optimal predicted anthocyanin values and measured values using VI3 (<b>a</b>); the prediction errors of the test data (<b>b</b>).</p>
Full article ">Figure 11
<p>The accuracy parameters of the vegetation index models. R<sub>m</sub><sup>2</sup> represents the training set’s R<sup>2</sup>, R<sub>v</sub><sup>2</sup> represents the test set’s R<sup>2</sup>, RPD represents the residual predictive deviation, RMSE<sub>m</sub> represents the root mean square error of the training set, and RMSE<sub>v</sub> represents the root mean square error of the test set.</p>
Full article ">Figure 12
<p>The fitness convergence curve of the UVE + SNV + CARS + DBO + ELM model (<b>a</b>) and the fitness convergence curve of the VI3 model (<b>b</b>).</p>
Full article ">
Back to TopTop