Improved grey wolf optimizer-conjugate gradient least squares (IGWO-CGLS) algorithm is proposed to solve the state estimation problems of large-scale magnetic target location, target recognition and magnetic moment es...
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Improved grey wolf optimizer-conjugate gradient least squares (IGWO-CGLS) algorithm is proposed to solve the state estimation problems of large-scale magnetic target location, target recognition and magnetic moment estimation. To address the state estimation problem of large-scale magnetic targets, a magnetic dipole array magnetic field observation model is established based on a single magnetic vector sensor, and the magnetic target modelparameter inversion based on IGWO-CGLS is used to obtain the state of the magnetic target. The state of the target is obtained by inverting the parameters of the magnetic target model. Firstly, the signal preprocessing is carried out by thresholding and down sampling to extract the complete magnetic field passing characteristics, and then the IGWO is used to optimize the magnetic target position, speed, heading and length, and then the magnetic moment parameter is calculated by CGLS to obtain the state parameters of the magnetic target. And numerical experiments are designed to sublicense the influencing factors of state estimation accuracy. The numerical simulation results show that IGWO-CGLS has higher state estimation accuracy than particle swarm optimization-CGLS, artificial hummingbird algorithm-CGLS, artificial rabbits optimization-CGLS, GWO-CGLS, IGWO-stepwise regression. The ship model test results show that IGWO-CGLS can estimate the state parameters of the ship model better.
Swarm phenomena are ubiquitous in the biological world. Researching swarm models can provide us with many biological insights, helping to reveal the behavioral mechanisms behind groups of birds, fish, insects, and mam...
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Swarm phenomena are ubiquitous in the biological world. Researching swarm models can provide us with many biological insights, helping to reveal the behavioral mechanisms behind groups of birds, fish, insects, and mammals, and providing many solutions for cooperative control in multi-agent systems. In the study of swarm models, it is often assumed that information exchange between model individuals is equal, but many researchers have found that rank mechanisms between leaders and followers are widespread in biological populations. Therefore, based on the leader mechanism in the Couzin model, this paper proposes a strictly metric-free model with a rank mechanism and optimizes swarm modelparameters using the differential evolution algorithm to explore the impact of rank mechanisms on swarm efficiency. Through numerous numerical simulation experiments, we found that the smaller the population size, the larger the required preference direction weight., and the larger the population size, the smaller the required preference direction weight.. After comparing the optimized model with the unoptimized model through quantitative analysis, the optimized model showed higher consistency after the system reached stability, proving the effectiveness of the differential evolution algorithm in optimizing swarm modelparameters.
Due to the large scatters in Sheet Molding Compound (SMC) mechanical properties, the uncertainty in the prediction of mechanical responses of SMC composite structures is significantly high as compared to that for cont...
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Due to the large scatters in Sheet Molding Compound (SMC) mechanical properties, the uncertainty in the prediction of mechanical responses of SMC composite structures is significantly high as compared to that for continuous fiber composite structures. Another challenge is the size effect resulting from the scatter in mechanical strengths, i.e., the measured material flexural strength is much higher than its tensile strength. As a result, classical approaches that rely on the mean tensile strength can substantially underpredict the flexural responses in Finite Element Analysis (FEA). This work investigates the use of a material model with bimodal Weibull distributions for its strength properties in Probabilistic FE (PFE) simulations. A Random Search-based optimization procedure was developed to obtain modelparameters which are difficult to determine. The material model was verified by PFE simulations of standard experiments, and then examined in simulations of open-hole tension and disk bending tests.
The coarse-to-fine architecture is a benchmark method designed to enhance the accuracy of 3D medical landmark detection. However, incorporating 3D convolutional neural networks into the coarse-to-fine architecture lea...
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The coarse-to-fine architecture is a benchmark method designed to enhance the accuracy of 3D medical landmark detection. However, incorporating 3D convolutional neural networks into the coarse-to-fine architecture leads to a significant increase in modelparameters, making it costly for deployment in clinical applications. This paper introduces a novel lightweight pseudo-3D coarse-to-fine architecture, consisting of a Plane-wise Attention Pseudo-3D (PA-P3D) model and a Spatial Separation Pseudo-3D (SS-P3D) model. The PAP3D inherits the lightweight structure of the general pseudo-3D and enhances cross-plane feature interaction in 3D medical images. On the other hand, the SS-P3D replaces the 3D model with three spatially separated 2D models to simultaneously detect 2D landmarks on axial, sagittal, and coronal planes. In comparison to the conventional coarse-to-fine architecture, the proposed method requires only approximately a quarter of the modelparameters (60% reduced by PA-P3D and 40% reduced by SS-P3D) while simultaneously improving landmark detection performance. Experimental results demonstrate the effectiveness of the proposed method, achieving state-of-the-art performance on both a public dataset for mandibular molar landmark detection and a private dataset for cephalometric landmark detection. Overall, this paper highlights the potential of the coarse-to-fine method for cost-effective model deployment, thanks to its lightweight model structure.
The processing and analysis of deformation monitoring data, as well as the establishment of effective forecasting models, form the foundation for assessing whether deformation is within a safe range and for selecting ...
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The processing and analysis of deformation monitoring data, as well as the establishment of effective forecasting models, form the foundation for assessing whether deformation is within a safe range and for selecting appropriate preventive and disaster reduction measures. Conventional forecasting models are difficult to accurately forecast future phenomena by analyzing deformation data with non-equidistant characteristic, so a non-equidistant grey model has emerged. The article optimizes the traditional non-equidistant grey model from three aspects, thus proposing an adaptive non-equidistant grey model with four parameters, which contains nonlinear and linear terms as well as stochastic perturbation term. First, the nonlinear function is used as a new grey action quantity in order to comprehensively reflect the grey information that affects the development of the system. Second, the particle swarm optimization algorithm is used to optimize the background value so that it can be adaptively adjusted according to the sequence characteristics as well as to obtain a mutually matching model structure based on the integral theory. Third, the optimal selection of initial value with the minimum relative error sum of squares as the objective function further enhances the modeloptimization. Finally, the model is applied to forecast three kinds of deformation monitoring for high-rise building settlement, highway soft soil roadbed settlement, and mining area GNSS settlement. The results show that the performance of the novel model is significantly better than the existing model, thus verifying its effectiveness and superiority.
Mass exchanger networks have been considered a promising solution for reducing impurity in streams and maximizing energy recovery in the chemical industry. This paper adjusts two non-structural models with distinct op...
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Mass exchanger networks have been considered a promising solution for reducing impurity in streams and maximizing energy recovery in the chemical industry. This paper adjusts two non-structural models with distinct optimization variables and a heuristic algorithm according to the MEN synthesis character-istics. Considering the requirement of the objective function, a two-step optimization method that com-bines these two models is proposed. In the first step, a feasible solution is determined by the model using the transferred mass as an optimization variable. In the second step, the aforementioned model is employed to maximize tray utilization by adopting the tray number as an optimization variable. The results of the two cases obtained by the proposed method are 406,330 $/yr and 329,326 $/yr, which are lower than the published results, and is verified on two cases regarding quality and efficiency. (c) 2023 Elsevier Ltd. All rights reserved.
In the process of classifying fresh-cut flowers, the classification accuracy of the algorithm plays a vital role in the control of quality stability, uniformity, and price of fresh-cut flowers, while the classificatio...
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In the process of classifying fresh-cut flowers, the classification accuracy of the algorithm plays a vital role in the control of quality stability, uniformity, and price of fresh-cut flowers, while the classification speed of an algorithm determines the possibility of industrial application. Currently, research on fresh-cut flower classification focuses on the breakthrough of classification accuracy, ignoring the real-time processing speed of the terminal, which seriously affects the use of fresh-cut flower online classification technology. In this study, RGB images and depth information data of 434 rose flowers were collected using a binocular stereo depth camera. Combined with the actual production line classification environment, a set of data argumentation solutions was developed under the condition of limited samples. The architecture was established and optimized based on the ShuffleNet V2 network backbone unit, transfer learning was performed, and an appropriate attention mechanism was invoked to classify flowers of five specifications. The experimental results showed that the proposed network structure had a competitive advantage in terms of parameter quantity, classification speed, and accuracy compared with traditional networks without an attention mechanism and other lightweight networks. The classification accuracy on the 3-channel (RGB channel) flower dataset and the 4-channel (RGB and depth channel) flower datasets were 98.891% and 99.915%, respectively, and the overall prediction classification speed can reach 0.020 seconds per flower. Compared to the fresh-cut flower classification machines currently on the market, the speed of the proposed method has a great advantage. These advantages are of great significance for the design and development of fresh-cut flower classification and grading systems, and the proposed method is instructive for the identification and application of multichannel data in the future.
Reducing greenhouse gas emissions is urgent for the global community with rising climates. Considering the importance of renewable energy in mitigating climate warming, forecasting renewable energy generation is vital...
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Reducing greenhouse gas emissions is urgent for the global community with rising climates. Considering the importance of renewable energy in mitigating climate warming, forecasting renewable energy generation is vital for the Chinese government's future low-carbon and green development plan. This paper proposes a novel multivariable grey model based on historical data on China's renewable energy generation and three industries. A novel information accumulation mechanism with two adaptive factors is designed to improve the traditional multivariable grey modeling defect. Based on the proposed mechanism, this paper optimizes the initial and background values and nonlinear model structure with the whale optimization algorithm. The forecasting results show that the fitting MAPE is 1.13%, comprehensive MAPE is 2.60%, MSE is 50.86, and RMSE is 7.13, which significantly improve the forecasting accuracy of traditional GM(1,N) and are better than other compared models. The forecasting results show that China's renewable energy generation will gradually increase to 5834.02 TWh. The Chinese government should keep the previous Five-Year Plans rising trend of the three industries in the future Five-Year Plans to support renewable energy industries. In China's future energy system, it is necessary to promote incentive policies and capital investment for actively accelerated development to make renewable energy the leading force.
Precision of the coordinate transformation modelparameters is crucial for the accuracy of the vision-based robot spatial motion measurement method. In this work, an optimization algorithm integrating RANSAC and itera...
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Precision of the coordinate transformation modelparameters is crucial for the accuracy of the vision-based robot spatial motion measurement method. In this work, an optimization algorithm integrating RANSAC and iterative weighted singular value decomposition (IR-SVD) is proposed for improving the coordinate transformation model solution precision, aiming at enhancing the spatial motion measurement accuracy of the binocular vision system. Considering noises existing in reference transformation point pairs, the RANSAC algorithm is introduced to filter the raw measurement point pairs and extract inliers, thereby eliminating potential gross errors and realizing the cluster of advantageous points. An enhanced SVD method based on iterative weighted constraints is proposed to substitute traditional SVD. After calculating the coordinate transformation modelparameters, the measurement errors of inliers are solved synchronously, and the weights are reallocated in light of the measurement errors value, subsequently recalculating the coordinate transformation modelparameters repeatedly until the errors converge. The validation experiments are conducted on the self-built three-degree-of-freedom rectangular coordinate robot platform. The experimental results of discrete point-to-point motion and continuous trajectory motion measurement show that the proposed method can improve the coordinate transformation modelparameters solution accuracy effectively, comparing with the traditional SVD method. Comparative experiment with existing commonly used coordinate transformation methods including Quaternion and iterative closest point indicates that the proposed method exhibits the best applicability and minimal errors in robot motion visual measurement. Both accuracy of the coordinate transformation model solution and the visual system's motion measurement are enhanced with this newly-proposed, optimized method.
Coilia nasus is an endangered freshwater fish in China. Due to overfishing and ecological environment deterioration, its resources are rapidly declining and even facing the risk of extinction. Therefore, conservation ...
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Coilia nasus is an endangered freshwater fish in China. Due to overfishing and ecological environment deterioration, its resources are rapidly declining and even facing the risk of extinction. Therefore, conservation measures must be taken immediately to ensure the sustainable resources of C. nasus. The purpose of this study is to predict the suitable habitats of C. nasus in the Yangtze River and to make a spatiotemporal and geographical analysis of the illegal fishing cases of C. nasus in the Yangtze River as part of the conservation efforts. In this study, the MaxEnt model was used to predict the suitable habitats of C. nasus, and the distribution characteristics of illegal fishing cases involving C. nasus were revealed through a spatiotemporal geographic analysis. Based on the collected data of 19 climatic variables, three topographic variables and one flow accumulation variable, we constructed the MaxEnt model, optimized the parameter settings of the MaxEnt software, and called the R package Kuenm to screen and determine the optimal parameters from the MaxEnt model with 1240 different parameter combinations, and predicted the suitable habitats of the C. nasus in the Yangtze River Basin. The results showed that the main breeding areas of C. nasus were mainly concentrated in Chongqing in the upper reaches of the Yangtze River and Jiangsu Province and Shanghai in the middle and lower reaches of the Yangtze River, which had suitable hydrological and topographic conditions for C. nasus survival. In addition, river flow accumulation and temperature are the main variables affecting the distribution of C. nasus in the Yangtze River. At the same time, we analyzed the spatial and temporal distribution of illegal fishing cases of C. nasus and found that there were relatively serious illegal fishing activities in Chongqing and Shanghai, especially in highly suitable habitats areas, where illegal fishing cases broke out frequently, and suggested that high-suitability areas s
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