Driver Assistance Systems (DAS) have been progressively incorporated into commercial vehicles in recent years. All these systems are paving the way for the forthcoming autonomous vehicle which will become a reality in...
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Driver Assistance Systems (DAS) have been progressively incorporated into commercial vehicles in recent years. All these systems are paving the way for the forthcoming autonomous vehicle which will become a reality in the near future. Existing systems are based on numerous electronic systems with advanced skills, high performances, and high degrees of adaptability and intelligence. As is to be expected, these cutting-edge features require, in most cases, the use of powerful computing platforms. However, the deployment of such platforms is not an easy task, since they have to be integrated in the vehicle where there exist important restrictions regarding size, power consumption and cost. In this sense, every smart proposal aimed at reducing the complexity of these systems without degrading performance, is always a valuable contribution in the field. In this work, we propose a methodology to reduce the dimensionality of a driver distraction recognition system. The methodology is based on a multi-objective genetic algorithm that looks for the minimum set of useful features collected during the driving task and also for the simplest recognition system. The recognition algorithm is an Extreme Learning Machine (ELM) whose simplicity and fast learning procedure make it especially suitable to be used by a geneticalgorithm which needs to evaluate thousands of candidate solutions. The proposed methodology has been tested with a real-world database collected from different drivers performing an itinerary with an instrumented car. The results obtained validate the proposal as a method to reduce the complexity of a driver distraction recognition system.
Considering the strict constraints on battery module space and cost, two types of ultra-thin battery heat transfer structures were proposed and numerically optimized in this paper. The grooved patterns of microstructu...
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Considering the strict constraints on battery module space and cost, two types of ultra-thin battery heat transfer structures were proposed and numerically optimized in this paper. The grooved patterns of microstructures are developed based on the manifold microchannel (MMC) and manifold micro pin fin (MMPF) concepts. The effects of geometrical parameter variations on the system's thermodynamic irreversibility are investigated. The structural optimization uses the Entropy Generation Minimization method and multi-objective genetic algorithm. The effects of eight independent geometrical parameters on the performance of the micro-structured heat sinks are analyzed by statistical analysis, and the finding is that the inlet manifold width and the height of the microchannel/micro-pin-fin strongly affect the entropy generation of the system. The entropy generation becomes lower as the wider the inlet manifold and the lower the microchannel/micro-pin-fin. The multi-objective genetic algorithm determines that the entropy generation characteristics are a function of these two crucial parameters. The irreversible losses of the optimized MMC and MMPF heat sinks are reduced by 88.53 % and 83.47 %, respectively, and the thermodynamic efficiencies, eta W- S, are increased from 97.51 % and 97.83 % to 99.59 % and 99.75 %, respectively, compared to the initial geometries.
PurposeThis paper aims to enhance the stability and control of twin rotor multi-input multi-output system (TRMS) helicopters by introducing a novel approach that utilizes a multi-objective genetic algorithm (MOGA) for...
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PurposeThis paper aims to enhance the stability and control of twin rotor multi-input multi-output system (TRMS) helicopters by introducing a novel approach that utilizes a multi-objective genetic algorithm (MOGA) for optimizing proportional, integral, derivative (PID) controllers in simultaneous pitch and yaw ***/methodology/approachThe TRMS, a common prototype for helicopter motion studies, is introduced, and a PID controller is designed for pitch and yaw stabilization. The gains of the PID controller are optimized using a MOGA, a technique not previously proposed for TRMS in the *** various controllers have been explored in literature for TRMS stabilization, a MOGA-optimized PID controller for TRMS has not been proposed before. Simultaneous optimization of both pitch and yaw motions using two PID controllers is expected to yield improved *** limitations/implicationsThe study focuses on simulations, and experimental validation is not conducted. The MOGA is introduced as an optimization technique, and future studies may explore its application in experimental ***/valueThis study introduces a novel approach by utilizing a MOGA to optimize PID controller gains for TRMS. Simultaneous optimization of pitch and yaw motions aims to enhance robustness, providing a unique contribution to the field of helicopter control.
A significant quantity of slime water generated during coal mining poses a serious threat to the health of underground workers and the environment. The decanter centrifuge is widely employed in slime water treatment d...
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A significant quantity of slime water generated during coal mining poses a serious threat to the health of underground workers and the environment. The decanter centrifuge is widely employed in slime water treatment due to its high efficiency in solid-liquid separation. This paper proposes a structural optimization framework for the mine decanter centrifuge based on the Response Surface Method (RSM) and multi-objective genetic algorithm (MOGA). Firstly, a three-dimensional numerical model of the decanter centrifuge was established, and the reliability of the model was verified by experimental and theoretical analysis. Subsequently, the Box-Behnken design method and RSM were employed to construct a response surface model that links input parameters (drum half cone angle, screw pitch, and spiral blade Inclination angle) with target variables (solid phase recovery rate and overflow liquid phase solids content). The interactions between each input parameter and target variable were assessed using analysis of variance (ANOVA), which confirmed the model's effectiveness and generalization capability. Finally, MOGA was employed to optimize the centrifuge's structural parameters, resulting in an 8.16 % increase in solid recovery rate and a 35.84 % reduction in overflow liquid solid content. It offers a valuable reference for the structural optimization of decanter centrifuges in coal slurry separation.
With the advancement of economic globalization, the distributed heterogeneous factory environment has become the mainstream in manufacturing enterprises. Scheduling flexible job shops in such a production environment ...
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With the advancement of economic globalization, the distributed heterogeneous factory environment has become the mainstream in manufacturing enterprises. Scheduling flexible job shops in such a production environment holds practical value. However, due to the high complexity of certain jobs, the transfer of jobs between different factories are often required in practical production to balance machine load rates. Accordingly, this study addresses the distributed heterogeneous assembly flexible job shop scheduling problem with transfers, aiming to minimize both the makespan and total energy consumption. First, a multi-objective optimization model is formulated to define the problem, wherein knowledge of factory assignment and processing sequence for operations is summarized. Subsequently, given the complexity of this problem, a Q-learning-based improved multi-objective genetic algorithm (QL-IMOGA) is proposed as an effective approach. Within the proposed algorithm, a hybrid population initialization method is designed, considering factory load balancing and the earliest product completion time, to generate a high-quality initial population. Furthermore, two types of crossover operators, four types of mutation operators, and six objective-oriented neighborhood search operators are devised to enhance the algorithm's exploration and exploitation capabilities. Q-learning is employed for adaptive adjustment of key parameters to improve both convergence speed and solution quality. The effectiveness of the proposed population initialization method and neighborhood search operators is validated through 15 test cases. The results demonstrate that the proposed algorithm significantly outperformed four advanced meta-heuristic algorithms. Furthermore, it is observed that the solution employing the job transfer strategy led to an average reduction of 7.5% in makespan, a 3.9% decrease in total energy consumption, and an 8.4 % improvement in factory load rates compared to the soluti
The deep learning and multi-objective genetic algorithm were employed to optimize the fuel reloading pattern for HPR1000, a state-of-the-art nuclear power reactor designed and operated in China, also known as Hualong-...
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The deep learning and multi-objective genetic algorithm were employed to optimize the fuel reloading pattern for HPR1000, a state-of-the-art nuclear power reactor designed and operated in China, also known as Hualong-1. In this study, the deep-learning algorithm was applied to establish the rapid evaluator for fuel-reloading patterns, for which the random samples between fuel-reloading patterns and corresponding key core parameters were generated by our home-developed nuclear-design code, named Bamboo-C. The advanced machine-learning platform TensorFlow was utilized for the deep-learning model. Then, the multi-objective genetic algorithm was applied to search the optimal fuel-reloading patterns, combined with the rapid evaluator to evaluate the key core parameters in a very short time. The DAKOTA toolkit was employed for optimization using a multi-objective genetic algorithm, for which the cycle length and power-peak factors were selected as the target parameters to establish the fitness function. For verification and application, the above method has been applied to the fuel- reloading optimization for Cycle 2 of HPR1000 operated in China. The optimization pattern results in an extension of the cycle length by about 21 EFPD (Effective Full Power Day), keeping all the key safety parameters satisfying corresponding safety criteria.
Tamping can effectively recover the geometry of a ballasted track. Nevertheless, it can decrease the mechanical properties of ballast bed. To mitigate the damage caused by tamping, this paper developed an intelligent ...
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Tamping can effectively recover the geometry of a ballasted track. Nevertheless, it can decrease the mechanical properties of ballast bed. To mitigate the damage caused by tamping, this paper developed an intelligent optimization method for tamping parameters using the DEM-RBF-MOGA. This intelligent optimization method enables automatic simulation and simultaneous data transmission. Additionally, it can reveal the interactions among tamping parameters. Hence, the developed intelligent method has higher accuracy and efficiency than traditional methods. Subsequently, the sensitive characteristics of the ballast bed for tamping parameters were investigated, and the corresponding objective functions for optimizing were developed. Finally, a surrogate model was constructed and optimal tamping parameters were proposed. The results indicate that the objective functions vary nonlinearly and irregularly with the tamping parameters. The optimal vibration frequency, vibration amplitude, and squeezing force of tamping operation for ballast bed with different mechanical properties can be easily determined using this intelligent method. This paper provides effective guidelines for improving the maintenance of ballasted tracks.
The cylinder mass affects the ball mill's operation and economy. To reduce the mass of the current cylinder, this paper utilized a response surface optimization module and a multi-objective genetic algorithm to op...
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The cylinder mass affects the ball mill's operation and economy. To reduce the mass of the current cylinder, this paper utilized a response surface optimization module and a multi-objective genetic algorithm to optimize the cylinder structure. First, the optimal parts of the cylinder were determined by static analysis. Subsequently, the mathematical model was established with the goal of achieving structural lightweight. Then, the size of the cylinder was optimized based on the response surface optimization module and multi-objective genetic algorithm. Finally, the static analysis and modal analysis results before and after optimization were compared to verify the stress and resonance of the structure, and the optimization effect was evaluated. The optimized cylinder had a mass reduction of 15.624 % without compromising the strength and deformation. The optimization design can save materials and costs, and provide a theoretical reference for the lightweight research of the ball mill's cylinder.
Purpose In early 2020, the world is amid a significant pandemic due to the novel coronavirus disease outbreak, commonly called the COVID-19. Coronavirus is a lung infection disease caused by the Severe Acute Respirato...
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Purpose In early 2020, the world is amid a significant pandemic due to the novel coronavirus disease outbreak, commonly called the COVID-19. Coronavirus is a lung infection disease caused by the Severe Acute Respiratory Syndrome Coronavirus 2 virus (SARS-CoV-2). Because of its high transmission rate, it is crucial to detect cases as soon as possible to effectively control the spread of this pandemic and treat patients in the early stages. RT-PCR-based kits are the current standard kits used for COVID-19 diagnosis, but these tests take much time despite their high precision. A faster automated diagnostic tool is required for the effective screening of COVID-19. Methods In this study, a new semi-supervised feature learning technique is proposed to screen COVID-19 patients using chest CT scans. The model proposed in this study uses a three-step architecture, consisting of a convolutional autoencoder based unsupervised feature extractor, a multi-objective genetic algorithm (MOGA) based feature selector, and a Bagging Ensemble of support vector machines based binary classifier. The proposed architecture has been designed to provide precise and robust diagnostics for binary classification (COVID ***). A dataset of 1252 COVID-19 CT scan images, collected from 60 patients, has been used to train and evaluate the model. Results The best performing classifier within 127 ms per image achieved an accuracy of 98.79%, the precision of 98.47%, area under curve of 0.998, and an F1 score of 98.85% on 497 test images. The proposed model outperforms the current state of the art COVID-19 diagnostic techniques in terms of speed and accuracy. Conclusion The experimental results prove the superiority of the proposed methodology in comparison to existing *** study also comprehensively compares various feature selection techniques and highlights the importance of feature selection in medical image data problems.
Phase Change Memory (PCM) has attracted widespread attention for its high-speed reading and writing capabilities and high-density non-volatile storage. However, reducing the reset current of PCM can result in an incre...
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Phase Change Memory (PCM) has attracted widespread attention for its high-speed reading and writing capabilities and high-density non-volatile storage. However, reducing the reset current of PCM can result in an increase in its set resistance, which affects the programming or readout performances. Therefore, further optimization of PCM under this trade-off remains a significant challenge. In this paper, multi-objective genetic algorithm (MOGA) is utilized to address this problem through the optimization of PCM's geometry. An enhanced PCM finite element model, considering the Seebeck, Peltier, and Thomson effects, is employed as the fitness function of MOGA to improve the accuracy of PCM's reset arguments and obtain precise solution. The PCM geometry solution set with optimal performance in different technology nodes are presented in this paper. Specifically, for the 22-nm node, the optimization result shows that the reset current can be reduced by up to 8.7 % when the PCM is employed for low-power applications, such as neuromorphic computing, and the read latency time can be reduced by up to 22.2 % when the PCM is utilized for fast reading purposes, such as in PCM-DRAM main memory. This proposed optimization scheme has great potential in improving the performance of PCM.
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