Path planning is a fundamental function of mobile robots that have been nowadays used in a variety of areas. evolutionary algorithms (EAs) have been experimentally showed to be efficient for the problem of mobile robo...
详细信息
Path planning is a fundamental function of mobile robots that have been nowadays used in a variety of areas. evolutionary algorithms (EAs) have been experimentally showed to be efficient for the problem of mobile robot path planning, an NP-problem. However, there is no theoretical work about EAs on the problem. In this paper, to understand more about why EAs are efficient and to give some advice on how to design more efficient EAs for this problem, we perform the first theoretical analysis of the expected runtime of a simple EA called (1+1) EA with three different mutations for the mobile robot path planning problem in two constructed environments. In addition, anew method of producing a path from an uncomplete path is proposed, in which anew Insert process is proposed. Meanwhile, an obvious disadvantage of one of these three mutations is discovered during the expected runtime analysis in the first environment. Based on this discovery, an improved version of this mutation is proposed. In the second constructed environment, the improved mutation is proved to be superior to the others. In detail, the (1+1) EA with the improved mutation can find the shortest path in runtime O(n(5)), while the (1+1) EA with any one of the other mutations may be trapped in local optima. Experiments have been performed on the two constructed environments and six randomly generated environments with different sizes and varying obstacle densities.
Sparse optimization problems at a large scale present considerable difficulties in diverse fields, such as machine learning, data mining, and signal processing. The aim is to identify the most efficient solutions with...
详细信息
The extraction of chitin and chitosan presents challenges due to the complexity of the process and the influence of many variables. This study aimed to optimize chitin and chitosan extraction from Fusarium verticillio...
详细信息
The extraction of chitin and chitosan presents challenges due to the complexity of the process and the influence of many variables. This study aimed to optimize chitin and chitosan extraction from Fusarium verticillioides by analyzing many additives and processing variables and modeling their yields using multiple linear regression (MLR) and evolutionary algorithms. FT-IR analysis confirmed the presence of characteristic bands in the extracted samples, and SEM analysis further revealed the microfibrillar appearance of the chitin and the dense, non-porous structure of the chitosan. The Ant Lion Optimizer (ALO) was employed to select significant factors and optimize model parameters. A transformation was applied to capture nonlinear relationships, and the finetuned models showed improved predictive power, with p-values of 0.00203 for chitin and 0.00884 for chitosan. Multi-objective optimization (MOO) using the Adaptive Geometry Estimation-based Multi-Objective evolutionary Algorithm (AGE-MOEA) further identified significant factors for optimal yields, achieving 3 g of Arginine, 100 ml of culture medium volume, 7 to 11 days of incubation time, 0.2 to 1.76 ml of Oligochitin, 1.4 g of FeSO4, 1.5 g of K2HPO4, and 1 g of NaCl. Therefore, the integration of ALO and AGE-MOEA algorithms effectively modeled and optimized chitin and chitosan yields by maximizing biopolymer recovery, enabling significant industrial exploitation.
This study focused on the seismic responses and numerical model update of fluid viscous dampers (FVDs) isolated cable-stayed bridges excited by ground motions with different frequency contents. A 1/20 scaled three-spa...
详细信息
This study focused on the seismic responses and numerical model update of fluid viscous dampers (FVDs) isolated cable-stayed bridges excited by ground motions with different frequency contents. A 1/20 scaled three-span cable-stayed bridge was designed, constructed, and tested on a facility with four shake tables. Four ground motions with different frequency contents were adopted to excite the shake model. Then, a numerical model update framework of the shake table test was introduced, which combines the differential evolution (DE) algorithm and the parallel finite element computing technique. In addition, a time history response-based objective function was established that considered various responses of the bridge components. The shake table test results reveal that frequency contents affect the seismic responses of the cable-stayed bridge, and the ground motions with strong velocity pulses can amplify the displacements of the pylons and girder. In addition, the accelerations of the girder are relatively small and less sensitive to input ground motions. In general, the proposed method is efficient and accurate for updating the numerical model of the shake table test model.
The present study aims to carry out a comparative Multi-Objective Optimization (MOO) of a 10 MW FOWT semi-submersible using three different metaheuristic optimization techniques and a sophisticated approach for optimi...
详细信息
The present study aims to carry out a comparative Multi-Objective Optimization (MOO) of a 10 MW FOWT semi-submersible using three different metaheuristic optimization techniques and a sophisticated approach for optimizing a floating platform. This novel framework enables highly efficient 3D plots, an optimization loop, and the automatic and comparative output of solutions. Python, the main interface, integrated PyMAPDL and Pymoo for intricate modeling and simulation tasks. For this case study, the ZJUS10 Floating Offshore Wind Turbine (FOWT) platform, developed by the state key laboratory of mechatronics and fluid power at Zhejiang University, was employed as the basis. Key criteria such as platform stability, overall structural mass, and stress were pivotal in formulating the objective functions. Based on a preliminary study, the three metaheuristic optimization algorithms chosen for optimization were Particle Swarm Optimization (PSO), Simulated Annealing (SA), and Ant Colony Optimization (ACO). Then, the solutions were evaluated based on Pareto dominance, leading to a Pareto front, a curve that represents the best possible trade-offs among the objectives. Each algorithm's convergence was meticulously evaluated, leading to the selection of the optimal design solution. The results evaluated in simulations elucidate the strengths and limitations of each optimization method, providing valuable insights into their efficacy for complex engineering design challenges. In the post-processing phase, the performances of the optimized FOWT platforms were thoroughly compared both among themselves and with the original model, resulting in validation. Finally, the ACO algorithm delivered a highly effective solution within the framework, achieving reductions of 19.8% in weight, 40.1% in pitch, and 12.7% in stress relative to the original model.
Reducing the environmental impact of air transport is one of today's most important challenges in aviation industry and research. A promising key enabler is the use of hydrogen as an alternative to fossil fuels. T...
详细信息
Reducing the environmental impact of air transport is one of today's most important challenges in aviation industry and research. A promising key enabler is the use of hydrogen as an alternative to fossil fuels. The development of hydrogen-powered aircraft poses new engineering challenges due to its low volumetric energy density requiring high-pressure or cryogenic storage. If the volume in the wing shall be further used for storing hydrogen under high pressure, new demands arise to airfoil design. The present work focuses on this issue by presenting a multi-objective optimization approach aiming for airfoils with both low drag and high volume for internal tubular high-pressure tanks. This allows to directly address the new design objective and to find novel airfoil shapes providing the best compromise between aerodynamic efficiency and high storage volume for pressurized hydrogen. The resulting optimization problem is solved using evolutionary algorithms. For an efficient aerodynamic evaluation, the open source viscous-inviscid panel method XFOIL is used. An application example, based on the flight conditions of a general aviation aircraft, demonstrates the applicability of the method. Comparisons of the resulting aerodynamic characteristics obtained by XFOIL with RANS simulations confirm the feasibility of the results.
In recent decades, the demand for optimization techniques has grown due to rising complexity in real-world problems. Hence, this work introduces the Hyperbolic Sine Optimizer (HSO), an innovative metaheuristic specifi...
详细信息
In recent decades, the demand for optimization techniques has grown due to rising complexity in real-world problems. Hence, this work introduces the Hyperbolic Sine Optimizer (HSO), an innovative metaheuristic specifically designed for scientific optimization. Unlike conventional approaches, HSO takes a unique approach by engaging individual members of the population, ensuring a comprehensive exploration of solution spaces. Employing distinctive exploration and exploitation phases, coupled with hyperbolic sinh\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$sinh$$\end{document} function convergence, the optimizer enhances speed, simplify parameter adjustment, alleviates slow convergence, and demonstrates efficiency in high-dimensional optimization. This approach is designed to tackle optimization challenges and enhance adaptability in unpredictable real-world scenarios. The evaluation of HSO's performance unfolds through four distinct testing phases. Initially, a set of 65 widely recognized benchmark functions is employed. These functions cover both unimodal and multi-modal varieties across dimensions of 30, 100, 500, and 1000, including fixed-dimensional functions, to comprehensively assess the exploration, exploitation, local optima avoidance, and convergence capabilities of the proposed algorithm. The results of the HSO algorithm are then compared to those of 15 state-of-the-art metaheuristic algorithms and 8 recently published algorithms. Secondly, HSO's performance is assessed in comparison with the benchmark suite from the Institute of Electrical and Electronics Engineers (IEEE) Congress on evolutionary Computation (CEC). This suite includes 15 benchmark functions for CEC-2015 and an additional 30 benchmark functions for CEC-2017. During the third phase, HSO tackles seven real-world
At present, wireless sensor networks (WSNs) play an important role in collecting and processing information in smart transportation monitoring. Inevitably, the performance of the resource scheduling algorithm directly...
详细信息
At present, wireless sensor networks (WSNs) play an important role in collecting and processing information in smart transportation monitoring. Inevitably, the performance of the resource scheduling algorithm directly determines the quality of service of WSNs. In this paper, we present a novel large-scale resource scheduling algorithm of WSNs based on differential ion coevolution and multi-objective decomposition (DIC-MOD) to optimize the performance of WSNs. We first introduce a certain number of mobile nodes with higher configuration into WSNs and consider them as relay nodes to strengthen the balance of energy consumption in the entire WSNs. Subsequently, we build a multi-index service quality evaluation model, including coverage, connectivity, energy efficiency and the number of nodes required to work, to characterize the comprehensive performance of WSNs. Afterward, to optimize the above complex model effectively, we propose a multi-objective resource scheduling algorithm, in which a differential ion coevolution strategy and a fast individual selection strategy based on multi-objective decomposition optimization are proposed in specific. Compared with other state-of-the-art algorithms, the experimental results finally show that the performance of WSNs on multiple indicators obtained by the proposed algorithm has been improved considerably.
The differential evolution algorithm has rich, successful experience in parameter settings. How to reasonably control strategies and parameters and effectively utilize feedback information from individuals in the popu...
详细信息
evolutionary Neural Architecture Search (ENAS) is a promising method for the automated design of deep network architecture, which has attracted extensive attention in the field of automated machine learning. However, ...
详细信息
evolutionary Neural Architecture Search (ENAS) is a promising method for the automated design of deep network architecture, which has attracted extensive attention in the field of automated machine learning. However, the existing ENAS methods often need a lot of computing resources to design CNN architecture automatically. In order to achieve efficient and automated design of CNNs, this paper focuses on two aspects to improve efficiency. On the one hand, efficient CNN-based building blocks are introduced to ensure the effectiveness of the generated architectures and a triplet attention mechanism is incorporated into the architectures to further improve the classification performance. On the other hand, a random forest-based performance predictor is used in the fitness evaluation to reduce the amount of computation required to train each individual from scratch. Experimental results show that the proposed algorithm can significantly reduce the computational resources required and achieve competitive classification performance on the CIFAR dataset. Also, the architecture designed for the traffic sign recognition task exceeds the accuracy of manual expert design.(c) 2022 Elsevier B.V. All rights reserved.
暂无评论