Region partition(RP) is the key technique to the finite element parallel computing(FEPC),and its performance has a decisive influence on the entire process of analysis and computation.The performance evaluation index ...Region partition(RP) is the key technique to the finite element parallel computing(FEPC),and its performance has a decisive influence on the entire process of analysis and computation.The performance evaluation index of RP method for the three-dimensional finite element model(FEM) has been given.By taking the electric field of aluminum reduction cell(ARC) as the research object,the performance of two classical RP methods,which are Al-NASRA and NGUYEN partition(ANP) algorithm and the multi-level partition(MLP) method,has been analyzed and compared.The comparison results indicate a sound performance of ANP algorithm,but to large-scale models,the computing time of ANP algorithm increases notably.This is because the ANP algorithm determines only one node based on the minimum weight and just adds the elements connected to the node into the sub-region during each iteration.To obtain the satisfied speed and the precision,an improved dynamic self-adaptive ANP(DSA-ANP) algorithm has been proposed.With consideration of model scale,complexity and sub-RP stage,the improved algorithm adaptively determines the number of nodes and selects those nodes with small enough weight,and then dynamically adds these connected elements.The proposed algorithm has been applied to the finite element analysis(FEA) of the electric field simulation of ARC.Compared with the traditional ANP algorithm,the computational efficiency of the proposed algorithm has been shortened approximately from 260 s to 13 s.This proves the superiority of the improved algorithm on computing time performance.展开更多
Traditional track dynamic geometric state(TDGS)simulation incurs substantial computational burdens,posing challenges for developing reliability assessment approach that accounts for TDGS.To overcome these,firstly,a si...Traditional track dynamic geometric state(TDGS)simulation incurs substantial computational burdens,posing challenges for developing reliability assessment approach that accounts for TDGS.To overcome these,firstly,a simulation-based TDGS model is established,and a surrogate-based model,grid search algorithm-particle swarm optimization-genetic algorithm-multi-output least squares support vector regression,is established.Among them,hyperparameter optimization algorithm’s effectiveness is confirmed through test functions.Subsequently,an adaptive surrogate-based probability density evolution method(PDEM)considering random track geometry irregularity(TGI)is developed.Finally,taking curved train-steel spring floating slab track-U beam as case study,the surrogate-based model trained on simulation datasets not only shows accuracy in both time and frequency domains,but also surpasses existing models.Additionally,the adaptive surrogate-based PDEM shows high accuracy and efficiency,outperforming Monte Carlo simulation and simulation-based PDEM.The reliability assessment shows that the TDGS part peak management indexes,left/right vertical dynamic irregularity,right alignment dynamic irregularity,and track twist,have reliability values of 0.9648,0.9918,0.9978,and 0.9901,respectively.The TDGS mean management index,i.e.,track quality index,has reliability value of 0.9950.These findings show that the proposed framework can accurately and efficiently assess the reliability of curved low-stiffness track-viaducts,providing a theoretical basis for the TGI maintenance.展开更多
针对人工蜂群(ABC)算法开发能力弱的缺点,提出一种基于适应度分割机制和自适应搜索策略的ABC算法(FSABC)。首先,在雇佣蜂和跟随蜂阶段开始前,根据适应度值将种群划分为高适应度子种群和低适应度子种群,并通过动态调整子种群大小,更好地...针对人工蜂群(ABC)算法开发能力弱的缺点,提出一种基于适应度分割机制和自适应搜索策略的ABC算法(FSABC)。首先,在雇佣蜂和跟随蜂阶段开始前,根据适应度值将种群划分为高适应度子种群和低适应度子种群,并通过动态调整子种群大小,更好地平衡算法的开发性和探索性,并更合理地分配搜索资源;其次,对跟随蜂中的高适应度子种群提出一个策略池和一种新的自适应搜索方式,以避免算法陷入局部最优解;再次,为了加强算法的开发能力,根据高适应度子种群的特点,设计一个新的搜索策略和一个策略池,以发挥该子种群的优势,从而提高算法的性能;最后,对于复杂的多峰问题,在适应度景观中存在许多局部最优解,其中一些可能接近全局最优解,因此,搜索一个好的解的邻域将有助于找到更好的解,甚至可能找到全局最优解,鉴于此,使用一个邻域搜索算子加强算法的开发能力。基于22个经典测试函数进行比较实验的结果表明,在30维和50维问题上,与ABCLGII(ABC algorithm with Local and Global Information Interaction)相比,所提算法的Friedman检验的秩次等级分别提高了30.8%和11.7%,可见,所提算法的性能求解精度更优,并能有效处理全局数值优化问题。展开更多
基金Supported by National Natural Science Foundation of China （61304079, 61125306, 61034002）, the Open Research Project from SKLMCCS （20120106）, the Fundamental Research Funds for the Central Universities （FRF-TP-13-018A）, and the China Postdoctoral Science. Foundation （201_3M_ 5305_27）_ _ _
文摘为有致动器浸透和未知动力学的分离时间的系统的一个班的一个新奇最佳的追踪控制方法在这份报纸被建议。计划基于反复的适应动态编程(自动数据处理) 算法。以便实现控制计划，一个 data-based 标识符首先为未知系统动力学被构造。由介绍 M 网络，稳定的控制的明确的公式被完成。以便消除致动器浸透的效果， nonquadratic 表演功能被介绍，然后一个反复的自动数据处理算法被建立与集中分析完成最佳的追踪控制解决方案。为实现最佳的控制方法，神经网络被用来建立 data-based 标识符，计算性能索引功能，近似最佳的控制政策并且分别地解决稳定的控制。模拟例子被提供验证介绍最佳的追踪的控制计划的有效性。
基金Project(61273187)supported by the National Natural Science Foundation of ChinaProject(61321003)supported by the Foundation for Innovative Research Groups of the National Natural Science Foundation of China
文摘Region partition(RP) is the key technique to the finite element parallel computing(FEPC),and its performance has a decisive influence on the entire process of analysis and computation.The performance evaluation index of RP method for the three-dimensional finite element model(FEM) has been given.By taking the electric field of aluminum reduction cell(ARC) as the research object,the performance of two classical RP methods,which are Al-NASRA and NGUYEN partition(ANP) algorithm and the multi-level partition(MLP) method,has been analyzed and compared.The comparison results indicate a sound performance of ANP algorithm,but to large-scale models,the computing time of ANP algorithm increases notably.This is because the ANP algorithm determines only one node based on the minimum weight and just adds the elements connected to the node into the sub-region during each iteration.To obtain the satisfied speed and the precision,an improved dynamic self-adaptive ANP(DSA-ANP) algorithm has been proposed.With consideration of model scale,complexity and sub-RP stage,the improved algorithm adaptively determines the number of nodes and selects those nodes with small enough weight,and then dynamically adds these connected elements.The proposed algorithm has been applied to the finite element analysis(FEA) of the electric field simulation of ARC.Compared with the traditional ANP algorithm,the computational efficiency of the proposed algorithm has been shortened approximately from 260 s to 13 s.This proves the superiority of the improved algorithm on computing time performance.
基金Project(52072412)supported by the National Natural Science Foundation of China。
文摘Traditional track dynamic geometric state(TDGS)simulation incurs substantial computational burdens,posing challenges for developing reliability assessment approach that accounts for TDGS.To overcome these,firstly,a simulation-based TDGS model is established,and a surrogate-based model,grid search algorithm-particle swarm optimization-genetic algorithm-multi-output least squares support vector regression,is established.Among them,hyperparameter optimization algorithm’s effectiveness is confirmed through test functions.Subsequently,an adaptive surrogate-based probability density evolution method(PDEM)considering random track geometry irregularity(TGI)is developed.Finally,taking curved train-steel spring floating slab track-U beam as case study,the surrogate-based model trained on simulation datasets not only shows accuracy in both time and frequency domains,but also surpasses existing models.Additionally,the adaptive surrogate-based PDEM shows high accuracy and efficiency,outperforming Monte Carlo simulation and simulation-based PDEM.The reliability assessment shows that the TDGS part peak management indexes,left/right vertical dynamic irregularity,right alignment dynamic irregularity,and track twist,have reliability values of 0.9648,0.9918,0.9978,and 0.9901,respectively.The TDGS mean management index,i.e.,track quality index,has reliability value of 0.9950.These findings show that the proposed framework can accurately and efficiently assess the reliability of curved low-stiffness track-viaducts,providing a theoretical basis for the TGI maintenance.
文摘针对人工蜂群(ABC)算法开发能力弱的缺点,提出一种基于适应度分割机制和自适应搜索策略的ABC算法(FSABC)。首先,在雇佣蜂和跟随蜂阶段开始前,根据适应度值将种群划分为高适应度子种群和低适应度子种群,并通过动态调整子种群大小,更好地平衡算法的开发性和探索性,并更合理地分配搜索资源;其次,对跟随蜂中的高适应度子种群提出一个策略池和一种新的自适应搜索方式,以避免算法陷入局部最优解;再次,为了加强算法的开发能力,根据高适应度子种群的特点,设计一个新的搜索策略和一个策略池,以发挥该子种群的优势,从而提高算法的性能;最后,对于复杂的多峰问题,在适应度景观中存在许多局部最优解,其中一些可能接近全局最优解,因此,搜索一个好的解的邻域将有助于找到更好的解,甚至可能找到全局最优解,鉴于此,使用一个邻域搜索算子加强算法的开发能力。基于22个经典测试函数进行比较实验的结果表明,在30维和50维问题上,与ABCLGII(ABC algorithm with Local and Global Information Interaction)相比,所提算法的Friedman检验的秩次等级分别提高了30.8%和11.7%,可见,所提算法的性能求解精度更优,并能有效处理全局数值优化问题。
