As the solutions of the least squares support vector regression machine （LS-SVRM） are not sparse, it leads to slow prediction speed and limits its applications. The defects of the ex- isting adaptive pruning algorit...As the solutions of the least squares support vector regression machine （LS-SVRM） are not sparse, it leads to slow prediction speed and limits its applications. The defects of the ex- isting adaptive pruning algorithm for LS-SVRM are that the training speed is slow, and the generalization performance is not satis- factory, especially for large scale problems. Hence an improved algorithm is proposed. In order to accelerate the training speed, the pruned data point and fast leave-one-out error are employed to validate the temporary model obtained after decremental learning. The novel objective function in the termination condition which in- volves the whole constraints generated by all training data points and three pruning strategies are employed to improve the generali- zation performance. The effectiveness of the proposed algorithm is tested on six benchmark datasets. The sparse LS-SVRM model has a faster training speed and better generalization performance.展开更多
As one of the most important part of weapon system of systems(WSoS),quantitative evaluation of reconnaissance satellite system(RSS)is indispensable during its construction and application.Aiming at the problem of nonl...As one of the most important part of weapon system of systems(WSoS),quantitative evaluation of reconnaissance satellite system(RSS)is indispensable during its construction and application.Aiming at the problem of nonlinear effectiveness evaluation under small sample conditions,we propose an evaluation method based on support vector regression(SVR)to effectively address the defects of traditional methods.Considering the performance of SVR is influenced by the penalty factor,kernel type,and other parameters deeply,the improved grey wolf optimizer(IGWO)is employed for parameter optimization.In the proposed IGWO algorithm,the opposition-based learning strategy is adopted to increase the probability of avoiding the local optima,the mutation operator is used to escape from premature convergence and differential convergence factors are applied to increase the rate of convergence.Numerical experiments of 14 test functions validate the applicability of IGWO algorithm dealing with global optimization.The index system and evaluation method are constructed based on the characteristics of RSS.To validate the proposed IGWO-SVR evaluation method,eight benchmark data sets and combat simulation are employed to estimate the evaluation accuracy,convergence performance and computational complexity.According to the experimental results,the proposed method outperforms several prediction based evaluation methods,verifies the superiority and effectiveness in RSS operational effectiveness evaluation.展开更多
With the development of technology, the relevant performance of unmanned aerial vehicles(UAVs) has been greatly improved, and various highly maneuverable UAVs have been developed, which puts forward higher requirement...With the development of technology, the relevant performance of unmanned aerial vehicles(UAVs) has been greatly improved, and various highly maneuverable UAVs have been developed, which puts forward higher requirements on target tracking technology. Strong maneuvering refers to relatively instantaneous and dramatic changes in target acceleration or movement patterns, as well as continuous changes in speed,angle, and acceleration. However, the traditional UAV tracking algorithm model has poor adaptability and large amount of calculation. This paper applies support vector regression(SVR)to the interacting multiple model(IMM) algorithm. The simulation results show that the improved algorithm has higher tracking accuracy for highly maneuverable targets than the original algorithm, and can adjust parameters adaptively, making it more adaptable.展开更多
The pruning algorithms for sparse least squares support vector regression machine are common methods, and easily com- prehensible, but the computational burden in the training phase is heavy due to the retraining in p...The pruning algorithms for sparse least squares support vector regression machine are common methods, and easily com- prehensible, but the computational burden in the training phase is heavy due to the retraining in performing the pruning process, which is not favorable for their applications. To this end, an im- proved scheme is proposed to accelerate sparse least squares support vector regression machine. A major advantage of this new scheme is based on the iterative methodology, which uses the previous training results instead of retraining, and its feasibility is strictly verified theoretically. Finally, experiments on bench- mark data sets corroborate a significant saving of the training time with the same number of support vectors and predictive accuracy compared with the original pruning algorithms, and this speedup scheme is also extended to classification problem.展开更多
建立准确的滚动轴承性能退化预测模型对于轴承故障分类、寿命预测等后续处理有着至关重要的作用。为了解决轴承性能退化模型预测不准确的问题,提出了一种改进的蝙蝠算法(improvement bat algorithm,IBA)来提高退化模型预测的准确度。首...建立准确的滚动轴承性能退化预测模型对于轴承故障分类、寿命预测等后续处理有着至关重要的作用。为了解决轴承性能退化模型预测不准确的问题,提出了一种改进的蝙蝠算法(improvement bat algorithm,IBA)来提高退化模型预测的准确度。首先将Cat混沌映射应用到种群初始位置,增强种群的遍历性,提高初始解的质量;其次在迭代过程中加入类反正切控制因子,提高算法寻优精度;最后改进位置更新策略,防止陷入局部最优。通过与蝙蝠算法(bat algorithm,BA)优化的支持向量回归机(support vector regression,SVR)、粒子群优化算法优化的SVR和灰狼优化算法优化的SVR所得的结果做对比,结果表明:IBA所优化预测模型的均值绝对误差分别下降了70.60%、67.19%、55.56%,均方根误差分别下降了76.64%、76.12%、30.29%,进一步证明了改进后的预测模型的准确性。展开更多
模型辅助检测概率(model-assisted probability of detection,MAPoD)和灵敏度分析对于量化涡流无损检测(eddy current nondestructive testing,ECNDT)系统的检测能力非常重要。由于不确定性在涡流无损检测的MAPoD和SA问题中的传播,传统...模型辅助检测概率(model-assisted probability of detection,MAPoD)和灵敏度分析对于量化涡流无损检测(eddy current nondestructive testing,ECNDT)系统的检测能力非常重要。由于不确定性在涡流无损检测的MAPoD和SA问题中的传播,传统基于实验方法和物理仿真模型对该问题的分析需要耗费大量的时间和人力成本,为了降低这些成本,提出基于粒子群算法(particle swarm optimization,PSO)的支持向量回归(support vector regression,SVR)模型取代传统的实验方法以及物理仿真模型,对涡流无损检测模型的响应进行预测,从而加速MAPoD和SA问题的分析。此外,创新性地将网格搜索、随机搜索、模拟退火算法和PSO等优化算法与SVR相结合,研究不同的优化算法对SVR的关键参数优化的精度和效率,验证PSO相较于其他优化算法的性能优势。最后,将PSO-SVR模型应用于ECNDT算例中,对表面裂缝长度的不确定性进行MAPoD和SA的分析。结果表明,所提算法在保证求解精度的同时,加速了涡流无损检测系统的MAPoD和SA问题的研究,并减少了计算开销。在计算量方面,对这两个问题的求解,平均分别仅需纯物理模型计算量的3.5%和0.06%。展开更多
基金supported by the National Natural Science Foundation of China (61074127)
文摘As the solutions of the least squares support vector regression machine （LS-SVRM） are not sparse, it leads to slow prediction speed and limits its applications. The defects of the ex- isting adaptive pruning algorithm for LS-SVRM are that the training speed is slow, and the generalization performance is not satis- factory, especially for large scale problems. Hence an improved algorithm is proposed. In order to accelerate the training speed, the pruned data point and fast leave-one-out error are employed to validate the temporary model obtained after decremental learning. The novel objective function in the termination condition which in- volves the whole constraints generated by all training data points and three pruning strategies are employed to improve the generali- zation performance. The effectiveness of the proposed algorithm is tested on six benchmark datasets. The sparse LS-SVRM model has a faster training speed and better generalization performance.
基金the National Defense Science and Technology Key Laboratory Fund of China(XM2020XT1023).
文摘As one of the most important part of weapon system of systems(WSoS),quantitative evaluation of reconnaissance satellite system(RSS)is indispensable during its construction and application.Aiming at the problem of nonlinear effectiveness evaluation under small sample conditions,we propose an evaluation method based on support vector regression(SVR)to effectively address the defects of traditional methods.Considering the performance of SVR is influenced by the penalty factor,kernel type,and other parameters deeply,the improved grey wolf optimizer(IGWO)is employed for parameter optimization.In the proposed IGWO algorithm,the opposition-based learning strategy is adopted to increase the probability of avoiding the local optima,the mutation operator is used to escape from premature convergence and differential convergence factors are applied to increase the rate of convergence.Numerical experiments of 14 test functions validate the applicability of IGWO algorithm dealing with global optimization.The index system and evaluation method are constructed based on the characteristics of RSS.To validate the proposed IGWO-SVR evaluation method,eight benchmark data sets and combat simulation are employed to estimate the evaluation accuracy,convergence performance and computational complexity.According to the experimental results,the proposed method outperforms several prediction based evaluation methods,verifies the superiority and effectiveness in RSS operational effectiveness evaluation.
基金supported by the Foundation of Key Laboratory of Near-Surface。
文摘With the development of technology, the relevant performance of unmanned aerial vehicles(UAVs) has been greatly improved, and various highly maneuverable UAVs have been developed, which puts forward higher requirements on target tracking technology. Strong maneuvering refers to relatively instantaneous and dramatic changes in target acceleration or movement patterns, as well as continuous changes in speed,angle, and acceleration. However, the traditional UAV tracking algorithm model has poor adaptability and large amount of calculation. This paper applies support vector regression(SVR)to the interacting multiple model(IMM) algorithm. The simulation results show that the improved algorithm has higher tracking accuracy for highly maneuverable targets than the original algorithm, and can adjust parameters adaptively, making it more adaptable.
基金supported by the National Natural Science Foundation of China(50576033)
文摘The pruning algorithms for sparse least squares support vector regression machine are common methods, and easily com- prehensible, but the computational burden in the training phase is heavy due to the retraining in performing the pruning process, which is not favorable for their applications. To this end, an im- proved scheme is proposed to accelerate sparse least squares support vector regression machine. A major advantage of this new scheme is based on the iterative methodology, which uses the previous training results instead of retraining, and its feasibility is strictly verified theoretically. Finally, experiments on bench- mark data sets corroborate a significant saving of the training time with the same number of support vectors and predictive accuracy compared with the original pruning algorithms, and this speedup scheme is also extended to classification problem.
文摘模型辅助检测概率(model-assisted probability of detection,MAPoD)和灵敏度分析对于量化涡流无损检测(eddy current nondestructive testing,ECNDT)系统的检测能力非常重要。由于不确定性在涡流无损检测的MAPoD和SA问题中的传播,传统基于实验方法和物理仿真模型对该问题的分析需要耗费大量的时间和人力成本,为了降低这些成本,提出基于粒子群算法(particle swarm optimization,PSO)的支持向量回归(support vector regression,SVR)模型取代传统的实验方法以及物理仿真模型,对涡流无损检测模型的响应进行预测,从而加速MAPoD和SA问题的分析。此外,创新性地将网格搜索、随机搜索、模拟退火算法和PSO等优化算法与SVR相结合,研究不同的优化算法对SVR的关键参数优化的精度和效率,验证PSO相较于其他优化算法的性能优势。最后,将PSO-SVR模型应用于ECNDT算例中,对表面裂缝长度的不确定性进行MAPoD和SA的分析。结果表明,所提算法在保证求解精度的同时,加速了涡流无损检测系统的MAPoD和SA问题的研究,并减少了计算开销。在计算量方面,对这两个问题的求解,平均分别仅需纯物理模型计算量的3.5%和0.06%。
