在采用高斯径向基函数的相关向量机(RVM)回归模型中,核参数与模型性能之间关系复杂,针对如何确定RVM核参数的问题,提出一种基于AIC准则选择RVM的核参数的方法。首先基于Akaike Information Criterion(AIC)思想,得出一种新的统计量Q,同时...在采用高斯径向基函数的相关向量机(RVM)回归模型中,核参数与模型性能之间关系复杂,针对如何确定RVM核参数的问题,提出一种基于AIC准则选择RVM的核参数的方法。首先基于Akaike Information Criterion(AIC)思想,得出一种新的统计量Q,同时将Q作为适应度函数;然后利用微分进化算法(Differential Evolution Algorithm,DE)对核参数进行寻优,以此选择确定核参数;最后利用该算法建立RVM回归模型对黄金价格进行短期预测。实验结果表明,该模型较传统方法建立的预测模型具有更高的拟合精度和更好的泛化能力,进一步证明基于AIC准则选择RVM的核参数的方法的可行性和有效性。展开更多
This paper extends the application of compressive sensing(CS) to the radar reconnaissance receiver for receiving the multi-narrowband signal. By combining the concept of the block sparsity, the self-adaption methods, ...This paper extends the application of compressive sensing(CS) to the radar reconnaissance receiver for receiving the multi-narrowband signal. By combining the concept of the block sparsity, the self-adaption methods, the binary tree search,and the residual monitoring mechanism, two adaptive block greedy algorithms are proposed to achieve a high probability adaptive reconstruction. The use of the block sparsity can greatly improve the efficiency of the support selection and reduce the lower boundary of the sub-sampling rate. Furthermore, the addition of binary tree search and monitoring mechanism with two different supports self-adaption methods overcome the instability caused by the fixed block length while optimizing the recovery of the unknown signal.The simulations and analysis of the adaptive reconstruction ability and theoretical computational complexity are given. Also, we verify the feasibility and effectiveness of the two algorithms by the experiments of receiving multi-narrowband signals on an analogto-information converter(AIC). Finally, an optimum reconstruction characteristic of two algorithms is found to facilitate efficient reception in practical applications.展开更多
地震波初至拾取是地震预警、地震定位等地震资料处理工作的重要基础,其实时性和准确性直接影响地震资料处理工作的效率.实际应用中,地震波初至拾取受日益增多的噪声干扰较大,传统地震波初至拾取算法很难兼顾实时性、准确性.针对上述问题...地震波初至拾取是地震预警、地震定位等地震资料处理工作的重要基础,其实时性和准确性直接影响地震资料处理工作的效率.实际应用中,地震波初至拾取受日益增多的噪声干扰较大,传统地震波初至拾取算法很难兼顾实时性、准确性.针对上述问题,本文提出一种基于Delaunay三角(简称为D三角)剖分的天然地震波初至实时拾取算法.首先,本文对STA/LTA-AIC(Short-Term Average/Long-Term Average-Akaike Information Criterion)算法特征函数进行参数分析,引用包含平方项和差分项的特征函数,增强算法的实时性;其次,通过改进时窗位置并加入取消时窗的方式,增加算法抗短时强噪声干扰的能力;最后,考虑到地震波在两台站间的最快传播速度,由台间距和地震波最大走时设置走时残差阈值,并依据D三角关系,提出D三角触发判别准则剔除部分干扰噪声.川渝地区现场数据验证表明,本文改进的STA/LTA-AIC算法提高了单台拾取地震波初至的抗短时强噪声能力,基于D三角剖分的天然地震波初至拾取算法能排除各台站误拾取信号,实时、准确、可靠拾取出实际地震波初至时刻.展开更多
精确估计多层材料超声回波信号的重数在超声检测上有着要意义。将小波变换方法用于多层材料超声回波参数估计中,根据高斯模型以超声回波信号的小波变换为基础、利用智能人工蜂群算法,估计出多重超声回波信号的各个参数。采用Akaike Info...精确估计多层材料超声回波信号的重数在超声检测上有着要意义。将小波变换方法用于多层材料超声回波参数估计中,根据高斯模型以超声回波信号的小波变换为基础、利用智能人工蜂群算法,估计出多重超声回波信号的各个参数。采用Akaike Information Criterion(AIC)准则,对叠加的两重和三重超声回波信号的重数进行估计。仿真结果表明,本算法可以实现多重超声回波信号重数的有效估计。用实验测试获得的回波对算法的性能进行了验证,结果证明了该算法的可行性和实用性。展开更多
文摘在采用高斯径向基函数的相关向量机(RVM)回归模型中,核参数与模型性能之间关系复杂,针对如何确定RVM核参数的问题,提出一种基于AIC准则选择RVM的核参数的方法。首先基于Akaike Information Criterion(AIC)思想,得出一种新的统计量Q,同时将Q作为适应度函数;然后利用微分进化算法(Differential Evolution Algorithm,DE)对核参数进行寻优,以此选择确定核参数;最后利用该算法建立RVM回归模型对黄金价格进行短期预测。实验结果表明,该模型较传统方法建立的预测模型具有更高的拟合精度和更好的泛化能力,进一步证明基于AIC准则选择RVM的核参数的方法的可行性和有效性。
基金supported by the National Natural Science Foundation of China(61172159)
文摘This paper extends the application of compressive sensing(CS) to the radar reconnaissance receiver for receiving the multi-narrowband signal. By combining the concept of the block sparsity, the self-adaption methods, the binary tree search,and the residual monitoring mechanism, two adaptive block greedy algorithms are proposed to achieve a high probability adaptive reconstruction. The use of the block sparsity can greatly improve the efficiency of the support selection and reduce the lower boundary of the sub-sampling rate. Furthermore, the addition of binary tree search and monitoring mechanism with two different supports self-adaption methods overcome the instability caused by the fixed block length while optimizing the recovery of the unknown signal.The simulations and analysis of the adaptive reconstruction ability and theoretical computational complexity are given. Also, we verify the feasibility and effectiveness of the two algorithms by the experiments of receiving multi-narrowband signals on an analogto-information converter(AIC). Finally, an optimum reconstruction characteristic of two algorithms is found to facilitate efficient reception in practical applications.
文摘地震波初至拾取是地震预警、地震定位等地震资料处理工作的重要基础,其实时性和准确性直接影响地震资料处理工作的效率.实际应用中,地震波初至拾取受日益增多的噪声干扰较大,传统地震波初至拾取算法很难兼顾实时性、准确性.针对上述问题,本文提出一种基于Delaunay三角(简称为D三角)剖分的天然地震波初至实时拾取算法.首先,本文对STA/LTA-AIC(Short-Term Average/Long-Term Average-Akaike Information Criterion)算法特征函数进行参数分析,引用包含平方项和差分项的特征函数,增强算法的实时性;其次,通过改进时窗位置并加入取消时窗的方式,增加算法抗短时强噪声干扰的能力;最后,考虑到地震波在两台站间的最快传播速度,由台间距和地震波最大走时设置走时残差阈值,并依据D三角关系,提出D三角触发判别准则剔除部分干扰噪声.川渝地区现场数据验证表明,本文改进的STA/LTA-AIC算法提高了单台拾取地震波初至的抗短时强噪声能力,基于D三角剖分的天然地震波初至拾取算法能排除各台站误拾取信号,实时、准确、可靠拾取出实际地震波初至时刻.
文摘精确估计多层材料超声回波信号的重数在超声检测上有着要意义。将小波变换方法用于多层材料超声回波参数估计中,根据高斯模型以超声回波信号的小波变换为基础、利用智能人工蜂群算法,估计出多重超声回波信号的各个参数。采用Akaike Information Criterion(AIC)准则,对叠加的两重和三重超声回波信号的重数进行估计。仿真结果表明,本算法可以实现多重超声回波信号重数的有效估计。用实验测试获得的回波对算法的性能进行了验证,结果证明了该算法的可行性和实用性。
