期刊文献+
共找到2篇文章
< 1 >
每页显示 20 50 100
基于小波和卡尔曼平滑的事件相关电位单次提取 被引量:1
1
作者 牟锴钰 韦明 郭建平 《中国生物医学工程学报》 CAS CSCD 北大核心 2012年第2期167-174,共8页
本研究提出一种事件相关电位单次提取方法,可有效减少实验次数,并可探索实验之间ERP的变异性。此方法基于小波和卡尔曼平滑,首先利用小波变换考察ERP平均信号的时频特性,根据ERP不同分量出现的时间位置,在不同尺度上选取特定的单次实验... 本研究提出一种事件相关电位单次提取方法,可有效减少实验次数,并可探索实验之间ERP的变异性。此方法基于小波和卡尔曼平滑,首先利用小波变换考察ERP平均信号的时频特性,根据ERP不同分量出现的时间位置,在不同尺度上选取特定的单次实验ERP小波系数构成观测向量,其为真实ERP小波系数状态向量与噪声之和,然后对观测向量进行卡尔曼平滑,最后对卡尔曼平滑后的小波系数进行小波重构,得到单次提取的ERP信号。仿真实验表明,基于小波和卡尔曼平滑的方法不仅信噪比提高约16~18 dB,优于30次叠加平均、简单小波方法和基于高斯基函数的卡尔曼滤波方法,还可以跟踪ERP的幅度趋势变异性。与基于高斯基函数的卡尔曼滤波方法相比,所提方法降低了计算量。真实脑电ERP提取实验表明本方法较好地从单次记录中提取出了事件相关电位,并可解释ERP因适应和应激引起的趋势变异性。 展开更多
关键词 事件相关电位 单次提取 小波变换 卡尔曼平滑 趋势变异性
下载PDF
Quantitative analysis of deformation in hollow cylinder tests on anisotropic clay formations
2
作者 You Shuang Ji Hongguang +2 位作者 Labiouse Vincent Hall Stephen A. Viggiani Gioacchino 《International Journal of Mining Science and Technology》 SCIE EI CSCD 2015年第2期299-303,共5页
A series of triaxial laboratory experiments are performed on thick-walled hollow cylindrical samples of boom clay.The aim of this testing program is to better understand the anisotropic deformation during the excavati... A series of triaxial laboratory experiments are performed on thick-walled hollow cylindrical samples of boom clay.The aim of this testing program is to better understand the anisotropic deformation during the excavation.The testing conditions are similar to those to be experienced by host rocks around disposal galleries for radioactive waste.X-ray computed tomography is performed at different steps for each test with the samples remaining inside the loading cell.Initial analysis of the tomography images allows of the observation of the deformation of the central hole.In addition,particles manual tracking and 3D volumetric digital image correlation processing methods are considered being used to analyze the particles displacements and the boundary deformation of the sample quantitatively.An unsymmetrical damaged zone is induced around the hole,with a reverse deformation trend being found at the boundary after unloading,which indicates that the significant anisotropic deformation of boom clay can be induced by mechanical unloading. 展开更多
关键词 Boom clay Hollow cylinder test Deformation X-ray computed tomography Particles manual tracking
下载PDF
上一页 1 下一页 到第
使用帮助 返回顶部