基于小波变换的混沌信号相空间重构研究

应用小波变换和非线性动力学方法研究了混沌信号在相空间中的行为，指出混沌时间序 列的小波变换实质上是在重构的相空间中，混沌吸引子向小波滤波器向量所张的空间中的投 影，与Packard等人提出的相空间重构方法本质上是一致的.实验结果表明，混沌信号经过 小波变换后，吸引子轨迹与原有轨迹具有相似的结构，同时，系统的关联维数、Kolmogorov 熵等非线性不变量仍然得到保留.这些结果表明，利用小波变换研究混沌信号是有效的. 关键词： 小波变换 相空间重构 混沌信号 脑电信号     

基于DSP的癫痫脑电信号处理

介绍了基于TI公司高速DSP芯片TMS320VC5402的开发平台对癫痫患者的脑电信号进行小波分解,滤除分解后的部分小尺度(高频)成分,保留大尺度(低频)成分,然后对处理后的波形进行重构。采用汇编语言实现定点型TMS320C54xDSP的浮点运算,处理结果既保留了脑电信号的主要信息,又可将高频噪声滤除,有利于对癫痫患者进行临床分析。     

Partial electrical potential distribution around nanospheres in metallic nanostructured films

In light of the nanostructured surface model, where half-spherical nanoparticles grow out symmetrically from a plane metallic film, the mathematical model for the partial electrical potential around nanospheres is developed when a uniform external electric field is applied. On the basis of these models, the three-dimensional spatial distribution of the partial electrical potential is obtained and given in the form of a curved surface using a numerical computation method. Our results show that the electrical potential distribution around the nanospheres exhibits an obvious geometrical symmetry. These results could serve as a reference for investigating many abnormal phenomena such as abnormal infrared effects, which are found when CO molecules are adsorbed on the surface of nanostructured transition metals.     

基于DSP Builder的通用调制信号发生器设计

介绍了基于2ASK,2FSK,BPSK,MSK和64QAM等多种通用调制器的调制原理,并提出了一种基于DDS技术的调制方式.然后在DSP Builder上进行系统设计与仿真,经验证该系统可以成功实现多模式信号调制功能,并且具有较好的可扩展性和灵活性.最后用FPGA实现,并用SignalTapII进行硬件验证.     

有缺陷的平行板电容器内的电场

利用复数坐标系上的保角变换和利用势的拉普拉斯方程分别讨论了带有半圆柱形凸出疤和半球形凸出疤两种有缺陷的平行板电容器内的电场分布,进而得出一些有益的结论     

相空间中脑电近似熵和信息熵的计算

提出一种基于相空间重构脑电信号来计算脑电近似熵和信息熵的新方法．实验计算结果表明，癫痫患者脑电和正常人脑电的近似熵和信息熵随相空间嵌入维数的变化有明显的不同．     

Electric potential distribution near nanocone arrays on metal substrates

Based on the nanostructured surface model,where conical nanoparticle arrays grow out symmetrically from a plane metal substrate,a theoretical model of the local electric potential near nanocones is built when a uniform external electric field is applied.In terms of this model,the electric potential distribution near the nanocone arrays is obtained and given by a curved surface using a numerical computation method.The computational results show that the electric potential distribution near the nanocone arrays exhibit an obvious geometrical symmetry.These results could serve as a basis for explaining many abnormal phenomena,such as the abnormal infrared effects(AIREs) which are found on nanostructured metal surfaces,as well as a reference for investigating the applications of nanomaterials,such as nanoelectrodes and nanosensors.     

锥形导体尖端的电场特性

以圆锥形导体为例，从求拉普拉斯方程在边界条件下的解出发，给出锥形导体尖端附近的电场表达式，并对电场特性作出详细分析，从而揭示尖端放电现象的物理本质。     

一种基于ICA的盲信号分离快速算法

基于ICA(独立成分分析:Independent Component Analylsis)原则,给出一种盲信号分离的快速学习算法.通过寻求观测变量线性组合的四阶累积量(即kurtosis系数)局部极值,得出该算法的模型和步骤.将该算法用于盲信号分离实验,实验结果表明,该算法在盲信号分离和信号特征提取方面具有收敛速度快、无需动态参数等优点.该算法能有效地分离出任意分布的非高斯盲源信号的各个独立成分,是信号处理的一种新的、高效可靠的方法.