小波包降噪在工业信号预处理中的应用     

吴洪艳  高国宏  李俊颖 《科技广场》2010,(3):115-117

针对工业过程数据含有噪声干扰的特点,本文提出了基于小波包分解的阈值降噪方法进行数据的降噪处理。以化工过程数据为例,通过MATLAB仿真实验,对比了小波包降噪、小波降噪、中值滤波三种方法的降噪效果。结果表明:小波包降噪具有明显的优越性。  相似文献   

Enhancive effect of N,N′-dinitrosopiperazine on inducing precancerous lesion on nasal and/or nasopharyngeal epithelia of TgN(p53mt-LMP1)/HT mice     

Dao-fa Tian  Ying-chun He  Fang-guo Lu  Fa-qing Tang 《Journal of Zhejiang University. Science. B》2009,10(3):172-179

Objective  To investigate the enhancive effect of N,N′-dinitrosopiperazine (DNP) on induced carcinogenesis in nasal and/or nasopharyngeal epithelia among TgN(p53mt-LMP1)/HT transgenic mice to examine the underlying mechanism for the development of nasopharyngeal carcinoma (NPC). Methods  TgN(p53mt-LMP1)/HT transgenic mice and the same strain of C₅₇BL/6J wild-type mice both at the age of 5 months were randomly divided into 2 groups in parallel, respectively, i.e., TgN(p53mt-LMP1)/HT cancerous lesion-inducing group (TI), TgN(p53mt-LMP1)/HT control group (TC), C₅₇BL/6J cancerous lesion-inducing group (CI), and C₅₇BL/6J control group (CC). TI and CI mice were treated only with DNP for 16 weeks, twice each week, while TC and CC mice were given the same volume of saline as controls. At the end of treatment, animals were sacrificed to collect epithelial tissue samples from nasal cavity and nasopharynx for pathohistological evaluation by haematoxylin and eosin (HE) staining and for determination on the expression of TRAF2, c-Jun, and p16 by immunohistochemistry. Results  Atypical hyperplasia was more significant in the samples of TI than in those of TC, CI, and CC, with the rates of lesions being 90%, 10%, 0, and 0 (P<0.01) respectively, though DNP was used alone in a much shortened inducing period at less dosage and without the use of carcinogenic promoter 12-O-tetradecanoylphorbol-13-acetate as usual. The expressions of tumor necrosis factor (TNF) receptor-associated factor 2 (TRAF2) and c-Jun in these samples were significantly up-regulated in TI (P<0.01), while the expression of p16 was significantly lower in TI than in the other groups (P<0.01). Conclusion  TgN(p53mt-LMP1)/HT mice hold inherited constitutional defect in immune surveillance function, which can be aggravated by environmental carcinogens, such as DNP used even though in a much less strength. The enhanced carcinogenesis-inducing effect of DNP on TgN(p53mt-LMP1)/HT mice should be closely associated with abnormal signaling of activator protein-1 (AP-1) pathway, especially up-regulated expressions of TRAF2 and c-Jun, and down-regulated expression of p16. Project supported by the National Natural Science Foundation of China (Nos. 30672738, 30572455 and 30572408), Hunan Provincial Natural Science Foundation for Distinguished Young Scholars (No. 03JJY1006) and for General Projects (Nos. 05JJ40029 and 07JJ6038), the Research Foundation of Hunan Provincial Scientific and Technological Department for International Cooperative Academic Projects (No. 06WK3016), and the Research Foundation of Hunan Provincial Education Department for Outstanding Young Scholars (No. 06B070), China  相似文献   

Nonlinear multifunctional sensor signal reconstruction based on least squares support vector machines and total least squares algorithm     

Xin Liu  Guo Wei  Jin-wei Sun  Dan Liu 《浙江大学学报(A卷英文版)》2009,10(4):497-503

Least squares support vector machines （LS-SVMs） are modified support vector machines （SVMs） that involve equality constraints and work with a least squares cost function, which simplifies the optimization procedure. In this paper, a novel training algorithm based on total least squares （TLS） for an LS-SVM is presented and applied to multifunctional sensor signal reconstruction. For three different nonlinearities of a multifunctional sensor model, the reconstruction accuracies of input signals are 0.00136%, 0.03184% and 0.504 80%, respectively. The experimental results demonstrate the higher reliability and accuracy of the proposed method for multifunctional sensor signal reconstruction than the original LS-SVM training algorithm, and verify the feasibility and stability of the proposed method.  相似文献   

抗痫中药的实验研究     

王玢  袁方曜  张峰  蔡元丽 《山东教育学院学报》2007,22(1):93-95

癫痫是神经系统功能异常常见病,严重危害人类健康。近年来,中医药在预防癫痫发作、提高疗效、减少抗痫药物毒副作用等方面取得较大进展。本文就神经递质、受体与离子通道、信号转导等方面总结了抗癫痫中药的作用机制。  相似文献   

远程控制系统中电话信号音识别方法     

陈凤苏 《广东广播电视大学学报》2003,12(2):82-84

介绍了用软件和硬件相结合的方法识别电话信号音，为自动拨号远程控制系统电话音识别提供了实践电路和应用程序。  相似文献   

声发射技术及其在变压器局部放电检测中的应用     

郭艳平  解武波  郑小平 《甘肃高师学报》2007,12(5):25-28

首先对声发射技术及其在变压器局部放电应用中的检测原理进行了阐述,随后分别从声发射传感器和声发射信号处理上对声发射检测仪的发展作了总结,在查阅大量文献的基础上,总结了声发射信号的两种分析方法(参数分析方法和波形分析方法)的具体应用和发展情况.其中在波形分析方法中说明了频谱分析、模态声发射分析、小波分析和人工神经网络分析的最新成果和存在的问题及解决途径.最后探讨了声发射技术及其在局部放电应用中存在的问题和发展方向.  相似文献   

模拟中继电路信号电平的自动调节     

吴拥民 《闽江学院学报》2006,27(5):84-87

专网通信中的模拟中继电路的信号电平失调是一种常见的问题．通过分析信号电平调整的原理,提出了2种能够实现信号电平自动调整的改良性方法．一种为模拟式信号电平自动调节,以导频信号为基础,通过调节可控增益放大器白动调节话音信号的电平变化．另一种为数字式信号电平自动调节,先将导频信号进行A/D转换并生成一个基准数值,通过PC机程序改变该基准数值的变化,达到调整语号信号电平的目的．  相似文献   

基于LabVIEW的振动测试分析系统   总被引：4，自引：0，他引：4  

钱阳  周月平  陈俊伟 《温州大学学报(社会科学版)》2005,18(4):58-61

基于LabVIEW的振动测试分析系统由系统硬件和振动测试分析软件两大部分组成．其中，振动测试分析软件是本系统的核心．振动测试分析软件的主要功能是控制数据采集板进行数据采集；根据信号处理的基本原理，对采集的数据进行幅值谱分析、自相关分析、互相关分析、自功率谱分析、互功率谱分析、相干函数分析等．  相似文献   

数字信号处理教学改革与实践探索     

郭素敏  郭素芳  吴波 《教学研究(河北)》2006,29(5):453-455

本文结合“数字信号处理”这门课程的特点,为使传统的课堂型教学逐渐过渡到探索型教学,从教学内容、教学方法以及教学实践等方面进行了实践和探讨。  相似文献   

MATLAB在数字信号处理教学中的应用     

欧阳华  吴正国  邵英 《海军院校教育》2003,(5)

介绍了 MATLAB科学计算软件在本科数字信号处理教学中的应用 ,并且阐述了 MATLAB在课堂教学演示和实验的应用  相似文献