嗓音的测试与处理系统

本文介绍了一种无侵入、直接、客观、定量地反映发声过程中声带振动特性及噪音嘶哑程度的自动测试与处理系统。该系统具有多路生理信号检测，电声门图参数提取，谐波噪声比分析，扰动分析，频谱分析，语谱图分析等多种信息处理功能。实验 临床使用结果表明，本系统在正常与病变发声检查、艺术噪音测试等方面具有重要应用价值。     

散斑干涉相位条纹图的频域滤波处理

为了解决在数字散斑干涉技术测量时,散斑干涉相位条纹图像中大量噪声对相位解包裹结果和精度产生严重影响的问题,介绍了一种条纹正余弦分解和频域低通滤波结合的方法,实现了散斑干涉相位条纹图的高精度滤波。该方法的基本思路是在对相位图像进行滤波处理前,先将相位图通过正余弦函数进行映射转换成两幅图,分别经过频域滤波,然后再合成为相位图。这种分解频域滤波方法可以在滤波的同时,有效保留相位跳变信息。实验结果表明：与传统的图像降噪方法相比,该方法能够在保留图像“尖峰”信息的基础上,较好地滤除图像中的散斑噪声,方法简单有效,有效解决了传统滤波方法应用在相位条纹图中,相图灰度信息丢失10%~40%的问题。     

振动噪声等高图的电驱动桥噪声预测及优化*

在项目开发前期通过优化电驱动桥扭矩特性的设计,可以规避噪声大问题。根据电驱动桥台架在对应扭矩下的振动噪声特性,提出了一套稳定高效的测试流程和分析方法。首先设计了一套完整的试验流程,制定了精准的数据分析方法。然后绘制出能够全面反映电驱动桥振动噪声特性的等高图。最后利用电驱动桥台架的振动噪声等高图,准确评估电驱动桥加速工况下振动噪声风险,为主机厂和电驱动桥零部件企业提供电驱动桥扭矩特性设计前期指导。利用该方法成功识别到某电驱动桥匀速及加速工况下电机及齿轮的啸叫问题。通过优化电驱动桥扭矩特性设计,电机48阶噪声峰值降低了8.5dB(A),确认该方法准确可靠,具备推广应用价值。     

射频SQUID心磁图数据自适应滤波研究

研究了滤除50Hz工频干扰的几种自适应算法，并应用于射频超导量子干涉仪（SQUID）心 磁图仪采集的心磁数据50Hz滤波中.对算法的性能进行了计算机仿真比较.结果表明，带50 Hz干扰的SQUID心磁信号通过自适应噪声对消法，干扰得到了很好的抑制. 关键词： SQUID 心磁图 自适应滤波 噪声消除     

条纹管激光成像雷达条纹图像噪音分析与处理

从条纹管激光成像雷达的结构和成像原理出发,讨论了各种噪音来源、噪音特点、影响因素、对最终图像的贡献大小和抑制方法.通过条纹管激光成像雷达阶梯目标扫描成像实验结果分析,噪音源理论分析得到了验证.结合条纹图像处理的特殊目的,通过对比几种边界保持类平滑滤波算法,得出K近邻平滑均值滤波器具有更低的时间复杂度和空间复杂度和更好的滤噪效果,当取N=7,K=25时,可以在允许的处理时间内极大地提高条纹图像信噪比,然后,利用阈值算法有效滤除了背景噪音,最终成功地从复杂的噪音中提取到了条纹数据.这项工作为后续的目标像重构奠定了基础,并指出了下一步工作的方向和重点.     

反应扩散系统中反螺旋波与反靶波的数值研究

采用三变量Brusselator扩展模型在二维空间对反应扩散系统中反螺旋波和反靶波进行了数值模拟,利用色散关系和参量的时空变化研究了反螺旋波与反靶波的形成机制和时空特性,分析了方程参数对反螺旋波与反靶波的影响,获得了多种不同臂数的反螺旋波.模拟结果表明：反螺旋波源于波失稳、霍普失稳,或两种失稳的共同作用,而在反靶波中除上述两种失稳外还同时存在图灵失稳,波的传播方向均由外向内;反螺旋波波头的相位运动方向与波的走向相同,且旋转周期随臂数的增加逐渐增大;多臂数的反螺旋波由于受微扰及边界条件的影响,在波头的持续旋转运动中可以向臂数少的反螺旋波发生转变,并且在一定条件下单臂反螺旋波可实现到反靶波的转变;当不活跃中间物质的浓度的扩散系数超过临界值时,波的传播方向发生改变,系统可以实现反螺旋波到螺旋波以及反靶波到靶波的转变.     

SPC数据采集与处理系统

SPC数据采集与处理系统实现了SPC数据的计算机采集与处理 ,大大提高了SPC分析的效率与准确性 ,对推动目前国内SPC应用 ,提高产品质量管理水平具有重要的现实意义。本文具体介绍了SPC数据采集与处理系统的结构与组成及软件实现和处理功能。     

超导动态电感单光子探测器的噪声处理

噪声是影响弱信号检测器件性能指标的主要因素之一,而最优滤波算法是白噪声背景中自适应提取弱有用信号的一种常见处理方法.本文针对极低温环境下微波动态电感探测器(microwave kinetic inductance detector, MKID)光子弱信号响应的噪声特性,在改进噪声模型的基础上利用最优滤波算法改进了探测信号的噪声处理.结果表明,经过改进噪声模型的算法处理, MKID的能量分辨(单光子探测器的主要性能指标之一)得到了15%左右的提升,实现了0.26 e V的红外单光子能量分辨.     

光静态散射测试系统的研究与实现

随着科学技术的发展,对粒子的大小、浓度及其他特性的探测已经发展成为一个专门的研究领域和现代测量学中的一个重要分支,而光散射法已经成为一种常用的粒子测量方法。为了满足应用需求,文中提出了一种基于C8051F500单片机的光静态散射测试系统方案,详细介绍了该测试系统的设计理论原理、硬件电路的设计依据、固件程序的设计思想和测试系统的具体实现。选取一定浓度的样品溶液,运用该系统进行光散射的角度依赖性测试,实际测量值与理论依据基本相符;在不同激光功率下,对同一角度的散射光强进行测试,将测量得到的数据分析,线性度良好,满足设计要求。     

冲击波测试系统的动态建模及应用

若测试系统的带宽不能完全覆盖冲击波信号的有效带宽,就会存在较大的动态误差。根据冲击波测试系统的激波管动态校准实验数据,建立了冲击波测试系统动态数学模型,设计了动态校正数字滤波器。仿真结果表明,动态校正滤波器明显提高了系统动态响应的快速性,展宽了工作频带。实弹测试结果显示,校正滤波器能提高冲击波测试的精度和可靠性。该方法能有效消除动态误差,提高测试数据的准确性。     

Judgments of voice quality and preference: Acoustic interpretations

Previous studies have shown that trained listeners are highly reliable in making perceptual judgments of several parameters of normal and pathologic voices. This study investigated objective measures of acoustic characteristics of high and low preference voices as determined by previous perceptual study. Four acoustic parameters were measured including harmonics-to-noise ratio, autocorrelation function, average jitter, and the standard deviation of the fundamental frequency. Useful correlations between perceptual and measured results were identified. Normal voices differ from pathologic voices in terms of the acoustic-perceptual relationships.     

Effects of initial consonant, pneumotachographic mask, and oral pressure tube on vocal perturbation, harmonics-to-noise, and intensity measurements

Vocal perturbation, harmonics-to-noise, and intensity measures were obtained for 10 subjects during three experimental tasks: (a) prolonged /a/, (b) /pa/ with vowel prolonged, and (c) same as (b) with subjects wearing a pneumotachographic mask and oral pressure tube inserted between the lips. There were no statistically significant differences among the experimental conditions for any of the measures. The findings suggest that a single task may be used to obtain airflow, oral pressure, and acoustic measures of vocal performance. Observed differences in jitter and harmonic-to-noise means for the male and female speakers are discussed.     

MEMS动态测试系统及其数据处理

介绍了基于频闪显微干涉技术的MEMS动态测试系统的测量原理,设计了数据分析处理算法。采用基于立方插值的亚像素模板匹配技术实现了1/50像素的面内位移测量精度。利用分割线去包裹算法实现了从干涉图到三维形貌图的重构。     

Relationship Between Masking Levels and Phonatory Stability in Normal-Speaking Women

Disruption of auditory feedback such as masking has been shown to influence vocal production. A reliable finding is an increase in intensity level; an increase in fundamental frequency (F0) is a less robust finding. Research is lacking concerning the effects of auditory masking on measures of phonatory stability such as jitter and harmonics-to-noise ratio (HNR). This study investigated changes in intensity, F0, jitter, and HNR in 22 normally speaking college aged women. Subjects produced the vowel /a/ under three conditions: no masking level (0-dB ML), 50-dB ML, and 80-dB ML. Significant differences between conditions emerged for intensity; means for the other measures were not significantly different. Intraindividual differences between conditions for each variable are discussed in the framework of auditory versus kinesthetic feedback.     

弹丸参数测试系统的数据处理

弹丸参数测试系统主要用于弹速度的测量,它可以测量弹丸速度的大小。弹丸速度的大小是弹道特性的重要参数之一。弹丸的速度测量是枪炮、弹药研制生产和开发验收中最基本的试验项目。天幕靶可以更快、更准确地测量弹速。基于天幕靶并利用Visual C++6.0开发了一款弹参数测试系统软件,可实现弹参数测试系统的数据处理。     

Hybrid laser-plasma system for processing and testing microelectronic devices

The possibility of using a new technique (a hybrid laser-plasma system) for processing microelectronic devices is discussed. The method will allow one to increase significantly the production rate preserving a sharp space pattern obtained by the laser beam of a given profile.     

Harmonics-to-Noise Ratio: An Index of Vocal Aging

Distinguishing between vocal changes that occur with normal aging and those that are associated with disease is an important goal of research in voice. Several acoustic measures have been used in an attempt to illuminate the integrity of the vocal mechanism, including harmonics-to-noise ratio (HNR), jitter, and fundamental frequency (F₀). HNR is a measure that quantifies the amount of additive noise in the voice signal; jitter reflects the periodicity of vocal fold vibration. In this study, measures of HNR, jitter and F₀ were used to compare vocal function in three groups of normally speaking women: young adults, middle-aged adults, and elderly adults. Significant differences in HNR emerged between the elderly women and the other two groups. F₀ differences were also apparent between the elderly group and the two younger groups; there were no significant differences in jitter between the three groups. HNR was found to be a more sensitive index of vocal function than jitter. The significant lowering of HNR evident in the elderly speakers may be attributable in part to medications taken by the majority of these elderly subjects.