低频

To validate the scheme,the backscattering of vacuum and filled spherical shell submerged in water was calculated.

结果表明，在低频时，散射声场的数值计算结果与解析解较吻合。

This research uses high sensitive piezoelectric sensor for developing a sensitive sphygmograph to detect anthropic pulse and to determine parameters to diagnose physiology of human. From spectrum of pulse, the analysis processes are to determine the high pass frequency used in the analysis, uses the IIR Buttorworth filter to remove the noise, to calculate the Hermite curve for filtering the oscillation parts caused by breathe, then to calculate the parameters in strength, time and angle domains from the processed signal to study their correlation with the physiology of the studied experimenters and compared the results with the machine from the market.

中文摘要本研究采用高灵敏度压电感测元件，发展敏锐的脉搏感测仪器，量测人体手腕脉搏波形，计算其中所包含之参数来探讨与研究人体生理状况相关性的适用性；藉由分析脉搏频谱成份并使用Buttorworth滤波器过滤高频杂讯，再使用Hermite方程式去除手腕低频振动杂讯，由过滤后的脉搏讯号萃取振幅强度、波形上升与下降时间、上升与下降角度等参数，经由统计分析探讨与人体生理之情况相关性，并将所获得指标结果与市售仪器所量测之数据变化进行比较。

The realization scheme of this project is also discussed in the paper, a data pick-up/control board using PCI bus protocol is designed, this board together with some softwares can finish many functions such as AD conversion of DC system generatrix and every DC spur track, sine wave generation which frequency is between 0-50Hz , and some control functions in fault analysis system.

本文还进行了故障检测装置实现方案的有关研究，设计了基于PC机的直流电网故障诊断系统，完成了基于计算机PCI总线的数据采集控制卡的设计，该卡配合计算机软件可以实现电网正负母线，各支路互感器输出等多路模拟量信号的采集，产生0-50Hz之间任意频率的低频信号源，并且能够完成故障检测中的各种控制功能。

The main research contents are the modeling of price or returns series and correspondent volatility and risk. The main contents of this course include: modeling of single stationary time series and single non-stationary time series, non-linear modeling of single series, cointegration and vector autoregression modeling, etc.

适用于低频和高频数据；分为时域分析、谱域分析和回归分析集中分析方法；主要研究内容为价格或收益序列的建模，以及相应的波动性或风险的建模；主要内容分为单个平稳时间序列的建模、单个非平稳序列的建模、单个序列的非线性建模、协整和向量自回归建模等等。

This method takes account of the signal's properties of statistical distribution and wavelet space time-frequency distribution.

在第八章给出了应用实例，能有效分离倍频机械信号，和水力脉动的低频信号，为故障诊断提供依据。

Based on structure characteristics of copper staves and the machining performance of Purple copper, the s...

论文在分析铜冷却壁结构特点和紫铜材料加工性能的基础上，提出以低频轴向振动切削技术和BTA深孔加工相结合的深孔加工方案。

Influence of steam turbine system on low frequency oscillation.

汽轮机系统对电力系统低频振荡的影响。

Xinglong Electronic Ceramics Factory is a professional ceramic factory production base, there are low-frequency porcelain, crafts porcelain, steatite porcelain, developed to 75 #, 85 # porcelain, used in electronics, electrical appliances, electric, light porcelain pieces.

兴隆电子陶瓷厂是本厂的专业陶瓷生产基地，有低频瓷，工艺瓷，滑石瓷，发展到75#，85#瓷，使用于电子，电器，电热，光源瓷件。

A motion compensated temporal filtering step between a previous reference frame A and a current frame B comprises in a first time a computation sub-step of the high frequency subband, followed by a computation sub-step of the low frequency subband.

在先前参考帧A和当前帧B之间的运动补偿时间滤波步骤包括首先计算高频子带的分步骤，之后为计算低频子带的分步骤。

In the paper,the low-frequency information which reflects the trend of stock price change is extracted using wavelet MRA and the Mallat method,and the time of stockjobbing is analyzed.

本文利用小波多分辨分析及快速Mallat算法提取反映股价基本变化趋势的低频信息，并分析了证券交易的时机选择。

I didn't watch TV last night, because it .

昨晚我没有看电视，因为电视机坏了。

Since this year, in a lot of villages of Beijing, TV of elevator liquid crystal was removed.

今年以来，在北京的很多小区里，电梯液晶电视被撤了下来。