It stems from the concept of instantaneous frequency, and it can describe accurately the local properties of dynamic data in the time-frequency plane.
该方法源于瞬时频率的概念，它能把动态信号的局部特征正确地在时频域内予以描述。
The methods of time frequency analysis include linear, quadratic and adaptive methods. They provide effective tools for analyzing signal time varying spectrum in time frequency plane.
时频分析方法分为线性、二次型和自适应等多种方法，它们提供了在时频二维平面上，分析信号时变功率谱的有效手段。
Due to the good localization feature of the wavelet transform both in time plane and in frequency plane, we present a wavelet-based denoising method for extracting EPs in single trails.
由于小波变换在时域和频域上都具有良好的局部化特性，本文提出了一种基于小波变换的去噪方法，以期达到从单次样本中提取视觉诱发电位的目的。
Due to the good localization feature of the wavelet transform both in time plane and in frequency plane, a wavelet-based de-noise method is presented for extracting EPs in single trails.
由于小波变换在时域和频域上都具有良好的局部化特性，基于小波变换的去噪方法，可以达到从单次样本中提取视觉诱发电位的目的。
The results of the simulation and real examples demonstrate that this new kernel function can remove the interference terms effectively and enhance the resolution of time-frequency plane.
仿真和实例分析表明：动态核函数能很好地去除交叉干扰项，提高分辨率，同时又证明了该方法的实用性和有效性。
The concept of local energy in time-frequency plane, based on local wave theory, is defined. Then a new feature extraction method based on the local energy in time-frequency plane is given.
在局域波理论的基础上，引入了时频局部能量的概念，进而提出了一种基于时频局部能量的特征提取方法。
This method is able to estimate precisely the initial Doppler frequency and the Doppler centroid, and to distinguish between multiple targets lying in the same line in the time-frequency plane.
该方法能够以较高精度估计目标的多普勒起始频率和中心频率，并能分辨在时频平面位于同一直线的多个目标。
With a phase grating located at Fourier frequency plane, optical image subtraction is obtained as a result of the coherent superposition of the zeroth and the first order of the diffracted light.
置一位相光栅于相干光学处理系统频谱平面，利用其零级与一级衍射光的相干迭加实现图象相减。
However, Will Stewart, of the Institute of Engineering and Technology, points out that plane electronics are designed not to operate on the same frequency as gadgets used by passengers.
然而，来自工程技术学会的威尔·斯图尔特却并不这样认为，他指出实际上飞机被设计为不可与乘客们的电子设备在同一波段下操作。
"Modulation domain" is a plane domain which is consisted of frequency and time signal axes.
“调制域”是由信号的频率和时间两个轴构成的平面域。
Modulation Domain and Pulse Analyzer(MDPA) analyzes signal using a plane domain which is consisted of frequency and time.
调制域及脉冲分析仪利用时间和频率构成的平面域对信号进行分析。
As the plane crossed state lines neither pilot realized the jet no longer was on the correct radio frequency and that controllers were growing worried about their failure to stay in contact.
飞机随后飞越了州界，两位飞行员都没有意识到飞机已经不在准确的无线电频率上，而地面塔台也对无法与飞机保持联系感到越来越担忧。
Based on the equivalent elasticity method, the plane coupling vibration of a rectangular piezoelectric ceramic plate was studied and the resonant frequency equation was derived out.
利用等效弹性法分析了压电矩形共振器的二维耦合振动，导出了振子共振频率的解析表达式。
A loudspeaker which emits sound of frequency 1000 Hz is placed several meters from a plane reflecting wall in a large chamber containing a gas.
扬声器发射的声音频率1000赫兹是放置数米，从平面反映墙在一个大型会议厅，载有天然气。
The L F signals are transformed by entropy based on wavelet packet algorithms for best basis selection, and the results are displayed in time- frequency space namely phase plane.
该方法采用基于熵的小波包最佳基选取准则，对局部损伤信号进行自适应小波包分解，将分解结果显示于时—频空间即相平面上。
This paper gives two kinds of calculation methods of natural frequency of a mass-even elliptic column which oscillates in miniamplitude on a plane, obtains two formulas of natural frequency.
本文给出了匀质椭圆柱体在平面上作无滑动的微幅摆动之固有频率的两种计算方法，得到两个固有频率的计算公式。
After frequency selecting when white light walks through the F-P sensor which cavity modulated by temperature, wavelength demodulating is realized with a plane grating and CCD.
采用铜管和端面镀膜的光纤制作f - P传感器，白光光源经过腔长受温度调制的F - P传感器选频后，用平面光栅和线阵CCD实现光波波长的解调。
The existing calculations for free frequency of the jib involve the vibration in the working plane and the vibration in the direction perpendicular to the working plane is usually neglected.
通常臂架自振频率的计算多关注于工作平面，而对垂直于工作平面的臂架自振频率的计算则被忽视。
The space frequency distribution on rear focal plane restores to the distribution of complex amplitude on image plane.
后焦面上的频率分布还原成像面上的光场复振幅空间分布。
This kind of antenna is called non frequency transforming antenna, a typical instance is plane isogonal corkscrew antenna.
我们将这一类天线称为非频变天线。平面等角螺旋天线是这一类天线的典型例子。
By inserting a slot at the edge of the rectangular slot on the ground plane and loading a C-shaped resonator near the microstrip line, dual band-notched characteristic at the central frequency at 3.
通过在地板上的矩形槽的边缘开槽和在馈线旁加载C形谐振器，该天线实现在中心频率3。
The frequency pseudocolor-coded speech spectrogram is then obtained by means of a sampling narrow slit placed at Fourier plane in white-light optical spectrum analyzer.
然后在白光光学频谱分析系统中，利用放置在傅里叶频谱面上的取样狭缝得到按频率假彩色编码的频谱图。
The effects of flapping frequency, wind velocity, Angle of attack, plane shape of wing and cambered aerofoil are investigated.
试验中进行了扑动频率、风速、迎角、机翼平面形状、翼型弯度对机翼气动特性影响的研究。
In many people's eyes, going by air would be the best choice when traveling, however, in recent years, the increasingly high frequency of plane crashes make some people hesitant to take the plane.
在许多人眼里，由空气中将在近几年旅游时的最佳选择，但是，飞机坠毁的频率越来越高使一些人不愿采取飞机。
Plasma was created by dielectric barrier discharge (DBD) system, which consisted of home-made middle frequency power supply and parallel plane electrode configurations.
等离子体的产生采用了自制中频电源和平行板电极结构组成的介质阻挡放电系统。
The formulas for calculating spectrum of plane acoustic pulses are obtained by using transfer function. These formulas can be used to evaluate the shift extent of centroid frequency of pulses.
利用传递函数，得到了平面脉冲声波在传播过程中任意位置处频谱的计算方法，用这种方法可以评价脉冲声波的主频偏移程度。
With the plane Archimedean spiral antenna a calculation of the current on the antenna as well as its radiation is carried out and its frequency independence was verified.
并以平面阿基米德螺旋天线为例，计算了天线上的电流分布和辐射特性，验证了天线的频率无关特性。
By using the plane wave expansion and finite-different time-domain (FDTD) methods, we can find a larger absolute band gap in the low and high frequency.
通过运用平面波展开方法以及有限差分时域(FDTD)方法进行分析，可以明显地发现，在低频和高频区域增大了光子晶体的光子禁带。
The vibration equation for thin flat plane loudspeaker with single point drive and four corners fixed is deduced and its simple harmonic vibration frequency in this condition is analyzed.
推导了固定四角薄型平板扬声器在单点激励下的振动方程，分析了在受激情况下的简正频率，并由简正频率方程导出其受力方程。
The vibration equation for thin flat plane loudspeaker with single point drive and four corners fixed is deduced and its simple harmonic vibration frequency in this condition is analyzed.
推导了固定四角薄型平板扬声器在单点激励下的振动方程，分析了在受激情况下的简正频率，并由简正频率方程导出其受力方程。
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