查询词典 noise-power-ratio

On the basis of direct modelling method by using extended Kalman filter, a new method combining extended Kalman filter with adaptive extended Kalman filter is presented to model gyro drift directly from rotate angle of turntable. Extended Kalman filter has great estimation error, what is more, may be divergent if the model and noise statistic are not accurate or wrong. The new method solves the problem of general extended Kalman filter by using fictious noise with timevarying statistic to compensate the linearized model error of extended Kalman filter. The parameter estimators of single-axis and double-axis servo test are designed from it.

本文深入研究了根据伺服试验数据进行陀螺仪漂移误差模型建模的方法，在应用广义Kalman滤波器直接建模的方法基础上，针对广义Kalman滤波器对于不精确或错误的模型和噪声统计，估计误差较大，甚至滤波发散的缺陷，借助于用带时变噪声统计的虚拟噪声补偿广义Kalman滤波的线性化模型误差的新思想，提出了用广义Kalman滤波和自适应广义Kalman滤波算法相结合的方法由转台的转角数据直接建模陀螺仪漂移误差模型，并设计了陀螺仪单轴伺服和双轴伺服测试时参数估计的滤波器。

The noise of filter and shunt capacitor installation is one of main noise source at converter station, it is necessary to study its calculation method.

滤波、并联电容器装置的噪声是换流站中噪音来源的主要因素之一，有必要对其计算方法进行研究。

In order to preserve more details while erasing mixed noise, a new algorithm based on the structure of modified trimmed mean filter was proposed. Characters of the new one are: 1 replaces the median filter with center weighted median which shows better performance in preserving details; 2 uses the filtering result to estimate the deviation of Gaussian noise. The estimating result is used to change the filter parameter, so the new algorithm is robust.

为了在滤除退化图像中混合噪声的同时能更好地保护图像的细节，文中提出了基于改进均值滤波结构的新算法，其特点为： 1）用中心加权中值滤波算法替代MTM 方法中的中值滤波算法以更好地保护细节； 2）提出了一种直接利用滤波结果来估计混合噪声中高斯噪声方差的方法，估计的结果被用于滤波器系数的调整，使得新算法有很好的鲁棒性。

The ADWM filter has the features of directional filter, which is especially effective at preserving edges, and the features of center weighted median filter, which can reduce random noise, and moderate amounts of impulsive noise also, to some extent, as well as preserve the details via adaptively determining the weight of the center pixel according to the lowest variance of pixels within all the sub-windows.

ADWM滤波器既有定向滤波器的特征，也有中心加权中值滤波器的特征。定向滤波器可以有效保持边缘，而中心加权中值滤波器对减少随机噪声尤其有效，同时也能在一定程度上减少冲击噪声的数量，并根据子窗口内像素的最低方差自适应地调整中心像素的权值以保持图像的细节。

Fifth, Applying the main idea of the improved center weighted median filter to the design of the optimal stack filter based on omnidirectional structural elements constrains, the dissertation raises a kind of improved filter algorithm for de-noising of pulse noise. The theory analysis and the simulation experiment of the image processing shows that this kind of filter can not only remove noise effectively but also keep detail of the image sufficiently.

根据最优全方位结构元约束层叠滤波器中常规中值滤波带来的图像高频细节信息的丧失，引入改进的中心加权中值滤波器，从而提出改进的最优全方位结构元约束层叠滤波新方案，实验和理论证明，它相对于最优全方位结构元约束层叠滤波方案，在滤除噪声的同时更有效保持了图像的高频细节信息。

The ADWM filter has the features of directional filter, which is especially effective at preserving edges, and th e features of center weighted median filter, which can reduce random noise , and moderate amounts of impulsive noise also, to some extent, as well as p reserve the details via adaptively determining the weight of the center pixe l according to the lowest variance of pixels within all the sub-windows.

ADWM滤波器既有定向滤波器的特征，也有中心加权中值滤波器的特征。定向滤波器可以有效保持边缘，而中心加权中值滤波器对减少随机噪声尤其有效，同时也能在一定程度上减少冲击噪声的数量，并根据子窗口内像素的最低方差自适应地调整中心像素的权值以保持图像的细节。

Sixth, Using the ability of the better keeping the image's detail of the morphological filter with omnidirectional multiple structuring elements and the ability of the strong removing noise of the improved center weighted median filter, this dissertation suggests a new kind of designing project of the hybrid filter for de-noising of pulse noise, which applied the idea of the stack filter based on omnidirectional structural elements constrains to the project.

利用全方位形态滤波的图像细节保持性能，中心加权中值滤波的噪声抑止能力和全方位结构元层叠滤波方案的并行处理思想，设计了一种新的脉冲噪声混合滤波新方案，它在滤除噪声的同时较好地保持了图像的细节部分，特别是其高频微小细节部分。

Both theoretical analyses and practical measurements indicate that the noise Vt can be eliminated by the peak area measurements and restrained in certain degree for filtered peak height signals, where as the other kind of noise Ui can not be eliminated or restrained in both measurements.

2峰面积测定值基本上能消除第一类噪声V(t〓，而峰高值经滤波后能在一定程度上抑制第一类噪声，但峰面积和峰高都无法消除或抑制第二类噪声。

Spectral subtraction for speech signal processing is a classic method for decreasing noise which easily leads to error by regard fixed silence fragment as noise sample.

语音信号处理中减谱法是一种传统的降噪方法，但减谱法利用固定的无音片段作为噪声样本容易产生误差。

Because one need to search H in the range of 110, 1 and calculate the autocorrelation function many times, the concise formula of autocorrelation function of discrete fractional Gaussian noise is used to improve the processing speed. Simulation results have shown that it can estimate H accurately and more effectively than conventional LMS based on autocorrelation ftinction for both pure fractal signal and noise-corrupted fractal signal.

接着我们研究了在白噪声背景下进行分形参数估计的相关函数法，针对其在计算中需反复使用自相关函数的特点，提出了一种改进的相关函数法，实验表明，改进的方法在精度上几乎没有损失，而大幅度地提高了计算效率。

On the other hand, the more important thing is because the urban housing is a kind of heterogeneity products.

另一方面，更重要的是由于城市住房是一种异质性产品。

Climate histogram is the fall that collects place measure calm value, cent serves as cross axle for a few equal interval, the area that the frequency that the value appears according to place is accumulated and becomes will be determined inside each interval, discharge the graph that rise with post, also be called histogram.

气候直方图是将所收集的降水量测定值，分为几个相等的区间作为横轴，并将各区间内所测定值依所出现的次数累积而成的面积，用柱子排起来的图形，也叫做柱状图。