查询词典 SNR

All lenses were classified using the lens opacities classification system Ⅲ based on four categories: nuclear color, nuclear opalescence, cortical cataract and posterior subcapsular cataract. ALs were measured 20 times with an IOL Master, 5 times with an IOL Master version 4.0, and 5 and 15 times with an IOL Master version 5.0 and the results were recorded.

IOL Master 5.0版相对于传统IOL Master采用了组合信号分析技术，将多个低信噪比（signal-to-noise ratio，SNR）的单次眼轴测量结果进行叠加组合，使噪音相互抵消，而反映黄斑中央凹位置的信号被放大，从而提高了SNR。

On the basis of the above, the bearing estimation property of vector sensor is discussed, including the probability density function and mathematical characteristic of bearing estimation, the influence of electrical rotation, bearing correction in the low SNR, the estimation method of SNR, the restriction of multiple targets bearing estimation, the postposition process and so on.

在此基础上，继续讨论单矢量传感器的方位估计性能问题，包括方位估计的概率密度函数及其数字特征、仿真、电子旋转产生的影响、低信噪比的方位纠偏、信噪比估计方法、多目标方位估计的局限、后置处理等内容。

Aimed at low-SNR infrared images, this paper analyzed principle and computational method of Zernike moments, proved rotation invariant property, proposed a method for low-SNR infrared target detection based on Zernike moments,and compared target recognition effect among template matching, Hu moments and Zernike moments via experiment.

由于低信噪比红外图像本身所具有的目标特征很不明显、背景特征比较强等特点，模板匹配识别方法、Hu不变矩等并不适用于低信噪比红外目标检测。

Two suboptimum alternatives are presented in the low or high SNR channel to reduce the energy consumption. Under the identical local sensor and the same channel SNR assumption, we study the fusion statistic in the last.5 Based on modified Apriori algorithm, this thesis proposes a novel node association rule mining algorithm for exploiting the inherent correlations between sensor readings.

考虑到传感器网络的资源受限，对信噪比较高或较低的情况下又提出了两种简化的次优融合规则，最后讨论了同类传感器模型下的融合情况。5通过对传统Apriori算法的改进，提出了一种节点关联规则挖掘方法来发现大量节点之间的有趣关联或相关联系，以此消除节点之间的信息冗余。

And images processed with the incorrect parameters will be worsened. This paper analyses the effect of SNR on autofocus and proposes an adaptive filter in SAR azimuth subsampling to keep SNR as high as possible, so that the performance of autofocus can be improved and higher image quality achieved.

该文分析了信噪比对自聚焦的影响，提出利用自适应滤波器来做方位向预滤波和降采样，在降低采样率的同时，保持原始图像的信噪比，再经有效的自动聚焦算法，得到较准确的多普勒参数估计值，从而获取高分辨率SAR图像。

A new feature, the variance of low-band energy ratio, is also introduced, which produces large improvements in classification accuracy at low SNR Performance of the proposed system is evaluated for different SNR.

考察了系统在不同的信噪比环境下的分类性能。

With Walnut Street model as its foundation, observed data were analyzed and processed, the SNR variation models during intermediate and long terms were built, combined with traditional Watterson channel model, the specified HF channel was simulated through SNR prediction.

该算法以Walnut Street信道模型为基础，通过对实际观测数据进行分析处理，建立接收端信噪比变化的中期和长期变化统计模型，联合Watterson模型实现信道模拟。

In this paper, the noise sources of the EBCCD imaging system have been analyzed and a SNR model has been established. It shows that the SNR of output image is related not only to the input illuminance on the cathode but also to the spatial frequency of the input image. This has been proved by a series of experiment. Unperfectness of the detecting equation has been pointed out in this paper.

分析了电子轰击电荷耦合器件微光成像系统的噪声源，建立了系统的信噪比模型，指出了在微光成像系统本身的增益和量子效率等性能确定的条件下，成像系统输出图像信噪比不仅仅与输入面照度有关，还与输入图像的空间频率有关，并通过实验得到了证明，指出了经典的图像探测方程的不完善之处。

Starting from the statistic characteristics of the signal and noise, the relationship between false-alarm probability and threshold SNR is deduced, as well as detection probability and SNR. The formula of operating range for spot target is given.

从信号和噪声的统计特性出发，文中详细推导了虚警概率与门限信噪比、探测概率与信噪比的关系，基于此推导了红外成像系统对点源目标的作用距离公式。

For example, the average number of retransmissions can be decreased 50% at 1 dB SNR in the Gaussian channel and 9 dB SNR in the Rayleigh channel.

如在高斯噪声环境下，信噪比为1dB时减少超过50%；在瑞利噪声环境下，信噪比为9dB时也减少了50%。

However, as the name（read－only memory）implies, CD disks cannot be written onorchanged in any way.

然而，正如其名字所指出的那样，CD盘不能写，也不能用任何方式改变其内容。

Galvanizes steel pallet is mainly export which suits standard packing of European Union, the North America. galvanizes steel pallet is suitable to heavy rack. Pallet surface can design plate type, corrugated and the gap form, satisfies the different requirements.

镀锌钢托盘多用于出口，替代木托盘，免薰蒸，符合欧盟、北美各国对出口货物包装材料的法令要求；喷涂钢托盘适用于重载上货架之用，托盘表面根据需要制作成平板状、波纹状及间隔形式，满足不同的使用要求。