信噪比

As the mine accidents happen frequently in recent years, the detecting technology for microseism becomes much more important. However, there is no advanced microseism detecting system at home. It's pretty important for microseisms denoising and Reversion. A wavelet denoising method is presented here to process microseism signal, and the microseism record can get high signal to noise ratio. Meanwhile based on the software of LabVIEW, s design of real-time detecting system for microseism based on virtual instrument is presented. The advantage of the virtual instrument was sufficiently exerted to achieve the real-time detecting and analyzing of the microseism.

以往基于DSP或其他单片机的微震系统，其资源的有限性很难达到理想的采集效果，同时也难以完成先进算法的实现，而对微震信号的去噪与还原在监测系统中起着很重要的作用；在深入分析小波变换的信号去噪方法基础上，对微震信号进行了处理，得到高信噪比的微震记录，实现了对噪声的有效抑止；同时在LabVIEW平台软件设计的基础上，实现了一种基于虚拟仪器微震实时检测的设计方案，充分发挥了虚拟仪器的优势，结果表明基于LabVIEW的微震系统能很好地完成实时监测及其分析。

Through wiping off yawp of prestack and poststack, we can increase signal-to-noise ratio of data.

有针对性的使用叠前去噪和叠后去噪技术，提高了剖面的信噪比。

Results of computer simulation experiments on this new method show that it has better image denoising than ecumenic methods .

结果表明：这种方法比一般的图像消噪方法有很大改进，特别是图像的均方误差有很大的降低，提高了信噪比。

Results of computer simulation experiments on this new method show that it has better image denoising than ecumenic methods. Especially the of image has been decreased a lot while the has been increased.

结果表明：这种方法比一般的图像消噪方法有很大改进，特别是图像的均方误差有很大的降低，提高了信噪比。

To obtain precise result, itis necessary, in the aspect of hardware, to set up one stable optics system with highSNR, only if so, can we do the measurement with the steady NIR. To do so, we designthe optics system using AOTF, and take some measures to increase the light energyand the system SNR, which includes the three layers structure of the light chamber,the equipments to cover the useless light, polarizing to reduce the influence of 0 gradelight and focalize the light with lens. Apart from the hardware aspect, according to theexperiments, we can see that the different temperatures between at setting up themodels and at predicting the results will affect the prediction results in a way, and theaffection extent will be increased along with the increase of the temperaturedifference. Moreover, the light energy that can be detected will be different with thecontact pressure, and the match of the refractive indexes between the tissue and thesurroundings will enhance the light transmission depth, which will take moreinformation of the tissue. So, during the measurement, we should ensure the sametemperature between measuring and predicting, the same contact pressure at everymeasurement and the match of the indexes between the tissue and the surroundings aspossible as we can.

要提高测量精度，从硬件方面就必须有一个稳定的、信噪比较高的分光光路系统，以此得到稳定的近红外光来进行无创检测，针对这个目的，我们设计了 AOTF 分光光路系统，并在系统中采用一定的措施如三层灯室结构、遮光筒以减小杂散光、起偏和检偏来减小 0 级光影响、透镜汇聚等等来提高出射光的能量和系统的信噪比；从其他影响因素方面，通过实验，我们得到不同的建模温度对于预测结果有一定的影响，且影响随着温度的差值越大而越大，另外散反射光谱的能量也随着接触压力的不同而不同，组织的折射率与环境匹配将加大光的入射深度，从而能携带更多的组织信息，所以在测量时我们尽可能保证同一温度、保证同一接触压力以及利用物理或者化学的方法使组织与环境折射率匹配等。

The invention performs pseudo bit error rate statistic by utilizing the message of multi sampling points in each modulation symbol of discretization system, and again performs one-to-one mapping by utilizing corresponding relation between the pseudo bit error rate and the signal-to-noise ratio, thereby obtaining signal-to-noise ratio estimation value.

本发明利用了离散系统每个调制符号中多个采样点的信息进行伪误码率统计，再利用伪误码率与信噪比之间的对应关系进行一一映射，从而得到信噪比估计值。

Finally both SNR and slope of modulation transfer spectra of I2 with different absorption length were compared experimentally while I2 cell temperature was held at -15 ℃. The results of comparison showed that modulation transfer spectra was optimal at three-pass (120 cm).

实验上比较了碘池温度为-15 ℃时一倍程(40 cm)，二倍程(80 cm)，三倍程(120 cm)和四倍程(160 cm)的光谱信号信噪比和谱线中心斜率，得到三倍程时信号信噪比和谱线中心斜率为最大，估算得到相应的激光稳频精度为9×10-14(1 s积分时间)。

All available three-component time series are used to extract the Rayleigh and Love waves. The Signal-to-Noise Ratio at different periods and the azimuth distribution of the inter-station pairs with high SNR are discussed.

通过对三个分量记录的相关运算，获得了Rayleigh波和Love波的经验格林函数，分析了其信噪比随周期的变化和高信噪比台站对的方位分布。

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%。

They weren't aggressive, but I yelled and threw a rock in their direction to get them off the trail and away from me, just in case.

他们没有侵略性，但我大喊，并在他们的方向扔石头让他们过的线索，远离我，以防万一。

In slot 2 in your bag put wrapping paper, quantity does not matter in this case.

在你的书包里槽2把包装纸、数量无关紧要。