square signal

To reduce the switching losses of IGBTs in PWM rectifier, a third order square wave is added to the phase voltage control signal on the basis of the Improved Period Average Model. This new control algorithm leads to no switching in about 1/ 3 cycle.

为降低PWM整流器的开关频率，本文在整流器的改进周期平均模型基础上，在相电压控制信号中叠加三次方波信号，使得整流器中的开关管有1／3时间不动作。

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At 6:21 pm Wednesday, the drone entered the areas where telecom services had been disrupted and started to provide stable and continuous mobile signal coverage for an area of about 50 square kilometers.

7月21日18点21分，无人机在米河镇上空搭起空中移动基站，实现了约50平方公里范围、长时稳定的连续移动信号覆盖。

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The Results by using Pick-pick Signal Noise Ratio ( PSNR) or mean square error ( mse) are different from by subjective psychological assessment, while the latter are usually inexactly and have subjectivity.

通常使用的峰-峰信噪比或均方误差与主观感觉并不相符，而主观评价又存在主观性和不确定性，其结果往往因人而异。

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It is proved that the coefficients in condition of minimal error energy are equal to the coefficients with minimal error of the average square when signal is expressed by linear combination of orthogonal functions.

证明了若将信号用正交函数的线性组合表示，在误差能量为最小条件的条件下，其系数与通常的按均方误差最小所得的结果一致。

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It performs better than widely used mean square error and peak signal to noise ratio.

该方法性能高于常用的均方误差和峰值信噪比图像质量评价方法,且简单有效.

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The photometric signal-to-noise ratio is roughly proportional to the square root of the signal intensity.

光度计的信噪比与信号强度的平方根粗略成比例.

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In the input enter the square wave, sine wave, triangle wave signal excitation, feed-side to collect different fault information, in particular the input sine wave excitation, and its most obvious fault features can be more easily collected current fault information.

输入端分别输入方波、正弦波、三角波等信号激励，馈电端能采集到不同的故障信息，特别是输入正弦波激励，其故障特征最为明显，能更容易采集到电流故障信息。

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Approaching to periodic square wave signal on three dimension with finite Fourier series

用有限项傅里叶级数三维趋近周期性方波信号

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The simulation results show that the semi-soft threshold denoising method reduces the noise effectively, improves the ratio of signal and noise, retains the detail of image and obtains the minimum mean square deviation. It finds some application in engineering.

仿真结果表明：半软阈值去噪方法有效地抑制了噪声，提高了信噪比，同时保留了图像细节，获得了最小的均方差，具有一定的应用价值。

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