threshold signal level 中文意思是什麼
threshold signal level
解釋
門限信號電平-
This thesis studies the law of affecting de - noise result and the selection of the threshold and the wavelet function, the combination of wavelet and fft in the fault diagnosis of turbine - generator sets : by the de - noise anslysis of blocks and sin signals, concludes : to blocks signals, usually adopts soft threshold ; the law of affecting de - noise result is when use wavelet auto - de - noise, with the increasing of decomposed level, the de - noise result becomes worse while the level blow the 3, when the level above 3 and when uses wavelet packet, it is the other way round ; the best de - noise methods of the signal is that uses " dbl " wavelet function, three level, soft and " rigrsure " threshold
本文研究了分解層數對消噪結果影響的規律和閾值、小波函數的選取，結合小波分析與fft分析診斷汽輪發電機組的故障。通過對brocks和sin兩信號的分析，得出：對blocks信號進行分析一般採用軟閾值；分解層數對消噪結果影響的規律為用小波自動降噪在分解層數小於3時，隨著分解層數的增加，消噪結果變好，反之，則變差，用小波包降噪時隨著分解層數的增加，消噪效果變好；適宜選用dbl小波軟rigrsure閾值自動消噪。 -
Receiver threshold - signal level
接收機門限電平 -
One is to use fourier transformation to convert the source signal from time domain to frequency domain and to discard high frequency harmonious components upwards of 19 ( gb / t14953 - 93 d5. 3 demanding ), then to have static huffman coding to the quantized char array which is composed of reserved direct current component and basic wave and each high frequency " s amplitudes and angles. the other is to use discrete wavelet transformation to convert the source signal from time domain to frequency domain and to set the high frequency coefficients that its absolute value is smaller than the given threshold to zero, then to have dynamic huffman coding to the quantized char array which is composed of multiple, wavelet ' s level, datum length, low frequency coefficients and reserved high frequency coefficients. mass simulinks and analyses under the two circumstances have done to show that data compression ratio is small and the relative error is also small and within the permission of engineering and the compression problem can be solved in theory of measured datum of power system
第一種情況的壓縮方法為：採用傳統的傅立葉變換把原始信號從時間域變換到頻率域，舍棄20次及其以上的高次諧波成分（保證了gb / t14953 ? 93d5 . 3要求） ，然後對保留的直流分量、基波和各次諧波的幅值和相角數據量化后和量化時分別乘以的倍數系數構成一個數組，以字元形式保存，採用靜態huffman編碼對變換數據進行壓縮；採用離散小波變換把原始信號從時間域變換到頻率域，然後對分解得到的高頻系數進行閾值量化處理，對乘以的倍數系數、小波變換的階數、小波變換后的低頻、各級高頻以及原始數據長度、量化后的低頻系數以及保留的高頻系數大小、位置構成一個數組，以字元形式保存，採用動態huffman編碼對這個文件進行壓縮。 -
On the one hand, the receiver must be self - adaptive to set as fast as possible the " 0 " and " 1 " bit level judgement threshold in a dynamic way ; on the other hand, the transmitter of onu should take some measures to minimize and compensate for the burst delay. the optical burst transmission circuit is thus required to switch on and off the laser in a snappy way to ensure fast signal sending. in that sense, the laser must be designed with a superb response speed
一方面，接收機必須具有自適應功能，能以最快的速度動態調定" 0 " 、 " 1 "比特電平判決門限；另一方面， onu的發射機應該採取-定的措施減小和補償突發時延，其光突發發送電路要求能夠非常快速地開啟和關斷激光器，迅速發送信號，所以，它需要使用響應速度很快的激光器。 -
Some issues associated with the algorithm such as wavelet function selection, analysis level, and boundary treatment and so forth have been discussed. the stein self - adapting threshold denoising method is used to the signal pretreatment, thus the snr and resolution are improved
採用基於stein無偏似然估計自適應閾值選擇原理的實用消噪方法對故障信號進行預處理，在改善信噪比的同時，又提高了對突變信息的解析度。 -
It also studies the influencing factors including sampling frequency, pd waveform, decline time, time intervals between pd pulses, mother wavelet, center frequency of interference, entropy threshold value and snr. in addition, it applies wavelet packet method （ wpm ） for non - stationary signal de - noising in on - line pd monitoring and analyzes the processing results under different pd waveform, sampling frequency and noise level. firstly, the curve of pd
基於小波包變換的非平穩信號消噪演算法（ wpm ）已較為成熟，本文將其應用於局部放電在線監測，通過研究其對不同局放波形、采樣率、噪聲水平下的處理效果，首次提出了理想白噪聲條件下提取局部放電信號的曲線，分析了各種因素對該演算法下信號失真的影響。 -
In electronics, a device that restrictsthe amplitude of a signal to a predetermined threshold level. limiters may act on positive or negative values of a signal, or both
電子學中使用的一種器件，能把信號的幅度限制在預定的閥電平上，可以使信號正向限幅，也可以使信號負向限幅或雙向限幅。 -
The result indicates that, as the noise level ascends, the threshold of human electric sense descends ; noise strengthens the weak - signal detectability in human body
實驗結果表明，隨著噪聲量級的增加，人體電感覺閾值下降，噪聲增強了人體對弱信號的感知能力。 -
In chapter 4, i performed the analyzing work with wavelet and fastica and find that wavelet was a high efficient way to filter the cep signal when i set the wavelet and scaling function to haar, decomposing level to 4, threshold method to fixed to threshold and white - noise structure to scaled white - noise. it took the advantage that reduced the accumulating times to 60 with more smooth signal and less distortion. but fastica takes no advantage on this facet
本文通過小波變換和獨立分量快速分析模式識別的方法對cep數據進行了分析處理，同時與數字低通橢圓濾波器的處理效果進行了比較，發現用小波對cep的數據進行濾波處理時，可以將數據的疊加次數從120降低到60次左右，且信號的質量要比以前的處理方法好；但是獨立分量快速分析方法效果不很好。
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