查询词典 threshold frequency

Comparing the mean of hearing threshold in each group at different frequency band, the threshold of audibility on 0.5, 1, 2, 3, 4, 6kHz was 22.98±6.28dB, 21.38±7.88dB, 22.04±10.19dB, 26.55±16.69dB, 31.52±18.86dBand 33.75±19.71dB, respectively.

联合组听力异常率明显高于单纯噪声组和对照组(P.05)，高频、语频、Ⅱ级、Ⅲ级及Ⅲ级以上听力损伤率均较噪声组、对照组明显升高(P.05)。

The main job and contribution of this paper are as follows:Based on narrowband signal processing, we propose a new method for FH signal blind detection and blind parameter estimation. Firstly, compute the cross-correlation function of FH signals from multichannels, then we get the cross power spectral density matrixCSDM Secondly, select the hops of FH signals from the CSDM via processing and analyzing the CSDM, meanwhile reduce the influence coming from noise, fixed frequency signal and other interferences; Lastly, estimating the DOA of every hop and according to the DOA, we can separate the hops, get the number of FH signals and their parameters. Propose a new method for designing the threshold in FH signal detection. This method makes it easy to get the threshold by theoretic computing and it can extremely reduce the interference of non-FH signals.Based on broadband signal processing, we propose a new method for FH signal blind detection and blind parameter estimation. Firstly, get the DOA of the signals by wideband spatial spectrum estimation; secondly, separate the signals by spatial filtering using wideband beamformer; Lastly, we propose two methods for FH signal blind detection and blind parameter estimation, one is for several constant hop-rate FH signals whose dwell-time are different and another is for a single FH signal whose hop-rate is alterable.By employing spatial interpolation in broadband signal beamforming, it can reduce the number of antenna elements and corresponding RF modules, A/D converters, etc. It can also eliminate the mutual coupling between antenna elements while getting the narrower main beamwidth and lower sidelobe level.

本文的主要研究工作和贡献如下：●提出了一种基于窄带处理的FH信号盲检测和参数盲估计的实现方法，即首先求出多路信号之间的互相关，进而得到互功率谱密度矩阵，然后通过对CSDM进行对折处理来抑制噪声、定频信号及其他干扰的影响，并将所有属于FH信号的hop(每一跳的驻留时间在时频图上持续的线段)从CSDM中筛选出来，最后用阵列信号处理中的到达方向估计理论在频域中估计出各个hop的方向参数，利用方位信息完成FH信号分离并得到FH信号的数目及其各自的参数集；●提出了一种确定FH信号检测门限的策略，该策略不仅使得检测门限能够通过理论计算得到，而且还显著地抑制了非跳频信号的干扰，从而能有效地检测出FH信号；●提出了一种基于宽带处理的短波FH信号盲检测和参数盲估计的实现方法，即首先利用宽带空间谱测向技术得到接收信号的DOA，然后采用宽带波束形成技术对特定方向进行空间滤波，实现多个信号的分离，最后分别提出了两种FH信号的盲检测和参数盲估计方法，第一种方法适用于空间某个特定方向上存在着几个驻留时间不同的恒跳速FH信号和其他干扰信号的混合信号，第二种方法适用于空间某个特定方向上仅含一个可变跳速的FH信号和噪声的混合信号；●将空间插值的概念和宽带波束形成技术结合起来，提出了一种基于频域处理的宽带恒定束宽的波束形成方法。

We get appropriate threshold with mean excess function plot, get severity distribution of losses over threshold with GPD and frequency distribution with hypothesis test.

首先根据均超函数图估计出恰当的阈值，利用假设检验估计超阈值的发生强度，用广义帕累托分布估计了超限参数。

The image is first reduced in dimension by Gaussian pyramid, and the Hu moment is applied to the fixed sized overlapping blocks of low-frequency image. The eigenvectors are lexicographically sorted. Then, similar eigenvectors are matched by a certain threshold value. Finally, the area threshold value is proposed to remove the wrong similar blocks. The mathematical morphology operations are performed to locate the tampered part.

该算法首先将图像进行高斯金字塔分解，将低频图像进行块分解，提取每块的Hu矩不变特征，并将特征向量排序，然后为每个特征向量搜索符合阈值的相似特征向量；最后利用区域面积阈值去除错误的相似块，并结合数学形态学定位篡改区域。

An embodiment of the invention discloses a reverse power control method of an orthogonal frequency-division multiple access system including: calculating decision threshold values of each adjacent subdistrict according to the current reverse traffic channel gain of an access terminal, channel differences between each adjacent subdistrict and the resources distributed by the access terminal; and adjusting the reverse traffic channel gain value of the access terminal according to the decision threshold values of each adjacent subdistrict and using the adjusted reverse traffic channel gain values to determine the transmit power of the reverse traffic channel.

本发明实施例公开了一种正交频分复用多址系统中的反向功率控制方法，包括：根据接入终端的当前反向业务信道增益、各个相邻小区的信道差异以及接入终端所分配的资源情况计算各个相邻小区的判决门限值；根据所述各个相邻小区的判决门限值调整接入终端的反向业务信道增益值，并且利用所调整的反向业务信道增益值决定反向业务信道发射功率。

For stable surface waves, there exist a frequency threshold, a power threshold and two cross-jumping powers.

研究了两非线性反铁磁晶体交界面上稳定传播的电磁表面波的传播特性。

The principle of MUSIC algorithm and theoretical analysis of the spectral separate frequency and frequency detection threshold are included. MUSIC algorithm compared with FFT based algorithm for harmonic frequency estimation using matlab simulation platform .

给出了MUSIC算法的基本原理，对MUSIC算法的频谱分辨能力和频率检测门限进行了理论分析，在Matlab仿真平台下对MUSIC算法和FFT算法的频率估计性能进行了比较。

The new function introduces a frequency sub-band threshold, supposing that the component value below than the threshold is noise, then filter it.

经过大量的实验，证明提出的方法具有单峰性好、灵敏度高等优点，特别是在抗噪声性能方面有很大提高。

Methods One hundred and twenty cases (165 ears) of tinnitus and/or hearing loss were differentiated into five syndrome patterns according to the theory of traditional Chinese medicine: invasion of wind-heat, liver-fire up-stirring, stagnation of phlegm-fire, kidney-essence deficiency and weakness of spleen-stomach. Hearing threshold of pure-tone, function test above hearing threshold and matching of tinnitus frequency and loudness were carried out in all cases and the data were analyzed by SPSS statistical software.

方法］选择具有典型中医证候表现的耳鸣耳聋患者120例（165耳），经传统方法辨证为风热侵袭、肝火上扰、痰火郁结、脾胃虚弱、肾精亏损5个证型，分别进行纯音听阈测试、阈上功能测试、耳鸣频率及响度匹配，数据经SPSS软件进行统计学处理。

Among the 45 neurons generating phasic firing, 8 (17.78﹪) neurons could still be induced phasic firing after treatment with 1×10-2 μg/mL SVHRP and 37 (82.22﹪) neurons had no responses to the stimulation. The AP firing of neurons was dramatically different after treatment with SVHRP (P＜0.01, n=45). Among the 7 repetitive firing neurons, all of them could only generate 1 or 0 AP instead of repetitive firing when SVHRP was applied. The number of APs was 14.57±1.00 and 0.57±0.20 before and after SVHRP treatment (P＜0.01, n=7). The AP rheobase was (75.10±8.99) pA and (119.85± 12.73) pA before and after 1 × 10-4 μg/mL SVHRP application, respectively (P＜0.01,n=8). The AP threshold was increased from (-41.17±2.15) mV to (-32.40±1.48) mV after 1×10-4 μg/mL SVHRP treatment (P＜0.01,n=8). The peak amplitude of AP was (68.49±2.33) mV for the neurons before treatment with 1×10-4 μg/mL SVHRP and (54.71±0.81)mV after treatment (P＜0.01, n=8). These results showed that SVHRP could decrease the AP firing frequency, increase the AP rheobase and threshold, but decrease the AP peak amplitude of hippocampal neurons.

在产生位相放电的45个细胞中，有8个细胞在SVHRP处理后仍可以诱发出位相放电(占17.78﹪)；37个细胞在SVHRP处理后无法诱导出位相放电(占82.22﹪)，SVHRP处理后动作电位的产生与处理前相比，有显著差异(P＜0.01，n=45)；在产生重复放电的7个细胞中，在1×10-2μg/mL SVHRP作用后均不能再次诱发出重复放电，而是产生一个动作电位或不再产生动作电位，药物处理前产生的动作电位个数为14.57±1.00，SVHRP处理后产生动作电位的个数为0.57±0.20，二者之间有显著性差异(P＜0.01，n=7)。1×10-4 μg/mLSVHRP处理后，诱发动作电位产生的基强度由(75.10±8.99)pA增加到(119.85±12.73)pA(P＜0.01，n=8)；阈电位由(-41.17±2.15)mV升至(-32.40±1.48)mV(P＜0.01，n=8)；动作电位峰值由(68.49±2.33)mV下降至(54.71±0.81)mV(P＜0.01，n=8)。

In the negative and interrogative forms, of course, this is identical to the non-emphatic forms.

。但是，在否定句或疑问句里，这种带有"do"的方法表达的效果却没有什么强调的意思。

Go down on one's knees;kneel down

屈膝跪下。。。下跪祈祷