查询词典 numerical signal

Using the amplification transfer function of type Ⅰ BBO crystal, the theoretical study of spatial properties of the optical parametric fluorescence generated by homochromatic signal and polychromatic signal in optical parametric amplification is investigated, The numerical simulation results demonstrate that when the homochromatic signal is injected into optical parametric amplifier, the fluorescence signal is first emitted in a cone and then in a ring while centering on the pump wave direction.

采用第Ⅰ类相位匹配BBO晶体的放大传递函数方法，分别对光参量放大过程中单波长信号光注入和多波长信号光注入出现的参量荧光的空间特性进行了详细的理论研究。

At the same time, combining with the actual condition of delivery pipeline of our country and some prevalent leak detection and location methods, this paper raised a method, which is based on wavelet analysis and negative- pressure-wave to detect and locate the leakage. Jobs in the paper are as follows:As affected by gas density, pressure, specific heat and pipe material, the velocity of negative-pressure-wave improved depending on the energy conservation. At one time, taking the affection of velocity of gas flow, the location formula was modified in some degree.When locating the leaks with location formula, the iterative approach algorithm was adopted as a new method to increase the location accuracy level of system.Multi-scale decomposition and reconstruction of wavelet transform is utilized to filter the noise of negative-pressure-wave, which was brought by leakage. With the capacity to detect the signal singularity fast and accurately, wavelet transform was used to catch the break point of pressure signal. The work improved the accuracy of At in location formula, accordingly improved the location accuracy.Wavelet is a suitable tool for signal analysis. The distinct character is that the mother-wavelet is of optional. That means choosing different mother-wavelet will get different analysis result. So we studied how to choose mother-wavelet and its scale for signal singularity detection. The method is to choose a wavelet by regularities of the wavelet and the signal.Finally, a plan, which bases on SCADA system for inspection and detection of natural gas leakage, is proposed in the article.

其中，主要进行了以下几方面的工作：针对泄漏产生的负压波在管道中的传播速度受媒介的密度、压力、比热及材质等因素的影响，而非声波在空气中传播的速度，本文利用能量守恒原理，对其进行了修正；考虑到管内气体流速对压力波速的影响，对原始的负压波定位公式进行了一定程度的改进，并在利用定位公式进行泄漏点定位时采用逐步迭代逼近算法，提高了系统的定位精度；利用小波变换的多分辨率分解和重构技术，对采集到的管道发生泄漏时产生的负压波信号进行了降噪处理；并利用小波变换技术对信号奇异点的快速、准确的识别能力，对经上述消噪后的负压波信号进行了奇异点捕捉，精确捕捉的结果提高了定位公式中上下游站点采集到的负压波奇异点的时间差△t的精度，从而进一步提高了定位的精度；考虑到小波变换是一种基波可变的信号分析工具，也就是说，不同的小波基波对信号分析的结果将有很大差别，这势必影响最终的处理结果，因此，我们又对比分析了本课题中小波基及尺度的选择问题，依据规则性系数相似性原理对母小波的选择进行了探索性研究；最后，还提出了基于SCADA的泄漏检测与定位系统的软件开发构想及系统的嵌入方案。

The mulitresolution analysis of wavelet can decomposite signal on different Scales.So it has the ability of processing for signal in frequency-band,which is very useful to analysis the details of signal on a given frequency-band,to build up the identification features of signal and to cancel the signal noise.

小波多分辨率分解能够将信号在不同的尺度上展开，因而具有对信号按频带进行处理的能力，这对于分析特定频段上信号的细节，建立表征识别故障信号的特征以及清除信号的干扰与噪声等方面具有十分重要的意义。

The use of mobile phone signal isolator, can be automatically designated to form the framework of an effective s你好eld to block mobile phone signals in the magnetic field, edsun-2010 mobile phone signal blocking s你好elding device is 10-40 meters in diameter in the range of effective to make GSM / DCS / CDMA / PHS mobile phone models, such as in你好bitory signals to the space to block the effects of mobile phone signals, so that can not be made and answered the phone, but do not affect the space outside the normal mobile phone signal transmission, leaving the MDPB set up mobile phone signal jammer-type space, the phone signal will not be interference, isolation, be able to resume normal use.

施用型手机信号断绝器，能在指定的规模内AUTO形成能够有用阻断手机信号的屏蔽磁力场，edsun-2010型手机信号阻断器的屏蔽直径是10-40米规模，在该规模内有用使GSM/DCS/CDMA/PHS等型号的手机信号被按捺，到达该空间内手机信号阻断的效验，使手机无法打出以及接听，但又不影响该空间之外的手机信号的正常传道输送，离开设置有MDPB型手机信号滋扰器的空间之外，手机信号将不会被滋扰、隔央视屏蔽外文减写离，便可恢复正常施用。

According to singular entropy and Percent of contribution to total energy, the de-noising rank is obtained and the signal is reconstructed. The thesis compares reconstruct wave form of different reconstruct rank and the error of original signal and reconstruct signal is contrasted.According to voltage flicker measurement, voltage flicker detection method based on Mathe Matical filtering and Teager Energy Operator is proposed. The multiple MM filter filters out pulse noise and white noise contained in fliker signal, then the filtered signal is tracked accurately and quikly via TEO.

提出了基于数学形态滤波和TEO能量算子的电压闪变快速测量方法，含噪电压闪变信号经过多结构元素复合数学形态滤波后，采用TEO能量算子计算跟踪电压闪变信号的包络，得到的包络信号用Pisarenco谱分析方法获得闪变调制信号的幅值频率等参数，对不同情况下的电压闪变信号进行了仿真验证。

It is the key factor regulating programmed cell death in pathogen,evocator and hormone responses.H_2O_2 has also been proved to play the signal role in defensive response to environmental stresses.H_2O_2 is known of directly regulating the expressions of numerous genes and some of these genes relate to plant defense and hypersensitive response.H_2O_2 also interacts with other signal systems,especially hormone signal system,and forms upstream or downstream components of hormone-mediated signal-transmitting passageways;more importantly,H_2O_2 also work to exert influence on or modify other secondary signals such as calcium signal between which and H_2O_2 many interactions take place;and both of these two signals regulate interactive tolerances of plants.

已知H2O2直接调节无数基因的表达，其中有些基因与植物防御和超敏反应有关。H2O2还与其它信号系统特别是激素信号相互作用，是激素介导的信号传导通路上的上游或下游组分；更重要的是H2O2还影响和修饰其它第二信使如钙信号的作用，在H2O2信号和钙信号之间发生众多的交互作用且这两种信号分子都调节植物对多种胁迫的交互耐性。

It contains: a continuous guide frequency generating module to generate DPCCH non-guide frequency emission estimation value according to input DPCCH de-spread signal and guide frequency emission signal, and combine the estimation value with the DPCCH guide frequency emission signal to generate continuous guide frequency; an average fading factor generating module to generate average fading factor of each DPCCH code according to the input continuous guide frequency and DPCCH de-spread signal; a demodulation signal generating module to generate DPCCH and DPDCH demodulation signals according to the input average fading factors and DPDCH and DPCCH de-expanding signals at the corresponding time.

这种码分多址通信系统的信号解调装置包含：连续导频产生模块，用于根据输入的DPCCH解扩信号以及导频发射信号，产生DPCCH非导频段发射估计值，并将所述DPCCH非导频段发射估计值与所述DPCCH导频发射信号合并，产生连续导频；平均衰落因子产生模块，用于通过输入的所述连续导频以及DPCCH解扩信号，产生DPCCH各个码元的平均衰落因子；解调信号产生模块，用于通过输入的所述DPCCH各个码元的平均衰落因子，以及对应时刻的DPDCH解扩信号和DPCCH解扩信号，产生DPCCH和DPDCH解调信号。

The project proposed and established the strict unique mathematical model of instantaneous frequency aiming at the currently existed problems in Hilbert Huang Transform form the viewpoint of physical connotative meaning; proposed and established the strict mathematical model of general intrinsic mode signal based on the concept of general continuous intrinsic mode signal and the compositive principle of practical general intrinsic mode signal; researched and proposed the fitting method of envelope lines in HHT from the viewpoint of theory, conquered the blindness and random in quondam EMD envelope line fitting and boundary treatment; developed a virtual time-frequency analyzer based on general intrinsic mode signal decomposition to open out the local time-frequency characteristics of nonlinear and nonstationary signal more deeply and accurately.

本项目针对希尔伯特-黄变换现阶段存在问题，从物理内涵的角度提出并建立了瞬时频率严格的唯一的数学模型；基于连续性的一般固有模态信号的概念和实际信号的一般固有模态信号的组成原理，提出并建立了一般固有模态信号严格的数学模型；从理论角度研究并提出HHT中的包络线构造方法，克服了原EMD的包络线构造和边界处理的盲目性和随意性；研发一台基于一般固有模态信号分解的虚拟式时频分析仪，使之可以更深入、准确地揭示非线性非平稳信号的时频局部特征。

When a noise signal is present, a pilot signal and noise signal passing through a capacitor are applied to the inverting input port of the subtracter via a second MOS transistor to cancel the noise signal contained in the composite input signal.

当噪声信号时，一个试验信号与噪声信号通过电容通过应用通过一个晶体管第二马鞍山到减法反相输入端口，取消噪声信号的复合输入信号中。

This thesis mainly discuss following issues, Theory and simple expressions for array covariance matrixes are derived when angular spread functions are symmetric distribution functions, i. e. the Uniform distribution, the Gauss distribution, the Laplace distribution and the Von Mises distribution, and a non-symmetric distribution function, i. e. the Gamma distribution. And the relation between the effective signal subspace and the array number, or and the nominal angle of the distributed source, the angular spread, the distributed functions, and the Signal-to-Noise Ratio is gained. The dimension of the effective signal subspace increases with increment of the array number. And it is more obvious to the non-symmetric distribution. The dimension of the effective signal subspace decreases with increment of the nominal angle. And the distributed source is equal to a point source as θ=π/2. The dimension of the effective signal subspace increases with increment of the angular spread.

本论文针对阵列信号处理中广泛存在的分布源现象，主要讨论了以下问题：推导了角度分布函数分别为对称的均匀分布、高斯分布、拉普拉斯分布、Von Mises分布和非对称的伽马分布时，分布源阵列接收信号协方差阵的严格模型和简化模型，得到了单个分布源的有效信号子空间随阵元数、分布源中心角、分布角、角度分布函数和信噪比的变化规律：随着阵元数的增加，对所有角度分布函数的有效信号子空间维数也随着增加，且非对称分布函数的有效信号子空间充满整个空间的可能性更大；随着分布源中心角逐步增加，有效信号子空间维数逐步减小，当θ=π/2时，等价于点源情形；随着分布源分布角逐渐加大，有效信号子空间维数也随之增加，直到有效信号子空间充满整个空间；随着信噪比的增加，有效信号子空间维数有一定程度的减少。

Liapunov—Schmidt method is one of the most important method in the bifurcation theory.

Liapunov—Schmidt方法是分叉理论的最重要方法之一。

Be courteous -- even when people are most discourteous to you .

要有礼貌──即使当別人对你最不礼貌的时候。