查询词典 analog signal

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。

Interference is most difficult to be avoided while measuring the weak signal, Especially when the signal is only at microvolt level.X9313 is a kind of digitally controlled dissurbacne potentiometer produced by Xicor company.We succeed in using it to solve the problem that the signal is too strong, and get the useful signal in a weak signal measurement device.

微信号检测中最难避免的就是干扰问题，特别是在信号仅为微伏级时，信号相对于干扰来说，几乎被完全淹没，因此，研究如何在干扰信号很大的情况下尽可能地检测出有用信号有着极其重要的意义。X9313是Xicor公司推出的一种数字电位器，在某微弱信号检测装置中，采用X9313可成功解决干扰信号过大的问题。

A sidelight here is that if you look at the mathematical representations of a PM signal versus an FM signal, the difference is that the modulation component in a PM signal is the mathematical derivative of the modulating signal in the FM signal.

如果你看调相PM信号和调频FM信号的数字表达式的对比，它们的不同点是调相PM信号调制向量是调频FM信号调制向量的数学派生。

The holistic design of the system and resolved the designs of software and hardware based on VXI bus are put forward according to the demand of test system. The hardware and software is designed, including the formation and design of hardware system, visual instrument software architecture, program design for instrument driver, high speed real-time data collection. In the dynamic test program, the idea of"software is instrument"was applied to meet the diverse test demands. Last, it is proposed that the VXI test system be developed to more totalization and networked. The basic theory of system identification was introduced briefly at first. The principle of spectrum analysis system identification based on Wiener-Hopf equation was expatiated. and the questions in applying Peusdo Random signal as spectrum analysis methods stimulate signal was studied, The generation principle of the peusdo random signal is researched, the characteristic of peusdo random are analyzed from time domain and frequency domain, the inverse repeat peusdo random signal is brought forward to make up the shortage of ordinary peusdo random signal. And a new chaos genetic algorithmis presented to solve the unprecise problem of the traditional method. In the servo valve dynamic characteristic test system, the spectrum analysis methods was applied successfully, the servo valve dynamic characteristic could be acquired rapidly and exactly, the test results were analyzed and the ameliorate methods were brought forward at last.

结合航天某集团液压测试中心测试系统的需求，提出了基于VXI总线的液压测试系统的整体设计方案，完成了测试系统的硬件设计与软件设计，包括硬件系统构成与设计、虚拟仪器软件结构、仪器驱动程序设计、高速同步实时数据采集等内容；以伺服阀动态特性测试为例设计了测试模块，该模块体现了VXI总线仪器软件开发所倡导的"虚拟仪器"的思想，以软件的灵活应用满足了不同的测试需求；结合自动测试系统的发展，研究了VXI测试系统与网络技术结合，实现各种软硬件资源共享，进一步提高设备及数据的利用率和系统的扩展性，使自动测试向综合化、网络化方向发展；研究了伪随机信号作为谱分析法辨识的激励信号时存在的问题，讨论了伪随机信号的产生机理，从频域和时域分析了伪随机信号的性质及其应用，提出了用逆重复伪随机信号弥补了普通伪随机信号的不足，并以混沌遗传算法对逆重复伪随机信号产生过程中的参数进行优化，可以更合理而不是凭经验产生需要的逆重复伪随机信号。

It can separate sync signals from NTSC, PAL and SECAM video signals, and produces composite sync output signal, back porch output signal, horizontal sync signal, vertical sync signal and odd/ even field output signal.

它可以对NTSC、AL、ECAM 制式的视频信号进行同步分离，获得所需的同步信号，还能准确地输出复合同步、沿输出、同步、同步和奇/场输出信号。

A control device (14) includes means for outputting a request signal to an electornic key (12) in response to the ON operation of a predetermined switch start switch (70 among a plurality of switches (winker switch, horn switch, etc.) arranged in the vicinity of a user who has sat on the driver seat of the vehicle (100B) request signal generation means (80, a transmission circuit (46), and a transmission antenna (72), means for detecting a response signal from the electronic key (12) a reception circuit (44 and response signal matching means (82), and monitoring means (84) for outputting a lock release instruction to a actuator (64) when the response signal shows that the request is from a regular user.

要约 一种控制装置(14)包括：响应安置在坐在车辆(100B)的驾驶员座位上的用户附近中的多个开关(方向灯开关、喇叭开关等)的预定开关启动开关(70的ON操作而将请求信号输出到电子密钥(12)的装置请求信号产生装置(80传输电路(46)和传输天线(72)；用于检测来自电子密钥(12)的响应信号的装置接收电路(44、和响应信号匹配装置(82)；以及用于当响应信号显示请求是来自正常的用户时将锁定释放指令输出到执行器(64)的监测装置(84)。

Firstly,we particularly explained the algorithmic of themusic recognition.Then,we made a study of the music characteristic and the musicrecognition methods.As for the burrs of the music signal,we put forward a curveplastic method to eliminate the burrs.Considering the difficulties of detecting thepoint of the music speech,we made use of the multi-frequency energy curve to detectthe end-point of the music signal with the crossing zeros rate.As for thedisadvantages of the large operation and influence of the formant,we improved theAMDF theory with the linear prediction algorithmic to detect the error.In order toobtain the characteristic parameter of the music signal,wo calculate the MFCCparameter to obtain the template and the pending signal characteristic parameter.Inorder to improve the rate of the recognition,considering the disadvantages of theDTW algorithmic,we find a new method to improved the DTW algorithmic bybroadening the point of the music signal and made simulation experimentation;As forthe disadvantages of the contraposition grade to the pitch,cadent and sing name,wefind a method to dynaic adjust the results of the recognition to improve the accuracyof the grade.

详细阐述了嵌入式音乐识别算法的详细设计与实现，研究了音乐语言的特点和音乐识别的侧重点，并阐述了基于音乐信号特色的语音处理及识别方法；针对音乐信号中的毛刺干扰，提出了曲线整形的思想，消除了音乐信号中的毛刺；针对音乐信号端点检测困难的特点，利用多频段能量曲线分割结合过零率来实现端点准确检测；针对音高提取运算量大且容易受共振峰影响的特点，利用线性预测残差的方法对传统的AMDF算法进行了改进并提取出了音高，在实际实现时，优化了AMDF算法，减少了计算量；为了得到较好的特征参数，通过求取梅尔频标倒谱系数的方法，分别提取了模板信号特征参数和待测信号特征参数；为了提高识别率，针对传统DTW算法的缺陷，采用了放宽端点和声刺激法改进了传统的DTW算法的性能并进行了仿真试验，使音乐识别率得到明显提高；在音高、节奏评分时，针对对位评分的缺点，采取了动态调整的方法提高了评分的准确度。

Through Hilbert transform, a signal's plane trace can be get. There are two frequencies in the tested signal, so the signal's plane trace may be looked as the track of the out pole's end when two poles rotate around parallel axles. Using the knowledge of motion synthesis in theory mechanics, a formula to describing the change of plane trace's step length and angle for two-frequency be get. So we may prolongate the tested signal's plane trace from the echo's initial arriving moment, and get a certain length of the signal's prolongation.

通过Hilbert变换可得到测试信号的平面迹线，测试信号中只含有两个频率成分，视为双频信号，双频信号的平面迹线相当于两连杆绕平行轴转动时外杆杆端迹线，利用理论力学中运动合成和瞬心知识，推导出双频信号平面迹线步长平方满足余弦线性复合函数，而迹线转角可视为线性变化，据此可对回波到来之前的测试信号平面迹线作延长，得到一定长度的信号延展段，信号延展段与实测段作差可得到一次、二次回波的第一个波峰值。

A carrier gas such as nitrogen is directed through line 20 and valve 22 to connect with line 26 and mix with the gas sample.

如氮气之类的载体通过管线20和阀22引入，与管线26相通，与气体样品混合。

But for the most part, knaves and parasites had the command of his fortune

然而支配他的家产的大多是恶棍和寄生虫。