查询词典 time signal

But, in the natural and artificial signal, a lot of signal phases don\'tvary linearly with time, for example, we usually use chirp signal in the radar technology,frequency step signal, linear modulation component of the ground echo in the SARtechnology, linear modulation component of the moving target echo, linear modulationcomponent while the airborn radar detecting the moving target, etc.

在自然界和人工信号中，许多信号的相位变化并不是随时间一次方变化，如雷达技术中常用的线性调频信号，频率步进信号，另外，SAR 技术中，地面回波所含有的线性调频分量，ISAR技术中，运动目标的回波所含有的线性调频分量，机载雷达探测运动目标时的线性调频分量，等等；傅里叶变换对此类信号分析所得的结果是信号在不同频率点上的能量分布，即信号在基函数上的投影。

This course will mainly discuss on time-domain analysis and frequency-domain analysis of determined signal, description and characteristic of linear time-invariant system, as well as time-domain analysis and transformation domain analysis of signal via linear time-invariant system.

本课程主要讨论确定性信号的时域和频域分析，线性时不变系统的描述与特性，以及信号通过线性时不变系统的时域分析与变换域分析。

Time domain signal is continuous signal, with continuous time Fourier transform as discrete signals, discrete-time Fourier transform.

当时域信号为连续信号时，用连续时间傅里叶变换；为离散信号时，用离散时间傅里叶变换。

The invention relates to an external synchronous TD-SCDMA cover network system, which comprises a main coverer and at least one driven coverer forming the cover network system; said main coverer, via synchronizing the TD-SCDMA descending signal of descending chain, outputs descending-ascending switch control signal to the main coverer, to obtain frame synchronization; sending the synchronous instruct signal to the driven coverer; obtaining the frame synchronization at the driven coverer, via external synchronous instruction signal, to complete the normal ascending-descending time slit switch.

本发明外同步TD-SCDMA覆盖网络系统，包括组成覆盖网络系统的主覆盖端和至少一个从覆盖端，所述主覆盖端通过对下行链路中的TD-SCDMA下行信号进行同步处理，向主覆盖端输出上下行切换控制信号，获得帧同步；并将同步指示信号发送至从覆盖端，从覆盖端根据外同步指示信号进一步获得帧同步，从而完成整个覆盖网络系统的正常上下行时隙切换。

The system has realized signal generator, signal"s sampling and averaging function, signal"s power spectral density and cross special density analysis, the design and application of digital filter, signal analysis in time, frequency and inverted frequency domain.

实现了波形发生器的设计、信号采集及平均处理、滤波器的设计及应用、信号的时域、频域以及倒频域分析。

Using the time-gain compensation technique to compensate for ultrasonic wave's weaking when transmitting in the air,and reduce the fluctuation of echo signal.The peak time detecting circuit which is composed of full-wave rectification circuit and differential circuit can detect the reach time of echo signal accurately.

和其他方法相比，如激光测距、微波测距等，由于声波在空气中传播速度远远小于光线和无线电波的传播速度，对于时间测量精度的要求远小于激光测距、微波测距等系统，因而超声波测距系统电路易实现、结构简单和造价低，且超声波在传播过程中不受烟雾、空气能见度等因素的影响，在各种场合均得到广泛应用。

The single a machine that should design to adopt serieses MCS-51s primarily conduct and actions main a measurement for, passing spreading feeling machine to the current of air measuring, its change is homologous pulse signal, this pulse signal through A/ D conversion with D/ A conversion after produce the certain electric voltage signal, will show the inceptive pulse signal a discharge for representing to come out at the same time.

该设计主要采用了MCS-51系列的单片机作为主要的芯片，通过传感器对燃气流量的测定，将其转变为相应的脉冲信号，这个脉冲信号经过A/D转换和D/A转化之后产生一定的电压信号，同时会将起初的脉冲信号所代表的流量显示出来。

The uncertainty principle of signal is proved according to the uncertainty principle of quantum mechanics, and is further interpreted by quantum mechanics. The signal can be considered as a kind of the quasi quantum system with wave-particle dualism. Because of the wave-particle dualism of the signal, time and frequency can not be measured at the same time.

根据量子力学的测不准原理，采用力学量算符的方法得到了信号在时频分析时的测不准原理，并对该原理进行量子诠释，认为信号在某种意义下可以看作是一个存在波粒二重性的类量子系统，正是由于信号的波粒二重性导致无法同时准确地测定信号的时间和频率。

The time-history velocity response signal of pile can be decomposed by Sym wavelet. The power spectrum value can be extracted from some specified spectrum range. These values from one signal makes up the characteristic vector representing this signal. The relationship between characteristic vector of pile and pile defect type can he established by using BP artificial neural network. Abundant time-history velocity response signals of pile can be acquired by numerical simulation method.

利用Sym小波对基桩速度响应时程曲线进行小波分解，对指定频带上的信号分量进行特征值提取，提取的特征值为反映各频带范围内体现能量分布的功率谱均值，提取的特征值可构成反映信号特征的特征向量，同时利用BP人工神经网络的非线性映射特性建立特征向量和基桩缺陷类别之间的一种对应关系。

Fluxgate sensor inducts the environment magnetic field, outputs the compass course signal to the CPU system. This signal then is transformed into digital signal. CPU processes it and then gains compass course. When use rotary mathod to measure the deviations, CPU first collects timed the compass course come from the Fluxgate sensor, then calculates automatically their deviations and the correspondent coefficients. Based on all this, CPU can calculates out the real-time magnetic course or the real-time ture course, then sents them to display on the digital displayer.

本系统采用磁通门传感器来直接敏感合成磁场，输出罗航向直流感应电压信号送A/D转换器进行转换，并经CPU计算处理得到罗航向度数值，以及利用&旋回法&测定自差时，CPU按照船舶旋回的角速度定时地采集罗航向度数值，在此基础上CPU自动地计算出各采集罗航向上的白差，再由此计算出自差系数，并实时地解算出磁航向值或真航向值，送数码显示器显示。

Finally, according to market conditions and market products this article paper analyzes the trends in the development of camera technology, and designs a color night vision camera.

最后根据市场情况和市面上产品的情况分析了摄像机技术的发展趋势，并设计了一款彩色夜视摄像机。

Only person height weeds and the fierce looks stone idles were there.

只有半人深的荒草和龇牙咧嘴的神像。