查询词典 stochastic signal

This paper is mainly the dynamic input-output model that the time lag is one, which is base on the above models. After studying, we consider stochastic factor step by step in it, namely when consumption coefficient matrix is stochastic (when investment matrix is stochastic, it is almost same. So we dont research it), and they are both stochastic, then we research the stable increase solution. We utilize the means of the modern stochastic analysis and Markov process, that the stochastic dynamic input-output model don not exist the stable solution is proved. Namely, economic system must is adjusted constantly. The probability that the collapse time of the economic system is o is one.

本文对在上述基础上构造的一类时滞为1的动态投入产出模型，进行了深入研究，将随机因素逐步考虑进去，即对投入产出消耗系数矩阵为随机的情况(投资系数矩阵为随机的情况与投入产出消耗系数矩阵为随机的情况大致相同，这里就不再证明)，以及二者同时为随机矩阵时所得到的动态投入产出模型的稳定增长解问题，利用现代概率分析及马氏过程的工具，证明了不存在随机动态投入产出模型的稳定增长解；即投入产出模型反映的经济系统必须经常进行调整，其崩溃时间为无穷大的概率为零。

By employing the local Lipschitz condition and Picard sequence, the local existence-uniqueness of solutions of stochastic functional differential equations of Ito-type is firstly obtained. Furthermore, a continuation theorem for stochastic functional differential equations of Ito-type is given by using stochastic analysis technique and the quasi-boundedness condition. Finally, by establishing some delay differential inequalities and using properties of H_m-functions, a stochastic version of Wintner theorem and the global existence-uniqueness of solutions of stochastic functional differential equations of Ito-type are given. The results generalize the earlier publications.

首先，利用局部Lipschitz条件和Picard序列，获得了伊藤随机泛函微分方程解的局部存在唯一性；其次，利用随机分析技巧和拟有界条件，建立了伊藤随机泛函微分方程解的延拓定理；最后，通过建立一些时滞微分不等式和利用H_m-函数的特性，得到了Wintner定理的随机版本和伊藤随机泛函微分方程解的全局存在唯一性，推广了已有的一些结果。

Quasi Hamiltonian system; nonlinear stochastic optimal control; robustness; robust control; parametric uncertainty; uncertain disturbance; Bouc-Wen hysteretic system; Preisach hysteretic system; minimax optimal control; stochastic stabilization; stochastic averaging method; stochastic dynamical programming principle; stochastic differential game; maximal Lyapunov exponent

国家自然科学基金；拟Hamilton系统；非线性随机最优控制；鲁棒性；鲁棒控制；参数不确定性；不确定扰动； Bouc-Wen滞迟系统； Preisach滞迟系统；极小极大最优控制；随机稳定化；随机平均法；随机动态规划原理；随机微分对策；最大Lyapunov指数

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。

First, the effects of magnetic RAM relaxation time and the rise-time of incident pulse signal on reflection signal are discussed, the relationship between the rise-time of incident pulse and relaxation time based on the energy of reflection signal is revealed. Then, the effects of magnetic hysteric, susceptibilities and saturation upon reflection signal are analyzed, the results reveal the reflection of RAM target and UWB signal design. In the meantime, dielectric relaxation time effect about dielectric RAM target is analyzed simply, and the effects of relaxation time and the width of incident pulse upon reflection signal are probed. Finally, a few RAM targets are measured in the chamber using the impulse radar experiment system which is developed by the team of anti-stealth impulse radar on Department of Electrical Engineering, National University of Defense Technology. The experimental results show the similarity of the rule of echos with the theory. From the compared results of different tagets, we concluded, compared with 15% wideband sinusoidal signal, the impulse signal has increased 10～12dB energy from the same loaded RAM target; this, in turn, shows the nonlinear effects of RAM to the echoes, and the potentiality of the impulse signal to RAM targets.

首先分析了磁性RAM的弛豫时间及入射脉冲信号的上升时间对反射信号的影响，从反射信号能量角度出发，给出了入射脉冲上升时间与弛豫时间的关系；接着分析了磁性RAM的磁滞特性、磁化率及磁化强度对反射信号的影响，给出了RAM目标辐射和有关UWB信号设计的一般性结论；其次，对介电RAM的弛豫时间效应作了简单的分析，探讨了介电弛豫时间及入射脉冲宽度对反射信号的影响；最后利用国防科技大学电子技术系&反隐身冲激雷达技术研究组&研制的冲激雷达实验系统，在微波暗室中对几种不同的RAM目标进行了测量，结果表明：其反射波形的基本规律与上述理论分析相一致；从各种不同目标回波的能量对比结果得出，涂覆RAM目标对冲激信号的吸收比15％带宽的正弦信号要小10～12dB，证实了RAM的非线性效应对回波的影响，也证实了冲激信号反隐身的潜力。

So we designed a adaptive synchronizing controller based on hereinbefore hardware environment: first a small magnitude reference signal r is outputted to system through the signal card (to ensure that the vibrating system works in a linear state), and this signal is sent to the moving coil of vibrator through the power amplifier, so vibration is produced through electromagnetic induction. Secondly the vibration signal can feedback to the data acquiring card in the servo system through the acceleration sensor on the Vibroseis reactor M〓 and the base-plate M〓, then the computer can get the current vibrating state y〓 of the coil of vibrator according to the feedback information from the data acquiring card, and give a real time comparing between the current state y〓 and the reference output y〓 of the set-in reference model with current reference input being r , then regulates the correlative controlling parameters according to the error e〓=y〓-y〓 till y〓→y〓, finally normal signal sweeping begins with a certain phase fixed. Meanwhile a synchronization signal for seismic signal record is sent to seismograph from synchronization signal outputting component in the Vibroseis system to perform the controlling process of synchronization of sweeping phases.

为此，我们基于以上的硬件环境设计了一个自适应同步控制器：首先通过信号发生卡对系统输出小幅度的参考信号r(从而保证振动系统工作处于线性状态)，信号通过前置放大器、功率放大器等送到激震器动圈，并通过电磁感应产生振动，振动信号通过可控震源激震器反应块M〓和基板M〓上的加速度传感器反馈给伺服系统中的数据采集卡，工控计算机根据采集卡的反馈信息，获取当前激震器动圈的振动状态y〓，并实时地将该状态与内置的参考模型在当前参考输入r下的参考输出y〓进行辨识，再将两者输出误差e〓＝y〓-y〓对系统的有关控制参数进行调整，直至y〓→y〓，最后在经过某一固定的相位后，开始信号的正常扫描过程，与此同时，由可控震源系统的同步信号输出部件向地震仪送出一地震信号记录同步信号，进而完成扫描相位同步控制过程。

A CW carrier signal, generated by Agilent Signal Generator, is transmitted to the subject, which reflects the modulated waves to the receiver antenna. The Agilent Spectrum Analyzer, with an under-conversion module inside, demodulates the received signal to 70MHz IF signal, which is then sampled by a ADC module in Agilent Vector Signal Analyzer. Digital quadrature demodulation is used to convert IF signal to baseband. We could finally get the respiration and heartbeat signal by further analyzing the baseband signal.

该系统由信号发射器产生载波，通过天线发射到被测物体；频谱分析仪内置的下变频模块将由物体反射回来的信号下变频到70MHz中频；中频信号经矢量信号分析仪采样，然后经过数字正交解调变频到基带信号；对基带信号进行滤波、FFT等进一步的数字信号处理后即可获得探测的心跳和呼吸信号。

According to the statistic analysis of Prof. Amari on static recognition with neural networks, and introducing the concept of vector position stochastic variable of vector stochastic sequence, the stochastic variable is processed by DRNN. The relationship between input and output variance is analyzed. The stochastic analysis of dynamic identification is given, so as to explain the DRNN characteristics in recognition process.

第二，根据Amari教授对神经网络静态识别时的统计分析，引入矢量随机序列的矢量位置随机变量的概念，以该随机变量经过DRNN处理后，分析其输入与输出方差之间的关系，试给出了DRNN做动态识别时的统计分析，以从理论上说明DRNN在识别过程中的特性。

According to the Logistic Equation and the impact of stochastic factors, a stochastic nonlinear dynamical model had been presenred. The max Lyapunov exponent was calculated by Oseledec multiplicative ergodic theory, the local stability conditions had been obtained; the global stability conditions had also been obtained by judging the modality of the singular boundary; the stochastic Hopf bifurcation was analyzed using the invariant measure of stable probability density, and the condition of stochastic Hopf bifurcation had been discussed. The key parameter impacting the urban domestic water consumption had been found by numerical emulation.

根据Logistic阻滞增长模型原理，考虑到诸多随机因素的影响，本文建立了一个城市生活用水量的随机非线性模型，运用Oseledec乘性遍历定理计算了模型的最大Lyapunov指数，得到了局部稳定性的条件；通过对扩散边界性态的分析，得到了全局稳定性的条件；通过分析系统平稳状态概率密度的不变测度，得到了模型随机Hopf分岔的条件，结合实际进行了数值仿真，得到了影响用水量的关键参数。

Aim at the efficiency and precision of the stochastic FEM, two kind of new stochastic FEM are put forward and the correlative theories and methods are established: 1 The stochastic FEM based on Gauss integral method Establish the method of Stochastic FEM based on the Legendre integration.

本论文针对如何提高非线性结构随机有限元计算精度和效率，提出了两种新的随机有限元法，建立了相应的理论和方法，具体如下： 1、Gauss类积分随机有限元方法建立了基于Legendre积分的随机有限元方法。

Salt is good, but if the salt becomes flat and tasteless, with what do you season it?

14：33 盐本是好的，盐若失了味，可用什么叫它再咸呢？

He reiterated that the PLA is an army of the people under the leadership of the Communist Party of China.

他重申，人民解放军是在中国共产党领导下的人民军队。