随机信号

However, with the development of electronic counterwork, thetransmission security of conventional spread-spectrum communication with fixedPseudo-Noise codes has been threatened.

然而，现在使用的扩频序列都是基本固定的伪随机序列，它的周期性和确定性与信息论对信号波形的要求相抵触，而且它可能被窃听者复制，使信息的安全性受到威胁。

The optimized weight is arrived by weighted the minimum variance distortionless response weights of these samples with their post probabilities. In addition, the samples with little post probabilities will be resampled and it improves the robustness of beamforming effectively.

在该算法中期望信号的波达方向被看成一个由若干样点组成的随机变量，利用后验概率对这些样点的最小畸变响应波束成形权值进行加权来取得优化的权值，并对小概率样点进行重采样，有效地提高了波束成形系统的鲁棒性。

Material and Methods:From March,2008 to January,2009,250 patients(146 Males and 104 Females,ranged from 18 to 82 years old,mean age was 48 years old) enrolled in the First Affiliated Hospital of Kunming Medical College were performed dual energy scan(Group A,200 patients) and Neuro-DSA scan(Group B,50 patients) using DSCT.The patients were randomly divided into Group A and Group B.Regarding to the justification of scan protocol,100 patients in Group A were selected as sub-group to explore the scan protocol.The image quality Was analyzed both in four categories(4.0/60、4.5/60、4.0/70、4.5/70) of flow rate and total amount of contrast-enhanced material and in three categories(100—150HU、150—200HU、200-250HU) of CT value of left common carotid artery.The comparison of two scan approach was based on image quality,radiation does, postprocessing methods,time of scanning and subtraction and data storage amount.To validate the diagnostic capability of DE-CTA virtual unenhanced images,100 patients in Group A were undergoing head scan both in routine non-contrast program and DE-CTA virtual unenhanced program.Mean CT values,signal-to-noise ratio,image quality,sensitivity of lesion identification,and radiation does were applied to comparison.According to diagnostic results of dual energy of cerebral arterial angiography,62 patients out of 200 patients in Group A were confirmed with cerebral vessel lesions,the results were complied with DSA findings(the time between the two methods were within 1 week).

材料与方法收集2008年3月到2009年1月间在昆明医学院第一附属医院行DSCT CTA检查者250例(男性146例，女性104例，年龄范围18-82岁，平均48岁)，随机分为A、B两组，A组200例行双能量头颅CTA扫描；B组50例行Neuro-DSA扫描。A组前100例按对比剂不同流率和总量分为4组(4.0/60、4.5/60、4.0/70、4.5/70)对图像质量比较；按触发时左颈总动脉内平均CT位分3组(100—150HU、150—200HU、200-250HU)，比较图像质量的差异；对A、B两组血管图像质量、辐射剂量、后处理的方法、扫描和后处理时间及数据的容量进行比较分析；A组中前100例行常规与DE-CTA虚拟平扫的平均CT值、信号噪声比、图像质量、病灶显示情况、辐射剂量的比较分析；A组中行DSA检查62例(两种方法间隔时间均1周内)，比较两种检查方法诊断结果是否符合，并对其中24例动脉瘤行动脉瘤部位、数目、形态、瘤颈显示程度、瘤颈大小及瘤体长径和短径的比较研究。

From estimation theory, the input and output signals can be modeled as stochastic process.

从估计理论，输入和输出信号可视为随机过程。

All the facts make it necessary to study the estimation theory for nonlinear systems with multiplicative noise.

本文在这两个研究方向的基础上，研究了带乘性噪声非线性离散随机系统的信号估计算法。

Random segments of code that have grouped together...

随机的信号序列组合在一起

Based on the summarizing of the exiting algorithms of the texture mapping and antialiasing, this paper goes deeply into the basic theory and processing of texture mapping. The texture compress algorithm which can satisfy the need of the memory and time is given for the stochastic sampling in the inverse texture mapping; the geometry transformation in the texture mapping are discussed and the concepts of the unitary parametrization and the patch parametrization is proposed, some kinds of the unitary parametrization methods of parametric surfaces and the geometry transformation in the patch parametrization are also presented; in order to solve the aliasing in the parametrization of intermediate surface-sphere in two-part texture mapping, an area-preserving transformation is presented also; to improve the quality of the graph the aliasing in the texture mapping is analyzed from the aspect of signal process, and the modified summed-area tables algorithms is proposed; the distortion of the scanline conversion algorithms under perspective transformation is analyzed and the proper interpolation algorithm is presented so the aliasing problem of the polyhedral object after the unitary parametrization is efficiently solved.

本文在总结现有的纹理映射和反走样算法的基础上，深入研究了纹理映射的基本原理与过程，根据反向纹理映射对纹理随机采样的特殊要求，提出了一种可满足存储空间和寻址时间的纹理压缩存储算法；通过对纹理映射中几何变换理论的进一步深入探讨，提出了整体参数化和面片参数化的概念，并给出了参数化曲面的各种整体参数化方法和面片参数化的几何变换形式；针对现有的两步映射算法所存在的中间曲面—球面的参数化问题，提出一种等积映射方法，较好地实现了由非参数化面片拼接而成的多面体表面的纹理映射；从信号采样的角度深入分析了纹理映射中走样产生的原因，提出了改进的区域求和表算法，使图形生成的效果有所提高；还分析了一般的扫描线算法在透视变换中所存在的问题，提出了一种正确的插值算法，从而解决了整体参数化后多面体表面纹理映射的几何变形问题。

To overcome the bulky , inflexibility of traditional analog d ither system,a new solution for ring laser gyroˉ scope was designed with field programmable gate array.T he digital dither control method was given and dither characteristics were analyzed by square wave driving signal s.

针对传统机抖激光陀螺模拟偏频系统体积大、难于控制的缺点，设计了一种基于 FPGA的全数字抖动控制方案，提出了数字抖动控制原理，分析了数字方波驱动信号的性能，实现了伪随机噪声的生成和注入。

This method uses periodic sequences of different magnitudes as inputs to extract a linear subsystem so that the set theory, parameter estimation, optimization, pole zero separation, can be applied.

该方法巧妙利用不同幅值的伪随机输入信号，从原系统中离析出线性子系统。基于线性子系统的参数估计值和集合理论，提出一个零极点划分的寻优准则。

The interpolation error is not detected directly by instruments of high accuracy but evaluated by errors of Lissajous figure, and reference instruments and time consuming comparisons are avoided in this method.

这种间接评定方法适用于含有五种误差形式的光栅信号，即高次谐波、非正交误差、不等幅误差、直流电平漂移和随机误差。

The labia have now been sutured together almost completely.The drains and the Foley catheter come out at the top.

此刻阴唇已经几乎完全的缝在一起了，排除多余淤血体液的管子和Foley导管从顶端冒出来。

To get the business done, I suggest we split the difference in price.

为了做成这笔生意，我建议我们在价格上大家各让一半。