作为信号的

Especially, the technology of Automatic Gain Control and signal processing are studied which are key factors working on the performance of the receiver. Based on analyzing the theory of automatic Gain Control, operational amplifiers 0P37 and logarithmic D/Aconverter AD7111A are used to design variable gain amplifiers which can be controlled numerally, A/D convector LTC1405 is Used to test the echo, Complex Programmable Logic device is used for controller, and an arithmetic is designed for automatic Gain Control which is simulated and analyzed in order to test its feasibility.

本文在分析自动增益控制AGC原理的基础上，采用集成运放OP37和数控增益衰减器AD7111A设计可数字控制的可变增益运放模块；采用高速A／D转换器LTC1405作为回波信号检测模块；采用复杂可编程逻辑器件CPLD作为核心控制模块，构成数字自动增益控制电路，并设计粗调和细调步进控制相结合的算法，对回波信号的增益进行精确而快速的调节控制，使回波信号振幅快速稳定在设计指标范围内，利于接收机后续信号处理电路对回波信号作进一步的处理。

The key function of lipid raft is to be a platform for cell signal.

脂筏的关键功能是它们能够作为信号的平台。

The singular value decomposition of wavelet transformation module maximum value matrix is proposed.

提出了基于小波变换模极大值矩阵奇异值分解的方法，用该方法获得的奇异值特征矢量作为信号的特征可以压缩特征维数，而且更容易进行计算机自动识别，同时还具有时间平移不变性的突出优点。

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。

A low frequency rolling bearing fault diagnosis method based on local projective noise reduction;2. According to characteristics of both the vibration signals and the stator currents when appering a fault in the rolling bearing of the induction motor,Park vector module signal of the three-phase current is calculated,and the envelope of vibration signals from the rolling bearing of the motor is analyzed.

根据感应电机轴承发生故障时的振动信号特性以及定子电流特性，求出三相电流的Park矢量模信号，并将其与电机滚动轴承振动信号经解调处理后的包络信号进行融合分析，可以从振动信号与电流信号的融合谱图中有效地提取轴承故障特征信息，并将其作为故障识别的依据。

Performance test shows that this telemetry system has reached the design requirement, and can be applied to study myocardial inotropism and chronotropism in mobile sites.

该系统由遥测发射机、遥测接收机、笔记本计算机等三部分组成，工作在433MHz免申请的开放频段，能同时测试10名受试者的心音信号；遥测发射机由受试者随身携带，每次发射一个心动周期的心音信号，并以心电信号的R波同步脉冲作为数据包的帧头标记，这样作为系统主机的笔记本计算机只需采用简单算法就能快速而准确地从接收到的遥测心音信号中提取研究心肌变力性和变时性所需的心力数据和心率数据，而无需遥测心电信号；遥测接收机通过专用的USB接口转换模块，实现了与笔记本计算机的USB口之间的高速数据传输，同时又无需额外的工作电源。

HMM is good at dealing with sequential inputs,while SVM shows superior performance in classification especially for limited samples.Therefore,they can be combined to get a better and effective multilayer architecture classifier.SVM is used to resolve the uncertainty of the remaining signal which is confusable after the HMM-based recognition.

针对战场环境下声信号的特点，算法综合考虑HMM适合处理连续动态信号及SVM小样本情况下的强分类能力，利用HMM处理待辨识的连续动态信号，将HMM易混淆的信号作为与待辨识信号较为相似的模式类，形成候选模式集，再由SVM在候选模式中对待辨识信号作最后决策。

As communicating madia is power line ,which needn't the extra line , and not take in the existing frepuncy resource.In the power system ,the power line is using steadily and reliable high press power line as the signal's trans madia,which may save a great deal of the building investment,in additional to the route is suitble ,scurity and may reuse the far away mobile signal ,of which makes this power system develop a particular communicating way ,while in number micro-wave,one point more address,optical fiber,super-high frequency repeatly renew today ,which also last developing.

由于电力线载波在电力系统中使用坚固可靠的高压电力线作为信号的传输媒介，可节省大量的通道建设投资，再加上电力线载波信息传输稳定可靠，路由合理，安全保密以及能够同时复用远动信号等特点，使得这种电力系统独有的通信方式在数字微波，一点多址，光纤，特高频等通信方式相继出现的今天仍得到持续的发展。

Objective Since the neurophysiological system is a highly nonlinear dynamic system,nonlinear dynamic information of EMG signals were extracted to describe its characteristics.

目的 由于运动神经系统本质上是一个高度非线性的动力学系统，尝试提取肌电信号的非线性动力学信息作为信号的特征。

Chapter 2 discusses the function of optimum array based on the minimum meansquared error principle in CDMA system, the method of produce the reference signal, and proved whether the reference signal is the correspond PN code sequence or respread signal, the result of the array's weight converge can converge the same optimum weight under the condition that the PN sequence in a bit of data is long enough. In this chapter, we finally get the beam pattern and the correlate bit error rate after converge when several CDMA signal arrives in different direction.

本文的主要贡献及创新之处是：首次从理论上探讨了基于最小均方误差准则的最优天线阵在CDMA系统中的多址干扰抑制性能及其参考信号的产生方法，证明了采用有用信号相应的扩频码作为参考信号与采用将解扩信息与扩频码进行重扩频后的信号作为参考信号来调节自适应天线的权值均可使权值收敛于同一最优解。

Neither the killing of Mr Zarqawi nor any breakthrough on the political front will stop the insurgency and the fratricidal murders in their tracks.

在对危险的南部地区访问时，他斥责什叶派民兵领导人对中央集权的挑衅行为。

In fact,I've got him on the satellite mobile right now.

实际上 我们已接通卫星可视电话了