强非线性系统符号分析的两种新结果

本文讨论一大类非线性系统的谐波振荡。文中根据等效小参量法的原理分别导出了主振荡为单谐波和双谐波的两种通用的二阶近似方程。在此基础上，介绍了一种迭代算法和一种图解法。这两种方法基于符号分析，精确度较高，适用于强非线性系统。像通常的解析法，这种迭代算法也有助于掌握非线性振荡的机理。图解法则可以用来确定多解系统的全部周期解。     

Symbolic Determinant Decision Diagrams and Their Use for Symbolic Modeling of Linear Analog Integrated Circuits

An efficient technique for the symbolic modeling of the frequency behavior of a linearized analog circuit is presented. It uses a compact graph representation based on the Laplace expansion of the system determinant, called determinant decision diagram or DDD. The construction of a circuit's DDD is explained and an analysis of the time and space complexity is given. These DDD's can be used in behavioral modeling by representing the exact numerical transfer function in a compact way. DDD's also enable the generation of symbolic transfer functions, resulting in a symbolic analysis technique with lower computational complexity than techniques not based on DDD's.     

Approximate Symbolic Analysis of Hierarchically Decomposed Analog Circuits

This paper presents a methodology for the symbolic analysis of large analog integrated circuits using a hierarchical approach. The drawbacks of previous approaches are solved by the introduction of error-controlled approximation strategies. A proper modeling methodology through the different hierarchical levels allows to combine the optimum techniques for generation of the symbolic expressions and the most efficient numerical techniques for error control. These approximation strategies together with mechanisms for partitioning and union of blocks through the hierarchy yield optimum results in terms of speed, accuracy and complexity of the symbolic results.     

非线性时变RLC电路的计算机辅助分析

本文导出非线性时变ＲＬＣ关于梯形算法和牛顿－拉夫逊算法的模型，提出一种便于用计算机对非线性时变ＲＬＣ电路进行瞬态分析的新方法，并介绍一个基于这种方法设计的计算机程序。     

Matlab符号运算在电路分析中的应用

目前采用仿真软件来分析电路时,一般在已知电路参数的情况下求数值解,或者得到电路仿真后的动态响应波形。而在电路的分析计算中,有时往往希望得到电路中待求量的解析解,方便进一步数学推导和理论分析计算。本文利用Matlab强大的符号处理能力进行电路的符号运算,并得到电路的解析表达式,为电路分析提供了一个有效的辅助手段。     

非线性时变互感的瞬态电路模型

基于电路理论和数值积分的原理，导出了非线性时变互感关于Ｂａｃｋｗａｒｄ Ｅｕｌｅｒ和Ｎｅｗｔｏｎ－Ｒａｐｈｓｏｎ算法的瞬态电路模型，将文献［１］中提出的非线性时变ＲＬＣ电路瞬态分析的方法推广到含非线性时变互感的情况，使非线性时变ＲＬＣＭ电路的瞬态分析简化为若干线性时不变电阻性电路的直流分析。     

Combining GAs and Symbolic Methods for High Quality Tests of Sequential Circuits

A symbolic fault simulator is integrated in a Genetic Algorithm (GA) environment to perform Automatic Test Pattern Generation (ATPG) for synchronous sequential circuits. In a two phase algorithm test length and fault coverage as well are optimized. Furthermore, not only the Single Observation Time Test Strategy is supported, but also test patterns with respect to the Multiple Observation Time Test Strategy are generated. However, there are circuits that are hard to test using random pattern sequences, even if these sequences are genetically optimized. Thus, deterministic aspects are included in the GA environment to improve fault coverage. Experiments demonstrate that both a priori time consuming strategies, the symbolic simulation approach and the GA, can be combined at reasonable costs: Tests with higher fault coverages and considerably shorter test sequences than previously presented approaches are obtained.     

非线性电阻电路分段线性分解拟合及仿真

在电路分析中,以经典电路理论探讨非线性电阻电路的问题。针对某些可以分段线性化的非线性电阻电路,当以曲线形式给出非线性电路的伏安特性时,探讨在凹电阻和凸电阻作基本积木块的方式下,依据电路KVL和KCL定律,运用串联分解法和并联分解法,分解拟合出满足分段线性要求的非线性电阻电路。通过对案例的仿真研究和误差分析,论证此方法在分析非线性电阻电路分段线性时,能比较方便地逆向解决以电路的伏安特性曲线完成实际电路的设计问题。     

GaAs MESFET微波非线性电路全频域谐波平衡分析

根据Fourier分析理论推导了全频域分析微波非线性电路的方法,此方法简单明了,适合于分析微波大信号强非线性电路.用此方法对GaAs MESFET微波非线性电路进行分析,给出了实用的分析计算结果.     

非线性跟踪微分器稳态性能分析及仿真研究

针对非线性跟踪微分器无法实现对所有输入信号的无差跟踪问题,研究3种不同形式跟踪微分器的稳态性能.通过分析抑制函数的特性和典型输入情况下系统的稳态误差,确定其适用范围,并对推论结果进行验证.仿真实验表明,非线性跟踪微分器为一阶无差系统,只能实现对阶跃输入信号的无差跟踪.     

General Stability Analysis of Periodic Steady-State Regimes in Nonlinear Microwave Circuits

The problem of analyzing the stability of periodic equilibrium regimes in nonlinear microwave circuits is tackled by a general-purpose computer-aided approach. By means of a perturbation technique, the search for instabilities is reduced to a generalized eigenvalue equation expressed in matrix form, and is then carried out by Nyquist's analysis. The use of a vector processor allows the computer time requirements to be kept well within reasonable limits, even in the case of large-size problems. In perspective, this could open the way to the complementation of existing nonlinear CAD packages by an on-line facility for automatic stability analysis.     

基于空间特征的非线性电路神经网络诊断

本文提出线性模拟电路的单、双、三故障空间特征,采用分段线性模型（PWL）将非线性电路线性化,通过遗传算法求电路的容羞范围,用神经网络对非线性嘲络进行诊断。本文的方法大火减少了模拟计算量,同时,使神经网络的训练过程加快,训练误差减少,并大大提高了诊断的正确率。     

SC电路混合分析的一种方法

本文提出了ＳＣ电路混合分析的一种方法，此法特别适合于计算机辅助电路分析，并且所推导的ＳＣ电路混合议程与状态议程有着紧密的联系，由此可方便地求得ＳＣ电路的频域传递函数。     

A Wavelet-Based Approach for Steady-State Analysis of Nonlinear Circuits With Widely Separated Time Scales

We propose a new wavelet method for steady-state analysis of nonlinear circuits. The new method inherits the robustness of wavelet-based technique in handling very strong nonlinear circuits while offering significant reduction of simulation costs for circuits with widely separated time scales     

微波非线性电路全频域谐波平衡分析

本文提出了有关全频域谐波平衡方程的牛顿－拉夫逊迭代求解的一种改进方法。     

非线性动态系统的宏观信息熵分析

本文针对一类以Ｉｔｏ型微积分方程所描述的随机非线性动态系统，分别基于微观Ｆ－Ｐ方程和宏观信息熵方法推断系统特性，进而分析系统的熵结构。结果表明，宏观方法不仅能获得与微观方法相似的结论，而且能以统一的方式处理各类系统。通过对一类非线性系统的应用进一步说明宏观信息熵分析方法。最后讨论了最小熵参数优化问题     

Symbolic Model Checking and Analysis for E-Commerce Protocol

The widely use of networks and e-commerce has brought great convenience to our daily life. The basis of normal e-commerce transaction between the seller and customers is the secure e-commerce protocols which must also include the two important properties, namely, non-repudiation and fairness, in addition to those basic properties such as secrecy, security, authentication and integrity[1]. So there are special and higher demands of the performance and function of the e-commerce protocol. To att…     

符号仿真在电路教学中的应用

介绍了符号运算语言的特点,并利用MATLAB的符号运算功能编写一MATLAB程序“Circuit.m”,通过节点列表法,实现了任意线性电路的自动解析求解,为电路分析及电路教学提供了一个有效的辅助工具。另外,该电路符号仿真软件的电路描述文件采用了与PSPICE一致的格式,故易于为广大电路分析及电路教学工作者所接受。     

一类高阶非线性动态系统周期解的逆算符表达

基于等效小参数法基本思想,应用分解法原理,通过引入逆算符和选择合适的线性与非线性算子,建立了一类非线性动态系统周期解的逆算符表达的递推算法,并利用Mathematica计算机代数语言开发出相应的软件系统,实现了该算法的计算机自动求解。利用该软件系统,可方便快速地求出周期解的解析表达式。文中给出了计算实例,并将算法所得结果与四阶Runge—Kutta数值方法的计算结果作了比较。理论和实例计算结果表明,该软件系统通用性强、精度高,是进行某类非线性动太民电路分析和计算的有力工具。