非马尔可夫随机Petri网模型的混合状态分析法

讨论具有发射时间任意分布之变迁的随机Petri网的解析问题.定义了随机Petri网 的混合状态和混合状态密度,提出混合状态分析法,并给出具有一步转移关系标识下的混合状 态密度的递推公式.使非马尔可夫型随机Petri网的分析成为可能.通过算例说明了混合状 态分析法在系统性能评估中的应用.     

基于布尔函数正规性的广义Bent函数构造

基于广义Bent函数的正规性,结合子空间上的特征函数,分析广义正规Bent函数的Chrestenson谱特征。利用间接构造Bent函数的方法,在整数模m的剩余类环Zm以及 元域Zp上,给出2类新的 元广义Bent函数。理论分析结果表明,与传统构造方法相比,该方法可构造出更多的 元广义Bent函数。     

A simple method of Walsh spectra multiplication

The paper presents a new easy method to obtain the product of the Walsh spectra of two functions. The method makes use of both the spectra of Walsh and block-pulse functions (b.p.f.s). The proposed method can be easily implemented with a digital computer. It will be very useful in the analysis and optimal control of time varying systems via Walsh functions.     

Sensitivity analysis of systems involving λ-variation via block-pulse functions

The problem of the sensitivity analysis of systems involving λ-variations may be treated by a new method based on the idea of solving the sensitivity equation of a system using orthogonal functions. Though the presented method is based on the set of block-pulse functions it can also be used for other sets of orthogonal functions. The approach can also be applied for solving other problems of a similar nature (inversion of Laplace transform involving Dirac impulses, analysis of singular perturbed systems etc.).     

可执行程序缺陷函数的静态检测方法

可执行程序的缺陷函数检测是软件漏洞发现的重要技术手段之一。从二进制代码指令流的角度出发,研究了缺陷函数的签名机制,提出了一种基于可执行程序静态分析的缺陷函数检测方法。该方法通过静态分析应用程序的可执行代码,建立进程运行过程中可能的函数调用序列集合。以该集合为基础,通过对比分析缺陷函数签名,可以准确检测该程序调用的缺陷函数集合,以及分析可能导致的脆弱性。通过实验分析,验证了该方法对于缺陷函数检测的有效性。     

An adaptive dimension decomposition and reselection method for reliability analysis

Recently, the research community in reliability analysis has seen a strong surge of interest in the dimension decomposition approach, which typically decomposes a multi-dimensional system response into a finite set of low-order component functions for more efficient reliability analysis. However, commonly used dimension decomposition methods suffer from two limitations. Firstly, it is often difficult or impractical to predetermine the decomposition level to achieve sufficient accuracy. Secondly, without an adaptive decomposition scheme, these methods may unnecessarily assign sample points to unimportant component functions. This paper presents an adaptive dimension decomposition and reselection (ADDR) method to resolve the difficulties of existing dimension decomposition methods for reliability analysis. The proposed method consists of three major components: (i) an adaptive dimension decomposition and reselection scheme to automatically detect the potentially important component functions and adaptively reselect the truly important ones, (ii) a test error indicator to quantify the importance of potentially important component functions for dimension reselection, and (iii) an integration of the newly developed asymmetric dimension-adaptive tensor-product (ADATP) method into the adaptive scheme to approximate the reselected component functions. The merits of the proposed method for reliability analysis are three-fold: (a) automatically detecting and adaptively representing important component functions, (b) greatly alleviating the curse of dimensionality, and (c) no need of response sensitivities. Several mathematical and engineering high-dimensional problems are used to demonstrate the effectiveness of the ADDR method.     

A step-by-step guide to non-linear regression analysis of experimental data using a Microsoft Excel spreadsheet

The objective of this present study was to introduce a simple, easily understood method for carrying out non-linear regression analysis based on user input functions. While it is relatively straightforward to fit data with simple functions such as linear or logarithmic functions, fitting data with more complicated non-linear functions is more difficult. Commercial specialist programmes are available that will carry out this analysis, but these programmes are expensive and are not intuitive to learn. An alternative method described here is to use the SOLVER function of the ubiquitous spreadsheet programme Microsoft Excel, which employs an iterative least squares fitting routine to produce the optimal goodness of fit between data and function. The intent of this paper is to lead the reader through an easily understood step-by-step guide to implementing this method, which can be applied to any function in the form y=f(x), and is well suited to fast, reliable analysis of data in all fields of biology.     

A meshless method for solving mKdV equation

A meshless method based on a global collocation with radial basis functions for the numerical solution of the modified Korteweg–de Vries (mKdV) equation is presented. Standard types of radial basis functions are applied in the method of collocation. The stability analysis of the method is dealt with using a linearized stability analysis. The method?s accuracy and efficiency are examined by the simulation of a single soliton and interaction of two solitary waves. The four invariants of the motion are evaluated to determine the conservation properties of the method. A comparison with some earlier reported results is also carried out.     

基于CFG的函数调用关系静态分析方法

函数调用关系能够反映软件系统中函数间的依赖关系,完整的函数调用关系可以更好地辅助程序验证和死锁分析,提升验证和分析的完备性.现有静态分析函数调用关系的方法不能准确分析函数指针和虚函数的调用,影响了其分析结果的准确性.针对这一问题本文提出了一种基于控制流图(Control Flow Graph, CFG)的函数调用关系静态分析方法,该方法首先使用GCC插件静态获取源代码中的类型和函数CFG等信息并构建分析路径,然后采用本文提出的模拟仿真算法分析程序中的语句,并解析函数指针和虚函数的调用,最后基于分析结果生成完整的函数调用关系.实验结果表明,该方法能够很好地支持对函数指针和虚函数的处理,提升了分析结果的准确性.     

System reliability analysis with saddlepoint approximation

System reliability is usually estimated through component reliability, which is commonly computed by the First Order Reliability Method (FORM). The FORM is computationally efficient, but may not be accurate for nonlinear limit-state functions. An alternative system reliability analysis method is proposed based on saddlepoint approximation. Unlike the FORM that linearizes limit-state functions in a transformed random space, the proposed method linearizes the limited-state functions without any transformation. After the linearization, the joint probability density of limit-state functions is estimated by the multivariate saddlepoint approximation. Without the nonnormal-to-normal transformation, the present method is more accurate than the FORM when the transformation increases the nonlinearity of limit-state functions. As demonstrated in the two examples, the new method is also as efficient as the FORM.     

基于TEMU的进程间通信过程逆向

传统的逆向分析方法在分析多进程架构软件时具有较多难以克服的困难, 针对这个问题提出了基于TEMU的进程间通信过程逆向方法。利用动态二进制分析平台TEMU记录多进程程序函数调用信息, 结合进程间通信函数的关联规则从函数调用信息中提取进程间通信的通信方法、通信数据和通信协作机制。根据该方法设计并实现了一个原型系统, 对多款多进程架构软件进行测试, 测试结果表明, 该方法能够准确提取多进程架构软件的进程间通信过程, 对多进程架构软件逆向起到了很大的辅助作用。     

Comparison of numerical methods in stability analysis†

The results of a numerical investigation of a number of techniques for stability analysis of non-linear systems are presented. The methods compared are the Ingwerson and Zubov procedures for construction of Liapounov functions, a number of methods for obtaining optimum Liapounov functions, tracking functions, the alternating extreme radius path, and the method of Luus and Lapidus.     

C语言中函数编写方法的分析与探讨

函数是C语言学习的难点和重点,通过分析函数的结构,将函数编写中难以确定的问题进行分解、细化。按照返回值的个数将函数分为:无返回值函数、单反回值函数、多返回值函数三种类型。对这三种类型函数的设计方法分别举例分析和说明,详细阐述了函数编写的具体过程。     

An Algorithm for Finding Recurrence Relations of Binomial Sums and its Complexity

A new algorithm to find recurrence relations of binomial sums and a complexity analysis are given. The algorithm is based on the theory of hypergeometric functions and algorithmic method to get contiguity relations of hyperegeometric functions.     

基于最大信息理论和共轭梯度寻优的ICA算法

独立分量分析是一种将观测向量分解为若干个独立统计的分量的一种统计学方法。提出了一种新的独立分量分析方法,该方法在最大信息理论的基础上引入目标函数,并利用共轭梯度搜索算法替代自然梯度算法,推导出用于训练转换矩阵的学习方程。运用核密度函数估算方法自适应地估算学习方程中包含的评价函数项。仿真结果表明,提出的基于独立分量分析的共轭梯度算法在求解盲源分离问题中切实有效。     

无模型控制方法控制功能的分析研究

无模型控制方法具有一系列良好的控制功能,从控制律的适应能力、收敛性能、抗干扰性能、解耦性能及克服大时滞的性能等5个方面分析了无模型控制方法的控制功能.把经典的PID调节器作为基本的比较对象,采用仿真比较和理论分析相结合的方法进行比较研究.分析与比较结果表明,无模型控制方法具有一系列良好的控制功能,即适应性功能、收敛性能、抗干扰、解耦功能及克服大时滞功能.     

计算最终线性秩函数的新方法

程序的终止性分析作为程序验证中重要的一环,在软件正确性验证中极为重要。对于一个线性循环程序,若该程序没有传统定义的线性秩函数,则基于传统定义的秩函数终止性分析方法失效。2013年,Bagnara提出了最终线性秩函数(Eventual Linear Ranking Functions)的定义,并证明了若某个程序存在最终线性秩函数,则该程序终止。由此,提出了新的方法来计算最终线性秩函数,构造了存在线性增函数和最终线性秩函数的等价半代数系统,并使用Mathematica工具对半代数系统进行求解,对比分析了各种最终秩函数求解方法的实际计算时间,结果证实了所提方法的优越性。     

A scene graph based visualization method for representing continuous simulation data

This paper proposes a scene graph based visualization method that can verify time-varying continuous analysis simulation in a virtual reality (VR) environment by using the computer-aided engineering (CAE) data of structural analysis in product development. In previous research, the use of CAE analysis data has been problematic because of the lack of any interactive simulation controls for visualizing continuous simulation data. Moreover, the research on post-processing methods for real-time evaluation of CAE analysis data has not been sufficient. We therefore propose a scene graph based visualization method for representing continuous simulation data. The method can continuously visualize static analysis data independently of any timeline; it can also continuously visualize dynamic analysis data that varies in relation to the timeline. The visualization system for continuous simulation data, which includes CAE2VR Middleware that interfaces with various formats of CAE analysis data as well as functions for visualizing continuous simulation data and operational functions, enables users to verify simulation results with more realistic scenes.     

基于plateaued函数的平衡布尔函数构造

布尔函数在对称密码的设计和分析中起着重要的作用。通过对谱不相交函数集中子函数平衡性的问题的研究给出了包含4个plateaued函数的函数集中有3个为平衡函数的充分条件。在此基础上,基于3个平衡的谱不相交plateaued函数,一类特殊的布尔置换以及一个高非线性度平衡函数,提出了一个构造高非线性度平衡布尔函数的方法。通过分析可知,利用该方法可以构造代数次数达到最优、非线性度不小于2^2k-1-2^k-1-2^k/2-2^{⌈(k-1)/2⌉}的2k元平衡函数。     

六维鼠标中力矩与转角转换的一种新方法

提出一种六维鼠标中矩与转换角转换的新方法，不但简化了RPY角计算方法中的繁琐过程，而且不需用任何三角、反三角，开方等这些对单片 机来非常耗时的复杂数学运算，大大缩减了计算量，提高了整个鼠标系统的快速性，因此该算法更便于单片机使用。误差分析表明在很宽的转角变化范围之内，用该方法得计算结果和RPY方法得到的计算结果之间存在很小的误差，而这种微量误差对于鼠标操作的系统来讲是完全可以接受的，运动学控制实验证明了该方法的可行性。