A note on the perturbation of an outer inverse

In this note, we present an explicit formula for perturbations of an outer inverse under certain conditions, which extends previous results. The second author was supported by the National Natural Science Foundation of China under grant 10871051 and the Shanghai Education Committee under grant 08511501703.     

A note on weak operator precedence grammars

Precedence grammars, operator precedence relations, Wirth–Weber precedence relations, parsing     

A note on Cauer's first form realization by integrators

A technique for the realization of Cauer's first form of continued fraction expansion using integrators is presented in this note. The proposed method gives accurate results on analogue computer simulation when compared with the other methods which use a combination of differentiators and integrators. In this approach the system matrices in the state-space formulation can be written directly from the partial quotients.     

结合扰动约束的低感知性对抗样本生成方法

目的 对抗样本是指在原始数据中添加细微干扰使深度模型输出错误结果的合成数据。视觉感知性和攻击成功率是评价对抗样本的两个关键指标。当前大多数对抗样本研究侧重于提升算法的攻击成功率,对视觉感知性的关注较少。为此,本文提出了一种低感知性对抗样本生成算法,构造的对抗样本在保证较高攻击成功率的情况下具有更低的视觉感知性。方法 提出在黑盒条件下通过约束对抗扰动的面积与空间分布以降低对抗样本视觉感知性的方法。利用卷积网络提取图像中对输出结果影响较大的关键区域作为约束,限定扰动的位置。之后结合带有自注意力机制的生成对抗网络在关键区域添加扰动,最终生成具有低感知性的对抗样本。结果 在3种公开分类数据集上与多种典型攻击方法进行比较,包括7种白盒算法FGSM(fast gradient sign method)、BIM(basic iterative method)、DeepFool、PerC-C&W(perceptual color distance C&W)、JSMA (Jacobian-based saliency map attacks)、APGD (auto projected g...     

A note on fractional-order derivatives of periodic functions

In this paper, it is shown that the fractional-order derivatives of a periodic function with a specific period cannot be a periodic function with the same period. The fractional-order derivative considered here can be obtained based on each of the well-known definitions Grunwald-Letnikov definition, Riemann-Liouville definition and Caputo definition. This concluded point confirms the result of a recently published work proving the non-existence of periodic solutions in a class of fractional-order models. Also, based on this point it can be easily proved the absence of periodic responses in a wider class of fractional-order models. Finally, some examples are presented to show the applicability of the paper achievements in the solution analysis of fractional-order systems.     

A note on the asymmetric part of an outranking relation

This paper discusses the properties of the asymmetric part of an outranking relation built as in ELECTRE. Such relations have been used in the pseudodisjunctive version of ELECTRE TRI‐B. We show that they have properties that are somewhat different from that of outranking relations. Indeed, contrary to outranking relations, they allow to have at the same time veto and bonus effects. We suggest that this explains the difficulty in analyzing the properties of the pseudodisjunctive version of ELECTRE TRI‐B and the complexity of the elicitation methods of its parameters. We present conditions that characterize such relations.     

A numerical algorithm for singular perturbation problems exhibiting weak boundary layers

A class of singularly perturbed two-point boundary-value problems (BVP) for second-order ordinary differential equations is considered here. To avoid the numerical difficulties in the solution to these problems, we divide the domain into two subdomains. The first BVP is a layer domain problem and the second BVP is a regular domain problem. Error estimates are derived for the numerical solution. Numerical examples are provided in support of the proposed method.     

时滞扰动Lorenz系统及其同步电路实现

以Lorenz系统为模型,构造一个具有多个正的Lyapunov指数的四维时滞混沌系统,分析了其基本动力学行为,并利用滤波网络技术对新系统进行了可切换电路设计.然后,基于Lyapunov方法给出了两个相同高维时滞系统的耦合同步条件,根据所提出的同步方法设计了自同步控制电路.实验表明了该时滞系统具有丰富的动力学行为,所设计的同步控制电路结构简单,易于实现,能够通过调节部分元件参数获得较好的同步性能.     

A note on thue systems with a single defining relation

A combinatorial characterization is given for those one-rule Thue systems of the form {(w ₁,w ₂)} with 0 |w ₂||ov(w ₁)| that are Church-Rosser. Here ov(w ₁) denotes the longest proper self-overlap ofw ₁. Further, it is shown that a Thue system of this form is Church-Rosser if and only if there is an equivalent Thue system that is Church-Rosser.This research was supported in part by the National Science Foundation under Grant No. MCS83-14977. It was performed while the first author was visiting the Department of Mathematics of the University of California at Santa Barbara.     

A note on special thue systems with a single defining relation

It is shown that a Thue system of the formT ₁ = {(w,e)} is Church-Rosser if and only if there is a Thue systemT ₂ that is Church-Rosser and is equivalent toT ₁.     

基于弱信任关系的可证实签名算法

弱信任关系下的指定的可证实数字签名,以参与的实体仅存在半信任关系为假定,要求签名数据产生与验证的分离性和排它性,证据的零知识性以及证据的防伪和不可转移等.提出了一个基于RSA公钥加密体系的可证实数字签名算法,给出了基于非形式化模型和Camenisch-Michels模型的验证过程,证明了该算法的安全性等价于RSA加解密的安全强度.     

A note on the connection between Bezier curves and linear optimal control

We show that Bezier curves can in fact be thought of as the solutions to linear optimal control problems, using results from Hermite interpolation in combination with traditional linear optimal control. This provides us with a computational view of Bezier curves that differs from the standard DeCasteljau Algorithm, and it furthermore points out the close relationship between Bezier curves and interpolating dynamic splines.     

A relation between the Hilbert and Vandermonde matrices

A relation is established between two famous matrices and two simple applications are proposed. We first study the asymptotic behaviour of the spectral condition number of a Vandermonde matrix with a particular configuration of points. We then apply our relation to the problem of the computation of the Christoffel number starting from the moments of the weight function; we show that the relative asymptotic condition number of the problem is essentially the Turing condition number of the Hilbert matrix as observed numerically by other authors in the past.     

A note on some differences between real and complex stability radii

Real and complex stability radii measure the robustness of stable linear systems under real and complex parameter perturbations, respectively. In this note we point out some basic differences between them. In particular, we investigate their different behaviour with respect to system interconnections and changes in system data.     

材料力学微应变信号检测系统设计与实现

材料力学应变测量实验中,试件在小负荷作用下所产生的应变信号十分微弱。根据微弱应变信号的特征,采用微弱信号检测原理设计出信号调理方案并对应变信号进行处理,在此基础上设计出微应变数据采集与处理系统。     

ADS7843与ATmega64通讯的设计和实现

以触摸屏为特征的嵌入式系统逐渐渗透到现代社会各个领域.本文以一个将实际应用于舰艇武器装备上的手持检测设备为例阐述如何用触摸屏及其相应控制器构成触摸屏输入系统.在系统设计中,触摸屏采用四线电阻式触摸屏,触摸屏控制器采用ADS7843控制芯片,微控制器采用ATmega64微处理器.在给出硬件连接的基础上提出基于ATmega64微处理器SPI传送的应用系统软件实现.     

A note on communicating between information systems based on including degrees

In order to study the communication between information systems, Gong and Xiao (2010, International journal of general systems, 39, 189–206) proposed the concept of general relation mappings based on including degrees. Some properties and the extension for fuzzy information systems of the general relation mappings have been investigated there. In this paper, we point out by counterexamples that several assertions (Lemmas 3.1 and 3.2, Theorems 4.1 and 4.3) in the aforementioned work are not true in general.     

A controller perturbation technique for transferring closed-loop stability between systems

This brief paper presents a perturbation technique with which a controller stabilizing one plant may be modified so that it stabilizes a second, related plant. The proposed technique produces an internally stable loop for a broad class of linear systems without requiring any further calculations on the part of the designer. Four seemingly different examples are described in terms of this result.