一类不可约多项式的邻接矩阵

Dong和Pei在文[Construction for de Bruijn sequences with large stage,Des.Codes Cryptogr,2017,85(2):343-358]中利用F_2[x]的n次不可约多项式构造大级数de Bruijn序列.不可约多项式的邻接矩阵从理论上给出了这种方法能构造de Bruijn序列的数目.我们给出一类特殊不可约多项式的邻接矩阵,从理论上给出了用这类不可约多项式能够构造的de Bruijn序列的数目.     

产生 M 序列的一个递推算法

§1.引言M 序列又称 de Bruijn 序列,是一类具有最长周期的非线性移位寄存器序列。本文研究产生 M 序列的算法。早在70年代万哲先等对构造 M 序列的方法已有系统的研究。此后有一系列的文章研究 M 序列的构造问题。最近 Fredricksen 对这方面的工作给出了一个很好的综述。产生 M 序列的一个常用方法是先由一个较简单的移位寄存器产生许多短圈,再用并圈法将这些短圈合并起来构成 M 序列。如在[1,6]中就已给出过一些将 n 级纯轮换移位寄存器(简记为 PCK_n)和 n 级补轮换移位寄存器(简记为 CCR_n)产生的圈合并为 M 序列的方法。与[1—7]不同,Fredricksen 给出一个将 PCR_n 产生的圈合并为 M 序列的递推算法。最近 Etzion 和 Lempe 在 Fredricksen 算法的基础     

一类三次Pisot数的一些性质

本文研究了当q〉1为三次Pisot数，利用递归的方法构造一个无穷序列，通过对此序列，得到mR[q]∩Z[q]与此序列间和mR^-[q]与mR[q]∩Z[q]之间的一些关系．     

G2型2-Toroidal李代数的顶点表示

在[4]和[5]中已经研究了sim p ly-laced型T oro idal李代数的顶点表示,[6]文据此给出了Bl型T oro idal李代数顶点表示的构造.受[6]文启发,本文给出了G2型T oro idal李代数的顶点表示的构造,这种构造方式与D(41)的D ynk in图的顶点粘合和一个2上循环有着紧密联系.     

James空间的推广

R.H.Lohman和P.G.Casazza[2]就自反的、具有对称的块P——Hilbert基的Banach空间进行了讨论,给出了一阶次自反Banach空间的一种构造方法。本文在一类具有IS型基的Banach空间上进行了推广,并给出了构造一阶次自反空间的更一般性的方法。 以下记号S、的意义同[2],文中IS序列、ESA序列、SA序列及单调基、正规基的定义可见[2]、[3]。并总设E是Banach空间,{x_i}是E之IS型单调正规基。 一般的James空间定义类似[2],区别在于对于a=(a_i)∈S和我们定义:     

非线性常微分方程转向点问题的数值解

本文利用文[3]的技巧得到了具转向点的非线性常微分方程边值问题的导数估计,再结合文[4]的方法,证明了所构造的差分格式关于小参数ε的一致收敛性.我们给出了数值例子,数值结果与理论分析完全符合.     

广义Laplace—Stieltjes变换的收敛性

关于广义Dirichlet级数,余家荣[1]给出了类似于Valiron公式的收敛公式。在本文中,结合K.Knopp[4]和T.Kojima的方法,我们把这个结果推广到广义Laplace-Stieltj-es变换。 设L是一条可求长曲线,由一个有限的端点z_o延续到无穷远点。用L_z表示L上由z_o     

广义baby TKK代数一类boson表示

利用文[3]中的结论构造群代数与对称代数在文[4]的基础上给出了广义baby TKK代数G(~T)的一类boson场表示.     

M-带双正交矩阵值小波包

1预备文[1]研究了矩阵值小波,并介绍了离散矩阵值小波变换的应用,表明了研究矩阵值小波的重要性。文[2][3]研究了M-带小波包,文[4]研究了向量值正交小波包。本文在此基础上构造了M-带双正交矩阵值小波包,并研究了它的性质。     

加速方法数学建模的若干研究

介绍了利用可积系统理论研究加速计算方法的数学建模的一些最新工作。首先给出了向量形式的E-变换的一种推广,并构造了计算这个序列变换的数学模型。此外,给出了Pfaff式的一种具体定义,这样定义的Pfaff式可以应用于序列变换的表示。     

环Z2l上广义Bent函数的稳定性

文献「４」为研究密钥流序列的线性复杂度稳定性和使一些流密码能抗ＢＡＡ（最佳仿射逼近）攻击,提出Ｂｅｎｔ函数稳定性概念,文献「７」研究了素域Ｚｐ上广义Ｂｅｎｔ函数的稳定性及其构造,并指出当ｍ是合数时,ｍ值广义Ｂｅｎｔ函数并不都有稳定性,本文进一步在环Ｚ２＾ｌ（ｌ〉１）上提出了广义Ｂｅｎｔ函数稳定性的概念,综合应用谱、概率和代数数论的方法考察了稳定的概率意义,给出了稳定函数的概率判别条件,提供了构造稳     

Affine inequivalence of cubic Maiorana–McFarland type bent functions

We consider cubic Maiorana–McFarland type bent functions having no affine derivatives. By using an invariant proposed by Dillon in 1975 we identify subclasses of inequivalent bent functions within this class. These can also be identified by [4, Theorem B]. However, our technique involves only elementary derivations. We also include some computational results.     

Relation between o-equivalence and EA-equivalence for Niho bent functions

Boolean functions, and bent functions in particular, are considered up to so-called EA-equivalence, which is the most general known equivalence relation preserving bentness of functions. However, for a special type of bent functions, so-called Niho bent functions there is a more general equivalence relation called o-equivalence which is induced from the equivalence of o-polynomials. In the present work we study, for a given o-polynomial, a general construction which provides all possible o-equivalent Niho bent functions, and we considerably simplify it to a form which excludes EA-equivalent cases. That is, we identify all cases which can potentially lead to pairwise EA-inequivalent Niho bent functions derived from o-equivalence of any given Niho bent function. Furthermore, we determine all pairwise EA-inequivalent Niho bent functions arising from all known o-polynomials via o-equivalence.     

Relations between two perfect ternary sequence constructions

Both R. Games [4] and V.P. Ipatov [8] have given constructions for perfect ternary sequences. Games uses difference sets and quadrics in projective space, while Ipatov uses q-ary m-sequences. We show that the Ipatov sequences are a subset of the Games sequences. Further, we show that a conjecture of Games relating to quadrics in projective spaces does not hold in general.     

Analyses of subensembles ofM/G/1 queueing sequences

Although many queueing processes of various principles have extensively been investigated, little attention has been paid to the sampling aspect of the theory, by which the nature of sample sequences of finite or infinite length can be examined with respect to some given ensemble of queueing sequences. In this paper we wish to identify classes of sample sequences of an M/G/1 model and investigate several hitherto unknown properties of queueing phenomenon of a given particular service system over a finite or infinite length of time. The method to be used is an extension of both the method of imbedded Markow chains, cf. D. G. Kendall [4], and semi-Markovian processes, Smith [9], Lévy [5], Pyke[7,8], Fabens [2], Neuts [6], etc.     

On the <Emphasis Type="Italic">p</Emphasis>-ary (cubic) bent and plateaued (vectorial) functions

Plateaued functions play a significant role in cryptography, sequences for communications, and the related combinatorics and designs. Comparing to their importance, those functions have not been studied in detail in a general framework. Our motivation is to bring further results on the characterizations of bent and plateaued functions, and to introduce new tools which allow us firstly a better understanding of their structure and secondly to get methods for handling and designing such functions. We first characterize bent functions in terms of all even moments of the Walsh transform, and then plateaued (vectorial) functions in terms of the value distribution of the second-order derivatives. Moreover, we devote to cubic functions the characterization of plateaued functions in terms of the value distribution of the second-order derivatives, and hence this reveals non-existence of homogeneous cubic bent (and also (homogeneous) cubic plateaued for some cases) functions in odd characteristic. We use a rank notion which generalizes the rank notion of quadratic functions. This rank notion reveals new results about (homogeneous) cubic plateaued functions. Furthermore, we observe non-existence of a function whose absolute Walsh transform takes exactly 3 distinct values (one being zero). We finally provide a new class of functions whose absolute Walsh transform takes exactly 4 distinct values (one being zero).     

Finding nonnormal bent functions

The question if there exist nonnormal bent functions was an open question for several years. A Boolean function in n variables is called normal if there exists an affine subspace of dimension n/2 on which the function is constant. In this paper we give the first nonnormal bent function and even an example for a nonweakly normal bent function. These examples belong to a class of bent functions found in [J.F. Dillon, H. Dobbertin, New cyclic difference sets with Singer parameters, in: Finite Fields and Applications, to appear], namely the Kasami functions. We furthermore give a construction which extends these examples to higher dimensions. Additionally, we present a very efficient algorithm that was used to verify the nonnormality of these functions.     

A novel algorithm enumerating bent functions

Based on the relationship between the Walsh spectra of a Boolean function at partial points and the Walsh spectra of its subfunctions, and on the binary Möbius transform, a novel algorithm is developed, which can theoretically construct all bent functions. Practically we enumerate all bent functions in 6 variables. With the restriction on the algebraic normal form, the algorithm is also efficient in more variables case. For example, enumeration of all homogeneous bent functions of degree 3 in 8 variables can be done in one minute with a P4 1.7 GHz computer; the nonexistence of homogeneous bent functions in 10 variables of degree 4 is computationally proved.     

拟Bent函数的性质和构造

本文将基本2-群中拟Bent函数的概念推广到一般的有限Abel群中,统一了目前几乎所有的Bent函数概念,完全刻画了一类拟Bent函数和Bent函数的本质联系,给出了几种拟Bent函数的构造方法,拟Bent函数和相对差集的一种关系以及一种用拟Bent函数构造Bent函数的方法.最后,利用Galois环和组合集,找到一类拟Bent函数.     

Generalization and acceleration of an algorithm of Sebastião e Silva and its duals

Summary In this paper, we extend Householder's [4] generalization of an algorithm of Sebastião e Silva [11] by adding a new elimination rule for defining the sequences which converge to the factors of the given polynomial. We then present the dual algorithm and show that the dual algorithm becomes equivalent to the direct algorithm in the generalized form. Next, we give accelerated forms of these algorithms which are quadratically convergent. We also study the relation of these methods to other methods.