GR(4,m)上本原序列最高权位的密码特征

刻划了特征为4的Galois环上本原序列最高权位序列的相关函数、线性度和元素分布等密码特征。     

环Z／（m）上两种序列综合算法之间的关系

有限域Fq上单条序列的综合算法有著名的Berlkamp-Massey算法(简记B-M算法)，Reeds和Sipane(1985)将这一算法推广到整数同余类环Z／(m)上．作者曾利用推广的Gr6bner基理论，蛤出了环Z／(m)上单条及多条序列的新的综合算法，简称G-算法．本文讨论这两种序列综合算法之间的关系，并证明了G-算法和B-M算法对域上序列的综合是等价的；对环Z／(m)上的序列，通过对G-算法适当改进，可以顺序得到由推广的B-M算法求得的特征多项式．     

环Z/(2~e)上压缩序列的0,1分布

本文研究环 Z/( 2 e)上本原序列最高权位的 0 ,1分布 ,证明了当 e≥ 8,次数 n≥2 0时 ,本原序列 a的最高权位序列 ae- 1 在一个周期中 0 (或 1 )所占的比例λ( ae- 1 )满足 43.6 76 8 <λ( ae- 1 ) <5 6 .32 32     

Z/(2e)上本原最高权位序列的随机性质

本文研究环Z/（2e）上本原序列最高权位的0,1分布,证明了当e≥16,次数n≥20时,本原序列a的最高权位序列a_（e-1）在一个周期中0（或1）所占的比例λ（a_（e-1））满足45.2306％<λ（a_（e-1））<54.7694％.     

环Z／（2^e）上压缩序列的0,1分布

本文研究环Ｚ／（２＾ｅ）上本原序列最高权位的０,１分布,证明了当ｅ≥８,次数ｎ≥２０时,本的序列ａ的最高权位序列ａｅ－１在一个周期中０（或１）所占的比例λ（ａｅ－１）满足４３．６７６８％〈λ（ａｅ－１）〈５６．３２３２％。     

环Z/(pe)上本原权位序列0元素分布的保熵性(Ⅱ)

设Re=Z/(3e)为整数模3e剩余类环, e≥2.环风Re上序列a有唯一的权位分解 ,其中ai是{0,1,2}上序列.称ai为a的第i权位序列,ae-1为a的最高权位序列.它们可自然视为Z/(3)上序列.设f(x)是Re上本原多项式,a和b是Re上由f(x)生成的序列,a≠0(mod3e-1),本文证明了最高权位序列 的0元素分布包含原序列a的所有信息,即,对所有非负整数t,若ae-1(t)=0当且仅当be-1(t)=0,则a=b.并由此得到: (i)两条不同的本原权位序列是线性无关的; (ii)任给正整数k,函数 是保熵函数,即对由f(x)生成的序列a和b,a=b当且仅当 (mod3).     

伽罗瓦环上的一类No序列的构造

近年来,伽罗瓦环上的序列理论成为人们研究的热点问题.有限域上的No序列是一类伪随机序列,它在序列密码中占具十分重要的角色.本文利用伽罗瓦环上的置换,构造了伽罗瓦环Z_(p~e)上的一类新的No序列,并且研究了其线性复杂度.研究的结果表明此类No序列具有相当大的线性复杂度.     

Galois环上极大周期序列的平移等价

本文给出了Galois环上两个具有相同特征多项式的极大周期序列是否平移等价的—个判定方法,以及在两个序列平移等价的情况下,利用模p方幂提升技术,给出了—个计算它们的平移距离的方法.     

斜环上酉Lie代数的Fermion表示

假设σ为一个任意Abel群上的特征,以及R_σ为对应于特征σ的斜Laurent多项式环.本文构造了坐标代数为Rσ的Allison-Faulkner型酉Lie代数的Fermion表示,并确定了该表示的不可约分支.     

环Z/(2e)上本原序列最高权位的0,1分布

研究环Z/(2^e)上本原序列的最高权位序列a_e-1的0,1分布问题,给出了序列a_e-1在1个周期中0,1个数的比值的上下界,并显示出当e越大时,a_e-1的0,1个数的比值越接近1。     

GR(4,r)上本原序列的元素分布

本文利用GR（4，r)上本原序列的迹表示及二次型的有关结论，给出了本原序列的第一权位序列的元素分布，同时求得本原序列的元素分布。     

Zpe上本原序列的元素分布

文研究了Zpe上本原序列的元素分布.利用Ga,lois环上的指数和估计和本原序列的迹表示,得到了Zpe中各元素在本原序列的一个周期中出现频率的一个估计.当n＞4e时(n为本原序列生成多项式的次数).我们的估计优于Kuzmin的结果[1].     

Zpe上本原序列的元素分布

文研究了Z_p^e上本原序列的元素分布。利用Galois环上的指数和估计和本原序列的迹表示,得到了Z_p^e中各元素在本原序列的一个周期中出现频率的一个估计。当n>4e时(n为本原序列生成多项式的次数),我们的估计优于Kuzmin的结果。     

0,1 distribution in the highest level sequences of primitive sequences over Z_(2~e)

In this paper, we discuss the 0,1 distribution in the highest level sequence αe-1 of primitive sequence over Z2e generated by a primitive polynomial of degree n. First we get an estimate of the 0,1 distribution by using the estimates of exponential sums over Galois rings, which is tight for e relatively small to n. We also get an estimate which is suitable for e relatively large to n. Combining the two bounds, we obtain an estimate depending only on n, which shows that the larger n is, the closer to 1/2 the proportion of 1 will be.     

0,1 distribution in the highest level sequences of primitive sequences over<Emphasis Type="Italic">Z</Emphasis><Subscript>2e</Subscript>

In this paper, we discuss the 0,1 distribution in the highest level sequence a_e-1 of primitive sequence over Z_2e generated by a primitive polynomial of degreen. First we get an estimate of the 0,1 distribution by using the estimates of exponential sums over Galois rings, which is tight fore relatively small ton. We also get an estimate which is suitable fore relatively large ton. Combining the two bounds, we obtain an estimate depending only onn, which shows that the largern is, the closer to 1/2 the proportion of 1 will be.     

环Z/(p~e)上本原序列压缩映射的新结果

令Z/(pe)表示整数剩余类环,其中p为素数且e 2为正整数.令f(x)表示Z/(pe)上的n次本原多项式,G′(f(x),pe)表示Z/(pe)上所有由f(x)生成的本原序列构成的集合.设序列a∈G′(f(x),pe),它有唯一的p进制展开a=a0+a1p+···+ae-1pe-1.令φ(x0,x1,...,xe-1)=g(xe-1)+μ(x0,x1,...,xe-2)表示由Fe p到Fp的一个e变元多项式.那么,φ可以诱导出一个从G′(f(x),pe)到F∞p的压缩映射.在p为奇素数且f(x)为强本原多项式的条件下,人们已经证明该压缩映射是保熵的.而本文证明该压缩映射在f(x)为本原多项式的条件下仍然是保熵的.当deg(g(x))2时,我们还要求deg(g(x))为奇数,或者g(x)=xk+∑k-2i=0cixi.     

Quasi-median hulls in Hamming space are Steiner hulls

A Hamming space Λⁿ consists of all sequences of length n over an alphabet Λ and is endowed with the Hamming distance. In particular, any set of aligned DNA sequences of fixed length constitutes a subspace of a Hamming space with respect to mismatch distance. The quasi-median operation returns for any three sequences u,v,w the sequence which in each coordinate attains either the majority coordinate from u,v,w or else (in the case of a tie) the coordinate of the first entry, u; for a subset of Λⁿ the iterative application of this operation stabilizes in its quasi-median hull. We show that for every finite tree interconnecting a given subset X of Λⁿ there exists a shortest realization within Λⁿ for which all interior nodes belong to the quasi-median hull of X. Hence the quasi-median hull serves as a Steiner hull for the Steiner problem in Hamming space.     

Admissible sequences and the preprojective component of a quiver

This paper concerns indecomposable preprojective modules over the path algebra of a finite connected quiver without oriented cycles. For each such module, an explicit formula in terms of the geometry of the quiver gives a unique, up to a certain equivalence, shortest (+)-admissible sequence such that the corresponding composition of reflection functors annihilates the module. An efficient way to compute the module is to recover it from its shortest (+)-admissible sequence. The set of equivalence classes of the above sequences has a natural structure of a partially ordered set. For a large class of quivers, the Hasse diagram of the partially ordered set is isomorphic to the preprojective component of the Auslander-Reiten quiver. The techniques of (+)-admissible sequences yield a new result about slices in the preprojective component.     

The 0 ,1 - Distribution of the First CoordinateSequences Derived from ML- Sequences over Z/(2~e)

§1.　IntroductionThereseachindetailonlinearrecurringsequencesovertheresideclassringZ/(pe)start-edfromWardworkin30s(see[1]).Inthepastfewyears,fromthepointofviewofcrypto-graphandcodetheory,peopleisinterestedparticularlyinstudyingthecoordinatesequencesde-rivedfromML-sequencesoverZ/(pe),asnon-linearrecurringsequencesoverFp(see[2],[3]).SomeanalogousresultsextendedtoGaliosringcanbefoundin[4],[5].Butthereisnobetterresultontheresearchofthe0,1-distributionproperties.Fromavastamountofcalcula-tion,t…