Some Notes on the Linear Complexity of Sidel’nikov-Lempel-Cohn-Eastman Sequences

We continue the study of the linear complexity of binary sequences, independently introduced by Sidel’nikov and Lempel, Cohn, and Eastman. These investigations were originated by Helleseth and Yang and extended by Kyureghyan and Pott. We determine the exact linear complexity of several families of these sequences using well-known results on cyclotomic numbers. Moreover, we prove a general lower bound on the linear complexity profile for all of these sequences.     

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].     

非交换陈特征的一个注记

此注记利用Moscovici的一个想法和热核渐近展开技术,给出了Clifford模 上Dirac算子的整循环陈特征的一个计算公式.     

关于Camina条件

Ａ．Ｒ．Ｃａｍｉｎａ曾研究过Ｆｒｏｂｅｎｉｕｓ群的一种类似．为此，他提出了两个假设并证明了这两个假设是等价的，在这篇文章中，我们提出比Ｃａｍｉｎａ假设弱且适合特征标表的两个假设，并证明我们的两个假设是等价的，然后，我们建立对这两个新假设而言最基本的情形的若干结果，这个最基本的情形被证明正好是有一个不可约特征标恰在两个共轭类上取非零值的群。     

Bounding the Fitting height of a solvable group by the number of zeros in a character table

In this paper, we bound the Fitting height of a solvable group by the number of zeros in a character table.

     

Noether环的几点注记

本文利用特征模给出了Ｎｏｅｔｈｅｒ环的一些充分必要条件，并由此讨论了Ｎｏｅｔｈｅｒ环上的内射模与平坦模的一些性质     

模糊综合评判在哈萨克文点阵库中的应用

哈萨克文的每个字母分四种字体，用于句子的不同位置，当用计算机处理哈文信息时，每个字母间靠近程度是模糊的。本文提出一种用模糊综合评判法来评价字库，且提出改进方案的方法。     

偶氮基染料掺杂薄膜的双光子图象存储

研究了偶氮基染料掺杂薄膜ＭＯ－ＰＶＡ和ＥＯ－ＰＶＡ的双光子存储特性。在对薄膜用Ａｒ＾＋激光作预激发下实现了Ｈｅ－Ｎｅ激光的红光存储。获得了实时和短时存储照片。光电记录存储曲线，分析了双光四能级系统的存储机制。实现确定了最佳预激发功率约为０．２８Ｗ／ｃｍ＾２，最小Ｈｅ－Ｎｅ光可存储功率密度低于０．２Ｗ／ｃｍ＾２。     

Fitting Height and Character Degree Graphs

Given a group G, Γ(G) is the graph whose vertices are the primes that divide the degree of some irreducible character and two vertices p and q are joined by an edge if pq divides the degree of some irreducible character of G. By a definition of Lewis, a graph Γ has bounded Fitting height if the Fitting height of any solvable group G with Γ(G)=Γ is bounded (in terms of Γ). In this note, we prove that there exists a universal constant C such that if Γ has bounded Fitting height and Γ(G)=Γ then h(G)≤C. This solves a problem raised by Lewis. Research supported by the Spanish Ministerio de Educación y Ciencia, MTM2004-06067-C02-01 and MTM2004-04665, the FEDER and Programa Ramón y Cajal.