Perpendicular Dissections of Space

For each pair (Q _i ,Q _j ) of reference points and each real number r there is a unique hyperplane h \perp Q _i Q _j such that d(P,Q _i ) ² - d(P,Q _j ) ² = r for points P in h . Take n reference points in d -space and for each pair (Q _i ,Q _j ) a finite set of real numbers. The corresponding perpendiculars form an arrangement of hyperplanes. We explore the structure of the semilattice of intersections of the hyperplanes for generic reference points. The main theorem is that there is a real, additive gain graph (this is a graph with an additive real number associated invertibly to each edge) whose set of balanced flats has the same structure as the intersection semilattice. We examine the requirements for genericity, which are related to behavior at infinity but remain mysterious; also, variations in the construction rules for perpendiculars. We investigate several particular arrangements with a view to finding the exact numbers of faces of each dimension. The prototype, the arrangement of all perpendicular bisectors, was studied by Good and Tideman, motivated by a geometric voting theory. Most of our particular examples are suggested by extensions of that theory in which voters exercise finer discrimination. Throughout, we propose many research problems. Received July 20, 2000, and in revised form September 29, 2001, and October 12, 2001. Online publication March 4, 2002.     

On maximal subalgebras and a generalized Jordan–Hölder theorem for Lie algebras

The purpose of this paper is to continue the study of chief factors of a Lie algebra and to prove a further strengthening of the Jordan–Hölder theorem for chief series.     

Primitive symmetric designs with up to 2500 points

By this article we conclude the construction of all primitive ( v, k,λ ) symmetric designs with v < 2500 , up to a few unsolved cases. Complementary to the designs with prime power number of points published previously, here we give 55 primitive symmetric designs with v ≠ p ^m , p prime and m positive integer, together with the analysis of their full automorphism groups. The research involves programming and wide‐range computations. We make use of the software package GAP and the library of primitive groups which it contains. © 2011 Wiley Periodicals, Inc. J Combin Designs 19:463‐474, 2011     

On a motivic interpretation of primitive,variable and fixed cohomology

If M is a smooth projective variety whose motive is Kimura finite‐dimensional and for which the standard Lefschetz Conjecture B holds, then the motive of M splits off a primitive motive whose cohomology is the primitive cohomology. Under the same hypotheses on M, let X be a smooth complete intersection of ample divisors within M. Then the motive of X is the sum of a variable and a fixed motive inducing the corresponding splitting in cohomology. I also give variants with group actions.     

有限域的原根在剩余理论中的应用

研究了p是正奇素数的情况下,有限域的原根在剩余理论中的应用．利用有限域Fp上原根的性质,给出了一类集合与平方剩余之间的关系,获得了这类集合所包含元素个数之间的关系,并且这个结论把关于这方面的结果从r=0推广到了r=0和2．     

围长为2的本原无限布尔方阵类的本原指数集

研究了围长为2的无限布尔方阵的本原性,通过无限有向图D（A）的直径给出了这类矩阵的本原指数的上确界,最后证明了直径小于等于d且围长为2的本原无限布尔方阵所构成的矩阵类的本原指数集为Ed^0={2,3,…,3d}．     

基于毕达哥拉斯犹豫模糊距离测度的灰关联双向投影决策法

为解决多属性决策单方向偏差难题所提出的灰关联投影法尚存在适用性差的技术不足。为此,在借鉴双向投影技术要点的基础上联合新型灰关联系数,并引入毕达哥拉斯犹豫模糊集的表达优势,提出基于毕达哥拉斯犹豫模糊距离测度的灰关联双向投影决策方法。新方法能够有效解决毕达哥拉斯犹豫模糊多属性决策问题,具有较高的分辨度。通过算例应用分析,直接验证了毕达哥拉斯犹豫模糊灰关联双向投影方法的实用性,间接验证了毕达哥拉斯犹豫模糊距离测度和灰关联双向投影法的有效性。     

钝头机体用嵌入式大气数据传感系统的 改进三点式算法1)

针对传统的用于钝头体飞行器的嵌入式大气数据传感系统的经典三点式算法对测压孔配置约束性严格的特点,对经典三点式算法进行了改进及验证。首先,对于经典三点式算法及改进算法进行了论述;其次,针对不同测压孔配置对算法精度的影响进行了系统的评估;最后,对于传统的经典三点式算法与改进三点式算法的优劣进行了比较。结论为：(1)改进的三点式算法对于测压孔的配置敏感性变差,即对测压孔约束很宽松,可用测压孔数增加,从而使得算法的适用性更强;(2)改进的三点式算法的精度与三点式算法相当,但是需要对测压孔进行系统选取及对比验证。     

ON THE 3D VISCOUS PRIMITIVE EQUATIONS OF THE LARGE-SCALE ATMOSPHERE

This paper is devoted to considering the three-dimensional viscous primitive equations of the large-scale atmosphere. First, we prove the global well-posedness for the primitive equations with weaker initial data than that in [11]. Second, we obtain the existence of smooth solutions to the equations. Moreover, we obtain the compact global attractor in V for the dynamical system generated by the primitive equations of large-scale atmosphere, which improves the result of [11].     

r－不可分矩阵的本原指数（Ⅱ）

本文给出了 n阶 r-不可分矩阵的本原指数的上界 ,即任 n阶 r—不可分矩阵 A的本原指数 (A)≤n+(r- ) 2r (1≤ r相似文献