The valuations of the near hexagons related to the Witt designs S(5,6,12) and S(5,8,24)

Valuations of dense near polygons were introduced in 16 . In the present paper, we classify all valuations of the near hexagons ??₁ and ??₂, which are related to the respective Witt designs S(5,6,12) and S(5,8,24). Using these classifications, we prove that if a dense near polygon S contains a hex H isomorphic to ??₁ or ??₂, then H is classical in S. We will use this result to determine all dense near octagons that contain a hex isomorphic to ??₁ or ??₂. As a by‐product, we obtain a purely geometrical proof for the nonexistence of regular near 2d‐gons, d ≥ 4, whose parameters s, t, t_i (0 ≤ i ≤ d) satisfy (s, t₂, t₃) = (2, 1, 11) or (2, 2, 14). The nonexistence of these regular near polygons can also be shown with the aid of eigenvalue techniques. © 2005 Wiley Periodicals, Inc. J Combin Designs 14: 214–228, 2006     

The Regular Near Polygons of Order (s, 2)

In this note we classify the regular near polygons of order (s, 2).     

Bounding the size of near hexagons with lines of size 3

We consider finite near hexagons with lines of size 3, and prove that there are only finitely many examples given the nondegeneracy condition that for each point there exists a point at distance 3 to it. © 2006 Wiley Periodicals, Inc. J Graph Theory 52: 108–122, 2006     

The structure of near polygons with quads

We develop a structure theory for near polygons with quads. Main results are the existence of sub 2j-gons for 2?j?d and the nonexistence of regular sporadic 2d-gons for d?4 with s>1 and t ₂>1 and t ₃≠t ₂(t ₂+1).     

On additively completely regular seminearrings

In an attempt to investigate the situation arising out of replacing additive regularity by additive complete regularity in our previous study on additively regular seminearrings, we introduce the notions of left (right) completely regular seminearrings and characterize left (right) completely regular seminearrings as bi-semilattices of left (resp., right) completely simple seminearrings. We also define left (right) Clifford seminearrings and show that they are precisely bi-semilattices of near-rings (resp., zero-symmetric near-rings).     

一类(a+1,3)型的距离正则图

设Γ是直径为d且型为(α 1,3)的距离正则图,其中α≥2.用l(c,a,b)表示交叉阵列l(Γ)中列(c,a,b)~t的个数,记r=r(Γ)=l(c_1,a_1,b_1),s=s(Γ)=l(c_(r 1),a(r 1),b_(r 1)).那末,若c_(r 1)=3且a_(r 1)=3a,则d=r s 1,c_d=4且Γ为正则拟2d边形.     

On the Finiteness of Near Polygons with 3 Points on Every Line

Let S be a near polygon of order (s, t) with quads through every two points at distance 2. The near polygon S is called semifinite if exactly one of s and t is finite. We show that S cannot be semifinite if s = 2 and derive upper bounds for t.     

Structure of regular solutions of Faddeev equations near the pair impact point

We study the two-and three-dimensional Faddeev equations for a three-particle system with central or S-wave pair interactions. The regular solutions of such equations are represented as infinite series in integer powers of the distance between two particles and the sought functions of the other three-particle coordinates. Constructing such functions reduces to solving algebraic recurrence relations. We derive the boundary conditions at the pair impact point for the regular solutions of the Faddeev equations. __________ Translated from Teoreticheskaya i Matematicheskaya Fizika, Vol. 156, No. 1, pp. 112–130, July, 2008.     

The Distance-2-Sets of the Slim Dense Near Hexagons

We determine all distance-2-sets and all valuations of the 11 slim dense near hexagons. We consider this as a necessary step in order to classify all slim dense near octagons. These near octagons will be classified in a forthcoming paper. Received November 29, 2004     

A classification of some regular p-groups and its applications

In this paper we classify regular p-groups with type invariants (e, 1,1,1) for e≥2 and (1,1,1,1,1). As a by-product, we give a new approach to the classification of groups of order p5, p ≥ 5 a prime.     

The regular points of simple functions

We extend the work of Ioffe and Lewis [A. Ioffe and A. Lewis, Critical points of simple functions, Optimization, 57 (2008), pp. 3–16] and relate it to the previous work of Morse [M. Morse, Topologically non-degenerate functions in a compact n-manifold, J. Anal. Math. 7 (1959), p. 243]. We show that the concept of regularity for piecewise linear functions can be explained in geometric topological terms and this explanation leads to a unified view of several concepts of regularity for such functions.     

考虑晶粒几何形状的尺度效应

复合材料方法中的混合律方法在研究纳米晶体材料力学性能时得到了广泛的使用,准确得出各相的体积分数对该方法结果的准确性具有十分重要的影响．将纳米晶体看成由晶界、晶粒和三叉晶三相组成的复合材料,根据晶粒具有多面体的几何特点,用二维的三相复合的正多边形模型来研究纳米晶体力学性能的尺度效应,对于不同几何形状的晶粒采用对应的正多边形模型,这样我们就可以更加准确地得到各相的体积分数,从而更好地预测纳米晶体材料的力学性能．     

关于子基的正则空间和相对正则性

给出了关于子基的正则空间和相对正则性概念,研究了各种正则性之间的关系,证明了各种正则空间的充要条件,丰富了一般拓扑学中的正则空间和相对正则性理论．     

The topology of the spaces of regular and absolutely regular Hankel‐transformable distributions

New topologies on the spaces of regular and absolutely regular Hankel‐transformable distributions are proposed and compared. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Extensions of regular polytopes with preassigned Schläfli symbol

We say that a (d+1)-polytope P is an extension of a polytope K if the facets or the vertex figures of P are isomorphic to K. The Schläfli symbol of any regular extension of a regular polytope is determined except for its first or last entry. For any regular polytope K we construct regular extensions with any even number as first entry of the Schläfli symbol. These extensions are lattices if K is a lattice. Moreover, using the so-called CPR graphs we provide a more general way of constructing extensions of polytopes.     

The Riesz decomposition property for the space of regular operators

If and are Banach lattices such that is separable and has the countable interpolation property, then the space of all continuous regular operators has the Riesz decomposition property. This result is a positive answer to a conjecture posed by A. W. Wickstead.