排序方式: 共有20条查询结果,搜索用时 15 毫秒
1.
2.
3.
Designs, Codes and Cryptography - The problem of classifying linear systems of conics in projective planes dates back at least to Jordan, who classified pencils (one-dimensional systems) of conics... 相似文献
4.
In this paper, we study the p-ary linear code Ck(n,q), q=ph, p prime, h1, generated by the incidence matrix of points and k-dimensional spaces in PG(n,q). For kn/2, we link codewords of Ck(n,q)Ck(n,q) of weight smaller than 2qk to k-blocking sets. We first prove that such a k-blocking set is uniquely reducible to a minimal k-blocking set, and exclude all codewords arising from small linear k-blocking sets. For k<n/2, we present counterexamples to lemmas valid for kn/2. Next, we study the dual code of Ck(n,q) and present a lower bound on the weight of the codewords, hence extending the results of Sachar [H. Sachar, The Fp span of the incidence matrix of a finite projective plane, Geom. Dedicata 8 (1979) 407–415] to general dimension. 相似文献
5.
We show that if the number of directions not determined by a pointset
of
, of size q2 is at least pe q then every plane intersects
in 0 modulo pe+1 points and apply the result to ovoids of the generalised quadrangles
and
. 相似文献
6.
A (q+1)-fold blocking set of size (q+1)(q4+q2+1) in PG(2, q4) which is not the union of q+1 disjoint Baer subplanes, is constructed 相似文献
7.
Michel Lavrauw 《Designs, Codes and Cryptography》2013,68(1-3):205-227
In this article, we give an overview of the classification results in the theory of finite semifields (note that this is not intended as a survey of finite semifields including a complete state of the art (see also Remark 1.10)) and elaborate on the approach using nonsingular tensors based on Liebler (Geom Dedicata 11(4):455–464, 1981). 相似文献
8.
In this article we introduce the notion of the BEL-rank of a finite semifield, prove that it is an invariant for the isotopism classes, and give geometric and algebraic interpretations of this new invariant. Moreover, we describe an efficient method for calculating the BEL-rank, and present computational results for all known small semifields. 相似文献
9.
In [8] Dempwolff gives a construction of three classes of rank two semifields of order , with q and n odd, using Dembowski–Ostrom polynomials. The question whether these semifields are new, i.e. not isotopic to previous constructions, is left as an open problem. In this paper we solve this problem for , in particular we prove that two of these classes, labeled and , are new for , whereas presemifields in family are isotopic to Generalized Twisted Fields for each . 相似文献
10.
A scattered subspace of PG(n-1,q) with respect to a (t-1)-spread S is a subspace intersecting every spread element in at most a point. Upper and lower bounds for the dimension of a maximum scattered space are given. In the case of a normal spread new classes of two intersection sets with respect to hyperplanes in a projective space are obtained using scattered spaces. 相似文献