Classification of 3-(24, 12, 5) Designs and 24-Dimensional Hadamard Matrices
Classification of 3-(24, 12, 5) Designs and 24-Dimensional Hadamard Matrices
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3-(24, 12, 5) 设计和 24 维 Hadamard 矩阵的分类
DOI:
10.1016/0097-3165(81)90054-6
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发表时间:
1981
期刊:
影响因子:
--
通讯作者:
J. Leon
中科院分区:
文献类型:
--
作者:
N. Ito;J. Leon
Recently the authors completed the classification of 3-(24, 12, 5) designs up to isomorphism. These designs are closely related to 24-dimensional Hadamard matrices, and the work on designs leads to a classification of the matrices up to equivalence. Hadamard matrices of lower dimension had been determined previously by Hall [2-41. This article described the techniques used in the classification and contains a summary of the results. It provides information from which each of the 129 designs and 59 matrices can be constructed, and it gives the order and orbit lengths of the automorphism group of each design and matrix. An explicit list of the matrices, together with generating permutations for their automorphism groups, may be found in [5]. The corresponding data for designs appear in 161. In general, a 3-(413.+ 4, 21+ 2, L) design D=(P, B) is called a Hadamard design (P and B denote the sets of points and blocks, respectively). In such a design the set of 8A+ 6 blocks is necessarily closed under complementation [7]; thus, if 6 denotes P-a, B consists of 4, l+ 3 block pairs 01*={a, C}, which we term parallel classes. For a E P, we let B, denote the set of blocks containing the point a.