158views Education» more  DM 2011»
8 years 9 months ago
A survey of homogeneous structures
A relational first order structure is homogeneous if it is countable (possibly finite) and every isomorphism between finite substructures extends to an automorphism. This artic...
Dugald Macpherson
132views more  JSC 2010»
9 years 3 months ago
Binary codes from the line graph of the n-cube
We examine designs and binary codes associated with the line graph of the n-cube Qn, i.e. the Hamming graph H(n, 2). We find the automorphism groups and the parameters of the cod...
W. Fish, Jennifer D. Key, E. Mwambene
82views more  ORDER 2000»
9 years 5 months ago
Embeddings into Orthomodular Lattices with Given Centers, State Spaces and Automorphism Groups
We prove that, given a nontrivial Boolean algebra B, a compact convex set S and a group G, there is an orthomodular lattice L with the center isomorphic to B, the automorphism grou...
John Harding, Mirko Navara
96views more  COMBINATORICS 2000»
9 years 5 months ago
Automorphisms and Enumeration of Switching Classes of Tournaments
Two tournaments T1 and T2 on the same vertex set X are said to be switching equivalent if X has a subset Y such that T2 arises from T1 by switching all arcs between Y and its comp...
László Babai, Peter J. Cameron
94views more  IJAC 2007»
9 years 5 months ago
Automorphism Groups of Squares and of Free Algebras
We show that certain finite groups do not arise as the automorphism group of the square of a finite algebraic structure, nor as the automorphism group of a finite, 2-generated, ...
Keith A. Kearnes, Steven T. Tschantz
9 years 5 months ago
Consistent Cycles in Graphs and Digraphs
Let Γ be a finite digraph and let G be a subgroup of the automorphism group of Γ. A directed cycle C of Γ is called G-consistent whenever there is an element of G whose restri...
Stefko Miklavic, Primoz Potocnik, Steve Wilson
9 years 5 months ago
A new family of locally 5-arc transitive graphs
We present a new family of locally 5–arc transitive graphs. The graphs constructed are bipartite with valency {2m + 1, 2m}. The actions of the automorphism group on the two bipa...
Michael Giudici, Cai Heng Li, Cheryl E. Praeger
66views more  JCT 2006»
9 years 5 months ago
Rank 3 Latin square designs
A Latin square design whose automorphism group is transitive of rank at most 3 on points must come from the multiplication table of an elementary abelian p-group, for some prime p...
Alice Devillers, J. I. Hall
129views more  DM 2007»
9 years 5 months ago
3-Designs with block size 6 from PSL(2, q) and their large sets
We investigate the existence of 3-designs and uniform large sets of 3-designs with block size 6 admitting PSL(2, q) as an automorphism group. We show the existence of simple 3-(28...
G. R. Omidi, M. R. Pournaki, Behruz Tayfeh-Rezaie
74views more  COMBINATORICS 2007»
9 years 5 months ago
Bipartite-Uniform Hypermaps on the Sphere
A hypermap is (hypervertex-) bipartite if its hypervertices can be 2-coloured in such a way that “neighbouring” hypervertices have different colours. It is bipartiteuniform i...
Antonio Breda d'Azevedo, Rui Duarte