Nonorientable biembeddings of cyclic Steiner triple systems generated by Skolem sequences

We give a characterization of a current assignment on the bipartite Mobius ladder graph with 2n+1 rungs. Such an assignment yields an index one current graph with current group Z"1"2"n"+"7 that generates an orientable face 2-colorable triangular ...

We construct a family of recursive constructions such that for any i { 0 , 1 , 3 , 4 , 6 , 7 , 9 , 10 } and j { 0 , 1 , , 11 } , several arbitrary nonorientable triangular embeddings of every complete graph K m , m i ( mod 12 ) , can be incorporated ...

The automorphism group of the Steiner triple system of order v ≡ 3 (mod 6), obtained from the Bose construction using any Abelian Group G of order 2s + 1, is determined. The main result is that if G is not isomorphic to Z₃ⁿ × Z₉^m, n ≥ 0, m ≥ 0, the full ...