
AbstractA t-design T=(X, B), denoted by (λ; t, k, v), is a system B of subsets of size k from a v-set X, such that each t-subset of X is contained in exactly λ elements of B. A hypergraph H=(Y, E) is a finite set Y where E=(Ei: iϵI) is a family of subsets (which we assume here are distinct) of Y such that Ei≠Ø, iϵl, and ⋃Ei=Y. Let G be an automorphism group of H=(Y, E) where Oli is the ith orbit of l-subsets of E. Let A(G; H; t, k)= (aij) be an m by n matrix, where aij is the number of copies of Oti that occur in the system of all t-subsets of all elements of Okj. Then there is a t-design T=(X, B) with X=E, with parameters (λ; t, k, v), and with G an automorphism groupof T iff there is an m by s submatrix M of A(G; H; t, k) where M has uniform row sums λ. The calculus for applying this theorem is illustrated and numerous t-designs for 10⩽v⩽16 are found and presented. Using a theorem of Alltop on our (12; 4, 6, 13) and (60; 4, 7, 15) we obtain a (12; 5, 7, 14) and a (60; 5, 8, 16).
Graph theory, Discrete Mathematics and Combinatorics, Other designs, configurations, Graphs and abstract algebra (groups, rings, fields, etc.), Theoretical Computer Science
Graph theory, Discrete Mathematics and Combinatorics, Other designs, configurations, Graphs and abstract algebra (groups, rings, fields, etc.), Theoretical Computer Science
| citations This is an alternative to the "Influence" indicator, which also reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically). | 120 | |
| popularity This indicator reflects the "current" impact/attention (the "hype") of an article in the research community at large, based on the underlying citation network. | Top 10% | |
| influence This indicator reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically). | Top 1% | |
| impulse This indicator reflects the initial momentum of an article directly after its publication, based on the underlying citation network. | Average |
