A graph Γ is said to be locally (G, 2)-arc transitive for G a subgroup of Aut(Γ) if, for any vertex α of Γ, G is transitive on the 2-arcs of Γ starting at α. In this talk, we will discuss general… (More)

A near-polygonal graph is a graph Γ which has a set C of m-cycles for some positive integer m such that each 2-path of Γ is contained in exactly one cycle in C. If m is the girth of Γ , then the… (More)

A partial difference set S in a finite group G such that S = S−1 and 1 / ∈ S corresponds to an undirected strongly regular Cayley graph Cay(G, S). Very few examples of PDSs are known, and there are… (More)

In a User-Private Information Retrieval (UPIR) scheme, a set of users collaborate to retrieve files from a database without revealing to observers which participant in the scheme requested the file.… (More)

(2001): Cytotoxic effect of three arsenic compounds in HeLa human tumor and bacterial cells. (1999): Successful treatment with arsenic trioxide of a patient with ATRA-resistant relapse of acute… (More)

In this paper we introduce a set of sufficient criteria for the construction of relative hemisystems of the Hermitian space H(3, q2), unifying all known infinite families. We use these conditions to… (More)

A set of proper subgroups is a covering for a group if its union is the whole group. The minimal number of subgroups needed to cover G is called the covering number of G, denoted by σ(G). Determining… (More)