Venerdì, 27 Maggio, 2016 - 11:00 to 16:00
Collana di seminari di Geometria ................................ Ore 11.00, aula Seminari (pal. RM004) Tao Feng (Beijing Jiaotong University, Cina) Cyclic Steiner quadruple systems and related topics Abstract: A Steiner system S(t,k,v) is a pair (X,B), where X is a set of v points and B is a set of k-subsets of X called blocks, such that every t-subset of X is contained in a unique block. An S(3,4,v) is called a Steiner quadruple system of order v, or briefly an Q(v). A cyclic Steiner quadruple system, briefly CSQS(v), is an SQS (X,B) of order v and with a cyclic group of automorphisms that acts regularly on X. This talk is to present a survey for the recent research on CSQSs including construction methods, enumerative results and applications to optical orthogonal codes. ........... Ore 12.00, aula Seminari Junling Zhou (Beijing Jiaotong University) Bounds and constructions of t-spontaneous emission error designs Abstract: The combinatorial aspects of quantum codes were demonstrated in the study of decay processes of certain quantum systems used in the newly emerging field of quantum computing. Among them, the configuration of t-spontaneous emission error design (t-SEED) was proposed to correct errors caused by quantum jumps. The number of designs (dimension) in a t-SEED corresponds to the number of orthogonal basis states in a quantum jump code. In this talk, the bounds on the dimension m of t-(v,k;m) SEEDs will be discussed, together with some combinatorial constructions for such designs. ........... Ore 15.00, aula 1B1 (pal. RM002) Daniel Horsley (Monasch University, Australia) Locating arrays and disjoint partitions Abstract: Locating arrays are combinatorial objects used for designing testing procedures that identify and locate faults. It turns out that the existence problem for a simple kind of locating array is equivalent to a natural question in extremal set theory concerning families of disjoint partitions. In this talk I will introduce locating arrays, discuss this equivalence, and outline a complete solution to the problem.