Building Error-Correcting-Codes from T-Designs and Graphs.

We present some combinatoric relations between two kinds of incidence structures like symmetric graphs and t-designs, and an algebraic structure as error-correcting-codes. Our goal is - using some fundamental properties of t-designs and graphs - to set some transformation to obtain or characterize families of codes. In the case of t-design we are interested in the quasisymmetric one, and in the case of the graph in the strongly-regular one.