Associating a numerical semigroup to the triangle-free configurations
Klara Stokes Maria Bras-Amorós
Advances in Mathematics of Communications 2011, 5(2): 351-371 doi: 10.3934/amc.2011.5.351
It is proved that a numerical semigroup can be associated to the triangle-free $(r,k)$-configurations, and some results on existence are deduced. For example it is proved that for any $r,k\geq 2$ there exists infinitely many $(r,k)$-configurations. Most proofs are given from a graph theoretical point of view, in the sense that the configurations are represented by their incidence graphs. An application to private information retrieval is described.
keywords: combinatorial configuration numerical semigroup. Block design girth partial linear space
Duality for some families of correction capability optimized evaluation codes
Maria Bras-Amorós Michael E. O'Sullivan
Advances in Mathematics of Communications 2008, 2(1): 15-33 doi: 10.3934/amc.2008.2.15
Improvements to code dimension of evaluation codes, while maintaining a fixed decoding radius, were discovered by Feng and Rao, 1995, and nicely described in terms of an order function by Høholdt, van Lint, Pellikaan, 1998. In an earlier work, 2006, we considered a different improvement, based on the observation that the decoding algorithm corrects an error vector based not so much on the weight of the vector but rather the ''footprint'' of the error locations. In both cases one can find minimal sets of parity checks defining the codes by means of the order function. In this paper we show that these minimal sets have a very useful closure property. For several important families of codes that we consider, this property allows us to construct a generating matrix for the code that has properties amenable to encoding. The generating matrix can be constructed by evaluating monomials in a set which also has the closure property.
keywords: dual code. toric code Reed-Muller code Hermitian code Algebraic-geometry code

Year of publication

Related Authors

Related Keywords

[Back to Top]