25 research outputs found
A Recursive Method for Determining the One-Dimensional Submodules of Laurent-Ore Modules
We present a method for determining the one-dimensional submodules of a
Laurent-Ore module. The method is based on a correspondence between
hyperexponential solutions of associated systems and one-dimensional
submodules. The hyperexponential solutions are computed recursively by solving
a sequence of first-order ordinary matrix equations. As the recursion proceeds,
the matrix equations will have constant coefficients with respect to the
operators that have been considered.Comment: To appear in the Proceedings of ISSAC 200
Three classes of new optimal cyclic locally recoverable codes
An -locally repairable code (-LRC for short) was
introduced by Prakash et al. for tolerating multiple failed nodes in
distributed storage systems, and has garnered significant interest among
researchers. An -LRC is called an optimal code if its parameters
achieve the Singleton-like bound. In this paper, we construct three classes of
-ary optimal cyclic -LRCs with new parameters by investigating
the defining sets of cyclic codes. Our results generalize the related work of
\cite{Chen2022,Qian2020}, and the obtained optimal cyclic -LRCs
have flexible parameters. A lot of numerical examples of optimal cyclic -LRCs are given to show that our constructions are capable of
generating new optimal cyclic -LRCs
Two classes of reducible cyclic codes with large minimum symbol-pair distances
The high-density data storage technology aims to design high-capacity storage
at a relatively low cost. In order to achieve this goal, symbol-pair codes were
proposed by Cassuto and Blaum \cite{CB10,CB11} to handle channels that output
pairs of overlapping symbols. Such a channel is called symbol-pair read
channel, which introduce new concept called symbol-pair weight and minimum
symbol-pair distance. In this paper, we consider the parameters of two classes
of reducible cyclic codes under the symbol-pair metric. Based on the theory of
cyclotomic numbers and Gaussian period over finite fields, we show the possible
symbol-pair weights of these codes. Their minimum symbol-pair distances are
twice the minimum Hamming distances under some conditions. Moreover, we obtain
some three symbol-pair weight codes and determine their symbol-pair weight
distribution. A class of MDS symbol-pair codes is also established. Among other
results, we determine the values of some generalized cyclotomic numbers
The Weight Hierarchies of Linear Codes from Simplicial Complexes
The study of the generalized Hamming weight of linear codes is a significant
research topic in coding theory as it conveys the structural information of the
codes and determines their performance in various applications. However,
determining the generalized Hamming weights of linear codes, especially the
weight hierarchy, is generally challenging. In this paper, we investigate the
generalized Hamming weights of a class of linear code \C over \bF_q, which
is constructed from defining sets. These defining sets are either special
simplicial complexes or their complements in \bF_q^m. We determine the
complete weight hierarchies of these codes by analyzing the maximum or minimum
intersection of certain simplicial complexes and all -dimensional subspaces
of \bF_q^m, where 1\leq r\leq {\rm dim}_{\bF_q}(\C)
A Family of -ary Binomial Bent Functions
For a prime with and an odd number
, the Bentness of the -ary binomial function is
characterized, where , a\in \bF_{p^n}^*, and b\in
\bF_{p^2}^*. The necessary and sufficient conditions of
being Bent are established respectively by an
exponential sum and two sequences related to and . For the
special case of , we further characterize the Bentness of the
ternary function by the Hamming weight of a sequence