Let P = ({1, 2, . . . , n,≤) be a poset that is an union of disjoint chains of the same length and V = Fq be the space of N -tuples over the finite field Fq. Let Vi = F ki q , 1 ≤ i ≤ n, be a family of finitedimensional linear spaces such that k1 + k2 + . . . + kn = N and let V = V1⊕V2⊕ . . .⊕Vn endow with the poset block metric d(P,π) induced by the poset P and the partition π = (k1, k2, . . ....

We present an algorithm that, given a channel, determines if there is a distance for it such that the maximum likelihood decoder coincides with the minimum distance decoder. We also show that any metric, up to a decoding equivalence, can be isometrically embedded into the hypercube with the Hamming metric, and thus, in terms of decoding, the Hamming metric is universal. keywords: Coding Theory;...

The paper deals with the perfect 1-error correcting codes over a finite field with q elements (briefly q-ary 1-perfect codes). We show that the orthogonal code to the q-ary non-full-rank 1-perfect code of length n = (q − 1)/(q − 1) is a q-ary constant-weight code with Hamming weight equals to qm−1 where m is any natural number not less than two. We derive necessary and sufficient conditions for...

In this note we determine the second generalized Hamming weight of the dual codes of binary doubleerror correcting BCH-codes.

We derive new estimates of the size of codes and orthogonal arrays in the ordered Hamming space (the Niederreiter-Rosenbloom-Tsfasman space). We also show that the eigenvalues of the ordered Hamming scheme, the association scheme that describes the combinatorics of the space, are given by the multivariable Krawtchouk polynomials, and establish some of their properties.

We consider the question of determining the higher weights or the generalized Hamming weights of affine Grassmann codes and their duals. Several initial as well as terminal higher weights of affine Grassmann codes of an arbitrary level are determined explicitly. In the case of duals of these codes, we give a formula for many initial as well as terminal higher weights. As a special case, we obta...

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The authors introduce a penalized minimum distance regression estimator. They show the estimator to balance, among a sequence of nested models of increasing complexity, the L1–approximation error of each model class and a penalty term which reflects the richness of each model and serves as a upper bound for the estimation error. Une note concernant l’estimation par distance minimale pénalisée e...

We describe a two-party wire-tap channel of type II in the framework of almost affine codes. Its cryptological performance is related to some relative profiles of a pair of almost affine codes. These profiles are analogues of relative generalized Hamming weights in the linear case.