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On the Construction of Codes from an Asymptotically Good Tower over F8

Caleb McKinley, Shor (2007)

Serdica Journal of Computing

In 2002, van der Geer and van der Vlugt gave explicit equations for an asymptotically good tower of curves over the field F8. In this paper, we will present a method for constructing Goppa codes from these curves as well as explicit constructions for the third level of the tower. The approach is to find an associated plane curve for each curve in the tower and then to use the algorithms of Haché and Le Brigand to find the corresponding Goppa codes.

On the construction of dense lattices with a given automorphisms group

Philippe Gaborit, Gilles Zémor (2007)

Annales de l’institut Fourier

We consider the problem of constructing dense lattices in n with a given non trivial automorphisms group. We exhibit a family of such lattices of density at least c n 2 - n , which matches, up to a multiplicative constant, the best known density of a lattice packing. For an infinite sequence of dimensions n , we exhibit a finite set of lattices that come with an automorphisms group of size n , and a constant proportion of which achieves the aforementioned lower bound on the largest packing density. The algorithmic...

On the Edge-Hyper-Hamiltonian Laceability of Balanced Hypercubes

Jianxiang Cao, Minyong Shi, Lihua Feng (2016)

Discussiones Mathematicae Graph Theory

The balanced hypercube BHn, defined by Wu and Huang, is a variant of the hypercube network Qn, and has been proved to have better properties than Qn with the same number of links and processors. For a bipartite graph G = (V0 ∪ V1,E), we say G is edge-hyper-Hamiltonian laceable if it is Hamiltonian laceable, and for any vertex v ∈ Vi, i ∈ {0, 1}, any edge e ∈ E(G − v), there is a Hamiltonian path containing e in G − v between any two vertices of V1−i. In this paper, we prove that BHn is edge-hy per-...

On the Error-Correcting Performance of some Binary and Ternary Linear Codes

Baicheva, Tsonka (2007)

Serdica Journal of Computing

In this work, we determine the coset weight spectra of all binary cyclic codes of lengths up to 33, ternary cyclic and negacyclic codes of lengths up to 20 and of some binary linear codes of lengths up to 33 which are distance-optimal, by using some of the algebraic properties of the codes and a computer assisted search. Having these weight spectra the monotony of the function of the undetected error probability after t-error correction P(t)ue (C,p) could be checked with any precision for a linear...

On the fundamentals of fuzzy sets.

Robert Lowen (1984)

Stochastica

A considerable amount of research has been done on the notions of pseudo complement, intersection and union of fuzzy sets [1], [4], [11]. Most of this work consists of generalizations or alternatives of the basic concepts introduced by L. A. Zadeh in his famous paper [13]: generalization of the unit interval to arbitrary complete and completely distributive lattices or to Boolean algebras [2]; alternatives to union and intersection using the concept of t-norms [3], [10]; alternative complements...

On the g -entropy and its Hudetz correction

Beloslav Riečan (2002)

Kybernetika

The Hudetz correction of the fuzzy entropy is applied to the g -entropy. The new invariant is expressed by the Hudetz correction of fuzzy entropy.

On the generators of T-indistinguishability operator.

Joan Jacas (1988)

Stochastica

The structure of the generators' set of a T-indistinguishability operator is analyzed. A suitable characterization of such generators is given. T-indistinguishability operators generated by a single fuzzy set, in the sense of the representation problem, are studied.

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