Displaying similar documents to “ 2 -modular lattices from ternary codes”

On extremal additive 𝔽 4 codes of length 10 to 18

Christine Bachoc, Philippe Gaborit (2000)

Journal de théorie des nombres de Bordeaux

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In this paper we consider the extremal even self-dual 𝔽 4 -additive codes. We give a complete classification for length 10 . Under the hypothesis that at least two minimal words have the same support, we classify the codes of length 14 and we show that in length 18 such a code is equivalent to the unique 𝔽 4 -hermitian code with parameters [18,9,8]. We construct with the help of them some extremal 3 -modular lattices.

New Binary [ 70 , 35 , 12 ] Self-Dual and Binary [ 72 , 36 , 12 ] Self-Dual Doubly-Even Codes

Dontcheva, Radinka (2001)

Serdica Mathematical Journal

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∗ This work was supported in part by the Bulgarian NSF under Grant MM-901/99 In this paper we prove that up to equivalence there exist 158 binary [70, 35, 12] self-dual and 119 binary [72, 36, 12] self-dual doubly-even codes all of which have an automorphism of order 23 and we present their construction. All these codes are new.

Universal codes and unimodular lattices

Robin Chapman, Patrick Solé (1996)

Journal de théorie des nombres de Bordeaux

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Binary quadratic residue codes of length p + 1 produce via construction B and density doubling type II lattices like the Leech. Recently, quaternary quadratic residue codes have been shown to produce the same lattices by construction A modulo 4 . We prove in a direct way the equivalence of these two constructions for p ≤ 31 . In dimension 32, we obtain an extremal lattice of type II not isometric to the Barnes-Wall lattice B W 32 . The equivalence between construction B modulo 4 plus density doubling...

Some MDS Codes over Gf(64) Connected with the Binary Doubly-Even [72,36,16] Code

Bouyuklieva, Stefka (2007)

Serdica Journal of Computing

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* The author is supported by a Return Fellowship from the Alexander von Humboldt Foundation. MDS [8,4,5] codes over a field with 64 elements are constructed. All such codes which are self-dual under a Hermitian type inner product are classified. The connection between these codes and a putative binary self- dual [72,36,16] code is considered.

On Binary Self-Dual Codes of Length 62 with an Automorphism of Order 7 Двоични самодуални кодове с дължина 62 притежаващи автоморфизъм от ред 7

Yankov, Nikolay (2011)

Union of Bulgarian Mathematicians

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Николай Янков - Класифицирани са с точност до еквивалетност всички оптимални двоични самодуални [62, 31, 12] кодове, които притежават автоморфизъм от ред 7 с 8 независими цикъла при разлагане на независими цикли. Използвайки метода за конструиране на самодуални кодове, притежаващи автоморфизъм от нечетен прост ред е доказано, че съществуват точно 8 нееквивалентни такива кода. Три от получените кодове имат тегловна функция, каквато досега не бе известно да съществува. We...

On Extremal Binary Doubly-Even Self-Dual Codes of Length 88*

Yorgova, Radinka, At, Nuray (2009)

Serdica Journal of Computing

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In this paper we present 35 new extremal binary self-dual doubly-even codes of length 88. Their inequivalence is established by invariants. Moreover, a construction of a binary self-dual [88, 44, 16] code, having an automorphism of order 21, is given. *This work was partly supported by the Norwegian Government Scholarship.

Divisible Codes - A Survey

Ward, Harold (2001)

Serdica Mathematical Journal

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This paper surveys parts of the study of divisibility properties of codes. The survey begins with the motivating background involving polynomials over finite fields. Then it presents recent results on bounds and applications to optimal codes.

On Multiple Deletion Codes

Landjev, Ivan, Haralambiev, Kristiyan (2007)

Serdica Journal of Computing

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In 1965 Levenshtein introduced the deletion correcting codes and found an asymptotically optimal family of 1-deletion correcting codes. During the years there has been a little or no research on t-deletion correcting codes for larger values of t. In this paper, we consider the problem of finding the maximal cardinality L2(n;t) of a binary t-deletion correcting code of length n. We construct an infinite family of binary t-deletion correcting codes. By computer search, we construct t-deletion...

Ternary constant weight codes.

Östergård, Patric R.J., Svanström, Mattias (2002)

The Electronic Journal of Combinatorics [electronic only]

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On a complete set of operations for factorizing codes

Clelia De Felice (2006)

RAIRO - Theoretical Informatics and Applications - Informatique Théorique et Applications

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It is known that the class of factorizing codes, i.e., codes satisfying the factorization conjecture formulated by Schützenberger, is closed under two operations: the classical composition of codes and substitution of codes. A natural question which arises is whether a finite set 𝒪 of operations exists such that each factorizing code can be obtained by using the operations in 𝒪 and starting with prefix or suffix codes. 𝒪 is named here a complete set of operations (for factorizing codes)....

New Binary Extremal Self-Dual Codes of Lengths 50 and 52

Buyuklieva, Stefka (1999)

Serdica Mathematical Journal

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* This work was partially supported by the Bulgarian National Science Fund under Contract No. MM – 503/1995. New extremal binary self-dual codes of lengths 50 and 52 are constructed. Some of them are the first known codes with such weight enumerators. The structure of their automorphisms groups are shown.

On some Optimal (n,t,1,2) and (n,t,1,3) Super Imposed Codes

Manev, Mladen (2009)

Serdica Journal of Computing

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Partially supported by the Technical University of Gabrovo under Grant C-801/2008 One of the main problems in the theory of superimposed codes is to find the minimum length N for which an (N, T,w, r) superimposed code exists for given values of T , w and r. Let N(T,w, r) be the minimum length N for which an (N, T,w, r) superimposed code exists. The (N, T,w, r) superimposed code is called optimal when N = N(T,w, r). The values of N(T, 1, 2) are known for T ≤ 12 and the values...