Displaying similar documents to “Extremal Polynomials for Obtaining Bounds for Spherical Codes and Designs.”

New Upper Bounds for Some Spherical Codes

Boyvalenkov, Peter, Kazakov, Peter (1995)

Serdica Mathematical Journal

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The maximal cardinality of a code W on the unit sphere in n dimensions with (x, y) ≤ s whenever x, y ∈ W, x 6= y, is denoted by A(n, s). We use two methods for obtaining new upper bounds on A(n, s) for some values of n and s. We find new linear programming bounds by suitable polynomials of degrees which are higher than the degrees of the previously known good polynomials due to Levenshtein [11, 12]. Also we investigate the possibilities for attaining the Levenshtein bounds [11, 12]....

Distance Distributions and Energy of Designs in Hamming Spaces

Boyvalenkov, Peter, Marinova, Tanya, Stoyanova, Maya, Sukalinska, Mila (2015)

Serdica Journal of Computing

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We obtain new combinatorial upper and lower bounds for the potential energy of designs in q-ary Hamming space. Combined with results on reducing the number of all feasible distance distributions of such designs this gives reasonable good bounds. We compute and compare our lower bounds to recently obtained universal lower bounds. Some examples in the binary case are considered.

A Method for Classification of Doubly Resolvable Designs and Its Application

Zhelezova, Stela (2011)

Serdica Journal of Computing

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This article presents the principal results of the Ph.D. thesis Investigation and classification of doubly resolvable designs by Stela Zhelezova (Institute of Mathematics and Informatics, BAS), successfully defended at the Specialized Academic Council for Informatics and Mathematical Modeling on 22 February 2010. The resolvability of combinatorial designs is intensively investigated because of its applications. This research focuses on resolvable designs with an additional...

New Symmetric (61,16,4) Designs Invariant Under the Dihedral Group of Order 10

Landjev, Ivan, Topalova, Svetlana (1998)

Serdica Mathematical Journal

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∗ This work has been partially supported by the Bulgarian NSF under Contract No. I-506/1995. In this note we construct five new symmetric 2-(61,16,4) designs invariant under the dihedral group of order 10. As a by-product we obtain 25 new residual 2-(45,12,4) designs. The automorphism groups of all new designs are computed.