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Optimal Codes in the Enomoto-Katona Space

Published online by Cambridge University Press:  09 October 2014

YEOW MENG CHEE
Affiliation:
Division of Mathematical Sciences, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Singapore (e-mail: [email protected], [email protected], [email protected])
HAN MAO KIAH
Affiliation:
Coordinated Science Lab, University of Illinois, Urbana-Champaign, 1308 W. Main Street, Urbana, IL 61801, USA (e-mail: [email protected])
HUI ZHANG
Affiliation:
Division of Mathematical Sciences, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Singapore (e-mail: [email protected], [email protected], [email protected])
XIANDE ZHANG
Affiliation:
Division of Mathematical Sciences, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Singapore (e-mail: [email protected], [email protected], [email protected])

Abstract

Coding in a new metric space, called the Enomoto-Katona space, has recently been considered in connection with the study of implication structures of functional dependencies and their generalizations in relational databases. The central problem is the determination of C(n,k,d), the size of an optimal code of length n, weight k, and distance d in the Enomoto-Katona space. The value of C(n,k,d) was known only for some congruence classes of n when (k,d) ∈ {(2,3),(3,5)}. In this paper, we obtain new infinite families of optimal codes in the Enomoto-Katona space and verify a conjecture of Brightwell and Katona in certain instances. In particular, C(n,k, 2k − 1) is determined for all sufficiently large n satisfying either n ≡ 1 mod k and n(n − 1) ≡ 0 mod 2k2, or n ≡ 0 mod k. We also give complete solutions for k = 2 and determine C(n,3,5) for certain congruence classes of n with finite exceptions.

Type
Paper
Copyright
Copyright © Cambridge University Press 2014 

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References

[1]Abel, R. J. R., Bennett, F. B. and Greig, M. (2007) PBD-closure. In The CRC Handbook of Combinatorial Designs (Colbourn, C. J. and Dinitz, J. H., eds), second edition, CRC Press, pp. 247255.Google Scholar
[2]Abel, R. J. R., Colbourn, C. J. and Dinitz, J. H. (2007) Mutually orthogonal Latin squares (MOLS). In The CRC Handbook of Combinatorial Designs (Colbourn, C. J. and Dinitz, J. H., eds), second edition, CRC Press, pp. 160193.Google Scholar
[3]Armstrong, W. W. (1974) Dependency structures of data base relationships. In Proc. IFIP Congress 1974, pp. 580–583.Google Scholar
[4]Beeri, C., Fagin, R. and Howard, J. H. (1977) A complete axiomatization for fuzzy functional and multivalued dependencies in fuzzy database relations. In Proc. ACM SIGMOD International Conference on Management of Data, pp. 47–61.Google Scholar
[5]Bernstein, P. A. (1976) Synthesizing third normal form relations from functional dependencies. ACM Trans. Database Syst. 1 277298.Google Scholar
[6]Bollobás, B., Füredi, Z., Kantor, I., Katona, G. O. H. and A, Leader, I. coding problem for pairs of subsets. Preprint.Google Scholar
[7]Brightwell, G. and Katona, G. (2001) A new type of coding problem. Studia Sci. Math. Hungar. 38 139147.Google Scholar
[8]Chee, Y. M., Kiah, H. M., Zhang, H. and Zhang, X. Addendum to optimal codes in the Enomoto–Katona space. http://sites.google.com/kiahhanmao/optimalekGoogle Scholar
[9]Chee, Y. M., Kiah, H. M., Zhang, H. and Zhang, X. (2013) Optimal codes in the Enomoto–Katona space. In Proc. IEEE International Symposium on Information Theory, pp. 321–325.Google Scholar
[10]Codd, E. F. (1970) A relational model of data for large shared data banks. Commun. Assoc. Comput. Mach. 13 377387.Google Scholar
[11]Demetrovics, J., Katona, G. O. and Sali, A. (1995) Minimal representations of branching dependencies. Acta Sci. Math. (Szeged) 60 213224.Google Scholar
[12]Demetrovics, J., Katona, G. O. H. and Sali, A. (1992) The characterization of branching dependencies. Discrete Appl. Math. 40 139153.Google Scholar
[13]Demetrovics, J., Katona, G. O. H. and Sali, A. (1998) Design type problems motivated by database theory. J. Statist. Plann. Inference 72 149164.Google Scholar
[14]Enomoto, H. and Katona, G. O. H. (2001) Pairs of disjoint q-element subsets far from each other. Electron. J. Combin. 8 R7.Google Scholar
[15]Hanani, H. (1971) Truncated finite planes. In Proc. Symposium Pure Mathematics (AMS), Vol. 19, pp. 115–120.Google Scholar
[16]Katona, G. O. H. and Sali, A. (2004) New type of coding problem motivated by database theory. Discrete Appl. Math. 144 140148.CrossRefGoogle Scholar
[17]Lamken, E. R. and Wilson, R. M. (2000) Decompositions of edge-colored complete graphs. J. Combin. Theory Ser. A 89 149200.Google Scholar
[18]Quistorff, J. (2009) Combinatorial problems in the Enomoto–Katona space. Studia Sci. Math. Hungar. 46 121139.Google Scholar
[19]Rissanen, J. (1977) Independent components of relations. ACM Trans. Database Syst. 2 317325.Google Scholar
[20]Sali, A. (2011) Coding theory motivated by relational databases. In Proc. International Conference on Semantics in Data and Knowledge Bases: SDKB'10, Springer, pp. 96–113.Google Scholar
[21]Wilson, R. M. (1972) An existence theory for pairwise balanced designs I: Composition theorems and morphisms. J. Combin. Theory Ser. A 13 220245.Google Scholar