Abstract
Approaches for classifying resolvable balanced incomplete block designs (RBIBDs) are surveyed. The main approaches can roughly be divided into two types: those building up a design parallel class by parallel class and those proceeding point by point. With an algorithm of the latter type — and by refining ideas dating back to 1917 and the doctoral thesis by Pieter Mulder — it is shown that the list of seven known resolutions of 2-(28, 4, 1) designs is complete; these objects are also known as the resolutions of unitals on 28 points.
Similar content being viewed by others
References
APPA, G.— MAGOS, D.— MOURTOS, I.: An LP-based proof for the non-existence of a pair of orthogonal Latin squares of order 6, Oper. Res. Lett. 32 (2004), 336–344.
BETH, T.— JUNGNICKEL, D.— LENZ, H.: Design Theory, Vol. I, II (2nd ed.), Cambridge University Press, Cambridge, 1999.
BROUWER, A. E.: Some unitals on 28 points and their embeddings in projective planes of order 9. In: Geometries and Groups (M. Aigner, D. Jungnickel, eds.). Lecture Notes in Math. 893, Springer, Berlin, 1981, pp. 183–188.
COLE, F. N.: Kirkman parades, Bull. Amer. Math. Soc. 28 (1922), 435–437.
COLE, F. N.— CUMMINGS, L. D.— WHITE, H. S.: The complete enumeration of triad systems in 15 elements, Proc. Natl. Acad. Sci. USA. 3 (1917), 197–199.
DINITZ, J. H.— GARNICK, D. K.— MCKAY, B. D.: There are 526, 915, 620 nonisomorphic one-factorizations of K 12, J. Combin. Des. 2 (1994), 273–285.
FARADŽEV, I. A.: Constructive enumeration of combinatorial objects. In: Problèmes Combinatoires et Théorie des Graphes (Université d’Orsay, July 9–13, 1977), CNRS, Paris, 1978, pp. 131–135
FURINO, S.— MIAO, Y.— YIN, J.: Frames and Resolvable Designs. Uses, Constructions, and Existence, CRC Press, Boca Raton, 1996.
HALL, M., Jr.: Combinatorial Theory (2nd ed.), Wiley, New York, 1986.
KASKI, P.— MORALES, L. B.— ÖSTERGÅRD, P. R. J.— ROSENBLUETH, D. A.— VELARDE, C.: Classification of resolvable 2-(14, 7, 12) and 3-(14, 7, 5) designs, J. Combin. Math. Combin. Comput. 47 (2003), 65–74.
KASKI, P.— ÖSTERGÅRD, P. R. J.: There exists no (15, 5, 4) RBIBD, J. Combin. Des. 9 (2001), 357–362.
KASKI, P.— ÖSTERGÅRD, P. R. J.: Miscellaneous classification results for 2-designs, Discrete Math. 280 (2004), 65–75.
KASKI, P.— ÖSTERGÅRD, P. R. J.: The Steiner triple systems of order 19, Math. Comp. 73 (2004), 2075–2092.
KASKI, P.— ÖSTERGÅRD, P. R. J.: One-factorizations of regular graphs of order 12, Electron. J. Combin. 12 (2005) No. 1, #R2, 25pp.
KASKI, P.— ÖSTERGÅRD, P. R. J.: Classification Algorithms for Codes and Designs, Springer, Berlin, 2006.
KASKI, P.— ÖSTERGÅRD, P. R. J.— POTTONEN, O.: The Steiner quadruple systems of order 16, J. Combin. Theory Ser. A 113 (2006), 1764–1770.
KRČADINAC, V.: Steiner 2-designs S(2, 4, 28) with nontrivial automorphisms, Glas. Mat. Ser. III 37(57) (2002), 259–268.
LAM, C. W. H.— THIEL, L.: Backtrack search with isomorph rejection and consistency check, J. Symbolic Comput. 7 (1989), 473–485.
LAM, C.— TONCHEV, V. D.: Classification of affine resolvable 2-(27, 9, 4) designs, J. Statist. Plann. Inference 56; 86 (1996; 2000), 187–202; 277–278.
MATHON, R.— LOMAS, D.: A census of 2-(9, 3, 3) designs, Australas. J. Combin. 5 (1992), 145–158.
MATHON, R.— ROSA, A.: A census of Mendelsohn triple systems of order nine, Ars Combin. 4 (1977), 309–315.
MATHON, R.— ROSA, A.: Some results on the existence and enumeration of BIBD’s. Mathematics Report 125-Dec-1985, Department of Mathematics and Statistics, McMaster University, Hamilton, 1985.
MATHON, R.— ROSA, A.: Tables of parameters of BIBDs with r ≤ 41 including existence, enumeration, and resolvability results, Ann. Discrete Math. 26 (1985), 275–307.
MATHON, R.— ROSA, A.: Tables of parameters of BIBDs with r ≤ 41 including existence, enumeration and resolvability results: An update, Ars Combin. 30 (1990), 65–96.
MATHON, R.— ROSA, A.: 2-(υ, k, λ) designs of small order. In: The CRC Handbook of Combinatorial Designs (C. J. Colbourn, J. H. Dinitz, eds.), CRC Press, Boca Raton, 1996, pp. 3–41.
MATHON, R.— ROSA, A.: 2-(υ, k, λ) designs of small order. In: Handbook of Combinatorial Designs (C. J. Colbourn, J. H. Dinitz, eds.; 2nd ed.), Chapman & Hall/CRC Press, Boca Raton, 2007, pp. 25–58.
MCKAY, B. D.: nauty User’s guide (version 1.5). Technical Report TR-CS-90-02, Computer Science Department, Australian National University, Canberra, 1990.
MCKAY, B. D.: autoson —A distributed batch system for UNIX workstation networks (version 1.3). Technical Report TR-CS-96-03, Computer Science Department, Australian National University, Canberra, 1996.
MCKAY, B. D.: Isomorph-free exhaustive generation, J. Algorithms 26 (1998), 306–324.
MORALES, L. B.— VELARDE, C.: A complete classification of (12, 4, 3)-RBIBDs, J. Combin. Des. 9 (2001), 385–400.
MORALES, L. B.— VELARDE, C.: Enumeration of resolvable 2-(10, 5, 16) and 3-(10, 5, 6) designs, J. Combin. Des. 13 (2005), 108–119.
MORGAN, E. J.: Some small quasi-multiple designs, Ars Combin. 3 (1977), 233–250.
MULDER, P.: Kirkman-Systemen. PhD Thesis, Rijksuniversiteit Groningen, 1917.
NISKANEN, S.— ÖSTERGÅRD, P. R. J.: Cliquer user’s guide, version 1.0. Technical Report T48, Communications Laboratory, Helsinki University of Technology, Espoo, 2003.
ÖSTERGÅRD, P. R. J.: Enumeration of 2-(12, 3, 2) designs, Australas. J. Combin. 22 (2000), 227–231.
ÖSTERGÅRD, P. R. J.— KASKI, P.: Enumeration of 2-(9, 3, λ) designs and their resolutions, Des. Codes Cryptogr. 27 (2002), 131–137.
PENTTILA, T.— ROYLE, G. F.: Sets of type (m, n) in the affine and projective planes of order nine, Des. Codes Cryptogr. 6 (1995), 229–245.
READ, R. C.: Every one a winner; or, How to avoid isomorphism search when cataloguing combinatorial configurations, Ann. Discrete Math. 2 (1978), 107–120.
SEMAKOV, N. V.— ZINOV’EV, V. A.: Equidistant q-ary codes with maximal distance and resolvable balanced incomplete block designs, Problemy Peredachi Informatsii 4 (1968), No. 2, 3–10 (Russian). [English translation: Probl. Inf. Transm. 4 (1968), No. 2, 1–7].
WHITE, H. S.— COLE, F. N.— CUMMINGS, L. D.: Complete classification of triad systems on fifteen elements, Memoirs Natl. Acad. Sci. USA. 27 (1919) No. 2, 1–89.
Author information
Authors and Affiliations
Corresponding author
Additional information
(Communicated by Peter Horák)
Dedicated to Alex Rosa on the occasion of his seventieth birthday
This research was supported in part by the Academy of Finland, Grants No. 107493, 110196, and 117499.
About this article
Cite this article
Kaski, P., Östergård, P.R.J. Classification of resolvable balanced incomplete block designs — the unitals on 28 points. Math. Slovaca 59, 121–136 (2009). https://doi.org/10.2478/s12175-009-0113-8
Received:
Published:
Issue Date:
DOI: https://doi.org/10.2478/s12175-009-0113-8