New Steiner 2-designs from old ones by paramodifications
Techniques of producing new combinatorial structures from old ones are commonly called trades. The switching principle applies for a broad class of designs: it is a local transformation that modifies two columns of the incidence matrix. In this paper, we present a construction, which is a generaliza...
Elmentve itt :
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| Dokumentumtípus: | Cikk |
| Megjelent: |
2021
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| Sorozat: | DISCRETE APPLIED MATHEMATICS
288 |
| Tárgyszavak: | |
| doi: | 10.1016/j.dam.2020.08.026 |
| mtmt: | 31616227 |
| Online Access: | http://publicatio.bibl.u-szeged.hu/29115 |
| Tartalmi kivonat: | Techniques of producing new combinatorial structures from old ones are commonly called trades. The switching principle applies for a broad class of designs: it is a local transformation that modifies two columns of the incidence matrix. In this paper, we present a construction, which is a generalization of the switching transform for the class of Steiner 2-designs. We call this construction paramodification of Steiner 2-designs, since it modifies the parallelism of a subsystem. We study in more detail the paramodifications of affine planes, Steiner triple systems, and abstract unitals. Computational results show that paramodification can construct many new unitals. |
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| Terjedelem/Fizikai jellemzők: | 114-122 |
| ISSN: | 0166-218X |