Zobrazeno 1 - 10
of 106
pro vyhledávání: '"Krčadinac, Vedran"'
Autor:
Krčadinac, Vedran
We give the first example of a mosaic of three combinatorial designs with distinct parameters $2$-$(13,3,1)$, $2$-$(13,4,2)$, and $2$-$(13,6,5)$. Furthermore, we give examples of mosaics of $2$-$(9,3,2)$ designs that are not resolvable, thereby answe
Externí odkaz:
http://arxiv.org/abs/2405.12672
We describe a construction of three-dimensional Hadamard matrices of even order $v$ such that $v-1$ is a prime power. The construction covers infinitely many orders for which the existence was previously open.
Comment: 6 pages
Comment: 6 pages
Externí odkaz:
http://arxiv.org/abs/2305.12415
We study $n$-dimensional matrices with $\{0,1\}$-entries ($n$-cubes) such that all their $2$-dimensional slices are incidence matrices of symmetric designs. A known construction of these objects obtained from difference sets is generalized so that th
Externí odkaz:
http://arxiv.org/abs/2304.05446
We study combinatorial configurations with the associated point and line graphs being strongly regular. Examples not belonging to known classes such as partial geometries and their generalizations or elliptic semiplanes are constructed. Necessary exi
Externí odkaz:
http://arxiv.org/abs/2104.04880
We study sums of the form $\sum_{k=m}^n a_{nk} b_{km}$, where $a_{nk}$ and $b_{km}$ are binomial coefficients or unsigned Stirling numbers. In a few cases they can be written in closed form. Failing that, the sums still share many common features: co
Externí odkaz:
http://arxiv.org/abs/2012.15307
Autor:
Krčadinac, Vedran
We construct a new partial geometry with parameters pg(5,5,2), not isomorphic to the partial geometry of van Lint and Schrijver.
Comment: 5 pages
Comment: 5 pages
Externí odkaz:
http://arxiv.org/abs/2009.07946
Computational techniques for the construction of quasi-symmetric block designs are explored and applied to the case with $56$ points. One new $(56,16,18)$ and many new $(56,16,6)$ designs are discovered, and non-existence of $(56,12,9)$ and $(56,20,1
Externí odkaz:
http://arxiv.org/abs/2003.05556
Publikováno v:
In Discrete Mathematics July 2023 346(7)
Autor:
Krčadinac, Vedran
Publikováno v:
Journal of Combinatorial Designs 26 (2018) 193-200
We establish the existence of simple designs with parameters $2$-$(55,10,4)$, $3$-$(20,5,4)$, $3$-$(21,7,30)$, $4$-$(15,5,2)$, $4$-$(16,8,45)$, $5$-$(16,7,10)$, and $5$-$(17,8,40)$, which have previously been unknown. For the corresponding $t$, $v$,
Externí odkaz:
http://arxiv.org/abs/1706.01682
Autor:
Krčadinac, Vedran
Publikováno v:
In Journal of Combinatorial Theory, Series A October 2021 183