Zobrazeno 1 - 10
of 2 133
pro vyhledávání: '"Vorob'ev, P."'
Autor:
Vorob'ev, Konstantin
We consider extended $1$-perfect codes in Hamming graphs $H(n,q)$. Such nontrivial codes are known only when $n=2^k$, $k\geq 1$, $q=2$, or $n=q+2$, $q=2^m$, $m\geq 1$. Recently, Bespalov proved nonexistence of extended $1$-perfect codes for $q=3$, $4
Externí odkaz:
http://arxiv.org/abs/2403.10992
We obtain a classification of the completely regular codes with covering radius 1 and the second eigenvalue in the Hamming graphs H(3,q) up to q and intersection array. Due to works of Meyerowitz, Mogilnykh and Valyuzenich, our result completes the c
Externí odkaz:
http://arxiv.org/abs/2403.02702
Autor:
Landjev, Ivan, Vorob'ev, Konstantin
We consider the problem of finding $A_2(n,\{d_1,d_2\})$ defined as the maximal size of a binary (non-linear) code of length $n$ with two distances $d_1$ and $d_2$. Binary codes with distances $d$ and $d+2$ of size $\sim\frac{n^2}{\frac{d}{2}(\frac{d}
Externí odkaz:
http://arxiv.org/abs/2402.13420
We study nowhere-zero integer eigenvectors of the block graphs of Steiner triple systems and the Johnson graphs. For the first eigenvalue we obtain the minimums of $L_{\infty}$-norm for several infinite series of Johnson graphs, including J(n,3) as w
Externí odkaz:
http://arxiv.org/abs/2304.00922
Autor:
Mogilnykh, I. Yu., Vorob'ev, K. V.
We prove that any completely regular code with minimum eigenvalue in any geometric graph G corresponds to a completely regular code in the clique graph of G. Studying the interrelation of these codes, a complete characterization of the completely reg
Externí odkaz:
http://arxiv.org/abs/2210.11184
We finish the classification of equitable 2-partitions of the Johnson graphs of diameter 3, $J(n,3)$, for $n>10$.
Externí odkaz:
http://arxiv.org/abs/2206.15341
A graph $G$ on $n$ vertices of diameter $D$ is called $H$-palindromic if $\alpha(G,k) = \alpha(G,D-k)$ for all $k=0, 1, \dots, \left \lfloor{\frac{D}{2}}\right \rfloor$, where $\alpha(G,k)$ is the number of unordered pairs of vertices at distance $k$
Externí odkaz:
http://arxiv.org/abs/2112.11164
Publikováno v:
Вестник медицинского института «Реавиз»: Реабилитация, врач и здоровье, Vol 13, Iss 3, Pp 88-92 (2023)
Purpose of the study. To reveal the relationship between the serum concentration of vascular endothelial growth factor and the structural and functional state of the myocardium in patients in the post-infarction period at the stage of rehabilitation.
Externí odkaz:
https://doaj.org/article/16b4b145a4a640a6b8be8db590733602
Autor:
L.V. Rozhkova, V.P. Vorob'ev
Publikováno v:
Известия высших учебных заведений. Поволжский регион: Общественные науки, Iss 4 (2024)
Background. 2022 – the beginning of Russia’s special military operation in Ukraine, when there were dramatic shifts in political, socio-economic and socio-cultural spheres that affected the entire Russian society and showed significant “margin
Externí odkaz:
https://doaj.org/article/a15abb6910f04c6cba4d0fa8999a0cd1
Autor:
Akhmejanova, Margarita, Olmezov, Konstantin, Volostnov, Aleksei, Vorobyev, Ilya, Vorob'ev, Konstantin, Yarovikov, Yury
The Wiener index $W(G)$ of a connected graph $G$ is a sum of distances between all pairs of vertices of $G$. In 1991, \v{S}olt\'{e}s formulated the problem of finding all graphs $G$ such that for every vertex $v$ the equation $W(G)=W(G-v)$ holds. The
Externí odkaz:
http://arxiv.org/abs/2012.08786