Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

English (EN)·Polski (PL)·Yкраїнський (UK)
Przejdź do strony domowej biblioteki Centralna Biblioteka Wojskowa Link otwiera się w nowym oknie Logo biblioteki Prolib Integro - strona głównaCentralna Biblioteka Wojskowa

Wyszukujesz frazę "quasi-monochromatic digraph" wg kryterium: Temat

  Lista filtrów
Wyrównaj
    Wyświetlanie 1-4 z 4
    Tytuł:
    Monochromatic paths and monochromatic sets of arcs in 3-quasitransitive digraphs
    Autorzy:
    Galeana-Sánchez, Hortensia
    Rojas-Monroy, R.
    Zavala, B.
    Powiązania:
    https://bibliotekanauki.pl/articles/744398.pdf
    Data publikacji:
    2009
    Wydawca:
    Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
    Tematy:
    m-coloured digraph
    3-quasitransitive digraph
    kernel by monochromatic paths
    γ-cycle
    quasi-monochromatic digraph
    Opis:
    We call the digraph D an m-coloured digraph if the arcs of D are coloured with m colours. A directed path is called monochromatic if all of its arcs are coloured alike. A set N of vertices of D is called a kernel by monochromatic paths if for every pair of vertices of N there is no monochromatic path between them and for every vertex v ∉ N there is a monochromatic path from v to N. We denote by A⁺(u) the set of arcs of D that have u as the initial vertex. We prove that if D is an m-coloured 3-quasitransitive digraph such that for every vertex u of D, A⁺(u) is monochromatic and D satisfies some colouring conditions over one subdigraph of D of order 3 and two subdigraphs of D of order 4, then D has a kernel by monochromatic paths.
    Źródło:
    Discussiones Mathematicae Graph Theory; 2009, 29, 2; 337-347
    2083-5892
    Pojawia się w:
    Discussiones Mathematicae Graph Theory
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Monochromatic paths and monochromatic sets of arcs in quasi-transitive digraphs
    Autorzy:
    Galeana-Sánchez, Hortensia
    Rojas-Monroy, R.
    Zavala, B.
    Powiązania:
    https://bibliotekanauki.pl/articles/744061.pdf
    Data publikacji:
    2010
    Wydawca:
    Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
    Tematy:
    m-coloured quasi-transitive digraph
    kernel by monochromatic paths
    Opis:
    Let D be a digraph, V(D) and A(D) will denote the sets of vertices and arcs of D, respectively. We call the digraph D an m-coloured digraph if each arc of D is coloured by an element of {1,2,...,m} where m ≥ 1. A directed path is called monochromatic if all of its arcs are coloured alike. A set N of vertices of D is called a kernel by monochromatic paths if there is no monochromatic path between two vertices of N and if for every vertex v not in N there is a monochromatic path from v to some vertex in N. A digraph D is called a quasi-transitive digraph if (u,v) ∈ A(D) and (v,w) ∈ A(D) implies (u,w) ∈ A(D) or (w,u) ∈ A(D). We prove that if D is an m-coloured quasi-transitive digraph such that for every vertex u of D the set of arcs that have u as initial end point is monochromatic and D contains no C₃ (the 3-coloured directed cycle of length 3), then D has a kernel by monochromatic paths.
    Źródło:
    Discussiones Mathematicae Graph Theory; 2010, 30, 4; 545-553
    2083-5892
    Pojawia się w:
    Discussiones Mathematicae Graph Theory
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Kernels by Monochromatic Paths and Color-Perfect Digraphs
    Autorzy:
    Galeana-Śanchez, Hortensia
    Sánchez-López, Rocío
    Powiązania:
    https://bibliotekanauki.pl/articles/31340961.pdf
    Data publikacji:
    2016-05-01
    Wydawca:
    Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
    Tematy:
    kernel
    kernel perfect digraph
    kernel by monochromatic paths
    color-class digraph
    quasi color-perfect digraph
    color-perfect digraph
    Opis:
    For a digraph D, V (D) and A(D) will denote the sets of vertices and arcs of D respectively. In an arc-colored digraph, a subset K of V(D) is said to be kernel by monochromatic paths (mp-kernel) if (1) for any two different vertices x, y in N there is no monochromatic directed path between them (N is mp-independent) and (2) for each vertex u in V (D) \ N there exists v ∈ N such that there is a monochromatic directed path from u to v in D (N is mp-absorbent). If every arc in D has a different color, then a kernel by monochromatic paths is said to be a kernel. Two associated digraphs to an arc-colored digraph are the closure and the color-class digraph C(D). In this paper we will approach an mp-kernel via the closure of induced subdigraphs of D which have the property of having few colors in their arcs with respect to D. We will introduce the concept of color-perfect digraph and we are going to prove that if D is an arc-colored digraph such that D is a quasi color-perfect digraph and C(D) is not strong, then D has an mp-kernel. Previous interesting results are generalized, as for example Richardson′s Theorem.
    Źródło:
    Discussiones Mathematicae Graph Theory; 2016, 36, 2; 309-321
    2083-5892
    Pojawia się w:
    Discussiones Mathematicae Graph Theory
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    H-Kernels in Unions of H-Colored Quasi-Transitive Digraphs
    Autorzy:
    Campero-Alonzo, José Manuel
    Sánchez-López, Rocío
    Powiązania:
    https://bibliotekanauki.pl/articles/32083861.pdf
    Data publikacji:
    2021-05-01
    Wydawca:
    Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
    Tematy:
    quasi-transitive digraph
    kernel by monochromatic paths
    alternating kernel
    obstruction
    H-kernel
    Opis:
    Let $H$ be a digraph (possibly with loops) and $D$ a digraph without loops whose arcs are colored with the vertices of $H$ ($D$ is said to be an $H$-colored digraph). For an arc $(x, y)$ of $D$, its color is denoted by $c(x, y)$. A directed path $W = (v_0, . . ., v_n)$ in an $H$-colored digraph $D$ will be called $H$-path if and only if $(c(v_0, v_1), . . ., c(v_{n−1}, v_n))$ is a directed walk in $H$. In $W$, we will say that there is an obstruction on $v_i$ if $(c(v_{i−1}, v_i), c(v_i, v_{i+1})) ∉ A(H)$ (if $v_0 = v_n$ we will take indices modulo $n$). A subset $N$ of $V(D)$ is said to be an $H$-kernel in $D$ if for every pair of different vertices in $N$ there is no $H$-path between them, and for every vertex $u$ in \(V(D) \backslash N\) there exists an $H$-path in $D$ from $u$ to $N$. Let $D$ be an arc-colored digraph. The color-class digraph of $D,\mathcal{C}_C(D)$, is the digraph such that $V(\mathcal{C}_C(D)) = \{c(a) : a ∈ A(D)\}$ and $(i, j) ∈ A(\mathcal{C}_C(D))$ if and only if there exist two arcs, namely $(u, v)$ and $(v, w)$ in $D$, such that $c(u, v) = i$ and $c(v, w) = j$. The main result establishes that if $D = D_1 ∪ D_2$ is an $H$-colored digraph which is a union of asymmetric quasi-transitive digraphs and $\{V_1, . . ., V_k\}$ is a partition of $V(\mathcal{C}_C(D))$ with a property $P^\ast$ such that 1. $V_i$ is a quasi-transitive $V_i$-class for every i in $\{1, . . ., k\}$, 2. either \(D[\{a ∈ A(D) : c(a) ∈ V_i\}]\) is a subdigraph of $D_1$ or it is a sudigraph of $D_2$ for every $i$ in $\{1, . . ., k\}$, 3. $D_i$ has no infinite outward path for every $i$ in $\{1, 2\}$, 4. every cycle of length three in $D$ has at most two obstructions, then $D$ has an $H$-kernel. Some results with respect to the existence of kernels by monochromatic paths in finite digraphs will be deduced from the main result.
    Źródło:
    Discussiones Mathematicae Graph Theory; 2021, 41, 2; 391-408
    2083-5892
    Pojawia się w:
    Discussiones Mathematicae Graph Theory
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
      Wyświetlanie 1-4 z 4

      Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies