Results 71 to 80 of about 37,501 (244)

Experiments with language combinatorics in text classification: lessons learned and future implications [PDF]

open access: yes, 2017
This paper presents a meta-analysis of experiments performed with language combinatorics (LC), a novel language model generation and feature extraction method based on combinatorial manipulations of sentence elements (e.g., words).
Masui, Fumito, Ptaszynski, Michal
core   +1 more source

Combinatorics of Positroids [PDF]

open access: yesDiscrete Mathematics & Theoretical Computer Science, 2009
Recently Postnikov gave a combinatorial description of the cells in a totally-nonnegative Grassmannian. These cells correspond to a special class of matroids called positroids.
Suho Oh
doaj   +1 more source

Obstructions for Homomorphisms to Odd Cycles in Series‐Parallel Graphs

open access: yesJournal of Graph Theory, EarlyView.
ABSTRACT For a graph H $H$, an H $H$‐colouring of a graph G $G$ is a vertex mapping ϕ : V ( G ) → V ( H ) $\phi :V(G)\to V(H)$ such that adjacent vertices are mapped to adjacent vertices. A graph G $G$ is C 2 k + 1 ${C}_{2k+1}$‐critical if G $G$ has no C 2 k + 1 ${C}_{2k+1}$‐colouring but every proper subgraph of G $G$ has a C 2 k + 1 ${C}_{2k+1 ...
Eun‐Kyung Cho   +3 more
wiley   +1 more source

Algorithmic complexity of protein identification: combinatorics of weighted strings [PDF]

open access: yes, 2004
Cieliebak M, Erlebach T, Lipták Z, Stoye J, Welzl E. Algorithmic complexity of protein identification: combinatorics of weighted strings. Discrete Applied Mathematics.
Lipták, Zsuzsanna   +9 more
core   +1 more source

A note on global existence for boundary value problems

open access: yesInternational Journal of Mathematics and Mathematical Sciences, 1989
Upper and lower solutions are used in establlsning global existence results for certain two–point boundary value problems for y‴=f(x,y,y′,y″) and y(n)=f(x,y,y′,...,y(n−1)).
Chuan J. Chyan, Johnny Henderson
doaj   +1 more source

The 1 3 $\frac{1}{3}$‐Conjectures for Domination in Cubic Graphs

open access: yesJournal of Graph Theory, EarlyView.
ABSTRACT A set S $S$ of vertices in a graph G $G$ is a dominating set of G $G$ if every vertex not in S $S$ is adjacent to a vertex in S $S$. The domination number of G $G$, denoted by γ ( G ) $\gamma (G)$, is the minimum cardinality among all dominating sets in G $G$. In a breakthrough paper in 2008, Löwenstein and Rautenbach proved that if G $G$ is a
Paul Dorbec, Michael A. Henning
wiley   +1 more source

On Coloring of Fractional Powers of Star, Wheel, Friendship, and Fan Graphs

open access: yesIndonesian Journal of Combinatorics
Let G be a simple, connected, and undirected graph. For m, n ∈ ℕ, the fractional power Gm/n = (G1/n)m of G is constructed by taking the n-subdivision of G (replacing each edge by a path of length n), and then raising the resulting graph to the m-th power
Farisan Hafizh   +4 more
doaj   +1 more source

Extremal skew energy of digraphs with no even cycles [PDF]

open access: yesTransactions on Combinatorics, 2014
Let $D$ be a digraph with skew-adjacency matrix $S(D)$. Then the skew energy of $D$ is defined to be the sum of the norms of all eigenvalues of $S(D)$. Denote by $mathcal{O}_n$ the class of digraphs on order $n$ with no even cycles, and by $mathcal{O ...
Jing Li, Xueliang Li, Huishu Lian
doaj  

Graphs with 3-Rainbow Index n − 1 and n − 2

open access: yesDiscussiones Mathematicae Graph Theory, 2015
Let G = (V (G),E(G)) be a nontrivial connected graph of order n with an edge-coloring c : E(G) → {1, 2, . . . , q}, q ∈ N, where adjacent edges may be colored the same. A tree T in G is a rainbow tree if no two edges of T receive the same color.
Li Xueliang   +3 more
doaj   +1 more source

The generalized 3-connectivity of Lexicographic product graphs [PDF]

open access: yesDiscrete Mathematics & Theoretical Computer Science, 2014
Graph ...
Xueliang Li, Yaping Mao
doaj   +1 more source

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