Results 61 to 70 of about 169,932 (295)
The generalized 3-connectivity of Lexicographic product graphs [PDF]
Discrete Mathematics & Theoretical Computer Science, 2014 Graph ...
Xueliang Li, Yaping Mao
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On Regular Quaternary Hadamard Matrices
Journal of Combinatorial Designs, EarlyView.ABSTRACT Through the use of regularizing vectors, all regular quaternary Hadamard matrices of orders 10 and 18 have been successfully identified. Of these, two matrices of order 10 and 184 matrices of order 18 were found to have unbiased mates. Converting the quaternary Hadamard matrices of order 18 to real Hadamard matrices, the study uncovered that ...
Hadi Kharaghani +2 more
wiley +1 more source
Graphs with 3-Rainbow Index n − 1 and n − 2
Discussiones 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
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Cluster‐Randomized Trials in Emergency Care Research
Academic Emergency Medicine, EarlyView.ABSTRACT Objective Cluster‐randomized trials (also called group‐randomized trials) are increasingly common in emergency care research. In such trials, groups of participants are allocated to different interventions based on naturally occurring “clusters,” such as clinics, hospitals, or emergency medical services agencies. In this methodological review,
Howard S. Kim +2 more
wiley +1 more source
, 2015 We introduce Quintessence: a family of burr puzzles based on the geometry and combinatorics of the 120-cell. We discuss the regular polytopes, their symmetries, the dodecahedron as an important special case, the three-sphere, and the quaternions. We then
Schleimer, Saul, Segerman, Henry
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Compatible cycles and CHY integrals
Journal of High Energy Physics, 2019 The CHY construction naturally associates a vector in ℝ(n−3)! to every 2- regular graph with n vertices. Partial amplitudes in the biadjoint scalar theory are given by the inner product of vectors associated with a pair of cycles.
Freddy Cachazo +2 more
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The Role of Dice in the Emergence of the Probability Calculus
International Statistical Review, EarlyView.Summary The early development of the probability calculus was clearly influenced by the roll of dice. However, while dice have been cast since time immemorial, documented calculations on the frequency of various dice throws date back only to the mid‐13th century.
David R. Bellhouse, Christian Genest
wiley +1 more source
Combinatorics in the Art of the Twentieth Century [PDF]
, 2017 This paper is motivated by a question I asked myself: How can combinatorial structures be used in a work of art? Immediately, other questions arose: Whether there are artists that work or think combinatorially?
Barrière Figueroa, Eulalia
core
Unimodality Problems in Ehrhart Theory
, 2017 Ehrhart theory is the study of sequences recording the number of integer points in non-negative integral dilates of rational polytopes. For a given lattice polytope, this sequence is encoded in a finite vector called the Ehrhart $h^*$-vector. Ehrhart $h^*
A. Stapledon +45 more
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Extremal skew energy of digraphs with no even cycles [PDF]
Transactions 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