Results 51 to 60 of about 147,491 (227)

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 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

Cluster‐Randomized Trials in Emergency Care Research

open access: yesAcademic 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

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

Augmented Simplicial Combinatorics through Category Theory: Cones, Suspensions and Joins [PDF]

open access: gold, 2022
J.M. García-Calcines   +2 more
openalex   +1 more source

A complex network perspective on brain disease

open access: yesBiological Reviews, EarlyView.
ABSTRACT If brain anatomy and dynamics have a complex network structure as it has become standard to posit, it is reasonable to assume that such a structure should play a key role not only in brain function but also in brain dysfunction. However, exactly how network structure is implicated in brain damage and whether at least some pathologies can be ...
David Papo, Javier M. Buldú
wiley   +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  

The Role of Dice in the Emergence of the Probability Calculus

open access: yesInternational 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

Coxeter-biCatalan combinatorics [PDF]

open access: yesDiscrete Mathematics & Theoretical Computer Science, 2015
We consider several counting problems related to Coxeter-Catalan combinatorics and conjecture that the problems all have the same answer, which we call the $W$ -biCatalan number. We prove the conjecture in many cases.
Emily Barnard, Nathan Reading
doaj   +1 more source

Enumeration of three term arithmetic progressions in fixed density sets [PDF]

open access: yes, 2014
Additive combinatorics is built around the famous theorem by Szemer\'edi which asserts existence of arithmetic progressions of any length among the integers. There exist several different proofs of the theorem based on very different techniques.
Sjöland, Erik
core  

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