Results 41 to 50 of about 211,771 (176)

On Lev's periodicity conjecture

Bulletin of the London Mathematical Society, EarlyView.
Abstract We classify the sum‐free subsets of F3n${\mathbb {F}}_3^n$ whose density exceeds 16$\frac{1}{6}$. This yields a resolution of Vsevolod Lev's periodicity conjecture, which asserts that if a sum‐free subset A⊆F3n${A\subseteq {\mathbb {F}}_3^n}$ is maximal with respect to inclusion and aperiodic (in the sense that there is no non‐zero vector v$v$
Christian Reiher
wiley   +1 more source

Effects of altitude and exercise intensity on cardiac function in rats

Experimental Physiology, EarlyView.
Abstract High‐altitude exercise affects cardiac function. This study investigated how altitude and exercise intensity interacted to affect cardiac function of Sprague‐Dawley rats. Four altitudes (410, 3600, 4600 and 5600 m) and three exercise intensities (non‐exercise (N), low‐intensity exercise (L) and high‐intensity exercise (H)) were tested ...
Minxia Zhu, Xiaofeng Li, Bing Liu, Jing Guo, Yuanyuan Xiao, Zhiyao Liu, Mengru Duan, Yi Liu   +7 more
wiley   +1 more source

On Galvin's lemma and Ramsey spaces [PDF]

Annals of Combinatorics 16 (2002), no. 2, 319-330, 2009
An abstract version of Galvin's lemma is proven, within the framework of the theory of Ramsey spaces. Some instances of it are explored.
arxiv  

The Combinatorics of Iterated Loop Spaces

, 2003
It is well known since Stasheff's work that 1-fold loop spaces can be described in terms of the existence of higher homotopies for associativity (coherence conditions) or equivalently as algebras of contractible non-symmetric operads.
Batanin, M. A.
core   +1 more source

General combinatorical structure of truth tables of bracketed formulae connected by implication [PDF]

arXiv, 2012
In this paper we investigate the general combinatorical structure of the truth tables of all bracketed formulae with n distinct variables connected by the binary connective of implication, an m-implication.
arxiv  

Being Aware of Data Leakage and Cross‐Validation Scaling in Chemometric Model Validation

Journal of Chemometrics, Volume 39, Issue 4, April 2025.
ABSTRACT The main goal of our investigation is to raise awareness among chemometricians about how easy it is to introduce data or parameter leakage by inappropriate methods and to demonstrate that high precision is necessary in the interpretation of opinions found in the literature on the preference of leave‐one‐out, leave‐many‐out, and repeated cross ...
Péter Király, Gergely Tóth
wiley   +1 more source

Hyperbolicity and stable polynomials in combinatorics and probability [PDF]

arXiv, 2012
This was the basis of two lectures in the Current Developments in Mathematics conference in 2011. These lectures survey the theory of hyperbolic and stable polynomials, from their origins in the theory of linear PDE's to their present uses in combinatorics and probability theory.
arxiv  

Combinatorics of balanced carries [PDF]

, 2013
We study the combinatorics of addition using balanced digits, deriving an analog of Holte's "amazing matrix" for carries in usual addition. The eigenvalues of this matrix for base b balanced addition of n numbers are found to be 1,1/b,...,1/b^n, and ...
Diaconis, Persi, Fulman, Jason
core  

New Families of Strength‐3 Covering Arrays Using Linear Feedback Shift Register Sequences

Journal of Combinatorial Designs, Volume 33, Issue 4, Page 156-171, April 2025.
ABSTRACT In an array over an alphabet of v symbols, a t‐set of column indices { c 1 , … , c t } is covered if each t‐tuple of the alphabet occurs at least once as a row of the sub‐array indexed by c 1 , … , c t. A covering array, denoted by CA( N ; t , k , v ), is an N × k array over an alphabet with v symbols with the property that any t‐set of ...
Kianoosh Shokri, Lucia Moura
wiley   +1 more source