Browsing Department of Mathematics and Statistics by Title
Now showing items 34-53 of 73
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Generating self-complementary uniform hypergraphs
(Discrete Mathematics, 2010-02)In 2007, Szymanski and Wojda proved that for positive integers n; k with k less than n, a self-complementary k-uniform hypergraph of order n exists if and only if n/k is even. In this paper, we characterize the cycle type ... -
Growth rate of binary words avoiding xxxR
(Elsevier, 2016-01)Abstract Consider the set of those binary words with no non-empty factors of the form xxx^R. Du, Mousavi, Schaeffer, and Shallit asked whether this set of words grows polynomially or exponentially with length. In this ... -
Infinite words containing squares at every position
(EDP Sciences, 2010)Richomme asked the following question: what is the infimum of the real numbers α > 2 such that there exists an infinite word that avoids α-powers but contains arbitrarily large squares beginning at every position? We resolve ... -
It’s okay to be okay too. Why calling out teachers’ “toxic positivity” may backfire
(Canadian Education Network, 2020) -
Latent Profile Analysis of Manitoban Teachers' Burnout during the COVID-19 Pandemic
(University of Winnipeg, 2021-03) -
Least Periods of Factors of Infinite Words
(EDP Sciences, 2009)We show that any positive integer is the least period of a factor of the Thue-Morse word. We also characterize the set of least periods of factors of a Sturmian word. In particular, the corresponding set for the Fibonacci ... -
Mathematical Concepts and Proofs from Nicole Oresme: Using the History of Calculus to Teach Mathematics
(2005)This paper examines the mathematical work of the French bishop, Nicole Oresme (c. 1323–1382), and his contributions towards the development of the concept of graphing functions and approaches to investigating infinite ... -
The metric dimension and metric independence of a graph
(The Charles Babbage Research Centre, 2001)A vertex x of a graph G resolves two vertices u and v of G if the distance from x to u does not equal the distance from x to v. A set S of vertices of G is a resolving set for G if every two distinct vertices of G are ... -
The minimal automaton recognizing mN in a linear numeration system
(Integers, 2011-12-02)We study the structure of automata accepting the greedy representations of N in a wide class of numeration systems. We describe the conditions under which such automata can have more than one strongly connected component ... -
Multi-dimensional sets recognizable in all abstract numeration systems
(EDP Sciences, 2011)We prove that the subsets of Nd that are S-recognizable for all abstract numeration systems S are exactly the 1-recognizable sets. This generalizes a result of Lecomte and Rigo in the one-dimensional setting. -
Non repetitive walks in graphs and digraphs
(The University of CalgaryUniversity of Calgary, 1987-06)A word $w$ over alphabet $\Sigma$ is {\em non-repetitive} if we cannot write $w=abbc$, $a,b,c\in\Sigma^*$, $b\ne\epsilon$. That is, no subword of $w$ appears twice in a row in $w$. In 1906, Axel Thue, the Norwegian number ... -
Non-Repetitive Tilings
(The Electronic Journal of Combinatorics, 2002-07-03)In 1906 Axel Thue showed how to construct an infinite non-repetitive (or square-free) word on an alphabet of size 3. Since then this result has been rediscovered many times and extended in many ways. We present a two-dimensional ... -
A Note on Antichains of Words
(The Electronic Journal of Combinatorics, 1995-10-14)We can compress the word 'banana' as xyyz, where x= 'b', y= 'an',z= 'a'. We say that 'banana' encounters yy. Thus a 'coded' version of yy shows up in 'banana'. The relation 'u encounters w' is transitive, and thus generates ... -
The number of order–preserving maps of fences and crowns
(Springer, 1991-06)We perform an exact enumeration of the order-preserving maps of fences (zig-zags) and crowns (cycles). From this we derive asymptotic results. -
The Number of Ternary Words Avoiding Abelian Cubes Grows Exponentially
(2004-06-19)We show that the number of ternary words of length n avoiding abelian cubes grows faster than r^n, where r = 2^{1/24} -
On avoidability of formulas with reversal
(EDP Sciences, 2018-02-13)While a characterization of unavoidable formulas (without reversal) is well-known, little is known about the avoidability of formulas with reversal in general. In this article, we characterize the unavoidable formulas ... -
Opportunity solving: Ordinary people doing extraordinary things, every day
(Canadian Education Network, 2020-10-16) -
Overlap-Free Words and Generalizations
(University of WinnipegUniversity of Waterloo, 2007)The study of combinatorics on words dates back at least to the beginning of the 20th century and the work of Axel Thue. Thue was the first to give an example of an infinite word over a three letter alphabet that contains ... -
Planning for Teacher Recovery from the COVID-19 Pandemic: Adaptive Regulation to Promote Resilience
(Rivera Open, 2021-06-25)Increased job demands coupled with insufficient resources, typically result in job strain which can lead to burnout. However, in a series of studies conducted with Canadian teachers during the COVID-19 pandemic, the findings ...