Browsing Department of Mathematics and Statistics by Title
Now showing items 45-64 of 73
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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 ... -
Prediction of the Moisture Content of Eastern Canadian Corn using Measurements of Capacitance and Test Weight
(NRC Research Press, 1989-01)A statistical regression model for rapid prediction of moisture content based on measurements of dielectric capacitance and test weight was developed for Eastern Canadian corn (Zea mays L.). For 336 samples of the 1986 ... -
Regular Two-Graphs and Equiangular Lines
(University of WinnipegUniversity of Waterloo, 2004)Regular two-graphs are antipodal distance-regular double coverings of the complete graph, and they have many interesting combinatorial properties. We derive a construction for regular two-graphs containing cliques of ... -
Self-Complementary Hypergraphs
(University of OttawaUniversity of Ottawa and Carleton University (joint program), 2009)In this thesis, we survey the current research into self-complementary hypergraphs, and present several new results. We characterize the cycle type of the permutations on n elements with order equal to a power of 2 which ... -
Shuffling and unshuffling
(Bulletin of the European Association for Theoretical Computer Science, 2012)We consider various shuffling and unshuffling operations on languages and words, and examine their closure properties. Although the main goal is to provide some good and novel exercises and examples for undergraduate formal ... -
Skeleton Cave, Leigh Woods, Bristol
(University of Bristol Spelaeological Society, 2017)An account is given of the discovery and excavation of this small cave in the 1960s. It is recorded that archaeological finds were made, but of these, only a single human mandible can now be traced. Radiocarbon dating shows ... -
Sliding Down Inclines with Fixed Descent Time: a Converse to Galileo's Law of Chords
(Canadian Mathematical Society, 2008-12) -
Square-free Words with Square-free Self-shuffles
(The Electronic Journal of Combinatorics, 2014-01-12)We answer a question of Harju: For every n ≥ 3 there is a square-free ternary word of length n with a square-free self-shuffle. -
Squares and overlaps in the Thue-Morse sequence and some variants
(EDP Sciences, 2006)We consider the position and number of occurrences of squares in the Thue-Morse sequence, and show that the corresponding sequences are 2-regular. We also prove that changing any finite but nonzero number of bits in the ... -
Suffix conjugates for a class of morphic subshifts
(Cambridge University Press, 2015-09)Let A be a finite alphabet and f: A^* --> A^* be a morphism with an iterative fixed point f^\omega(\alpha), where \alpha{} is in A. Consider the subshift (X, T), where X is the shift orbit closure of f^\omega(\alpha) and ... -
Supporting Teachers in Times of Change: The Job Demands- Resources Model and Teacher Burnout During the COVID-19 Pandemic
(RedFame, 2020-10)Burnout in teachers has been broadly investigated, but no studies have investigated burnout in teachers during a pandemic. The current study is based on a survey of 1278 Canadian teachers and examined whether the Job ... -
Teachers' Voices: Pandemic Lessons for the Future of Education
(University of Windsor, 2021-05-26)In late 2019 and early 2020, governments around the world closed educational institutions due to the COVID-19 pandemic. A similar response occurred in Canada and resulted in a sudden pivot by teachers from classroom-based ...
