WinnSpace Repository

Browsing James D. Currie by Title

Browsing James D. Currie by Title

Sort by: Order: Results:

  • Blanchet-Sadri, F.; Currie, James D.; Rampersad, Narad; Fox, Nathan (Integers, 2014-02-20)
    We study the combinatorics of vtm, a variant of the Thue-Morse word generated by the non-uniform morphism 0 ↦ 012, 1 ↦ 02, 2 ↦ 1 starting with 0. This infinite ternary sequence appears a lot in the literature and finds ...
  • Currie, James; Lafrance, Philip (The Electronic Journal of Combinatorics, 2016-02-19)
    For every pattern p over the alphabet {x, x^R, y, y^R}, we specify the least k such that p is k-avoidable.
  • Currie, J.; Linek, V. (Canadian Mathematical Society, 2001-08)
    We classify all 3 letter patterns that are avoidable in the abelian sense. A short list of four letter patterns for which abelian avoidance is undecided is given. Using a generalization of Zimin words we deduce some ...
  • Currie, James D.; Rampersad, Narad; Shallit, Jeffrey (The Electronic Journal of Combinatorics, 2006-09-22)
    We characterize the squares occurring in infinite overlap-free binary words and construct various α power-free binary words containing infinitely many overlaps.
  • Currie, James; Nowakowski, Richard (Ars Combinatoria, 1991)
    A graph is called well-covered if every maximal independent set has the same size. One generalization of independent sets in graphs is that of a fractional cover -- attach nonnegative weights to the vertices and require ...
  • Williams, Kenneth S.; Currie, James D. (Cambridge University Press, 1982)
  • Crochemore, Maxime; Currie, James D.; Kucherov, Gregory; Nowotka, Dirk (Dagstuhl Publishing, 2014-03-09)
    Strings (aka sequences or words) form the most basic and natural data structure. They occur whenever information is electronically transmitted (as bit streams), when natural language text is spoken or written down (as words ...
  • Currie, James (Carleton UniversityCarleton University, 1984-08)
    The thesis begins by giving background in linear programming and Simplex methods. Topics covered include the duality theorem, Lemke's algorithm, and the pathological programs of Klee-Minty. Because of the bad behaviour ...
  • Currie, James D.; Rampersad, Narad (Discrete Mathematics and Theoretical Computer Science, 2014-05-13)
    We construct infinite cubefree binary words containing exponentially many distinct squares of length n . We also show that for every positive integer n , there is a cubefree binary square of length 2n.
  • Currie, James; Rampersad, Narad (EDP Sciences, 2009)
    We show that Dejean’s conjecture holds for n ≥ 27. This brings the final resolution of the conjecture by the approach of Moulin Ollagnier within range of the computationally feasible.
  • Currie, James D. (Utilitas Mathematica, 1984)
  • Allouche, Jean-Paul; Currie, James D.; Shallit, Jeffrey (The Electronic Journal of Combinatorics, 1998-05-03)
    Let t be the infinite fixed point, starting with 1, of the morphism μ:0→01, 1→10. An infinite word over {0,1} is said to be overlap-free if it contains no factor of the form axaxa, where a∈{0,1} and x∈{0,1}∗. We prove that ...
  • Currie, James D.; Rampersad, Narad (The Electronic Journal of Combinatorics, 2008-08-31)
    The critical exponent of an infinite word w is the supremum of all rational numbers α such that w contains an α-power. We resolve an open question of Krieger and Shallit by showing that for each α>2 there is an infinite ...
  • Currie, James; Rampersad, Narad (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 ...
  • Currie, James D.; Saari, Kalle (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 ...
  • Currie, James Daniel (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 ...
  • Currie, James D.; Simpson, Jamie (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 ...
  • Currie, James D. (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 ...
  • Currie, James D.; Saari, Kalle (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.
  • Currie, James D.; Rampersad, Narad; Saari, Kalle (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 ...

Search WinnSpace


Browse

My Account