Now showing items 18-21 of 21

    • Shuffling and unshuffling 

      Henshall, Dane; Rampersad, Narad; Shallit, Jeffrey (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 ...
    • Squares and overlaps in the Thue-Morse sequence and some variants 

      Brown, Shandy; Rampersad, Narad; Shallit, Jeffrey; Vasiga, Troy (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 

      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 ...
    • Words with many palindrome pair factors 

      Borchert, Adam; Rampersad, Narad (The Electronic Journal of Combinatorics, 2015-10-30)
      Motivated by a conjecture of Frid, Puzynina, and Zamboni, we investigate infinite words with the property that for infinitely many n, every length-n factor is a product of two palindromes. We show that every Sturmian word ...