We show that the following unlinking strategy does not always yield an optimal sequence of crossing changes: first split the link with the minimal number of crossing changes, and then unknot the resulting components. The unlinking number u(L) of a link L in S is the minimal number of crossing changes required to turn a diagram of L into a diagram of the unlink. Here we take the minimum over all...

This paper presents a new family of complex spreading sequences designed using mutually orthogonal(MO) complementary sets. Based on the technique described in this paper, the correlation properties ofsets ofsequences are compared to well-known Walsh-Hadamard sequence sets. Further improvement of correlation qualities can be achieved by employing a diagonal modification method. We also present s...

Background: The purpose of this study was to describe advertisements of children's entertainment products in a popular magazine, Parents, and to determine if they illustrated behavior that was physically active or sedentary. Methods: The sample was comprised of Parents magazines (January 2010 to December 2015). Coding involved determining if the advertisement was promoting sedentary or active b...