Second-year undergraduated students from 2008, 2009, and 2010 cohorts were asked to respond a questionnaire to determine their learning style preferences, the VARK questionnaire (where V is visual, A is aural, R is reading-writing, and K is kinesthetic), which was translated into Spanish by the author. The translated questionnaire was tested for wording comprehension before its application in t...

Research in the field of nonparametric shape constrained regression has been extensive and there is need for such methods in various application areas, since shape constraints can reflect prior knowledge about the underlying relationship. It is, for example, often natural that some intensity first increases and then decreases over time, which can be described by a unimodal shape constraint. But...

While the forward trajectory of a point in discrete dynamical system is always unique, general can have infinitely many backward trajectories. The union limit points all trajectories through $x$ was called by M.~Hero "special $\alpha$-limit" ($s\alpha$-limit for short) $x$. In this article we show that there hierarchy $s\alpha$-limits under iterations S-unimodal map: size $s\alpha$-limit increa...