[EN] The variation in the vertical rigidity of the track produced between masonry and natural terrain generates an increase in vertical accelerations that affect the comfort of travelers, as well as the safety and maintenance ...

[EN] Let X be a smooth fan and denote its set of endpoints by E(X). Let E be one of the following spaces: the natural numbers, the irrational numbers, or the product of the Cantor set with the natural numbers. We prove ...