Let C be a nondegenerate planar curve and for a real, positive decreasing function ψ let C(ψ) denote the set of simultaneously ψ-approximable points lying on C. We show that C is of Khintchine type ...

The Census and BLS ratio-to-moving-average seasonal adjustment methods are usually specified by procedural steps. They can be written mathematically as combinations of linear and non-linear operations ...