Part of the publication 'Visionaries and unsung heroes : engineers, design, tomorrow'. It was written to accompany the exhibition "Visionäre und Alltagshelden. Ingenieure - Bauen - Zukunft" at the Oskar-von Miller Forum in Munich.
Bounding the range of a sum of rational functions is an important task if, e.g., the global polynomial sum of ratios problem is solved by a branch and bound algorithm. In this paper, bounding methods are discussed which rely on the expansion of a multivariate polynomial into Bernstein polynomials.