Within just one week, Michael Wagner attended IWOCA2021 and the 2021 World Congress on Global Optimization (WCGO 2021). Scientists, engineers, mathematicians and practitioners from a variety of related disciplines exchanged ideas and presented original research results in the theory and applications of global optimization. On July 8th, Michael talked about his research on “In-Parameter-Order strategies for covering perfect hash families”, a joint work with Dimitris E. Simos and Charles J. Colbourn from the Arizona State University in Tempe, Arizona. By applying the well-researched In-Parameter-Order (IPO) strategy for covering array generation to construct covering perfect hash families – which can be considered a compact representation of a certain family of covering arrays – an algorithm was developed that can generate small (uniform) covering arrays very efficiently, even for large instances. These experiments establish new upper bounds on the size of optimal covering arrays for tens of thousands of instances. In addition, by applying this approach to covering perfect hash families with subspace restrictions, the vast majority of upper bounds for covering arrays of strength 3 with alphabet 4 and 5 were improved.
09 July, 2021