From my childhood I have been interested in organizing information—in computers and on paper. In fact, my earliest algorithms and data structures were designed for pen and paper. In my role as mentor of the Arnhems Interscholair Orkest, a youth orchestra with a non-trivial cash flow managed by teenagers, I set up an accounting system based on paper forms designed to be filled out by children. With these forms they could calculate all the numbers they needed for their financial reports. From 1999 to 2004 I worked as a researcher at the University of Utrecht in the Netherlands, while completing basic courses (propedeuse) in law and developing, manufacturing, and selling board games as one of the partner-founders of Splotter Games. In 2004 I obtained my PhD for my research on spatial data structures. After that I worked as a researcher at the Karlsuhe Institute of Technology in Germany and Aarhus University in Denmark, where I gained experience with designing and implementing robust and efficient algorithms for massive data. From 2005 until 2018 I worked as a lecturer and researcher at the Eindhoven University of Technology in the Netherlands. Since September 2018, I have been working at the University of Bonn in Germany.
Through the years I have been teaching and organizing several courses, seminars, lab projects and research projects on algorithms, ranging from the basics to advanced topics such as external-memory algorithms, computations on terrain models, clustering, and route planning. I tend to pay particular attention to the benefits and limitations of theoretical models for the analysis of algorithms, that is, how they relate to performance in practice. Occasionally I have given guest lectures on external-memory algorithms in other universities. In 2011 and 2014 I was a jury member of the Benelux Algorithm Programming Contest, creating programming challenges and developing test data to evaluate the contestants' solutions. For several years I was a member of the examination and quality assurance committee of the TU Eindhoven computer science department. Recently I have been working on collecting or developing concise material on general research skills (such as formulating research questions, assessing references, charting results, writing, ethical decision making) targeted at computer science students.
In recent years the focus of my research has been on the theory and applications of recursive tilings and space-filling curves, cache-efficient algorithms for mesh traversals in computational science and geographic information science, and schematization in automated cartography. Currently I am studying, among other things, how algorithms can be used to explore possible solutions to architectural design problems (with architecture historian Sergio Figueiredo from the TU Eindhoven Department of the Built Environment), and how high-dimensional space-filling curves and their properties can be illustrated and explored using sound (with Julian Rohrhuber from the Robert Schumann University of Music and Media). I have supervised PhD students' and Master students' projects on various topics in space-filling curves, external-memory algorithms, GPU algorithms, automated cartography, computations on terrain models, computer vision (for cars), speech recognition, geometric combinatorial optimization, spatial index structures, and more.
I have served on the programme committees of several workshops and conferences, including 32nd IEEE International Conference on Data Engineering (ICDE 2016), the 9th International Conference on Algorithms and Complexity (CIAC 2015) and the Schematic Mapping Workshop 2014. I am an editor for the Journal of Computational Geometry and Springer's Encyclopedia of Algorithms.
I live in Bonn with my wife and our two children Emma (2011) and Frida (2015).