Aalto University School of Science and Technology, Department of Information and Computer Science, Helsinki Institute for Information Technology HIIT, PO Box 15400, FI-00076 Aalto, Espoo, Finland. ilkka.huopaniemi@tkk.fi|Aalto University School of Science and Technology, Department of Information and Computer Science, Helsinki Institute for Information Technology HIIT, PO Box 15400, FI-00076 Aalto, Espoo, Finland. ilkka.huopaniemi@tkk.fi|Aalto University School of Science and Technology, Department of Information and Computer Science, Helsinki Institute for Information Technology HIIT, PO Box 15400, FI-00076 Aalto, Espoo, Finland. ilkka.huopaniemi@tkk.fi|Aalto University School of Science and Technology, Department of Information and Computer Science, Helsinki Institute for Information Technology HIIT, PO Box 15400, FI-00076 Aalto, Espoo, Finland. ilkka.huopaniemi@tkk.fi|Aalto University School of Science and Technology, Department of Information and Computer Science, Helsinki Institute for Information Technology HIIT, PO Box 15400, FI-00076 Aalto, Espoo, Finland. ilkka.huopaniemi@tkk.fi