 As part of this work he introduced the logarithmic norm (also introduced by Russian mathematician Sergei Lozinskii the same year).In 1959 he moved to the Royal Institute of Technology (KTH), where he would later establish what became the Department of Numerical Analysis and Computer Science (NADA) in 1962 (now part of the School of Computer Science and Communication), and become Sweden's first Professor of Numerical Analysis in 1963.He helped establish the Nordic journal of numerical analysis, BIT, in 1961.