Sven Leyffer, a computational mathematician in the Mathematics and Computer Science Division has been named a Fellow of the Society for Industrial and Applied Mathematics (SIAM).

Leyffer is developing and applying nonlinear optimization methodologies to emerging areas such as mixed-integer nonlinear optimization and optimization problems with complementarity constraints. Examples include seeing how electricity producers maximize profit in a deregulated market while exploiting government- allocated NOx permits to drive up costs of their competitors.

Leyffer, along with two colleagues, received the Lagrange Prize in Continuous Optimization in 2006 for seminal work on filter methods; the prize is awarded jointly by the Mathematical Programming Society and SIAM once every three years. He is also a fellow of the Argonne/University of Chicago Computation Institute and an adjunct professor at Northwestern University.

Leyffer served as the INFORMS Optimization Society vice-chair for nonlinear programming and was the program director of the SIAM activity group on optimization. He currently is on the editorial boards of the SIAM Journal on Optimization, Computational Optimization and Applications, and Computational Management Science. He also is an editor-in-chief of Mathematical Methods of Operations Research and the coordinating editor for nonlinear optimization of Mathematical Programming Computation.