Discrete optimization as decision support

It is fascinating that mathematical models and algorithms can be used to compute and suggest good decisions when faced with a choice situation so complex that it is difficult for a human to grasp all aspects of it. Research within optimization is about pushing the limits for which problems that can successfully be addressed. My research is within discrete optimization, with a special interest in decomposition methods, and I mainly work with applications related to scheduling and resource allocation.

Professional activities

Student theses

  • "Work Distribution for a Heterogeneous Library Staff: A Personnel Task Scheduling Problem" by Emelie Karlsson and Claes Arvidson, 2016. Initiated by Lyskraft and carried out in collaboration with Norrköpings Stadsbibliotek.
  • "Conditional steepest descent directions over Cartesian product sets: With application to the Frank-Wolfe method" by Johan Högdahl, 2015.
  • "Handover Optimization in GSM" by Johann Joachim Pavski, 2015. In collaboration with Ericsson.

List of student theses in DiVA

List of student theses not in DiVA (PDF)

Current teaching

  • Operations Research, Extended Course (TAOP37) for Industrial Engineering and Management, and Industrial Engineering and Management - International
  • Project - Applied Mathematics (TATA62) for Applied Physics and Electrical Engineering

Research domain

PhD students

Former PhD students

Yixin Zhao, 2012-2016



Fred Mayambala, Elina Rönnberg, Torbjörn Larsson

Tight Upper Bounds on the Cardinality Constrained Mean-Variance Portfolio Optimization Problem Using Truncated Eigendecomposition

Conference paper

Yixin Zhao, Torbjörn Larsson, Di Yuan, Elina Rönnberg, Lei Lei

Power efficient uplink scheduling in SC-FDMA: benchmarking by column generation

Article in journal

Yixin Zhao, Torbjörn Larsson, Elina Rönnberg

A Large Neighbourhood Search Principle for Column-Oriented Models: Theoretical Derivation and Example Applications

Conference paper


Fred Mayambala, Elina Rönnberg, Torbjörn Larsson

Eigendecomposition of the mean-variance portfolio optimization model

Chapter in book


Elina Rönnberg, Torbjörn Larsson

All-integer column generation: Basic principles and extensions

Article in journal


Hongmei Zhao, Lei Lei, Di Yuan, Torbjörn Larsson, Elina Rönnberg

Power efficient uplink scheduling in SC-FDMA: Bounding global optimality by column generation

Conference paper