Systems and Control > Operations research and discrete optimization


Focus

The Operations Research and Discrete Optimization (ORDO) group investigates and develops mathematical models and optimization methods for tackling complex decision-making problems. The main research focus is the study and the solution of linear and nonlinear discrete optimization problems, with an emphasis on those related to graphs and networks. The areas of application range from telecommunications and transportation to data mining and health care management. The expertise is in: mathematical programming; design and analysis of exact, approximate and heuristic algorithms; combinatorial optimization; graph theory and computational complexity. Research is often motivated by important applications but simplified versions of the problems or abstractions are also investigated from a theoretical point of view.

Most relevant research achievements


• Methodological work includes: hybrid methods combining Constraint Programming and Mathematical Optimization in particular within a column generation framework which allowed us to solve many open instances of graph coloring, improved cutting plane generation strategies for integer programming based on the new idea of cut coordination, and an efficient relaxation-based method for the maximum feasible subsystem problem (MaxFS).
• Innovative mathematical models and optimization algorithms for several important decision problems arising in the design and management of telecommunication networks, both wired and wireless. Concerning wired networks, the main focus was on designing virtual private networks under traffic uncertainty, broadband networks (fiber to the home), and two-layer networks, taking into account fault protection. As to the wireless case, the emphasis was on planning Wireless Local Area networks and Mesh networks.
• Optimization models and algorithms for planning and managing hybrid flexible collective transportation systems, freight and hazardous material transportation and personnel workforce scheduling in public transportation. The results of this last research have been implemented and used by some of the main Italian transportation companies, within a collaboration with MAIOR s.r.l.