Francesco Demelas
PhD Student
PhD student in Computer Science, member of the LIPN (Laboratoire d'Informatique de Paris Nord), at the University of Sorbonne Paris Nord in France.
I teach at the Institut Galilee.
My research focuses on the intersection of Operations Research and Machine Learning.
I already work on specialized Machine Learning techniques within the context of Lagrangian Relaxation
and the unrolling of the Bundle method.
Lagrangian relaxation stands among the most efficient approaches for solving Mixed Integer Linear Programs (MILPs) with difficult constraints. Given any duals for these constraints, called Lagrangian Multipliers (LMs), it returns a bound on the optimal value of the MILP, and Lagrangian methods seek the LMs giving the best such bound. But these methods generally rely on iterative algorithms resembling gradient descent to maximize the concave piecewise linear dual function: the computational burden grows quickly with the number of relaxed constraints.
The concept of Algorithm Unrolling entails the transformation of an iterative algorithm's execution into a continuous differential representation. This adaptation facilitates the incorporation of neural networks within the algorithm's execution, while retaining the ability to compute gradients for subsequent backpropagation steps. Currently, my research focuses on refining this technique within the framework of the Bundle Algorithm, a highly efficient iterative method commonly employed for optimizing piecewise linear functions.
Francesco Demelas, Joseph Le Roux, Mathieu Lacroix, Axel Parmentier (2024)
International Conference of Machine Learning, (ICML)
Vienna, Austria, July 21-27.