## Resources

On this page I will provide codes, data and solutions related to papers I published.

Besides, here is a list of interesting other websites related to scheduling and operations research:

- Complexity results for scheduling problems (P. Brucker, S. Knust),
- Taillard's instances for flowshop, jobshop and openshop scheduling problems,
- Instances for shop scheduling problems from the SOA group,
- Fan of complexity classes? Have a look to the complexity zoo,
- The famous MIPLIB repository of instances,
- Instances of various OR problems (Beasley's lib),
- The Vehicle Routing Repository (VRP-REP).

## Total tardiness problem

A new exact algorithm for solving the single machine problem with minimization of the total tardiness has been released here. This algorithm makes use of a memorization technique and strongly outperforms state-of-the-art exact algorithms for this problem.

The code of this algorithm is available here. In this repository, all the instances on which the algorithm has been tested are also provided.

## The memorization paradigm for branch-and-bound algorithms

A memorization technique has been considered in branch-and-bound algorithms for some scheduling problems, leading to improve drasticaly the effectiveness of such algorithms. It has been applied to 4 scheduling problems: single machine scheduling problems with minimization of the total tardiness (1||Sum Tj), of the sum of completion times with release dates (1|rj|Sum Cj), of the weighted sum of completion times with deadlines (1|Dj|Sum wjCj), and a 2-machine flowshop scheduling problem with minimization of the sum of completion times (F2||Sum Cj).

This research work is described here. The codes and the data sets are also available:

## Solving a time-indexed formulation for an unrelated parallel machine scheduling problem by preprocessing and cutting planes

A joint work with Lotte Berghman (University of Toulouse, Toulouse Business School, France) and Frits Spieksma (ORSTAT, KU Leuven, Belgium).

A draft of the paper and the instances used for evaluation of the models are available on the HAL website: click here.

## Graph Matching problems and the Graph Edit Distance Problem: a contribution of Operations Research

Graphs are powerfull tools to model various objects extracted from real-life applications. For example, in Pattern Recognition they be can used to model images or objects in images. In chemistry, again, to compare two molecules we may be interested to compare the two associated graph representations. Graph Matching is an extensively studied research field. During the Ph.D. thesis of Mostafa DARWICHE (2015-2018) we proposed effective Operations Research heuristic and exact algorithms to solve a particular Graph Matching problem: the Graph Edit Distance problem. More information on these contributions are available here.