In this paper, we use a reformulation of the symmetric and the asymmetric travelling salesman problem more suitable for Lagrangean relaxation and analyse the new approach on examples from TSP Lib. Furthermore the Lagrangean relaxed subproblems are travelling salesman alike which means that...

Maritime bunker management (MBM) controls the procurement and consumption of the fuels used on board and therefore manages one of the most important cost drivers in the shipping industry. At the operational level, a shipping company needs to manage its fuel consumption by making optimal routing...

The shipping industry carries over 90 percent of the world's trade, and is hence a major contributor to CO2 and other airborne emissions. As a global effort to reduce air pollution from ships, the implementation of the ECA (Emission Control Areas) regulations has given rise to the wide usage of...

Bernard Gendron and Operations Research -- Methodological Developments -- Variable Neighbourhood Search with Dynamic Exploration for the Set Union Knapsack Problem -- Common-Flow Formulations for the Diameter Constrained Spanning Tree Problem -- Models and Methods for Two-Level Uncapacitated...