The stochastic multi-modal hub location problem with direct link strategy and multiple capacity levels for cargo delivery systems
Xiaoting Shang, Kai Yang, Bin Jia, Ziyou Gao
Abstract
This paper introduces the stochastic multi-modal hub location problem with direct link strategy and multiple capacity levels for cargo delivery systems under demand uncertainty. For capturing the uncertain nature of demand, we present a stochastic optimization model to formulate this problem formally via the expected value and the chance-constrained programming techniques. Under some mild assumptions, we propose a computationally tractable approach to turn the original model into a crisp equivalent integer second-order cone programming model, which can be efficiently solved by CPLEX for only small instances. Hence, we design a memetic algorithm incorporating genetic search and local intensification for realistic size instances. Furthermore, we provide extended analyses of the original model by considering the mode-specific hub and incorporating the fixed transportation cost. To demonstrate the superiority of the proposed model and the effectiveness of the solution approach, we conduct a series of computational experiments based on Turkish network data set.