Truck synchronization at single door cross-docking terminals
Authors: Antonino Chiarello, Manlio Gaudioso, Marcello Sammarra
Journal: OR Spectrum (2018),
URL: https://doi.org/10.1007/s00291-018-0510-x
Abstract: We address the problem of synchronizing the loading and discharging operations of trucks at a particular cross-docking center, with one door at both the inbound and outbound sides, aiming at minimizing the makespan of the whole process. We propose a mixed integer linear model and a Lagrangian decomposition scheme. We derive conditions for optimally solving both the Lagrangian relaxation and the dual problems. Based on the theoretical results, we propose a Lagrangian heuristic for computing many feasible solutions and gathering the best one among them. An extensive computational experience validates our Lagrangian heuristic, also in comparison with a state-of-the-art benchmark solver and a heuristic algorithm from the literature.
Keywords: Scheduling, Optimization models, Lagrangian relaxation, Heuristics
Some Complexity Results for the Minimum Blocking Items Problem
Authors: T. Bacci, S. Mattia, and P. Ventura
Book: Optimization and Decision Science: Methodologies and Applications
URL: http://doi.org/10.1007/978-3-319-67308-0_48
Abstract: In this paper, we study the Minimum Blocking Items Problem (MBIP) as a generalization of the Bounded Coloring Problem for Permutation Graphs and we motivate our interest by discussing some practical applications of MBIP to the context of minimizing reshuffle operations in a container yard. Then we present some results on the computational complexity of MBIP.
Keywords: Bounded coloring problem, Block relocation problem, Complexity.
Managing the ship movements in the Port of Venice
Authors: E. Canestrelli, M. Corazza, G. De Nadai, and R. Pesenti
Journal: Networks and Spatial Economics
URL: http://dx.doi.org/10.1007/s11067-017-9350-5
Summary: The new mobile gates at the inlets of the Venice lagoon and the new previous environmental laws issued in response of the Costa Concordia wreckage in 2012 have forced the Port Authority of Venice to rethink the harbor activities. In this paper, we tackle the Port Scheduling Problem that the Port Authority faces in scheduling both ships’ and tugs’ movements within its canal harbor in this new context. We introduce the problem, explain which data it needs, and provide the description of an original heuristic algorithm for its solution. Finally, we present some practical applications..
Keywords: Scheduling problem, Network design, Optimization, Port of Venice.
The best stack algorithm for the block relocation problem
Authors: T. Bacci, S. Mattia, and P. Ventura
Workshop: EU/ME 2017
URL: https://sites.google.com/view/eume2017/book-of-abstracts?authuser=0
Abstract: In this paper we present a new beam search algorithm for the Block Relocation Problem. We show that our algorithm outperforms the other existing heuristic approaches on most of the instances in the literature.
Keywords: Block Relocation, Container Relocation, Beam Search.