metaheuristics

A heuristic framework for a class of vehicle routing problems

Categories Combinatorial Optimization, Meta Heuristics, Transportation Tags , , ,

We propose GenericILS, a general-purpose heuristic framework for generating high-quality upper bounds for Vehicle Routing Problems whose pricing subproblems are modeled, in column-generation-based exact algorithms, as resource-constrained shortest path problems described through Resource Extension Functions (REFs), the standard device for encoding constraints in branch-and-price algorithms. GenericILS reuses REFs implemented for the exact method, without a … Read more

Rethinking Last-Mile Routing at Scale: Near-Linear Planning on Commodity Hardware

Categories Optimization Software and Modeling Systems, Production and Logistics, Supply Chain Management Tags , , , , , , , , , , , , , ,

This paper presents a practical architecture for last-mile delivery routing at scales reaching one million stops under realistic operational conditions, including vehicle capacity, package volume, route stop limits, and time windows. Unlike conventional systems that require pre-partitioning or large-scale infrastructure, the proposed system addresses the full fleet planning problem through a single coherent planning pipeline … Read more

An Efficient Tabu Search Algorithm for the Tool Indexing Problem

Categories Meta Heuristics, Production and Logistics Tags , , ,

In this paper, we look at the tool indexing problem in which a single copy of each tool is allowed in the tool magazine. We develop problem specific methods to search the neighborhood efficiently and design a Tabu Search algorithm based on them. Computational experiments show that our algorithm is competent. CitationIndian Institute of Management … Read more

Robust Optimization of a Broad Class of Heterogeneous Vehicle Routing Problems under Demand Uncertainty

Categories Robust Optimization, Transportation Tags , , , , ,

This paper studies robust variants of an extended model of the classical Heterogeneous Vehicle Routing Problem (HVRP), where a mixed fleet of vehicles with different capacities, availabilities, fixed costs and routing costs is used to serve customers with uncertain demand. This model includes, as special cases, all variants of the HVRP studied in the literature … Read more

A Decision Tool based on a Multi-Objective Methodology for designing High-Pressure Thermal Treatments in Food Industry

Categories Meta Heuristics, Optimization of Systems modeled by PDEs, Systems governed by Differential Equations Optimization Tags , , , ,

In this work, we propose a methodology for designing High-Pressure Thermal processes for food treatment. This approach is based on a multi-objective preference-based evolutionary optimization algorithm, called WASF-GA, combined with a decision strategy which provides the food engineer with the best treatment in accordance with some quality requirements. The resulting method is compared to a … Read more

A Biased Random-Key Genetic Algorithm for the Berth Allocation and Quay Crane Assignment Problem

Categories Applications - OR and Management Sciences Tags , , , , ,

Maritime transportation plays a crucial role in the international economy. Port container terminals around the world compete to attract more traffic and are forced to offer better quality of service. This entails reducing operating costs and vessel service times. In doing so, one of the most important problems they face is the Berth Allocation and … Read more

Cutting Box Strategy: an algorithmic framework for improving metaheuristics for continuous global optimization

Categories Constrained Nonlinear Optimization, Stochastic Approaches Tags , , ,

In this work, we present a new framework to increase effectiveness of metaheuristics in seeking good solutions for the general nonlinear optimization problem, called Cutting Box Strategy (CBS). CBS is based on progressive reduction of the search space through the use of intelligent multi-starts, where solutions already obtained cannot be revisited by the adopted metaheuristic. … Read more

A hybrid Lagrangean metaheuristic for single machine scheduling problem with sequence-dependent setup times and due dates

Categories Meta Heuristics, Scheduling Tags , , , ,

In this article, a hybrid Lagrangean metaheuristic is proposed for single machine scheduling problems with sequence-dependent setup times and due dates. The objective function considered throughout this work, is to minimize the total tardiness. Related works and taxonomies for hybrid metaheuristics are analyzed, through a thorough historical overview. The proposed hybrid Lagrangean metaheuristic is a … Read more

Nonmonotone GRASP

Categories Meta Heuristics Tags , , , , ,

A Greedy Randomized Adaptive Search Procedure (GRASP) is an iterative multistart metaheuristic for difficult combinatorial optimization problems. Each GRASP iteration consists of two phases: a construction phase, in which a feasible solution is produced, and a local search phase, in which a local optimum in the neighborhood of the constructed solution is sought. Repeated applications … Read more

Exact and Heuristic Approaches for Directional Sensor Control

Categories (Mixed) Integer Nonlinear Programming, Branch and Cut Algorithms, Control Applications Tags , , ,

Directional sensors are gaining importance due to applications, in- cluding surveillance, detection, and tracking. Such sensors have a limited fi eld-of-view and a discrete set of directions they can be pointed to. The Directional Sensor Control problem (DSCP) consists in assigning a direction of view to each sensor. The location of the targets is known with … Read more