Demand modelling and optimal vertiport placement for airport-purposed eVTOL services

Recent technological advances have only recently made Urban Air Mobility feasible as a realistic alternative to existing transport modes. Despite the growing interest, this disruptive service requires accurate strategic investments to ensure its viability in the short- and long-term. While airports have been identified as potential sites for vertiports, extending operations to the urban rest … Read more

An Adaptive and Near Parameter-free BRKGA Using Q-Learning Method

The Biased Random-Key Genetic Algorithm (BRKGA) is an efficient metaheuristic to solve combinatorial optimization problems but requires parameter tuning so the intensification and diversification of the algorithm work in a balanced way. There is, however, not only one optimal parameter configuration, and the best configuration may differ according to the stages of the evolutionary process. … Read more

On the propagation of quality requirements for mechanical assemblies in industrial manufacturing

A frequent challenge encountered by manufacturers of mechanical assemblies consists of the definition of quality criteria for the assembly lines of the subcomponents which are mounted into the final product. The rollout of Industry 4.0 standards paves the way for the usage of data-driven, intelligent approaches towards this goal. In this work, we investigate such … Read more

Predicting the vibroacoustic quality of steering gears

In the daily operations of ThyssenKrupp Presta AG, ball nut assemblies (BNA) undergo a vibroacoustical quality test and are binary classified based on their order spectra. In this work we formulate a multiple change point problem and derive optimal quality intervals and thresholds for the order spectra that minimize the number of incorrectly classified BNA. … Read more

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

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

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

Biased and unbiased random-key genetic algorithms: An experimental analysis

We study the runtime performance of three types of random-key genetic algorithms: the unbiased algorithm of Bean (1994); the biased algorithm of Gonçalves and Resende (2011); and a greedy version of Bean’s algorithm on 12 instances from four types of covering problems: general-cost set covering, Steiner triple covering, general-cost set K-covering, and unit-cost covering by … Read more

Approximate-KKT stopping criterion when Lagrange multipliers are not available

In this paper we investigate how to efficiently apply Approximate-Karush-Kuhn-Tucker (AKKT) proximity measures as stopping criteria for optimization algorithms that do not generate approximations to Lagrange multipliers, in particular, Genetic Algorithms. We prove that for a wide range of constrained optimization problems the KKT error measurement tends to zero. We also develop a simple model … Read more

A biased random-key genetic algorithm for a 2D and 3D bin packing problem

We present a novel multi-population biased random-key genetic algorithm (BRKGA) for the 2D and 3D bin packing problem. The approach uses a maximal-space representation to manage the free spaces in the bins. The proposed algorithm uses a decoder based on a novel placement procedure within a multi-population genetic algorithm based on random keys. The BRKGA … Read more

A C++ application programming interface for biased random-key genetic algorithms

In this paper, we describe brkgaAPI, an efficient and easy-to-use object oriented application programming interface for the algorithmic framework of biased random-key genetic algorithms. Our cross-platform library automatically handles the large portion of problem-independent modules that are part of the framework, including population management and evolutionary dynamics, leaving to the user the task of implementing … Read more