Volumetric Techniques for Product Routing and Loading Optimisation in Industry 4.0: A Review

Industry 4.0 has become a crucial part in the majority of processes, components, and related modelling, as well as predictive tools that allow a more efficient, automated and sustainable approach to industry. The availability of large quantities of data, and the advances in IoT, AI, and data-driven frameworks, have led to an enhanced data gathering, assessment, and extraction of actionable information, resulting in a better decision-making process. Product picking and its subsequent packing is an important area, and has drawn increasing attention for the research community. However, depending of the context, some of the related approaches tend to be either highly mathematical, or applied to a specific context. This article aims to provide a survey on the main methods, techniques, and frameworks relevant to product packing and to highlight the main properties and features that should be further investigated to ensure a more efficient and optimised approach

Novel approaches to container loading: from heuristics to hybrid tabu search

A thesis submitted for the degree of Doctor of Philosophy of the University ofBedford shireThis work investigates new approaches to the container loading problem which address the issue of how to load three-dimensional, rectangular items (e.g. boxes) into the container in such a way that maximum utilisation is made of the container space. This problem occurs in several industry sectors where the loading approach places cargo effectively into aeroplanes, ships, trailers or trucks in order to save considerable cost. In carrying out this work, the investigation starts by developing a new heuristic approach to the two-dimensional bin packing problem, which has lower complexity than container loading in the aspects of constraints and geometry. A novel approach, including the heuristic strategies and handling method for remaining areas, is developed that can produce good results when testing with benchmark and real world data. Based on the research for two-dimensional bin packing, a novel heuristic approach is developed to deal with the container loading problem with some practical constraints. The heuristic approach to container loading also includes heuristic strategies and the handling of remaining spaces. The heuristic strategies construct effective loading arrangements where combinations of identical or different box types are loaded in blocks. The handling method for remaining spaces further improves the loading arrangements through the representation, partitioning and merging of remaining spaces. The heuristic approach obtains better volume utilisation and the highest stability compared with other published heuristic approaches. However, it does not achieve as high a volume utilisation as metaheuristic approaches, e.g. genetic algorithms and tabu search.To improve volume utilisation, a new hybrid heuristic approach to the container loading problem is further developed based on the tabu search technique which covers the encoding, evaluation criterion and configuration of neighbourhood and candidate solutions. The heuristic strategies as well as the handling method for remaining spaces developed in the heuristic approach are used in this new hybrid tabu search approach. It is shown that the hybrid approach has better volume utilisation than the published approaches under the condition that all loaded boxes with one hundred per cent support from below. In addition, the experimental results show that both the heuristic and hybrid tabu search approaches can also be applied to the multiple container loading problem

Calibration of the numerical model of a freight railway vehicle based on experimental modal parameters

The simulation of the dynamic behavior of the train-track system is strongly dependent on the accuracy of the numerical models of the train and track subsystems. The use of calibrated numerical models of the railway vehicles, based on experimental data, enhances their ability to correctly reproduce the dynamic responses of the train under operational conditions. In this scope, studies involving the experimental calibration of freight wagon models are still scarce. This article aims to fill this gap by presenting an efficient methodology for the calibration of a numerical model of a freight railway wagon based on experimental modal parameters. A dynamic test was performed during the unloading operation of the train, adopting a dedicated approach which does not interfere with its tight operational schedule. From data collected during the dynamic test, five natural frequencies and mode shapes associated with rigid-body and flexural movements of the wagon platform were identified through the Enhanced Frequency-Domain Decomposition (EFDD) method. A detailed 3D finite-element (FE) model of the loaded freight wagon was developed, requiring precise knowledge of the vehicle design details which, in most situations, are difficult to obtain due to confidentiality reasons of the manufacturers. The model calibration was performed through an iterative method based on a genetic algorithm and allowed to obtain optimal values for seven numerical parameters related to the suspension’s stiffnesses and mass distribution. The stability of the parameters considering different initial populations demonstrated the robustness of the optimization algorithm. The average error of the natural frequencies decreased from 8.5% before calibration to 3.2% after calibration, and the average MAC values improved from 0.911 to 0.950, revealing a significant improvement of the initial numerical model.The authors would like to acknowledge the support of the Base Funding UIDB/04708/2020 and Programmatic Funding UIDP/04708/2020 of the CONSTRUCT (Instituto de I&D em Estruturas e Construções) funded by national funds through the FCT/MCTES (PIDDAC). The authors also express their gratitude to Dr. Nuno Pinto and Mr. Valdemar Luís, both technicians of LESE laboratory, for their indispensable assistance during the preparation and execution of the experimental testinfo:eu-repo/semantics/publishedVersio

Optimization for Decision Making II

In the current context of the electronic governance of society, both administrations and citizens are demanding the greater participation of all the actors involved in the decision-making process relative to the governance of society. This book presents collective works published in the recent Special Issue (SI) entitled “Optimization for Decision Making II”. These works give an appropriate response to the new challenges raised, the decision-making process can be done by applying different methods and tools, as well as using different objectives. In real-life problems, the formulation of decision-making problems and the application of optimization techniques to support decisions are particularly complex and a wide range of optimization techniques and methodologies are used to minimize risks, improve quality in making decisions or, in general, to solve problems. In addition, a sensitivity or robustness analysis should be done to validate/analyze the influence of uncertainty regarding decision-making. This book brings together a collection of inter-/multi-disciplinary works applied to the optimization of decision making in a coherent manner

Time-domain simulation of seakeeping and manoeuvring of ships in deep and shallow water waves

The present thesis deals with the topic of ship manoeuvring in waves and the effects imposed by the shallow water. In this aspect, ship's manoeuvrability is investigated using a numerical method, which was developed according to a hybrid approach where seakeeping and manoeuvring contributions are blended. In order to ensure that the aforementioned model incorporates correctly seakeeping and calm water manoeuvring approaches, separate validation processes are followed beforehand. In case of nonlinear seakeeping analysis, parametric roll investigation is undertaken as well, as a mean to verify that the developed methodology evaluates properly the fundamental external forces, especially roll damping. In this way, a framework is established which offers the ability to perform holistic hydrodynamic assessment of marine vessels as well.;Validation of the developed computational code is conducted using experimental turning circle trajectories, which refer to deep water conditions. The case studies concern the horizontal motions of the S-175 container ship at long waves and four values of under keel clearance corresponding to medium-deep (UKC=3.0, 2.5, 2.0) and shallow waters (UKC=1.5). In this aspect, the wave forces as well as the manoeuvring-related ones are corrected using relevant methodologies. In particular, a 3D potential flow method is adopted for the evaluation of the former, whilst corrections are applied on the various manoeuvring-related force components defined by the Manoeuvring Modelling Group (Ogawa et al., 1977). Especially in case of the added resistance, near and far-field methods are implemented based on the size of the wavelength with respect to the ship's length.;The empirical corrections which refer to the manoeuvring-related forces and are used in order to incorporate the shallow water effect, concern the hydrodynamic hull forces, the calm water resistance and various hull-rudder-propeller interaction coefficients and are based on regression formulae which are functions of the under keel clearance ratio.The present thesis deals with the topic of ship manoeuvring in waves and the effects imposed by the shallow water. In this aspect, ship's manoeuvrability is investigated using a numerical method, which was developed according to a hybrid approach where seakeeping and manoeuvring contributions are blended. In order to ensure that the aforementioned model incorporates correctly seakeeping and calm water manoeuvring approaches, separate validation processes are followed beforehand. In case of nonlinear seakeeping analysis, parametric roll investigation is undertaken as well, as a mean to verify that the developed methodology evaluates properly the fundamental external forces, especially roll damping. In this way, a framework is established which offers the ability to perform holistic hydrodynamic assessment of marine vessels as well.;Validation of the developed computational code is conducted using experimental turning circle trajectories, which refer to deep water conditions. The case studies concern the horizontal motions of the S-175 container ship at long waves and four values of under keel clearance corresponding to medium-deep (UKC=3.0, 2.5, 2.0) and shallow waters (UKC=1.5). In this aspect, the wave forces as well as the manoeuvring-related ones are corrected using relevant methodologies. In particular, a 3D potential flow method is adopted for the evaluation of the former, whilst corrections are applied on the various manoeuvring-related force components defined by the Manoeuvring Modelling Group (Ogawa et al., 1977). Especially in case of the added resistance, near and far-field methods are implemented based on the size of the wavelength with respect to the ship's length.;The empirical corrections which refer to the manoeuvring-related forces and are used in order to incorporate the shallow water effect, concern the hydrodynamic hull forces, the calm water resistance and various hull-rudder-propeller interaction coefficients and are based on regression formulae which are functions of the under keel clearance ratio

Dynamics in Logistics

This open access book highlights the interdisciplinary aspects of logistics research. Featuring empirical, methodological, and practice-oriented articles, it addresses the modelling, planning, optimization and control of processes. Chiefly focusing on supply chains, logistics networks, production systems, and systems and facilities for material flows, the respective contributions combine research on classical supply chain management, digitalized business processes, production engineering, electrical engineering, computer science and mathematical optimization. To celebrate 25 years of interdisciplinary and collaborative research conducted at the Bremen Research Cluster for Dynamics in Logistics (LogDynamics), in this book hand-picked experts currently or formerly affiliated with the Cluster provide retrospectives, present cutting-edge research, and outline future research directions

Sedimentation of halloysite nanotubes from different deposits in aqueous media at variable ionic strengths

Halloysite clay is a natural nanomaterial that is attracting a growing interest in colloidal science. The halloysite aqueous dispersion stability is a key aspect for the configuration of a purification protocol as well as to establish the durability of a formulation. A physico-chemical study demonstrated the role of ionic strength and nanotube characteristic sizes on the sedimentation behavior. We highlighted the importance of the electrostatic repulsions exercised between the particles in the settling process. A protocol for image analysis has been proposed to provide robust information from time resolved optical images on the suspensions. In conclusion, we managed to correlate microscopic aspect to the peculiar sedimentation process of halloysite nanotubes