Adopting different wind-assisted ship propulsion technologies as fleet retrofit: An agent-based modeling approach

The maritime shipping industry will increasingly switch to low carbon fuels and adopt energy saving technologies (ESTs) to achieve the industry target of decarbonization. Among ESTs, deck equipment, including those based on wind propulsion technologies (WPTs), represents the largest potential fuel savings and a source of increasing innovation initiatives by industry actors. Previous contributions to WPT innovation have addressed barriers and drivers for increased adoption in the industry but failed to consider the specific aspects of the fleet retrofitting market. Through an agent-based simulation model, this work studies the effects of different policy and market scenarios (subsidies, fuel prices, and networking) on the adoption of WPT retrofitting solutions. The proposed model incorporates two decision steps for each vessel to adopt the technology (acquiring awareness of the technology, and a utility decision process to determine the WPT option). The study also expands on previous knowledge by modeling three WPT options and by integrating real world data of technology costs and their fuel savings as well as vessel features. Insights from simulations allow to identify the most convenient policies as well as the potential of alternative models to reduce introduction barriers (e.g., product-service business models).Interreg North Sea Region project WASP: Wind Assisted Ship Propulsion, "Run Wind Propulsion Technology real life trials on sea going ships in operation, showcase proven concepts, market adaptation, green sea transport" 38-2-6-19Spanish Ministry of Science, Andalusian GovernmentEuropean Commission RYC-2016-19800ERDF under CONFIA PID2021-122916NB-I00ERDF under SIMARK P18-TP-447

Car Sequencing Problem con flotas de vehículos especiales. Presentación

Car Sequencing Problem con demanda parcial incierta. Robustez en una multi-secuencia de vehículos mixtos.Partiendo del Car Sequencing Problem (CSP), introducimos el concepto demanda parcial incierta a través de la incorporación de Flotas de vehículos especiales en un plan de demanda. Tras resaltar las peculiaridades de una Flota y establecer las hipótesis de trabajo, proponemos un modelo de programación lineal entera mixta orientado a satisfacer el máximo número de restricciones CSP. Posteriormente, introducimos el concepto multi-secuencia de producción y proponemos funciones para medir su robustez. La versión robusta del CSP considera un conjunto de escenarios de la demanda para las Flotas y presenta funciones que miden el exceso sobre el requerimiento estándar de las opciones del CSP en planes de demanda, opciones concretas y ciclos de fabricación. Dichas funciones pueden emplearse como función objetivo en problemas de optimización y como métricas ante una muli-secuencia de producción concreta.Preprin

Sustainability in tourism determined by an asymmetric game with mobility

M.C. was supported by the Spanish Ministry of Science, Andalusian Government, University of Granada, and ERDF under grants SIMARK (P18-TP-4475) , RYC-2016-19800, and PPJIA2020-09 (TURCOMPLEX) . J.H. was supported by the University of Las Palmas de Gran Canaria, under grant COVID-19 04. M.P. was supported by the Slovenian Research Agency (Grant Nos. P1-0403 and J1-2457) . Funding for open access charge: Universidad de Granada/CBUA.Many countries worldwide rely on tourism for their economic well-being and development. But with issues such as over-tourism and environmental degradation looming large, there is a pressing need to determine a way forward in a sustainable and mutually rewarding manner. With this motivation, we here propose an asymmetric evolutionary game with mobility where local stakeholders and tourists can either cooperate or defect in a spatially structured setting. Our study reflects that sustainable tourism is primarily determined by an optimal trade-off between economic benefits of the stakeholders and their costs related to the application of sustainability policies. In contrast, the specific benefits and costs of the tourists are comparatively less relevant. The reader can also observe that allowing for greater tourist mobility decreases cooperation and leads to faster polarization among local stakeholders. In agreement with observations worldwide, we identify decreasing population densities in tourist areas in terms of both, stakeholders and tourists, to be a key aid to greater cooperation and overall sustainability of tourism. These results are rooted in spatial formations and complex alliances that manifest spontaneously through the evolutionary dynamics in a structured population.Spanish Ministry of Science, Andalusian Government, University of GranadaEuropean Commission P18-TP-4475 RYC-2016-19800 PPJIA2020-09University of Las Palmas de Gran Canaria COVID-19 04Slovenian Research Agency - Slovenia P1-0403 J1-2457Universidad de Granada/CBU

Discernment of bee pollen loads using computer vision and one-class classification techniques

In this paper, we propose a system for authenticating local bee pollen against fraudulent samples using image processing and classification techniques. Our system is based on the colour properties of bee pollen loads and the use of one-class classifiers to reject unknown pollen samples. The latter classification techniques allow us to tackle the major difficulty of the problem, the existence of many possible fraudulent pollen types. Also presented is a multi-classifier model with an ambiguity discovery process to fuse the output of the one-class classifiers. The method is validated by authenticating Spanish bee pollen types, the overall accuracy of the final system of being 94%. Therefore, the system is able to rapidly reject the non-local pollen samples with inexpensive hardware and without the need to send the product to the laboratory

Evolution of cooperation and trust in an N-player social dilemma game with tags for migration decisions

S.D. would like to acknowledge the support of an Australian Government Research Training Program scholarship to study a PhD degree in Computer Science at the University of Newcastle, Australia, supervised by R.C.We present an evolutionary game model that integrates the concept of tags, trust and migration to study how trust in social and physical groups influence cooperation and migration decisions. All agents have a tag, and they gain or lose trust in other tags as they interact with other agents. This trust in different tags determines their trust in other players and groups. In contrast to other models in the literature, our model does not use tags to determine the cooperation/defection decisions of the agents, but rather their migration decisions. Agents decide whether to cooperate or defect based purely on social learning (i.e. imitation from others). Agents use information about tags and their trust in tags to determine how much they trust a particular group of agents and whether they want to migrate to that group. Comprehensive experiments show that the model can promote high levels of cooperation and trust under different game scenarios, and that curbing the migration decisions of agents can negatively impact both cooperation and trust in the system.We also observed that trust becomes scarce in the system as the diversity of tags increases. This work is one of the first to study the impact of tags on trust in the system and migration behaviour of the agents using evolutionary game theory.Australian GovernmentDepartment of Industry, Innovation and Scienc

Approximation of Smectic-A liquid crystals

In this paper, we present energy-stable numerical schemes for a Smectic-A liquid crystal model. This model involve the hydrodynamic velocity-pressure macroscopic variables (u, p) and the microscopic order parameter of Smectic-A liquid crystals, where its molecules have a uniaxial orientational order and a positional order by layers of normal and unitary vector n. We start from the formulation given in [E’97] by using the so-called layer variable φ such that n = ∇φ and the level sets of φ describe the layer structure of the Smectic-A liquid crystal. Then, a strongly non-linear parabolic system is derived coupling velocity and pressure unknowns of the Navier-Stokes equations (u, p) with a fourth order parabolic equation for φ. We will give a reformulation as a mixed second order problem which let us to define some new energy-stable numerical schemes, by using second order finite differences in time and C 0 - finite elements in space. Finally, numerical simulations are presented for 2D-domains, showing the evolution of the system until it reachs an equilibrium configuration. Up to our knowledge, there is not any previous numerical analysis for this type of models.Ministerio de Economía y CompetitividadMinistry of Education, Youth and Sports of the Czech Republi

Note on an apparently forgotten theorem about solid rigid dynamics

We re-derive a general procedure to substitute any rigid body by an equivalent system of exactly four masses, located at the vertices of an irregular tetrahedron

Numerical methods for solving the Cahn-Hilliard equation and its applicability to related Energy-based models

In this paper, we review some numerical methods presented in the literature in the last years to approximate the Cahn-Hilliard equation. Our aim is to compare the main properties of each one of the approaches to try to determine which one we should choose depending on which are the crucial aspects when we approximate the equations. Among the properties that we consider desirable to control are the time accuracy order, energy-stability, unique solvability and the linearity or nonlinearity of the resulting systems. In particular, we concern about the iterative methods used to approximate the nonlinear schemes and the constraints that may arise on the physical and computational parameters. Furthermore, we present the connections of the Cahn-Hilliard equation with other physically motivated systems (not only phase field models) and we state how the ideas of efficient numerical schemes in one topic could be extended to other frameworks in a natural way.Ministry of Education, Youth and Sports of the Czech RepublicMinisterio de Economía y Competitivida

The Role of the Tourism Network in the Coordination of Pandemic Control Measures

The emergence and spread of COVID-19 has severely impacted the tourism industry worldwide. In order to limit the effect of new pandemics or any unforeseen crisis, coordinated actions need to be adopted among tourism stakeholders. In this paper, we use an evolutionary game model to analyze the conditions that promote cooperation among different stakeholders in a tourism network to control high-risk crises. A data sample of 280 EU regions is used to define the tourism network of regions with a heterogeneous dependence on tourism. The results show that cooperation is helped by the existence of a structured tourism network. Moreover, cooperation is enhanced when coordination groups include small numbers of participants and when they are formed according to the similarity of tourism dependence.University of Las Palmas de Gran Canaria COVID-19-04Spanish GovernmentAndalusian GovernmentEuropean Commission P18-TP-4475 PID2021-122916NB-I00 RYC-2016-1980