Simheuristics: an introductory tutorial

© 2022 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting /republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other worksBoth manufacturing and service industries are subject to uncertainty. Probability techniques and simulation methods allow us to model and analyze complex systems in which stochastic uncertainty is present. When the goal is to optimize the performance of these stochastic systems, simulation by itself is not enough and it needs to be hybridized with optimization methods. Since many real-life optimization problems in the aforementioned industries are NP-hard and large scale, metaheuristic optimization algorithms are required. The simheuristics concept refers to the hybridization of simulation methods and metaheuristic algorithms. This paper provides an introductory tutorial to the concept of simheuristics, showing how it has been successfully employed in solving stochastic optimization problems in many application fields, from production logistics and transportation to telecommunication and insurance. Current research trends in the area of simheuristics, such as their combination with fuzzy logic techniques and machine learning methods, are also discussed.Peer ReviewedPostprint (author's final draft

Solving the VRP with probabilistic algorithms supported by constraint programming

Among the human-being problems, there are those which carry with the exploration of a number of feasible and unfeasible possible solutions. These have been a challenge faced constructing specific strategies. Thus, techniques rising from several areas have been used. They can be complete or incomplete, with mathematical background or a more computational one, single techniques, greedy, constructive, etc. Most of these have proven to work fine when they are tailor-made solutions. Therefore, usually, the solution for a problem is totally useless for a different one or even for the same problem with new/different constraints. With this position paper, we claim a hybrid methodology combining probabilistic algorithms with a complete technique might be useful in order to separate the optimisation engine and the validation tool. This eases the possibility to have a general optimisation tool, with an acceptable minimal fine tuning, which includes neither the problem model nor validation jobs.Peer ReviewedPostprint (published version

Solving the capacitated vehicle routing problem with environmental criteria based on real estimations in road transportation: a case study

One of the most important objectives in company logistics is the optimization of goods distribution considering the whole value chain. There are many algorithms to optimise the capacitated vehicle routing problems (CVRP) associated to problems of road transportation. The objective function of those problems usually involves distance, cost, number of vehicles, or profits, among others. In this contribution we also take into account environmental costs. Here, we want to manage environmental costs estimations based on surveys about road transportation crossing rural areas having valuable biological and natural stock. Thus, we develop some variants (AWEC) to traditional heuristic algorithms, such as those of Clarke and Wright or Mole and Jameson, in which we include environmental cost estimates in real scenarios in Spain. This raises the value of the global objective function, but permits a more realistic cost estimate that includes not only the internal costs involved in the problem but also the related externalities. Finally, we discuss several solutions to a real case in the agribusiness sector in Navarre (Spain)Peer ReviewedPostprint (published version

Energía eólica y empleo: el caso de Navarra como paradigma

El trabajo analiza el caso de una de las regiones pioneras en el desarrollo de la energía eólica, la Comunidad Foral de Navarra, mostrando cómo se ha generado, fruto de una política energética específica, un sector empresarial competitivo, con un importante impacto en términos de empleo de alta cualificación. De esta manera, se comprueba cómo a escala regional es posible compatibilizar la preocupación medioambiental con el crecimiento económico y la creación de empleo, convirtiendo a Navarra en modelo a imitar por otras regiones europeas. No obstante, y a partir del proceso de prognosis realizado, conviene advertir las carencias formativas que presenta el mercado laboral. Por ello, los autores proponen que, junto a las políticas de apoyo tradicionales, se consideren políticas de mejora de la formación en el ámbito de la energía eólic

The urban freight distribution in medium size cities: Descriptive data taken from Pamplona (Spain) and Angers (France)

Trabajo presentado en: R-Evolucionando el transporte, XIV Congreso de Ingeniería del Transporte (CIT 2021), realizado en modalidad online los días 6, 7 y 8 de julio de 2021, organizado por la Universidad de BurgosMedium-size cities around the world are experiencing rapid changes in their urban centers regarding sustainable mobility, pedestrianization of streets, and vehicle-access control to their city center. This situation is particularly important in the last-mile urban distribution in city centers due to the fact that private cars, public transportation, and freight transportation fiery compete for the same space. This article contextualizes this phenomenon in two European medium-size cities: Angers (France) and Pamplona (Spain). The paper also draws the current situation regarding their mobility and freight-delivery systems in their city centers. Thus, an apposite survey has been deployed in both cities in order to collect social perceptions and mobility patterns data. Additionally, we have included a conjoint analysis study for examining the characteristic determinants for aerial (drone) distribution. Likewise, meaningful conclusions can be extracted from the analysis of the results generated by the current analysis. Firstly, we have realized the immediate effects of a recent sustainable urban-mobility plan at Pamplona, which contrasts with the Angers case, where no similar plan has been deployed yet. Secondly, we have focused our attention on the socio-economic factors that determine the mobility in both cities. Thirdly, we have observed, in both cities, a clear preference for electric vehicles and cargo-bikes for driving inside the city center. Finally, there is a rejection to use drones for merchandise delivery.We would like to acknowledge the partial financial support given by the Spanish Ministry of Science, Innovation, and Universities (RED2018-102642-T), and the following projects: IoF2020-H2020 (731884), “la Caixa” Foundation (LCF/PR/PR15/51100007), and AGAUR (2018-LLAV-00017) to the authors of this paper

Expansión de las energías renovables a nivel regional

Razones económicas y medioambientales han hecho que las energías renovables vayan adquiriendo una gran importancia en las regiones europeas. La Comunidad de Navarra es un claro ejemplo de esta sensibilidad, que le ha llevado a convertirse en un modelo de desarrollo energético en este campo. El presente trabajo recoge la situación actual de las energías renovables en la región, analizándolas desde el punto de vista de las empresas que conforman este sector mediante una investigación de mercados. De este modo, se ponen de manifiesto las interrelaciones entre una política energética regional y la creación y desarrollo de un sector empresarial dinámico y competitivo. El trabajo ofrece también una prospectiva para el período 2002-2005, contrastando los resultados obtenidos con distintos estudios nacionales y europeos

Developing an information system for monitoring student's activity in online collaborative learning

In this paper we address the issue of monitoring students’ and groups’ activity in online collaborative learning environments. This issue is especially important in the collaborative e-learning context, since an efficient monitoring process can provide valuable information to online instructors who may guide and support the development of collaborative learning projects. We have developed and tested an information system model which facilitates the automatic generation of weekly monitoring reports derived from data contained in server log files. These reports provide online instructors with visual information regarding students’ and groups’ activity, thus allowing for a quick and easy classification of students and groups according to their activity level. Therefore, entities with a low activity level are identified as soon as possible and just-in-time assistance can be established for them. Furthermore, instructors can use these monitoring reports to forecast potential problems –such as students’ dropouts or possible conflicts inside the groups due to unbalanced distribution of tasks– and take operational and tactical decisions oriented to avoid themPeer Reviewe