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The city of Seville is currently developing a land-use reorganisation policy aimed at increasing the number of pedestrian spaces. This paper contains the microscopic simulation built to assess one of those pedestrianisation initiatives from the point of view of its effects on traffic flows and, more specifically, freight deliveries. Two different alternatives are compared with the current scenario from the point of view of traffic congestion, parking space occupation and route times. Due to the complexity of the freight delivery practices involved, the use of a standard traffic simulation package was not appropriate, and the simulations were carried out using the commercial package Arena, which enabled the representation of all that complexity with a specifically built simulation model.

The management of fixed-income securities investment portfolios enjoys a long tradition in the capital markets. This paper analyses robust optimisation models as efficient tools for risk management of fixed-income securities. The study includes the analysis of scenario-based optimisation models applied to the portfolio selection and on the basis of indeterminate initial endowment. A detailed analysis is made for a case study involving the composition of fixed-income investment portfolios, which is solved using robust scenario-based optimisation models. Finally, a sensitivity analysis is carried out for different scenarios occurring for each of the models.

The static environments of optimization are not efficient when there is Uncertainty. The vehicle routing is a common case of it. For example, there usually is uncertainty in the transit time due to the congestion, traffic jam, etc. Dynamic optimization has been more efficient in these environments. To determinate when a reoptimization have to be run is fundamental., Los entornos estáticos de optimización no son todo lo eficientes que se esperaría en situaciones donde existe incertidumbre. El rutado de vehículos es una caso común donde existe incertidumbre, por ejemplo en el tiempo de tránsito, motivado principalmente por los diferentes niveles de congestión existentes. La reoptimización dinámica se ha mostrado más eficaz en este tipo de sistemas. Determinar en que momentos realizar la reoptimización es fundamental en la eficiencia de este tipo de sistemas.

El transporte por carretera ha sido líder en el movimiento de mercancías. Sin embargo, el incremento de la congestión y la necesidad de buscar modos más sostenibles ha animado a las diferentes instituciones a promover la intermodalidad como alternativa; que combina la eficiencia del transporte ferroviario o marítimo con la flexibilidad del transporte por carretera. Sin embargo, el transporte intermodal presenta varias dificultades para llegar a ser viable. Uno de ellos es un alto coste fijo, que hace a la intermodalidad ineficiente en trayectos cortos, por debajo de una distancia umbral. En la cadena intermodal, los trayectos iniciales y finales realizados por carretera son llamados acarreo terrestre, y representan el 40 % de los costes totales. La adecuada planificación del acarreo presenta un gran potencial para reducir los costes intermodales y reducir la distancia a partir de la cual la intermodalidad es rentable; el principal objetivo es la asignación de tareas de transporte a vehículos, a veces en presencia de restricciones temporales. Esta asignación ha sido tradicionalmente realizada una vez al comienzo del día, de modo que ante cualquier suceso inesperado podrían producirse retrasos. Esta tesis propone el uso de información en tiempo real relativa a la posición de los vehículos para una solución dinámica del problema, donde el planificador está siempre habilitado a rehacer la programación en el caso de que las condiciones cambien. Este conocimiento de la posición de los vehículos es posible gracias al uso de sistemas de posicionamiento por satélite. Los resultados demuestran que esta información permite mejorar la solución dinámicamente., Road transport has always been prevalent in the movement of freight. However, the increasing road congestion and the necessity to find more sustainable means of transport have encouraged different governments to promote intermodality as an alternative. This combines the cost effectiveness of railways or ships with the flexibility of trucks. However, intermodal transport has several difficulties to overcome in order to become viable. One of them is a high fixed cost, which is why intermodality is unsuitable for trips shorter than a certain threshold distance. In an intermodal transport chain, the initial and final trips, also called drayage operations, represent 40 % of total transport costs. The proper planning of drayage operations has the potential to reduce the threshold distance, thus it raises the viability of intermodal transport. The intermodal transport chain can become more efficient by means of a good organization of drayage movements; the main objective is normally the assignment of transportation tasks to the different vehicles, often with the presence of time windows. This scheduling has traditionally been done once a day and, under these conditions, any unexpected event could cause timetable delays. This thesis proposes to use the real-time knowledge about vehicle position to solve this problem, which permanently allows the planner to reassign tasks in case the problem conditions change. This exact knowledge of the position of the vehicles is possible due to the use of a geographic positioning system by satellite (GPS, Galileo, Glonass). The results show that these additional data can be used to dynamically improve the solution.

High-rise buildings with a considerable number of elevators represent a major logistic problem concerning saving space and time due to economic reasons. For this reason, complex Elevator Group Control Systems are developed in order to manage the elevators properly. Furthermore, the subject of energy is acquiring more and more industrial relevance every day as far as sustainable development is concerned. In this paper, the first entirely dynamic Fuzzy Logic Elevator Group Control System to dispatch landing calls so as to minimize energy consumption, especially during interfloor traffic, is proposed. The fuzzy logic design described here constitutes not only an innovative solution that outperforms usual dispatchers but also an easy, cheap, feasible and reliable solution, which is possible to be implemented in real industry controllers.

Telecommunication is one of the fastest growing business sectors. Future networks will need to integrate a wide variety of services demanding different qualities and capacities from the network. In this paper, network architecture based on hybrid fiber optic-coaxial cable (HFC) is proposed to develop cable integrated telematic services. An evolutionary algorithm is presented to solve the problem in suitable computation times when dealing with real times civil works problems. Finally we present the results over both problem library and real life scenarios.

This paper presents a methodology used to provide important and useful information to select dynamically the comfort set-point of the rooms for a central heating system without using fixed values based on programmed time schedules or any other methodology. It is possible to observe the users comfort level of a Heating, Ventilation and Air-conditioning (HVAC) system through online surveys. Using fuzzy logic applied to the behaviour patterns that generally occur in an office it is possible to detect situations when it can be decided to maximise comfort and/or maximise savings. This methodology is designed to save energy in these systems depending on the occupation and comfort perception of its occupants.

The intermodal transport chain can become more e cient by means of a good organization of drayage movements. Drayage in intermodal container terminals involves the pick up and delivery of containers at customer locations, and the main objective is normally the assignment of transportation tasks to the di erent vehicles, often with the presence of time windows. This scheduling has traditionally been done once a day and, under these conditions, any unexpected event could cause timetable delays. We propose to use the real-time knowledge about vehicle position to solve this problem, which permanently allows the planner to reassign tasks in case the problem conditions change. This exact knowledge of the position of the vehicles is possible using a geographic positioning system by satellite (GPS, Galileo, Glonass), and the results show that this additional data can be used to dynamically improve the solution.

The objective of our work is to solve the problem of transferring workers from a resort set on two cays (islets sandy) in the Sabana-Camaguey archipelago, north of Cuba, from their home areas to the resort and vice versa. We start with an economic analysis of the possible alternatives to solve the problem. Those that result most favorable economically are then subject to an environmental analysis, for tourism development in the area is based on the physical environment of high ecological and landscape that surrounds it. After completing the environmental impact study of each alternative, we choose the most appropriate and favorable one. In the case of the introduction of a means to transport workers, we proposed light rail as the most economically feasible option, due to the conditions of our problem. Finally, we arranged the transfer of workers using buses from the terminal to the various hotels in the resort area.

This paper addresses the recyclable waste collection problem in urban areas. The work focuses on the recyclable glass bins collection, but with the peculiarity that these are provided with a device that sends fill level data daily to the control center. With this additional real time information we propose a collection policy that minimizes the length of the routes of vehicles on two levels, one daily and other for a larger planning horizon. This proposed policy is compared to the one used in the current literature and only optimizes the daily routes. Several simulations of the two policies are performed on a model of the city of Seville. Results show the proposed policy achieves better results in terms of meeting demand and better utilization of resources.

The freight transportation is one of the main sectors in the European Union. In the last decades, it grew up more than the GPB. This growth was not proportional on ali the transportation modes. It has associated negative effects: accidents, pollution and congestion. The UE looked to the intermodality like the main alternative. However, the crisis in Europe do not possible the inversion on great infrastructure. This work pretends to optimize and improve the use of the intermodality through the drayage., El transporte de mercancías es uno de los sectores más importantes dentro de la Unión Europea. Su crecimiento en los últimos años ha incluso superado al crecimiento del PIB. Este crecimiento no ha sido proporcional entre todos los modos de transporte, siendo el mayor beneficiario el transporte por carretera. Esto ha traído asociado una serie de fenómenos negativos: accidentalidad, polución y congestión. La Unión ha señalado a la intermodalidad como la alternativa. Sin embargo, en el actual periodo de crisis que vive Europa, inversión en las grandes infraestructuras necesarias es posiblemente una quimera. Este artículo pretende optimizar y facilitar el uso de la intermodalidad a través de la optimización de uno de los eslabones principales de la cadena intermodal, el acarreo terrestre.

Nowadays is very common the presence of tall buildings in the business centres of the main cities of the world. Such buildings require the installation of numerous lifts that are coordinated and managed under a unique control system. Population working in the buildings follows a similar traffic pattern generating situations of traffic congestion. The problem arises when a passenger makes a hall call wishing to travel to another floor of the building. The dispatching of the most suitable car is the optimization problem we are tackling in this paper. We develop a viral system algorithm which is based on a bio-inspired virus infection analogy to deal with it. The viral system algorithm is compared to genetic algorithms, and tabu search approaches that have proven efficiency in the vertical transportation literature. The experiments undertaken in tall buildings from 10 to 24 floors, and several car configurations from 2 to 6 cars, provide valuable results and show how viral system outperforms such soft computing algorithms.

The design and implementation of innovative infrastructures to support business activities have been carried out in our country over the last years. There have been significant investments, which have often been unsuccessful and very expensive, since they have been based on opportunistic criteria far away from objective and professional criteria. However, there have also been successful cases that have endured over time. This paper proposes a model to help managers and authorities to make future decisions concerning the design and implementation of such infrastructures. This model should be based on a future-oriented focus and on knowledge and experience of the different stakeholders from different fields of knowledge who have an important participation in the design and development process. This model should allow assessing, a priori or at any stage thereof, the probabilities of success of such initiatives in a quantitative way., En el diseño e implementación de infraestructuras innovadoras de apoyo al desarrollo empresarial que se han venido desarrollando en nuestro país, se han producido importantes inversiones que en muchos casos han sido fallidas y muy costosas, ya que se han basado, a veces, en criterios oportunistas alejados de criterios objetivos y profesionales. No obstante, sí que se han producido iniciativas de éxito que han perdurado en el tiempo. En este trabajo se propone diseñar un modelo orientado al futuro y basado en el conocimiento y experiencia profesional de los diferentes promotores y gestores profesionales que han participado en el diseño y desarrollo de este tipo de infraestructuras, provenientes de diferentes campos de conocimiento. Este modelo debería permitir evaluar a priori, o en cualquier estadio del mismo, las probabilidades de éxito de tales iniciativas de forma cuantitativa.

This paper presents a guided and deep introduction to Viral Systems (VS), a novel bio-inspired methodology based on a natural biological process taking part when the organism has to give a response to an external infection. VS has proven to be very efficient when dealing with problems of high complexity. The paper discusses on the foundations of viral systems, presents the main pseudocodes that need to be implemented and illustrates the methodology application. A comparison between VS and other metaheuristics, as well between different VS approaches is presented. Finally trends and new research opportunities are presented for this bio-inspired methodology.

De la implantación de tecnologías y aplicaciones RFID se espera un cambio total de las operaciones logísticas, una vez superadas las limitaciones de costes, generando enormes beneficios en aspectos como control de inventario, trazabilidad o integración de la cadena de suministros. En cualquier caso, los primeros pasos de implementación del RFID pueden dar lugar a una serie de problemas y deficiencias operativas en los centros de distribución, no sólo relacionados con costes o gestión de la información, sino además con el diseño y la fiabilidad de los propios sistemas. Estos problemas pueden dar lugar a empeoramientos significativos del rendimiento, y deben ser tenidos en cuenta a la hora de plantear la introducción de la tecnología. Analizamos aquí los problemas a los que se tuvo que enfrentar una distribuidora de productos lácteos española durante un proyecto piloto de implantación de RFID en su sección de expediciones, cuantificados mediante los indicadores correspondientes.

The analyses prior to the introduction of access time window policies in the centre of European cities often neglect the evaluation of the extra costs imposed on carriers through the additional number of vehicles required and the increase in tour length. To facilitate this evaluation, we have developed a vehicle routing algorithm that takes into account the existence of access time windows and adapts tours in the best possible manner to this restriction. The algorithm is based on a Genetic Algorithm, which we use to make this evaluation through the analysis of several experiments in a test network.

Método de control difuso de grupo de ascensores para la optimización del consumo energético de los del tipo que se emplea por sistemas de control de ascensores de transporte vertical que se caracteriza porque comprende las etapas de evaluar la aptitud energética de cada cabina y asignar las llamadas de planta según un orden conforme (i) una primera valoración energética absoluta (1); (ii) una segunda valoración energética relativa (5); y (iii) una tercera valoración conforme a la contigüidad (8) de las llamadas.

La asignación de tareas en sistemas de transporte ha sido tradicionalmente hecho una vez al día. Al comienzo de la jornada, el decisor establece que tareas deben ser llevadas a cabo por cada vehículo. Entonces, atascos, averías y cualquier problema inesperado causaría grandes retrasos e inconvenientes sobre lo planificado. En este trabajo se propone el uso de información en tiempo real relativa a la posición de los vehículos para solventar el problema. De este modo, el decisor está permanentemente reconsiderando mejoras en la asignación si las condiciones lo aconsejan. Un mecanismo heurístico ha sido elegido para solventar el problema dada la necesidad de una gran velocidad computacional., The scheduling of transportation systems has traditionally been done once a day. At beginning of a working day, the planner establishes which tasks will be carried out by each vehicle. Then, traffic jam, breakdown and any unexpected problem will cause delays on our timetable. In this paper, we propose to use real-time vehicle position knowledge to solve this problem. So, the planner is permanently enabled to reallocate tasks as the problem conditions change. As both drayage problem is a NP-Hard problem and a high-speed procedure is required, exact methods are not computationally feasible. So, a heuristic algorithm has been implemented to perform the problem described.

[ESP] El transporte por carretera es el principal modo de envío de mercancías en el ámbito terrestre. Observando los últimos datos proporcionados por el Instituto Nacional de Estadística, el transporte interregional de mercancías en el año 2008 fue de 119.559 Tn·Km en el caso del transporte por carretera y de tan sólo 10.287 Tn·Km en el caso del transporte ferroviario. Esta contundente preferencia del mercado hacia la carretera se debe principalmente a una serie de ventajas que esta presenta para el movimiento de bienes dentro de España; entre ellas cabe destacar una gran flexibilidad de operación, la posibilidad de comenzar un envío desde cualquier lugar y en cualquier momento. Sin embargo, el aumento de la congestión en las principales vías españolas y la creciente preocupación por la sostenibilidad han hecho a los diferentes gobiernos buscar modos alternativos de transporte. Desde las diferentes administraciones, se está señalando al transporte intermodal como una alternativa. La intermodalidad, definida por la Comisión Europea como una característica de un sistema de transportes en virtud de la cual se utilizan de forma integrada al menos dos modos de transporte diferentes para completar una cadena de transporte puerta a puerta, permite mediante un planteamiento global una utilización más racional de la capacidad de transporte disponible.

Revenue Management es una técnica que cada vez está tomando más importancia en el sector servicios en general, y en el turismo en particular. Ello es debido a que la mayoría de estas empresas presentan simultaneidad en la producción y consumo del servicio prestado, junto con la imposibilidad de su almacenamiento por ser perecedero. El objetivo es vender cada unidad de inventario al tipo de cliente adecuado, en el instante preciso y al precio conveniente. En este trabajo se repasan los sectores de mayor aplicación y se propone una novedosa, aparcamientos de coches, que le permita mejorar su gestión e ingresos finales., Revenue management is a technique that is taking on a more important role in the service sector due to the majority of the companies that present similarities in the production and consumption of services, combined with the inability to store perishable products. The aim is to sell each inventory unit to the appropriate customer, at the precise moment and price. This paper examines the major application areas and proposes it in a new sector, car parks, enabling it to improve their management and final profits.

This paper deals with the dynamic routing problem in ATM cell-switching networks. We present a mathematical programming model based on cell loss and a Tabu Search algorithm with short-term memory that is reinforced with a long-term memory procedure. The estimation of the quality of the solutions is fast, due to the specific encoding of the feasible solutions. The Tabu Search algorithm reaches good quality solutions, outperforming other approaches such as Genetic Algorithms and the Minimum Switching Path heuristic, regarding both cell loss and the CPU time consumption. The best results were found for the more complex networks with a high number of switches and links.

The intermodal transport chain can become more efficient by means of a good organization of the drayage movements. Drayage in intermodal container terminals involves the pick up or delivery of containers at customer locations, and the main objective is normally the assignment of transportation tasks to the different vehicles, often with the presence of time windows. The literature shows some works on centralised drayage management, but most of them consider the problem only from a static and deterministic perspective, whereas the work we present here incorporates the knowledge of the real-time position of the vehicles, which permanently enables the planner to reassign tasks in case the problem conditions change. This exact knowledge of position of the vehicles is possible thanks to a geographic positioning system by satellite (GPS, Galileo, Glonass), and the results show that this additional data can be used to dynamically improve the solution.

We study the problems associated with allocating berths for containerships in the port of Seville. It is the only inland port in Spain and it is located on the Guadalquivir River. This paper addresses the berth allocation planning problems using simulation and optimisation with Arena software. We propose a mathematical model and develop a heuristic procedure based on genetic algorithm to solve non-linear problems. Allocation planning aims to minimise the total service time for each ship and considers a first-come-first-served allocation strategy. We conduct a large amount of computational experiments which show that the proposed model improves the current berth management strategy.