A rolling horizon optimization framework for the simultaneous energy supply and demand planning in microgrids

This work focuses on the development of optimization-based scheduling strategies for the coordination of microgrids. The main novelty of this work is the simultaneous management of energy production and energy demand within a reactive scheduling approach to deal with the presence of uncertainty associated to production and consumption. Delays in the nominal energy demands are allowed under associated penalty costs to tackle flexible and fluctuating demand profiles. In this study, the basic microgrid structure consists of renewable energy systems (photovoltaic panels, wind turbines) and energy storage units. Consequently, a Mixed Integer Linear Programming (MILP) formulation is presented and used within a rolling horizon scheme that periodically updates input data information

Análisis y mejora del proceso de previsión de ventas de una empresa embotelladora de agua

El presente proyecto, titulado Análisis y mejora del proceso de previsión de ventas de una empresa embotelladora de agua, realizado en el departamento de Supply Chain de la empresa Aguas Font Vella y Lanjarón, S.A. pretende analizar el proceso actual de previsión de ventas para introducir mejoras mediante la implantación de la herramienta informática SAP/APO destinada a determinar la previsión de ventas a partir del histórico de cada producto. La memoria comienza con la descripción de la empresa Aguas Font Vella y Lanjarón, S.A. y el análisis de la tendencia del sector del agua embotellada. También se analiza el departamento de la Cadena de Suministro, prestando especial atención al proceso de obtención de la previsión de ventas. Posteriormente, se presentan los sistemas SAP R/3 y SAP/APO. Se analiza el proceso de determinación de modelos estadísticos con el objetivo de obtener la previsión de ventas de cada producto en función de su evolución histórica. También se detalla el proceso de planificación para nuevos productos. Con los resultados obtenidos, se estudia el modelo de planificación de la producción y la posibilidad de reducir el stock de seguridad, ya que con la implementación de esta herramienta informática se reduce la incertidumbre en la previsión de ventas, lo cual implica una reducción del nivel del stock de seguridad. Finalmente, se realiza un análisis ambiental y se estudia el impacto social y económico para determinar la viabilidad del proyecto. Los resultados obtenidos en este proyecto ya se han empezado a aplicar en la empresa con resultados satisfactorios

Reflections on the exhibition fact: The case of Málaga

In this paper we think on the act of exposing. From the first cabinets of curiosities to artistic practices who challenge or camouflage themselves as exhibition events; imaginary museums to relational practices; of large and small museums to personal and domestic initiatives. This new century, more than ever, requires a reflection on the political and tourism management and the creation and dissemination of culture. Great museums have their worth in the millions of visitors attracted by the desire to check and document the iconic image that adorns its walls. Its success lies in being part of routes of cruisers and tour operators. The crisis reduced government subsidies and endangers the maintenance of these large institutions, while museums arising on any subject almost spontaneously, as the only solution to some bumpkin councils, while consuming the very small funds to support culture. At the bottom of all this is the questioning of the images and of the process to file. About those images that tell stories and objects that are part of what we decided we want to remember, and how we tell that story. The increasing burden of memories of history, has become a general problem in society for the relentless growth of data volumes that must be known. The information society, longed until recently, has integrated all vital manifestations in a global network, turning the dream into a nightmare. In conclusion, the process of democratization and access to technology has enabled the creation of images is no longer the domain of a few specialists. And that change is coming to the storage and dissemination of images, which were historical make by the museum. A few years ago became the amateur artist, and that changed the ways of doing, from photography to video. Currently the amateur becomes curator and director of his great little museum ... what changes will bring this situation to the consolidated institutions? How exposures will arise in the near future? We will try to investigate these and other issues throughout this paper. And we are going to focus in Malaga and the changes in its cultural network during the last decade.Reflexionamos en esta ponencia sobre la acción de exponer. Desde los primeros gabinetes de curiosidades a las prácticas artísticas que cuestionan o se camuflan como eventos expositivos; de los museos imaginarios a las prácticas relacionales; de los grandes y pequeños museos a las iniciativas personales y domésticas. Este principio de siglo, más que nunca, exige una reflexión entre la gestión político-turística y la creación y difusión de cultura. Los grandes museos cuentan su valía en cifras millonarias de visitantes, atraídos por el deseo de verificación y documentación de la imagen icónica que adorna sus paredes. Su éxito reside en formar parte de las rutas de cruceristas y tour operadores. La crisis reduce las subvenciones públicas y pone en peligro el mantenimiento de estas grandes instituciones, al tiempo que que surgen museos sobre cualquier tema casi de forma espontánea, como única solución a la gestión algo pazguata de ayuntamientos y comunidades, al tiempo que consumen las únicas y muy reducidas subvenciones de apoyo a la cultura. En el fondo de toda esta situación está el cuestionamiento de las imágenes y del propio proceso de archivo. Sobre aquellas imágenes que nos cuentan historias y los objetos que decidimos forman parte de lo que queremos recordar, y cómo contamos esa historia. La creciente carga de recuerdos de la historia, se ha convertido en un problema general de la sociedad: El incesante crecimiento de las cantidades de datos que deben ser conocidos. La sociedad de la información, hace poco aún anhelada, integradora de todas las manifestaciones vitales en una red global, se ha hecho realidad de forma tan plena, que con su realización el sueño se ha convertido ya en pesadilla. En conclusión, el proceso de democratización y acceso a la tecnología que ha posibilitado que la creación de imágenes no sea dominio de unos pocos especialistas, está llegando a la búsqueda, almacenamiento y difusión de imágenes, las labores históricamente realizas por el museo. Si hace unos años el aficionado se convirtió en artista, y eso modificó las formas de hacer, desde la fotografía al vídeo, el presente nos sitúa en un umbral en el que el aficionado-amater se convierte en comisario de exposiciones y en director de su pequeño gran museo... ¿qué cambios traerá esta situación a las instituciones consolidadas? ¿De qué manera se plantearán las exposiciones en un futuro cercano? Intentaremos investigar estas y otras cuestiones a lo largo de la ponencia y para no divagar por territorios en exceso amplios, centraremos los ejemplos en Málaga y en los cambios en su tejido cultural durante la última década.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Optimal management of bio-based energy supply chains under parametric uncertainty through a data-driven decision-support framework

This paper addresses the optimal management of a multi-objective bio-based energy supply chain network subjected to multiple sources of uncertainty. The complexity to obtain an optimal solution using traditional uncertainty management methods dramatically increases with the number of uncertain factors considered. Such a complexity produces that, if tractable, the problem is solved after a large computational effort. Therefore, in this work a data-driven decision-making framework is proposed to address this issue. Such a framework exploits machine learning techniques to efficiently approximate the optimal management decisions considering a set of uncertain parameters that continuously influence the process behavior as an input. A design of computer experiments technique is used in order to combine these parameters and produce a matrix of representative information. These data are used to optimize the deterministic multi-objective bio-based energy network problem through conventional optimization methods, leading to a detailed (but elementary) map of the optimal management decisions based on the uncertain parameters. Afterwards, the detailed data-driven relations are described/identified using an Ordinary Kriging meta-model. The result exhibits a very high accuracy of the parametric meta-models for predicting the optimal decision variables in comparison with the traditional stochastic approach. Besides, and more importantly, a dramatic reduction of the computational effort required to obtain these optimal values in response to the change of the uncertain parameters is achieved. Thus the use of the proposed data-driven decision tool promotes a time-effective optimal decision making, which represents a step forward to use data-driven strategy in large-scale/complex industrial problems.Peer ReviewedPostprint (published version

A rolling horizon approach for optimal management of microgrids under stochastic uncertainty

This work presents a Mixed Integer Linear Programming (MILP) approach based on a combination of a rolling horizon and stochastic programming formulation. The objective of the proposed formulation is the optimal management of the supply and demand of energy and heat in microgrids under uncertainty, in order to minimise the operational cost. Delays in the starting time of energy demands are allowed within a predefined time windows to tackle flexible demand profiles. This approach uses a scenario-based stochastic programming formulation. These scenarios consider uncertainty in the wind speed forecast, the processing time of the energy tasks and the overall heat demand, to take into account all possible scenarios related to the generation and demand of energy and heat. Nevertheless, embracing all external scenarios associated with wind speed prediction makes their consideration computationally intractable. Thus, updating input information (e.g., wind speed forecast) is required to guarantee good quality and practical solutions. Hence, the two-stage stochastic MILP formulation is introduced into a rolling horizon approach that periodically updates input information

Efficient planning of energy production and maintenance of large-scale combined heat and power plants

In this study, an efficient optimization framework is presented for the simultaneous planning of energy production and maintenance in combined heat and power plants, and applied in the largest coal-fired cogeneration plant of Kazakhstan. In brief, the proposed optimization model considers: (i) unit commitment constraints for boilers and turbines; (ii) minimum and maximum runtimes as well as minimum idle times for boilers and turbines; (iii) bounds on the operating levels for boilers and turbines within desired operating regions; (iv) extreme operating regions for turbines; (v) energy balances for turbines; (vi) total electricity and heat balances for satisfying the corresponding demands for electricity and heat (for each heat network); and (vii) maintenance tasks for units that must occur within given flexible time-windows. The minimization of the annual total cost of the cogeneration plant constitutes the optimization goal here, and consists of startup and shutdown costs, fixed operating and fuel costs, maintenance costs, and penalties for deviation from heat and electricity demands, and penalties for turbines for operating outside the desired operating regions. An extensive data analysis of historical data has been performed to extract the necessary input data. In comparison to the implemented industrial solution that follows a predefined maintenance policy, the solutions derived by the proposed approach achieve reductions in annual total cost more than 21% and completely avoid turbines operation outside their desired operating regions. Our solutions report substantial reductions in startup/shutdown, fuel and fixed operating costs (about 85%, 15%, and 13%, respectively). The comparative case study clearly demonstrates that the proposed approach is an effective means for generating optimal energy production and maintenance plans, enhancing significantly the resource and energy efficiency of the plant. Importantly, the proposed optimization framework could be readily applied to other cogeneration plants that have a similar plant structure

Use of ontological structures for integrated supply chain management

The integration of the different hierarchical decision making levels involved within a Chemical Supply Chain is essential for its adequate management in dynamic and competitive markets. Any approach encompassing design issues, planning, coordination and responses to customer demands, requires the consideration of huge amounts of data, which are a valuable source of information only if properly managed. But these data could also cause a lack of coordination if not stored and interpreted appropriately, so standardizing information structures and tools to improve the availability and communication of data information between different hierarchical decision levels is essential. Thus, this work addresses the problem of making the best use of the information systems associated to a Supply Chain, in order to improve the knowledge and the information comprehension capabilities in the area of Process Systems Engineering.Postprint (published version

Knowledge-based approach for the integration of the planning and scheduling decision-making levels

This work aims to integrate the tactical and operational decision making levels. A typical Scheduling mixed integer linear programming (MILP) model has been solved using several demand scenarios. The results have been analyzed and accordingly the operation cost vs. production levels nonlinear equations have been obtained. The aforementioned equations have been included as constraints of the SC planning problem. Hence, production, inventory and distribution variables along the complete SC have been optimized using a NLP model.Postprint (published version

Influence of the Titanium Implant Surface Treatment on the Surface Roughness and Chemical Composition

The implant surface features affect the osseointegration process. Different surface treatment methods have been applied to improve the surface topography and properties. Trace of different elements may appear on the implant surface, which can modify surface properties and may affect the body’s response. The aim was to evaluate the roughness based on the surface treatment received and the amount and type of trace elements found. Ninety implants (nine different surface treatment) were evaluated. Roughness parameters were measured using white-light-interferometry (WLI). The arithmetical mean for Ra, Rq, Rt, and Rz of each implant system was calculated, and Fisher’s exact test was applied, obtaining Ra values between 0.79 and 2.89 µm. Surface chemical composition was evaluated using X-ray photoelectron spectroscopy (XPS) at two times: as received by the manufacturer (AR) and after sputter-cleaning (SC). Traces of several elements were found in all groups, decreasing in favor of the Ti concentration after the sputter-cleaning. Within thelimitations of this study, we can conclude that the surface treatment influences the roughness and the average percentage of the trace elements on the implant surface. The cleaning process at the implant surface should be improved by the manufacturer before assembling the implant

Effect of Rough Surface Platforms on the Mucosal Attachment and the Marginal Bone Loss of Implants: A Dog Study

The preservation of peri-implant tissues is an important factor for implant success. This study aimed to assess the influence of the surface features of a butt-joint platform on soft-tissue attachment and bone resorption after immediate or delayed implant placement. All premolars and first molars of eight Beagle dogs were extracted on one mandible side. Twelve-weeks later, the same surgery was developed on the other side. Five implants with different platform surface configurations were randomly inserted into the post-extracted-sockets. On the healed side, the same five different implants were randomly placed. Implants were inserted 1 mm subcrestal to the buccal bony plate and were connected to abutments. The primary outcome variables were the supracrestal soft tissue (SST) adaptation and the bone resorption related to the implant shoulder. The SST height was significantly larger in immediate implants (IC95% 3.9–4.9 mm) compared to delayed implants (IC95% 3.1–3.5 mm). Marginal bone loss tended to be higher in immediate implants (IC95% 0.4–0.9 mm) than in delayed implants (IC95% 0.3–0.8 mm). Linear-regression analysis suggested that the SST height was significantly affected by the configuration of the platform (0.3–1.9 mm). Roughened surface platforms resulted in higher SST height when compared to machined surface platforms. Marginal bone loss was less pronounced in roughened designs