Control por Planificación de Ganancia con Modelos Borrosos

[ES] En este artículo se presentan los tipos de modelos borrosos y metodologías de identificación (por agrupamiento borroso) más adecuados para obtener modelos locales de sistemas no lineales. En particular, se muestra qué técnicas de control por planificación de ganancia son aplicables a los modelos así identificados. Estas técnicas, basándose en el diseño de controladores lineales para los modelos locales identificados, consiguen obtener de forma sencilla controladores para un sistema borroso.Trabajo parcialmente financiado por el proyecto DPI2002-0525 del Ministerio de Ciencia y Tecnología.Diez Ruano, JL.; Navarro Herrero, JL.; Sala Piqueras, A. (2010). Control por Planificación de Ganancia con Modelos Borrosos. Revista Iberoamericana de Automática e Informática industrial. 1(1):32-43. https://doi.org/10.4995/riai.2004.8022OJS32431

Algoritmos de Agrupamiento en la Identificación de Modelos Borrosos

[ES] La aplicación de las técnicas de agrupamiento borroso para la identificación de modelos borrosos se está extendiendo cada vez más. Sin embargo, y dado que su origen es bien distinto a la ingeniería de control, aparecen numerosos problemas en su aplicación en la identificación de modelos locales de sistemas no lineales para control. En este trabajo se revisan las principales técnicas de agrupamiento para la identificación de modelos borrosos, incluyendo propuestas propias que permiten desarrollar modelos que mejoran (respecto a algoritmos previamente existentes) la interpretabilidad y el descubrimiento de estructuras afines locales en los modelos borrosos obtenidos.Parcialmente financiado por el proyecto CICYT DPI2002-0525 (Ministerio Ciencia y Tecnología).Diez Ruano, JL.; Navarro Herrero, JL.; Sala Piqueras, A. (2010). Algoritmos de Agrupamiento en la Identificación de Modelos Borrosos. Revista Iberoamericana de Automática e Informática industrial. 1(2):32-41. http://hdl.handle.net/10251/146622OJS32411

Modelling and control of a continuous distillation tower through fuzzy techniques

This paper presents a methodology for the design of a fuzzy controller applicable to continuous processes based on local fuzzy models and velocity linearizations. It has been applied to the implementation of a fuzzy controller for a continuous distillation tower. Continuous distillation towers can be subjected to variations in feed characteristics that cause loss of product quality or excessive energy consumption. Therefore, the use of a fuzzy controller is interesting to control process performance.A dynamic model for continuous distillation was implemented and used to obtain data to develop the fuzzy controller at different operating points. The fuzzy controller was built by integration of linear controllers obtained for each linearization of the system. Simulation of the model with controller was used to validate the controller effectiveness under different scenarios, including a study of the sensibility of some parameters to the control.The results showed that the fuzzy controller was able to keep the target output in the desired range for different inputs disturbances, changing smoothly from a predefined target output to another. The developed techniques are applicable to more complex distillation systems including more operating variablesThe authors acknowledge the partial funding of this work by the projects: Regional Government Project GVPRE/2008/108, and National Projects DPI2007-66728-C02-01 and DPI2008-06737-C02-01.Barceló Rico, F.; Gozálvez Zafrilla, JM.; Diez Ruano, JL.; Santafé Moros, MA. (2011). Modelling and control of a continuous distillation tower through fuzzy techniques. Chemical Engineering Research and Design. 89(1):107-115. https://doi.org/10.1016/j.cherd.2010.04.015S10711589

Classification of customers based on temporal load profile patterns

[EN] The deployment of Advanced Metering Infrastructure (AMI) is providing to utilities large amounts of energy consumption data from their customers, in form of daily load profiles with energy consumed per hour or a smaller period. These data can yield valuable results when analyzed, in order to extract useful knowledge about the typical patterns of consumption of energy from the customers. The proper mechanisms and tools have to be developed and implemented for this objective. Big Data and Big Data Analytics systems will contribute to analyze this information and help to extract knowledge from the data, summarized in form of patterns or other mining knowledge, that will aid experts in decision support. In the present work a classification of customers based on their temporal load profiles is proposed. This classification procedure could be implemented in the current Big Data Analytics software systems, providing an added value to their statistical analysis options. Previous works in the literature present algorithms that allow to classify load profiles from customers by processing batch datasets and obtaining static patterns of load profiles. The proposed technique allows to analyze patterns not only in shape but also in their evolution or trend of energy consumption at each hour of the day through time. Specific quantitative indicators that characterize the patterns (and the consumers associated to them) are described and tested for this purpose.Benítez Sánchez, IJ.; Quijano Lopez, A.; Delgado Espinos, I.; Diez Ruano, JL. (2017). Classification of customers based on temporal load profile patterns. Cigre Science & engineering. (7):143-148. http://hdl.handle.net/10251/104883S143148

La entrada en la Universidad: un reto para la orientación académica

[EN] Improve transition from secondary education to university has always been a challenge in academic guidance. Freshmen face a new personal, social, and academic context. Universities play a fundamental role in the insertion process of students coming from high school and vocational education into the university studies. During last years, a number of resources have been invested by the universities in order to develop actions that facilitate a wide range of information to prospective students. In this work we present the transition project of the Universitat Politècnica de València (UPV), focused in two moments: pre-university guidance and first year of college. The core goals of the project are to facilitate the transition of students to college, raising informational and practical actions about the studies offered by the university in order to help future students in their decisionmaking process, and to set different ways of support through tutoring that promote the adaptation to the university environment and the development of their students. The institutional project of transition from secondary education to college studies of the UPV is coordinated by the Communication Area and the Institute of Educational Sciences (ICE-UPV) of this university. This is an open project that permits adaptations attending to the necessities reported by the school counselors, prospective and university students, and tutors.[ES] La transición de los estudios de secundaria a la Universidad ha sido y es un reto para la orientación. El estudiante se enfrenta a un contexto nuevo, tanto en el ámbito personal como en los ámbitos social y académico. Las universidades tienen un papel relevante en todo el proceso de inserción de los estudiantes de bachillerato y de ciclos formativos en los estudios universitarios. En los últimos años han sido numerosos los recursos invertidos por las universidades con el fin de desarrollar acciones encaminadas a facilitar una información amplia y clara a los futuros alumnos. En este trabajo se presenta el proyecto de transición de la Universitat Politècnica de València (UPV), atendiendo a dos momentos: orientación preuniversitaria y primer año en la universidad. Los objetivos primordiales del proyecto son facilitar la transición de los estudiantes a la universidad, planteando acciones informativas y prácticas sobre los estudios ofertados para ayudar al futuro alumno en su toma de decisiones; y establecer distintas vías de apoyo a través de la tutoría que favorezcan la adaptación del estudiante al entorno universitario y su desarrollo integral. El proyecto institucional de transición de educación secundaria a la universidad de la UPV está coordinado por el Área de Comunicación y el Instituto de Ciencias de la Educación (ICE-UPV) de esta universidad. Éste es un proyecto vivo y abierto que permite adaptaciones según las necesidades que se plantean por parte de los orientadores, tutores y de alumnos preuniversitarios y universitarios.García Félix, VE.; Conejero Casares, JA.; Diez Ruano, JL. (2014). La entrada en la Universidad: un reto para la orientación académica. REDU. Revista de Docencia Universitaria. 12(2):255-280. https://doi.org/10.4995/redu.2014.5650S25528012

A multiple local models approach to accuracy improvement in continuous glucose monitoring

This is a copy of an article published in the Diabetes Technology & Therapeutics © 2012 copyright Mary Ann Liebert, Inc.; Diabetes Technology & Therapeutics is available online at: http://online.liebertpub.com/toc/dia/14/1[EN] Background: Continuous glucose monitoring (CGM) devices estimate plasma glucose (PG) from measurements in compartments alternative to blood. The accuracy of currently available CGM is yet unsatisfactory and may depend on the implemented calibration algorithms, which do not compensate adequately for the differences of glucose dynamics between the compartments. Here we propose and validate an innovative calibration algorithm for the improvement of CGM performance. Methods: CGM data from GlucoDay (R) (A. Menarini, Florence, Italy) and paired reference PG have been obtained from eight subjects without diabetes during eu-, hypo-, and hyperglycemic hyperinsulinemic clamps. A calibration algorithm based on a dynamic global model (GM) of the relationship between PG and CGM in the interstitial space has been obtained. The GM is composed by independent local models (LMs) weighted and added. LMs are defined by a combination of inputs from the CGM and by a validity function, so that each LM represents to a variable extent a different metabolic condition and/or sensor-subject interaction. The inputs best suited for glucose estimation were the sensor current I and glucose estimations (G) over cap, at different time instants [I-k, Ik-1, (G) over cap (k-1)] (IIG). In addition to IIG, other inputs have been used to obtain the GM, achieving different configurations of the calibration algorithm. Results: Even in its simplest configuration considering only IIG, the new calibration algorithm improved the accuracy of the estimations compared with the manufacturer's estimate: mean absolute relative difference (MARD) = 10.8 +/- 1.5% versus 14.7 +/- 5.4%, respectively (P = 0.012, by analysis of variance). When additional exogenous signals were considered, the MARD improved further (7.8 +/- 2.6%, P<0.05). Conclusions: The LM technique allows for the identification of intercompartmental glucose dynamics. Inclusion of these dynamics into the calibration algorithm improves the accuracy of PG estimations.The authors acknowledge the partial funding of this work by the Spanish Ministry of Science and Innovation projects DPI2007-66728-C02-01 and DPI2010-20764-C02-01 and by the European Union through FEDER funds and grant FP7-PEOPLE-2009-IEF, Reference 252085. F.B.R. is the recipient of a fellowship (FPU AP2008-02967) from the Spanish Ministry of Education.Barceló Rico, F.; Bondía Company, J.; Diez Ruano, JL.; Rossetti ., P. (2012). A multiple local models approach to accuracy improvement in continuous glucose monitoring. Diabetes Technology & Therapeutics. 14(1):74-82. https://doi.org/10.1089/dia.2011.0138S748214

Dynamic clustering of residential electricity consumption time seriesdata based on Hausdorff distance

[EN] As the analysis of electrical loads is reaching data measured from low voltage power distribution networks, there is a need for the main agents involved in the operation and management of the power grids to segment the end users as a function of their shapes of daily energy consumption or load profiles, and to obtain patterns that allow to classify the users in groups based on how they consume the energy. However, this analysis is usually limited to the analysis of single days. Since the smart metering data are time series formed by sequential measurements of energy through each hour or quarter of hour of the day, and also through each day, thanks to the implementation of Advanced Metering Infrastructure (AMI) and the Smart Grid technologies, it becomes clear that the analysis of the data needs to be extended to consider the dynamic evolution of the consumption patterns through days, weeks, months, seasons, and even years. This is the objective of the present work. A new framework is presented that addresses the dynamic clustering, visualization and identification of temporal patterns in load profiles time series, fulfilling the detected gap in this area. The present development is a generic framework that allows the clustering and visualization of load profiles time series applying different classical clustering algorithms. A novel dynamic clustering algorithm is also presented, based on an initial segmentation of the energy consumption time series data in smaller surfaces, and the computation of a similarity measure among them applying the Hausdorff distance. Following, these developments are presented and tested on two dataset of energy consumption load profiles from a sample of residential users in Spain and London.The data set for the Spanish case used in this work has been provided by the Spanish DSO Iberdrola Distribucion Electrica S.A. as part of the works developed in the Spanish R&D project GAD. The GAD or "Active Demand Management" (in Spanish) project was a project financed by the INGENIO 2010 program and supported by the CDTI (Technological Development Centre of the Ministry of Science and Innovation of Spain).Benítez Sánchez, IJ.; Diez Ruano, JL.; Quijano Lopez, A.; Delgado Espinos, I. (2016). Dynamic clustering of residential electricity consumption time seriesdata based on Hausdorff distance. Electric Power Systems Research. 140:517-526. doi:10.1016/j.epsr.2016.05.023S51752614

Técnicas de agrupamiento para identificación y control por modelos locales

Una opción interesante para el modelado de sistemas no lineales son los modelos borrosos, sin olvidar que una de las metas del modelado borroso es la interpretabilidad de los modelos. Además, si se pretenden usar los modelos identi?cados para una posterior aplicación a control, será necesario tener en cuenta algunas consideraciones adicionales que podrían modificar los criterios empleados en identificación para predicción. En esta Tesis, tras resaltar algunos conceptos poco claros relacionados con los criterios de modelado local encontrados en la bibliografía, se proponen las características deseables de las técnicas de modelado e identificación borrosa cuando el propósito es el control por modelos locales. Tras estudiar el comportamiento de las funciones objetivo de los algoritmos de agrupamiento borroso adecuados en el modelado para control, se presenta un nuevo índice que incorpora algunas características deseables relacionadas con la convexidad y suavidad de las clases finales identificadas, con ventajas respecto a otras metodologías como Gustaffson-Kessel. A continuación se define una familia de algoritmos de agrupamiento que minimizan la función objetivo previamente definida. Estos algoritmos llevan a una identificación más adecuada de modelos locales, aproximando los modelos locales el modelo linealizado de la planta en sus zonas de validez y, adicionalmente, con características deseables respecto a la interpretabilidad de las funciones de pertenencia (convexidad y suavidad). El algoritmo proporciona simultáneamente modelos locales lineales y agrupamiento de los datos de entrada, siendo especialmente aplicable para identi?cación de modelos borrosos Takagi-Sugeno y descomposición de sistemas no lineales en modelos locales lineales para control.Diez Ruano, JL. (2003). Técnicas de agrupamiento para identificación y control por modelos locales [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/2684Palanci

A comparative study of codification techniques for clustering heart disease database

[EN] This paper compares various proposals for codifying categorical attributes in a heart disease database so that numerical clustering algorithms can be applied to them. An approach for the codification of categorical attributes based on polar coordinates is proposed. This is compared with other codifications and methods for clustering mixed databases found in the literature. Our proposal has many advantages: it is relatively easy to understand and apply; the increment in the length of the input matrix is not excessively large; and the committed error is under control. The proposed codification has been combined in this case with the well-known k-means algorithm and has shown a very good performance in a heart disease database benchmark.Partially supported by national project DPI2007-66728-C02-01, regional project GVPRE-2008-108, and the authors’ institution.Barceló Rico, F.; Diez Ruano, JL.; Bondía Company, J. (2011). A comparative study of codification techniques for clustering heart disease database. Biomedical Signal Processing and Control. 6(1):64-69. https://doi.org/10.1016/j.bspc.2010.07.004S64696