Recursos de colección

Repositorio Institucional de la Universidad de Cordoba :: Spain (18.682 recursos)

El repositorio recoge todo tipo de materiales digitales: artículos de revistas, comunicaciones a congresos, tesis doctorales, documentos de trabajo, materiales docentes y objetos de aprendizaje, así como los productos digitales del patrimonio bibliográfico de la Universidad de Córdoba.

DIAN-Artículos, capítulos...

Mostrando recursos 1 - 20 de 56

  1. Smith Predictor with Inverted Decoupling for Square Multivariable Time Delay Systems

    Garrido Jurado, Juan; Vázquez, Francisco; Morilla, Fernando; Normey-Rico, Julio E.
    This paper presents a new methodology to design multivariable Smith predictor for n×n processes with multiple time delays based on the centralized inverted decoupling structure. The controller elements are calculated in order to achieve good reference tracking and decoupling response. Independently of the system size, very simple general expressions for the controller elements are obtained. The realizability conditions are provided and the particular case of processes with all of its elements as first order plus time delay systems is discussed in more detail. A diagonal filter is added to the proposed control structure in order to improve the disturbance rejection...

  2. Inverted decoupling internal model control for square stable multivariable time delay systems

    Garrido Jurado, Juan; Vázquez, Francisco; Morilla, Fernando
    This paper presents a new tuning methodology of the main controller of an internal model control structure for n×n stable multivariable processes with multiple time delays based on the centralized inverted decoupling structure. Independently of the system size, very simple general expressions for the controller elements are obtained. The realizability conditions are provided and the specification of the closed-loop requirements is explained. A diagonal filter is added to the proposed control structure in order to improve the disturbance rejection without modifying the nominal set-point response. The effectiveness of the method is illustrated through different simulation examples in comparison with other...

  3. Aplicando minería de datos para descubrir rutas de aprendizaje frecuentes en Moodle

    Bogarín Vega, Alejandro; Romero Morales, C.; Cerezo Menéndez, Rebeca
    En este artículo, aplicamos técnicas de minería de datos para descubrir rutas de aprendizaje frecuentes. Hemos utilizado datos de 84 estudiantes universitarios, seguidos en un curso online usando Moodle 2.0. Proponemos agrupar a los estudiantes, en primer lugar, a partir de los datos de una síntesis de uso de Moodle y/o las calificaciones finales de los alumnos en un curso. Luego, usamos los datos de los logs de Moodle sobre cada cluster/grupo de estudiantes separadamente con el fin de poder obtener más específicos y precisos modelos de procesos del comportamiento de los estudiantes.

  4. Multivariable PID control by decoupling

    Garrido Jurado, Juan; Vázquez, Francisco; Morilla, Fernando
    This paper presents a new methodology to design multivariable PID controllers based on decoupling control. The method is presented for general n×n processes. In the design procedure, an ideal decoupling control with integral action is designed to minimize interactions. It depends on the desired open loop processes that are specified according to realizability conditions and desired closed loop performance specifications. These realizability conditions are stated and three common cases to define the open loop processes are studied and proposed. Then, controller elements are approximated to PID structure. From a practical point of view, the windup problem is also considered and...

  5. Centralized Inverted Decoupling Control

    Garrido Jurado, Juan; Vázquez, Francisco; Morilla, Fernando
    This paper presents a new methodology of multivariable centralized control based on the structure of inverted decoupling. The method is presented for general n×n processes, obtaining very simple general expressions for the controller elements with a complexity independent of the system size. The possible configurations and realizability conditions are stated. Then, the specification of performance requirements is carried out from simple open loop transfer functions for three common cases. As a particular case, it is shown that the resulting controller elements have PI structure or filtered derivative action plus a time delay when the process elements are given by first...

  6. Centralized multivariable control by simplified decoupling

    Garrido Jurado, Juan; Vázquez, Francisco; Morilla, Fernando
    This paper presents a generalized formulation of simplified decoupling to n×n processes that allows for different configurations depending on the decoupler elements set to unity. To apply this decoupling method, the realizability conditions are stated. Then, from the previous decoupling in combination with a decentralized control, the formulation of a centralized control by simplified decoupling is developed. After reducing the controller, this last proposed method is modified to a multivariable PID control. From an implementation point of view, the windup problem is addressed for these methods, and an anti-windup scheme for multivariable PID controllers is proposed. Comparisons with other works...

  7. An extended approach of inverted decoupling

    Garrido Jurado, Juan; Vázquez, Francisco; Morilla, Fernando
    This paper presents an extension of the inverted decoupling approach that allows for more flexibility in choosing the transfer functions of the decoupled apparent process. In addition, the expressions of the inverted decoupling are presented for general n × n processes, highlighting that the complexity of the decoupler elements is independent of the system size. The realizability conditions are stated in order to select a proper configuration, and the different possible cases for each configuration are shown. Comparisons with other works demonstrate the effectiveness of this methodology, through the use of several simulation examples and an experimental lab process.

  8. Practical advantages of inverted decoupling

    Garrido Jurado, Juan; Vázquez, Francisco; Morilla, Fernando; Hägglund, T.
    This paper presents a study of the main advantages of inverted decoupling in 2x2 processes. Two simulation examples and an experimental process are used to show these advantages in comparison with simplified decoupling. The study is focused on the following practical advantages: the apparent process is the same as that obtained if one loop changes to manual, bumpless transfer and anti-windup are achieved easily using a feedforward input in the controllers, and abnormalities of secondary loops do not affect the opposite loop. Thanks to them, inverted decoupling may be a good and easy way to improve the performance of industrial...

  9. Object oriented modelling and simulation of hydropower plants with run-of-river scheme: A new simulation tool

    Garrido Jurado, Juan; Zafra, Ángel; Vázquez, Francisco
    This paper presents the design of a component library for modelling hydropower plants, and describes the development of a new simulation tool for small hydropower plants with a run-of-river scheme. After reviewing the desirable features of simulation, an approach based on an object oriented modelling language, like EcosimPro, is presented. A general model of hydropower plant with run-of-river scheme is created with this component library. It provides the possibility of choosing a specific number of turbines and spillway gates. In this way, several hydropower stations of similar operating characteristics can be simulated using this same general model. It is expected...

  10. Utilización de un sistema de captura de movimiento 3D para el análisis cienemático del gesto técnico del paso de vallas

    Garrido Castro, Juan Luis; Gil Cabezas, Jesús; Beas Jiménez, J.D.; López López, C.; Rodríguez Fernández, C.; Da Silva Rigoletto, M.
    La carrera de vallas es una de las disciplinas más técnicas del atletismo. Consiste en una combinación cíclica de sprint y salto donde el mayor interés para entrenador y atleta es analizar y perfeccionar el estilo del paso de valla, uno de los elementos claves de esta disciplina. En el paso de la valla la perdida de velocidad horizontal debe ser lo menor posible. Esto depende de numerosos factores clave como el tiempo de vuelo, la distancia de vuelo, la altura sobre la valla, etc. El objetivo del estudio ha sido caracterizar cinemáticamente el gesto técnico de paso de vallas...

  11. JCLEC Meets WEKA!

    Cano, Alberto; Luna, J.M.; Olmo Ortiz, Juan Luis; Ventura Soto, S.
    WEKA has recently become a very referenced DM tool. In spite of all the functionality it provides, it does not include any framework for the development of evolutionary algorithms. An evolutionary computation framework is JCLEC, which has been successfully employed for developing several EAs. The combination of both may lead in a mutual bene t. Thus, this paper proposes an intermediate layer to connect WEKA with JCLEC. It also presents a study case which samples the process of including a JCLEC's EA into WEKA

  12. Nonlinear Boosting Projections for Ensemble Construction

    García-Pedrajas, Nicolás; García-Osorio, César; Fyfe, Colin
    In this paper we propose a novel approach for ensemble construction based on the use of nonlinear projections to achieve both accuracy and diversity of individual classifiers. The proposed approach combines the philosophy of boosting, putting more effort on difficult instances, with the basis of the random subspace method. Our main contribution is that instead of using a random subspace, we construct a projection taking into account the instances which have posed most difficulties to previous classifiers. In this way, consecutive nonlinear projections are created by a neural network trained using only incorrectly classified instances. The feature subspace induced by the hidden layer of this network is...

  13. Teaching push-down automata and Turing machines

    García-Osorio, César; Mediavilla-Sáiz, Iñigo; Jimeno-Visitación, Javier; García-Pedrajas, Nicolás
    In this paper we present the new version of a tool to assist in teaching formal languages and automata theory. In the previous version the tool provided algorithms for regular expressions, finite automata and context free grammars. The new version can simulate as well push-down automata and Turing machines

  14. An intruder detection approach based on infrequent rating pattern mining

    Luna, J.M.; Ramírez, A.; Romero, J.R.; Ventura Soto, S.

  15. Évolutionary neural network classifiers to predict the classification of R&D performance in EU countries

    Paz-Marín, Mónica de la; Campoy-Muñoz, P.; Hervás-Martínez, César

  16. Addressing remitting behavior using an ordinal classification approach

    Campoy-Muñoz, P.; Gutiérrez, Pedro A.; Hervás-Martínez, César

  17. Algoritmos de aprendizaje evolutivo y estadístico para la determinación de mapas de malas hierbas utilizando técnicas de teledetección

    Gutiérrez, Pedro A.; Fernández, J.C.; Hervás-Martínez, César
    Este trabajo aborda la resolución de problemas de clasificación binaria utilizando una metodología híbrida que combina la regresión logística y modelos evolutivos de redes neuronales de unidades producto. Para estimar los coeficientes del modelo lo haremos en dos etapas, en la primera aprendemos los exponentes de las funciones unidades producto, entrenando los modelos de redes neuronales mediante computación evolutiva y una vez estimados el número de funciones potenciales y los exponentes de estas funciones, se aplica el método de máxima verosimilitud al espacio de características formado por las covariables iniciales junto con las nuevas funciones de base obtenidas al entrenar los modelos de unidades producto. Esta metodología híbrida en el diseño del modelo y en la...

  18. Projection based ensemble learning for ordinal regression

    Pérez-Ortiz, María; Gutiérrez, Pedro A.; Hervás-Martínez, César
    The classification of patterns into naturally ordered labels is referred to as ordinal regression. This paper proposes an ensemble methodology specifically adapted to this type of problems, which is based on computing different classification tasks through the formulation of different order hypotheses. Every single model is trained in order to distinguish between one given class (k) and all the remaining ones, but grouping them in those classes with a rank lower than k, and those with a rank higher than k. Therefore, it can be considered as a reformulation of the well-known one-versus-all scheme. The base algorithm for the ensemble could be any threshold (or even probabilistic) method, such as the...

  19. Radar milimétrico

    Castro Lozano, Carlos de; García Salcines, Enrique; Ramírez Uceda, José Miguel; Robles González, Remedios María; Sainz de Abajo, Beatriz; Malgina, Natalia; Gutiérrez Ávila, Cándido; Castelo Pla, José Antonio; Parra Lozano, Manuel
    El sistema de radar consiste en un complejo grupo de medios técnicos de carácter universal y funcional (observación, control ecológico, vigilancia, dirección de tráfico marítimo) de las aguas del mar, del océano, de otros espacios acuosos y del litoral, mediante la utilización de radares con ondas milimétricas (los actuales utilizados en uso civil son en cm y dm) consiguiendo de este modo una mayor exactitud en la información recibida

  20. Speeding Up Evolutionary Learning Algorithms using GPUs

    Cano, Alberto; Zafra, Amelia; Ventura Soto, S.
    This paper propose a multithreaded Genetic Programming classi cation evaluation model using NVIDIA CUDA GPUs to reduce the computational time due to the poor perfor- mance in large problems. Two di erent clas- si cation algorithms are benchmarked using UCI Machine Learning data sets. Experi- mental results compare the performance us- ing single and multithreaded Java, C and GPU code and show the e ciency far better obtained by our proposal.

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