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El texto completo de este trabajo no se encuentra disponible por no haber sido facilitado aún por su autor, por restricciones de copyright, o por no existir una versión digital, This paper presents a new approach based on ant colony optimization (ACO) to determine the trajectories of a fleet of unmanned air vehicles (UAVs) looking for a lost target in the minimum possible time. ACO is especially suitable for the complexity and probabilistic nature of the minimum time search (MTS) problem, where a balance between the computational requirements and the quality of solutions is needed. The presented approach includes a new MTS heuristic that exploits the probability and spatial properties of the problem, allowing our ant based algorithm to quickly obtain high-quality high-level straight segmented UAV trajectories. The potential of the algorithm is tested for different ACO parameterizations, over several search scenarios with different characteristics such as number of UAVs, or target dynamicsand location distributions. The statistical comparison against other techniques previously used for MTS( ad hoc heuristics, cross entropy optimization, bayesian optimization algorithm and genetic algorithms) shows that the new approach outperforms the others. (C) 2017 Elsevier B.V. All rights reserved., AIRBUS, Sección Deptal. de Arquitectura de Computadores y Automática (Físicas), Fac. de Ciencias Físicas, TRUE, unpub

© 2002 Springer-Verlag London Limited. Part of the work has been performed under project CICYT TAP94-0832-C02-01. The constructive recommendations provided by the reviewers are also gratefully acknowledged., The key step in stereovision is image matching. This is carried out on the basis of selecting features, edge points, edge segments, regions, corners, etc. Once the features have been selected, a set of attributes (properties) for matching is chosen. This is a key issue in stereovision matching. This paper presents an approach for attribute selection in stereovision matching tasks based on a Probabilistic Neural Network, which allows the computation of a mean vector and a covariance matrix from which the relative importance of attributes for matching and the attribute interdependence can be derived. This is possible because the matching problem focuses on a pattern classification problem. The performance of the method is verified with a set of stereovision images and the results contrasted with a classical attribute selection method and also with the relevance concept., CICYT, Sección Deptal. de Arquitectura de Computadores y Automática (Físicas), Fac. de Ciencias Físicas, TRUE, pub

© 2004 Elsevier The authors would like to acknowledge the support of the CICYT Spanish Committee (Projects TAP97-0607- C03-01 and DPI 2000-0386-C03-01) and the Complutense Supercomputing Centre, and the collaboration of the CEHIPAR staff., This paper shows the design and implementation of a fuzzy control system used to reduce the vertical motion of a TF-120 fast ferry. The system increases the comfort of the passengers and crew by reducing the main cause of seasickness. The aim of this controller-which is based on a fuzzy model of the ship behaviour-is to decrease the pitch acceleration by controlling the position of some actuators and varying their working angles. Experiments have been carried out on a ship scaled-down replica. The motion sickness incidence has been evaluated and results have proved to be highly satisfactory. (C) 2004 Elsevier Ltd. All rights reserved., CICYT Spanish Committee, Complutense Supercomputing Centre, CEHIPAR staff, Sección Deptal. de Arquitectura de Computadores y Automática (Físicas), Fac. de Ciencias Físicas, TRUE, pub

© 2004 IEEE. The authors wish to acknowledge the constructive recommendations provided by the reviewers., This paper outlines a method for solving the stereovision matching problem using edge segments as the primitives. In stereovision matching, the following constraints are commonly used: epipolar, similarity, smoothness, ordering, and uniqueness. We propose a new strategy in which such constraints are sequentially combined. The goal is to achieve high performance in terms of correct matches by combining several strategies. The contributions of this paper are reflected in the development of a similarity measure through a support vector machines classification approach; the transformation of the smoothness, ordering and epipolar constraints into the form of an energy function, through an optimization simulated annealing approach, whose minimum value corresponds to a good matching solution and by introducing specific conditions to overcome the violation of the smoothness and ordering constraints. The performance of the proposed method is illustrated by comparative analysis against some recent global matching methods., Sección Deptal. de Arquitectura de Computadores y Automática (Físicas), Fac. de Ciencias Físicas, TRUE, pub

© Elsevier Science BV. The authors wish to acknowledge Prof. Dr. S. Dormido, Head of Department of Informática y Automática, CC Físicas, UNED, Madrid, for his support and encouragement. Part of this work has been performed under project CICYT TAP94-0832-C02-01. The constructive recommendations provided by the reviewers are also gratefully acknowledged., This paper presents an approach to the local stereo correspondence problem. The primitives or features used are groups of collinear connected edge points called segments. Each segment has several associated attributes or properties. We have verified that the differences of the attributes for the true matches cluster in a cloud around a center. Then for each current pair of primitives we compute a distance between the difference of its attributes and the cluster center. The correspondence is established in the basis of the minimum distance criterion (similarity constraint). We have designed an image understanding system to learn the best representative cluster center. For such purpose a new learning method is derived from the Fuzzy c-Means (FcM) algorithm where the dispersion of the true samples in the cluster is taken into account through the Mahalanobis distance. This is the main contribution of this paper. A better performance of the proposed local stereo-matching learning method is illustrated with a comparative analysis between classical local methods without learning., CICYT, Sección Deptal. de Arquitectura de Computadores y Automática (Físicas), Fac. de Ciencias Físicas, TRUE, pub

© 1999 Pattern Recognition Society, This paper outlines a method for solving the global stereovision matching problem using edge segments as the primitives. A relaxation scheme is the technique commonly used by existing methods to solve this problem. These techniques generally impose the following competing constraints: similarity, smoothness, ordering and uniqueness, and assume a bound on the disparity range. The smoothness constraint is basic in the relaxation process. We have verified that the smoothness and ordering constraints can be violated by objects close to the cameras and that the setting of the disparity limit is a serious problem. This problem also arises when repetitive structures appear in the scene (i.e. complex images), where the existing methods produce a high number of failures. We develop our approach from a relaxation labeling method ([1] W.J. Christmas, J. Kittler, M. Petrou, structural matching in computer vision using probabilistic relaxation, IEEE Trans. Pattern Anal. Mach. Intell. 17(8)(1995) 749-764), which allows us to map the above constraints. The main contribution is made, (1) by applying a learning strategy in the similarity constraint and (2) by introducing specific conditions to overcome the violation of the smoothness constraint and to avoid the serious problem produced by the required fixation of a disparity limit. Consequently, we improve the stereovision matching process. A better performance of the proposed method is illustrated by comparative analysis against some recent global matching methods., Sección Deptal. de Arquitectura de Computadores y Automática (Físicas), Fac. de Ciencias Físicas, TRUE, pub

© 2013 David Moreno-Salinas et al. The authors wish to thank the Spanish Ministry of Science and Innovation (MICINN) for support under Projects DPI2009-14552-C02-01 and DPI2009-14552-C02-02. The authors wish to thank also the National University Distance Education (UNED) for support under Project 2012V/PUNED/0003., One of the most important problems in many research fields is the development of reliable mathematical models with good predictive ability to simulate experimental systems accurately. Moreover, in some of these fields, as marine systems, these models play a key role due to the changing environmental conditions and the complexity and high cost of the infrastructure needed to carry out experimental tests. In this paper, a semiphysical modelling technique based on least-squares support vector machines (LS-SVM) is proposed to determine a nonlinear mathematical model of a surface craft. The speed and steering equations of the nonlinear model of Blanke are determined analysing the rudder angle, surge and sway speeds, and yaw rate from real experimental data measured from a zig-zag manoeuvre made by a scale ship. The predictive ability of the model is tested with different manoeuvring experimental tests to show the good performance and prediction ability of the model computed., Spanish Ministry of Science and Innovation (MICINN), National University Distance Education (UNED), Sección Deptal. de Arquitectura de Computadores y Automática (Físicas), Fac. de Ciencias Físicas, TRUE, pub

© EUCA. This development was supported by CICYT of Spain under contracts DPI2000-0386-C03-01 and TAP97-0607-C03-02., This work presents the formal approach for identifying continuous transfer functions of the vertical dynamics of a high-speed ship as a nonlinear optimization problem with linear constraints. The proposed solution is described with a hybrid optimization method (genetic algorithm + nonlinear optimization algorithm with linear constraints from the Matlab toolbox)., CICYT, Sección Deptal. de Arquitectura de Computadores y Automática (Físicas), Fac. de Ciencias Físicas, TRUE, pub

© 1998 Elsevier Science S.A. This paper is part of the work carried out by the first author in fulfillment of the requirements for obtaining a Doctorate degree (Universidad Nacional de Educación a Distancia, Madrid, Spain). The work described in this paper has been performed in the framework of an European Commission research training program., A plasma current profile control system has been designed and tested at Joint European Torus (JET). The system uses the one turn loop voltage for lower hybrid current drive (LHCD) control, and the normalised second current moment of the plasma current distribution for off-axis current control. These provide relatively simple measurements and calculations suitable for real time operation. Models for the response of the loop voltage and second current moment to Lower Hybrid power input are derived and validated against JET data. Based on these models, the components of the second current moment and loop voltage control systems are designed to suit prescribed performance. Loop voltage has been controlled in 2.5 MA discharges at 66% reduction, providing the means for LHCD regulation. Second current moment control during the current rise phase has contributed to 60% improvement of the neutron yield performance of shear optimisation discharges at JET., Sección Deptal. de Arquitectura de Computadores y Automática (Físicas), Fac. de Ciencias Físicas, TRUE, pub

© 2004 Elsevier. This development was supported by CICYT of Spain under contract DPI2003-09745-C04-01., This work serves as a pioneering contribution in the use of quantitative feedback theory methodology to the design of a controller for a high speed ship. We have improved the design of a multivariable robust controller so that it will be able to reduce incidences of motion sickness on high speed ferries. Motion sickness is caused by vertical accelerations associated with the heave and pitch motions induced by waves. Therefore we are dealing with regulation problems of a highly perturbed system. The design regulator has been validated in sea behaviour trials, using a scaled down replica 1/25 the size of a high-speed ferry. (c) 2004 Elsevier Ltd. All rights reserved., CICYT, Sección Deptal. de Arquitectura de Computadores y Automática (Físicas), Fac. de Ciencias Físicas, TRUE, pub

© Springer-Verlag 2002. We sincerely thank j.D. Karkera for assistence with protein prediction algorithms, W.B. Dobyns for reading the brain scans of the patients. R.D.B. is supported by a Cancer Research Fund Fellowship of the Damon Runyon-Walter Winchell Foundation. A.F.S. is a Scholar of the McKnight Endowment Fund for Neuroscience and the Irma T. Hirschl Trust. This work is supported by grants from the NIH (A.F.S.) and by the Division of Intramural Research, NHGRI, NIH (M.M.)., TDGF1 (CRIPTO) is an EGF-CFC family member and an obligate co-receptor involved in NODAL signaling, a developmental program implicated in midline, forebrain, and left-right axis development in model organisms. Previous studies of CFC1 (CRYPTIC), another member of the EGF-CFC family, demonstrated that normal function of this protein is required for proper laterality development in humans. Here we identify a mutation in the conserved CFC domain of TDGF1 in a patient with midtine anomalies of the forebrain. The mutant protein is inactive in a zebrafish rescue assay, indicating a role for TDGF1 in human midline and forebrain development., NIH (A. F. S.), Division of Intramural Research NHGRI, NIH (M. M.), Sección Deptal. de Arquitectura de Computadores y Automática (Físicas), Fac. de Ciencias Físicas, TRUE, pub

Part of the work has been performed under project CICYT TAP94-0832-C02-01. The constructive recommendations provided by the reviewers are also gratefully acknowledged., This paper presents an approach to the local stereovision matching problem using edge segments as features with four attributes. Based on these attributes we compute a matching probability between pairs of features of the stereo images. A correspondence is said to be true when this probability is maximum. The probability value is a weighted sum of the attributes. We use two combined ADALINE neural networks to compute the weight for each attribute. A comparative analysis among other recent matching methods is illustrated., CICYT, Sección Deptal. de Arquitectura de Computadores y Automática (Físicas), Fac. de Ciencias Físicas, TRUE, pub

© 2008 Elsevier Inc., This research study focuses on the modeling and simulation of a gas distribution pipeline network with a special emphasis on gas ducts. Gas ducts are the most important components of such kind of systems since they define the major dynamic characteristics. Isothermal, unidirectional flow is usually assumed when modeling the gas flow through a gas duct. This paper presents two simplified models derived from the set of partial differential equations governing the dynamics of the process. These models include the inclination term, neglected in most related papers. Moreover, two numerical schemes are presented for the integration of such models. Also, it is shown how the pressure drop along the pipe has a strong dependency with the inclination term. To solve the system dynamics through the proposed numerical schemes a based MATLAB-Simulink library was built. With this library it is possible to simulate the behavior of a gas distribution network from the individual simulation of each component. Finally, the library is tested through three application examples, and results are compared with the existing ones in the literature., Sección Deptal. de Arquitectura de Computadores y Automática (Físicas), Fac. de Ciencias Físicas, TRUE, pub

© 2002 IEEE. The authors would like to thank the reviewers and Associate Editor for constructive recommendations., This paper presents an approach to the local stereovision matching problem using edge segments as features with four attributes. From these attributes we compute a matching probability between pairs of features of the stereo images. A correspondence is said true when such a probability is maximum. We introduce a nonparametric strategy based on Parzen's window to estimate a probability density function (PDF) which is used to obtain the matching probability. This is the main finding of the paper. A comparative analysis of other recent matching methods is included to show that this finding can be justified theoretically. A generalization of the proposed method is made in order to give guidelines about its use with the similarity constraint and also in different environments where other features and attributes are more suitable., Sección Deptal. de Arquitectura de Computadores y Automática (Físicas), Fac. de Ciencias Físicas, TRUE, pub

© 2005 Elsevier. The authors would like to thank the Spanish MCYT, "Ministerio de Ciencia y Tecnología", for their support (Projects DPI2000-0386-C03-02 and DPI2003-09745-C04-02), the CEHIPAR staff for their cooperation, and IZAR for its recommendations., Fast ships are taking a relevant role with a clear interest for military purposes. Fast sea transportation encounters several problems to be solved. This article refers to the difficulties originated by brisk vertical motions. The waves encountered by fast ships induce such vertical motions, and this has negative effects: navigation risks, sea sickness, structural damages, and load displacement. It is also interesting for military uses to stabilize the ship when an aircraft is landing or when precision firing is required. By means of submerged actuators, it is possible to alleviate vertical motions. In this research, a pair of transom flaps and a T-foil near the bow are used to counteract the waves. These actuators must move with the maximum efficiency, taking into account the dynamical characteristics of the ship. As a consequence, there is a problem of automatic control design. To carry out this design, it is important to obtain mathematical models of all the aspects involved in the problem: the ship, the waves, the actuators, and the effect on crew and comfort. The aim of this paper is to present the development of these models and the use of them for problem analysis and control design., Spanish MCYT Ministerio de Ciencia y Tecnología, Sección Deptal. de Arquitectura de Computadores y Automática (Físicas), Fac. de Ciencias Físicas, TRUE, pub

© 2009 Elsevier Ltd. The authors would like to thank the Spanish Science and Technology Ministry for their support of project DPI2002-02924 and the Madrid, A multiproduct Pipeline provides an economic way to transport large Volumes of refined petroleum products over long distances. In such a pipeline, different products are pumped back-to-back without any separation device between them. Sometimes, multiproduct pipelines can be connected together, resulting in a more complex system commonly named multi-pipeline system. This paper proposes a new discrete mathematical approach to solve short-term operational planning Of multi-pipeline systems for refined products. This model is based on a discrete approach that divides both the planning horizon into time intervals of equal duration and the individual polyducts into packages of equal volume each containing a single product. Numerical examples are solved in order to show the performance of the proposed model. All the instances are implemented with the OPL modeling language running CPLEX as solver., Spanish Science and Technology Ministry, Madrid Autonomous Community, Sección Deptal. de Arquitectura de Computadores y Automática (Físicas), Fac. de Ciencias Físicas, TRUE, pub

The authors wish to acknowledge Dr. L. Jañez Head of the Instituto Complutense de Imagen y Telemedicina, E. Ortiz co-worker in the same Institution, and Dr. Carreras Head of PET Institute, for his support in the medical image fusion applications. They have provided us with the medical images shown in this work. The constructive recommendations provided by the reviewers are also gratefully acknowledged., The objective of image fusion is to combine information from multiple images of the same scene. The result of image fusion is a new image which is more suitable for human and machine perception or further image-processing tasks such as segmentation, feature extraction and object recognition. Different fusion methods have been proposed in literature, including multiresolution analysis. This paper is an image fusion tutorial based on wavelet decomposition, i.e. a multiresolution image fusion approach. We can fuse images with the same or different resolution level, i.e. range sensing, visual CCD, infrared, thermal or medical. The tutorial performs a synthesis between the multi scale-decomposition-based image approach (Proc. IEEE 87 (8) (1999) 1315), the ARSIS concept (Photogramm. Eng. Remote Sensing 66 (1) (2000) 49) and a multisensor scheme (Graphical Models Image Process. 57 (3) (1995) 235). Some image fusion examples illustrate the proposed fusion approach. A comparative analysis is carried out against classical existing strategies, including those of multiresolution., Sección Deptal. de Arquitectura de Computadores y Automática (Físicas), Fac. de Ciencias Físicas, TRUE, pub

© 2011 Elsevier. The authors wish to acknowledge to the Council of Education of the Autonomous Community of Madrid and the Social European Fund for the research contract with the author P. Javier Herrera. Also to Drs. Fernando Montes and Isabel Canellas from the Forest Research Centre (CIFOR, INIA) for his support and the imaged material supplied., We present a novel strategy for computing disparity maps from omni-directional stereo images obtained with fish-eye lenses in forest environments. At a first segmentation stage, the method identifies textures of interest to be either matched or discarded. Two of them are identified by applying the powerful Support Vector Machines approach. At a second stage, a stereovision matching process is designed based on the application of four stereovision matching constraints: epipolarity, similarity, uniqueness and smoothness. The epipolarity guides the process. The similarity and uniqueness are mapped once again through the Support Vector Machines, but under a different way to the previous case; after this an initial disparity map is obtained. This map is later filtered by applying the Discrete Simulated Annealing framework where the smoothness constraint is conveniently mapped. The combination of the segmentation and stereovision matching approaches makes the main contribution. The method is compared against the usage of simple features and combined similarity matching strategies. (C) 2011 Elsevier Ltd. All rights reserved., Council of Education of the Autonomous Community of Madrid, Social European Fund, Forest Research Centre (CIFOR, INIA), Sección Deptal. de Arquitectura de Computadores y Automática (Físicas), Fac. de Ciencias Físicas, TRUE, pub

© 2010 IEEE. This work was supported by the Community of Madrid under Project "COSICOLOGI" S-0505/DPI-0391, by the Spanish Ministry of Education and Science under Project DPI2006-15661-C02-01 and Project DPI2009-14552-C02-01, and by the European Aeronautic Defense and Space Company (Construcciones Aeronauticas Sociedad Anonima) under Project 353/2005. The work of E. Besada-Portas was supported by the Spanish Postdoctoral Grant EX-2007-0915 associated with the Prince of Asturias Endowed Chair of the University of New Mexico, University of New Mexico, Albuquerque, NM. This paper was presented in part at the Genetic Evolutionary Computation Conference, Atlanta, GA, 2008, and in part at the 8th International FLINS Conference, Madrid, Spain, 2008., This paper presents a path planner for multiple unmanned aerial vehicles (UAVs) based on evolutionary algorithms (EAs) for realistic scenarios. The paths returned by the algorithm fulfill and optimize multiple criteria that 1) are calculated based on the properties of real UAVs, terrains, radars, and missiles and 2) are structured in different levels of priority according to the selected mission. The paths of all the UAVs are obtained with the multiple coordinated agents coevolution EA (MCACEA), which is a general framework that uses an EA per agent (i.e., UAV) that share their optimal solutions to coordinate the evolutions of the EAs populations using cooperation objectives. This planner works offline and online by means of recalculating parts of the original path to avoid unexpected risks while the UAV is flying. Its search space and computation time have been reduced using some special operators in the EAs. The successful results of the paths obtained in multiple scenarios, which are statistically analyzed in the paper, and tested against a simulator that incorporates complex models of the UAVs, radars, and missiles, make us believe that this planner could be used for real-flight missions., Community of Madrid, Spanish Ministry of Education and Science, European Aeronautic Defense and Space Company (Construcciones Aeronauticas Sociedad Anonima), Spanish Postdoctoral Grant, Sección Deptal. de Arquitectura de Computadores y Automática (Físicas), Fac. de Ciencias Físicas, TRUE, pub

© Springer-Verlag London Limited 2008. Part of the work has been performed under project no. 143/2004 Fundacion General UCM. The authors are also grateful to the referees for their constructive criticism and suggestions on the original version of this paper., This paper proposes an automatic method based on the deterministic simulated annealing (DSA) approach for solving the image change detection problem between two images where one of them is the reference image. Each pixel in the reference image is considered as a node with a state value in a network of nodes. This state determines the magnitude of the change. The DSA optimization approach tries to achieve the most network stable configuration based on the minimization of an energy function. The DSA scheme allows the mapping of interpixel contextual dependencies which has been used favorably in some existing image change detection strategies. The main contribution of the DSA is exactly its ability for avoiding local minima during the optimization process thanks to the annealing scheme. Local minima have been detected when using some optimization strategies, such as Hopfield neural networks, in images with large amount of changes, greater than the 20%. The DSA performs better than other optimization strategies for images with a large amount of changes and obtain similar results for images where the changes are small. Hence, the DSA approach appears to be a general method for image change detection independently of the amount of changes. Its performance is compared against some recent image change detection methods., Fundación General UCM, Sección Deptal. de Arquitectura de Computadores y Automática (Físicas), Fac. de Ciencias Físicas, TRUE, pub

© Springer-Verlag Berlin Heidelberg 2003. Iberian Conference on Pattern Recognition and Image Analysis (1st.Jun 04-06, 2003. Mallorca, España), The aim of image fusion is to combine information from multiple images of the same scene. The result of image fusion is a new image,,which is more suitable for human and machine perception or further image-processing tasks such as segmentation, feature extraction and object recognition. Different fusion methods have been proposed in the literature. This paper presents new methods based on the computation of local and global gradient. A comparative analysis is carried out against other existing strategies. The results are encouraging., Sección Deptal. de Arquitectura de Computadores y Automática (Físicas), Fac. de Ciencias Físicas, TRUE, pub

This work has been supported by the Spanish Grants DPI2009-14552-C02-01 and CAM S-0505/DPI 0391., This paper presents a state of the art of the estimation algorithms dealing with Out-of-Sequence (OOS) measurements for non-linearly modeled systems. The state of the art includes a critical analysis of the algorithm properties that takes into account the applicability of these techniques to autonomous mobile robot navigation based on the fusion of the measurements provided, delayed and OOS, by multiple sensors. Besides, it shows a representative example of the use of one of the most computationally efficient approaches in the localization module of the control software of a real robot (which has non-linear dynamics, and linear and non-linear sensors) and compares its performance against other approaches. The simulated results obtained with the selected OOS algorithm shows the computational requirements that each sensor of the robot imposes to it. The real experiments show how the inclusion of the selected OOS algorithm in the control software lets the robot successfully navigate in spite of receiving many OOS measurements. Finally, the comparison highlights that not only is the selected OOS algorithm among the best performing ones of the comparison, but it also has the lowest computational and memory cost., Spanish Grants, Sección Deptal. de Arquitectura de Computadores y Automática (Físicas), Fac. de Ciencias Físicas, TRUE, pub

Part of the work has been performed under project CICYT TAP94-0832-C02-01., This paper presents an approach to the local stereovision matching problem using edge segments as features with four attributes. In this paper we design a Support Vector Machine classifier for solving the stereovision matching problem. We obtain a matching decision function to classify a pair of features as a true or false match. The use of such classifier makes up the main finding of the paper. A comparative analysis among other existing approaches is included to show that this finding can be justified theoretically. From these investigations, we conclude that the performance of the proposed method is appropriate for this task., CICYT, Sección Deptal. de Arquitectura de Computadores y Automática (Físicas), Fac. de Ciencias Físicas, TRUE, pub

© 2011 Elsevier Ltd. The authors would like to thank the Spanish Science and Technology Ministry for their support through project DPI2002-02924 and Madrid, The objective of this work is to develop several metaheuristic algorithms to improve the efficiency of the MILP algorithm used for planning transportation of multiple petroleum products in a multi-pipeline system. The problem involves planning the optimal sequence of products assigned to each new package pumped through each polyduct of the network in order to meet product demands at each destination node before the end of the planning horizon. All the proposed metaheuristics are combinations of improvement methods applied to solutions resulting from different construction heuristics. These improvements are performed by searching the neighborhoods generated around the current solution by different Global Search Metaheuristics: Multi-Start Search, Variable Neighborhood Search, Taboo Search and Simulated Annealing. Numerical examples are solved in order to show the performance of these metaheuristics against a standard commercial solver using MILP. Results demonstrate how these metaheuristics are able to reach better solutions in much lower computational time. (C) 2011 Elsevier Ltd. All rights reserved., Spanish Science and Technology Ministry, Madrid Autonomous Community, Sección Deptal. de Arquitectura de Computadores y Automática (Físicas), Fac. de Ciencias Físicas, TRUE, pub

© 2012 Elsevier Ltd. The research leading to these results has been funded by the European Union's Seventh Framework Programme [FP7/2007-2013] under Grant Agreement No. 245986 in the Theme NMP-2009-3.4-1 (Automation and robotics for sustainable crop and forestry management). The authors wish also to acknowledge to the project AGL2011-30442-C02-02, supported by the Ministerio de Economia y Competitividad of Spain within the Plan Nacional de I+D+i., It is well-known that one important issue emerging strongly in agriculture is related with the automation of tasks, where camera-based sensors play an important role. They provide images that must be conveniently processed. The most relevant image processing procedures require the identification of green plants, in our experiments they comes from barley and maize fields including weeds, so that some type of action can be carried out, including site-specific treatments with chemical products or mechanical manipulations. The images come from outdoor environments, which are affected for a high variability of illumination conditions because of sunny or cloudy days or both with high rate of changes. Several indices have been proposed in the literature for greenness identification, but under adverse environmental conditions most of them fail or do not work properly. This is true even for camera devices with auto-image white balance. This paper proposes a new automatic and robust Expert System for greenness identification. It consists of two main modules: (1) decision making, based on image histogram analysis and (2) greenness identification, where two different strategies are proposed, the first based on classical greenness identification methods and the second inspired on the Fuzzy Clustering approach. The Expert System design as a whole makes a contribution, but the Fuzzy Clustering strategy makes the main finding of this paper. The system is tested for different images captured with several camera devices. (C) 2012 Elsevier Ltd. All rights reserved., Unión Europea. FP7, Ministerio de Economía y Competitividad of Spain within the Plan Nacional de I+D+i, Sección Deptal. de Arquitectura de Computadores y Automática (Físicas), Fac. de Ciencias Físicas, TRUE, pub

© 2014 by the authors; licensee MDPI, Basel, Switzerland. This work has been supported by the Spanish Ministery of Education and Science (under the research grants DPI2006-15661-C02, DPI2009-14552-C02 and DPI2013-46665-C02) and by the EADS (CASSIDIAN) SAVIER AER-30459 project. The authors want to thank Juan A. Besada for his fruitful discussions about the sensor models., The minimum time search in uncertain domains is a searching task, which appears in real world problems such as natural disasters and sea rescue operations, where a target has to be found, as soon as possible, by a set of sensor-equipped searchers. The automation of this task, where the time to detect the target is critical, can be achieved by new probabilistic techniques that directly minimize the Expected Time (ET) to detect a dynamic target using the observation probability models and actual observations collected by the sensors on board the searchers. The selected technique, described in algorithmic form in this paper for completeness, has only been previously partially tested with an ideal binary detection model, in spite of being designed to deal with complex non-linear/non-differential sensorial models. This paper covers the gap, testing its performance and applicability over different searching tasks with searchers equipped with different complex sensors. The sensorial models under test vary from stepped detection probabilities to continuous/discontinuous differentiable/non-differentiable detection probabilities dependent on distance, orientation, and structured maps. The analysis of the simulated results of several static and dynamic scenarios performed in this paper validates the applicability of the technique with different types of sensor models., Spanish Ministery of Education and Science, EADS (CASSIDIAN) SAVIER, Sección Deptal. de Arquitectura de Computadores y Automática (Físicas), Fac. de Ciencias Físicas, TRUE, pub

This work has been supported by the Spanish Grants DPI2009-14552-C02-01 and CAM S-0505/DPI 0391., This paper presents a state of the art of the estimation algorithms dealing with Out-of-Sequence (OOS) measurements for non-linearly modeled systems. The state of the art includes a critical analysis of the algorithm properties that takes into account the applicability of these techniques to autonomous mobile robot navigation based on the fusion of the measurements provided, delayed and OOS, by multiple sensors. Besides, it shows a representative example of the use of one of the most computationally efficient approaches in the localization module of the control software of a real robot (which has non-linear dynamics, and linear and non-linear sensors) and compares its performance against other approaches. The simulated results obtained with the selected OOS algorithm shows the computational requirements that each sensor of the robot imposes to it. The real experiments show how the inclusion of the selected OOS algorithm in the control software lets the robot successfully navigate in spite of receiving many OOS measurements. Finally, the comparison highlights that not only is the selected OOS algorithm among the best performing ones of the comparison, but it also has the lowest computational and memory cost., Spanish Grants, Sección Deptal. de Arquitectura de Computadores y Automática (Físicas), Fac. de Ciencias Físicas, TRUE, pub

© 2005 Elsevier. Authors would like to thank the support of the CICYT TAP97-0607-C03-01 and DPI 2000-0386-C03-01 and the collaboration of the CEHIPAR staff., In order to stabilise the motion of a high speed craft, and so to improve the comfort of the passengers and the crew while maintaining the speed, control-oriented model are needed. For this purpose, neuro-fuzzy systems have been used to obtain general models of the nonlinear behaviour of a fast ferry. The sources of the available knowledge are the physical laws of the vertical dynamics of the craft, and some experimental and simulated data of the ship performance. Two non-linear models focused on the vertical motion of the craft, both heave and pitch, are proposed: an academic one and a predictive one. The modelling task is complex and the results are original as the problem has not been previously solved in a general way neither by applying artificial intelligence techniques. The models have been proved satisfactory with regular and also irregular waves, and they have been used for ship control purposes. (C) 2005 Elsevier Ltd. All rights reserved., CICYT, CEHIPAR staff, Sección Deptal. de Arquitectura de Computadores y Automática (Físicas), Fac. de Ciencias Físicas, TRUE, pub

The authors want to thank the support of the Consejo de Investigaciones Científicas y Tecnología (CICYT)Spanish Committee (projects TAP97-0607-C03-01 and DPI2000-0386) and the collaboration of the CEHIPAR staff and the advice of IZAR., As a main part of a research study on the control of active flaps and a T-foil of a high-speed ferry, a control-oriented model of vertical motions of the ship has been developed. The objective of the control is to improve comfort, decreasing the impact of heave and pitch motions. We have experimental data from a towing tank institution and simulations with PRECAL. The model is based on a decomposition of the physic phenomena into two main aspects: the coupling of the ship with distance between waves and the dynamics of a semisubmerged mass. The model can be handled with MATLAB-SIMULINK, which is useful for studying control strategies. The model shows good agreement (model validation) with the experimental and simulated data for regular and irregular waves. The article shows a methodology, based on MATLAB tools, for obtaining control-oriented models from computer-aided design (CAD)-based programs. That means that the control-oriented model can be derived from the ship design, even before the ship is built., CICYT, Sección Deptal. de Arquitectura de Computadores y Automática (Físicas), Fac. de Ciencias Físicas, TRUE, pub

© 2013. Spanish Ministry of Science and Innovation (MICINN) [DPI2009-14552-C02-02], The availability of adequate system models to reproduce, as faithfully as possible, the actual behaviour of the experimental systems is of key importance. In marine systems, the changing environmental conditions and the complexity of the infrastructure needed to carry out experimental tests call for mathematical models for accurate simulations. There exist a wide number of techniques to define mathematical models from experimental data. Support Vector Machines (SVMs) have shown a great performance in pattern recognition and classification research areas having an inherent potential ability for linear and nonlinear system identification. In this paper, this ability is demonstrated through the identification of the Nomoto second-order ship model with real experimental data obtained from a zig-zag manoeuvre made by a scale ship. The mathematical model of the ship is identified using Least Squares Support Vector Machines (LS-SVMs) for regression by analysing the rudder angle, surge and sway speed, and yaw rate. The coefficients of the Nomoto model are obtained with a linear kernel function. The model obtained is validated through experimental tests that illustrate the potential of SVM for system identification., Spanish Ministry of Science and Innovation (MICINN), Sección Deptal. de Arquitectura de Computadores y Automática (Físicas), Fac. de Ciencias Físicas, TRUE, pub

©2004 IEEE. The authors want to thank the support of the MCYT Spanish Ministry (projects TAP970607-C03-01 and DPI2000-0386-C03-02) and the collaboration of the Izar and the CEHIPAR staff., The research comprises two main steps: to develop a tool for control design in the form of a computer-based simulation and to use this tool to develop satisfactory controllers, MCYT, Sección Deptal. de Arquitectura de Computadores y Automática (Físicas), Fac. de Ciencias Físicas, TRUE, pub

© 2009 IEEE. This work was supported by the Spanish Grants TAP/97-0607-C03, DPI2006-15661-C02-01, and CAM-S-0505/DPI/0391 and by the Spanish post-doctoral Grant EX-2007-0915. Recommended by Associate Editor Z. Wang., The fusion center of a complex control system estimates its state with the information provided by different sensors. Physically distributed sensors, communication networks, pre-processing algorithms, multitasking, etc, introduce non-systematic delays in the arrival of information to the fusion center, making the information available Out-Of-Sequence (OOS). For real-time control systems, the state has to be efficiently estimated with all the information received so far. So, several solutions of the OOS problem for dynamic Multiple-Input Multiple-Output (MIMO) discrete control systems traditionally solved by the Kalman Filter (KF) have been proposed recently. This paper presents two new streamlined algorithms for the linear and non-linear case. IFAsyn, the linear algorithm, is equivalent to other optimal solutions but more general, efficient and easy to implement. EIFAsyn, the nonlinear one, is a new solution of the OOS problem in the Extended KF (EKF) framework., Spanish Grants, Spanish post-doctoral Grant, Sección Deptal. de Arquitectura de Computadores y Automática (Físicas), Fac. de Ciencias Físicas, TRUE, pub

© 2006 Pattern Recognition Society. Part of the work has been performed under Projects CICYT DPI2002-02924 and CICYT TAP94-0832-C02-01. The authors wish to acknowledge the constructive recommendations provided by the reviewers., This paper outlines a method for solving the stereovision matching problem using edge segments as the primitives. In stereovision matching the following constraints are commonly used: epipolar, similarity, smoothness, ordering and uniqueness. We propose a new matching strategy under a fuzzy context in which such constraints are mapped. The fuzzy context integrates both Fuzzy Clustering and Fuzzy Cognitive Maps. With such purpose a network of concepts (nodes) is designed, each concept represents a pair of primitives to be matched. Each concept has associated a fuzzy value which determines the degree of the correspondence. The goal is to achieve high performance in terms of correct matches. The main findings of this paper are reflected in the use of the fuzzy context that allows building the network of concepts where the matching constraints are mapped. Initially, each concept value is loaded via the Fuzzy Clustering and then updated by the Fuzzy Cognitive Maps framework. This updating is achieved through the influence of the remainder neighboring concepts until a good global matching solution is achieved. Under this fuzzy approach we gain quantitative and qualitative matching correspondences. This method works as a relaxation matching approach and its performance is illustrated by comparative analysis against some existing global matching methods. (c) 2006 Pattern Recognition Society. Published by Elsevier Ltd. All rights reserved., CICYT, Sección Deptal. de Arquitectura de Computadores y Automática (Físicas), Fac. de Ciencias Físicas, TRUE, pub

©2019 Elsevier B.V. We express our appreciation to the late Prof. Jesus Manuel de la Cruz, whose contribution to this work was of great significance. The work of D. Moreno-Salinas was supported by “Ministerio de Economia y Competitividad” under project CICYT DPI2014-55932-C2-2-R. The work of R. Moreno has been supported by Science Foundation Ireland under Grant No. SFI/12/RC/2289., This paper describes the use of Kernel Ridge Regression (KRR) and Kernel Ridge Regression Confidence Machine (KRRCM) for black box identification of a surface marine vehicle. Data for training and test have been obtained from several manoeuvres typically used for marine system identification. Thus, a 20/20 degrees Zig-Zag, a 10/10 degrees Zig-Zag, and different evolution circles have been employed for the computation and validation of the model. Results show that the application of conformal prediction provides an accurate model that reproduces with large accuracy the actual behaviour of the ship with confidence margins that ensure that the model response is within these margins, making it a suitable tool for system identification., Ministerio de Economia y Competitividad (MINECO), Science Foundation Ireland, Sección Deptal. de Arquitectura de Computadores y Automática (Físicas), Fac. de Ciencias Físicas, TRUE, pub

© 2016 SPIE. Artículo firmado por 79 autores. Conference on Ground-Based and Airborne Instrumentation for Astronomy (VI. 2016. Edinburgh, Scotland), MEGARA (Multi-Espectrografo en GTC de Alta Resolucion para Astronomia) is an optical Integral-Field Unit (IFU) and Multi-Object Spectrograph (MOS) designed for the GTC 10.4m telescope in La Palma that is being built by a Consortium led by UCM (Spain) that also includes INAOE (Mexico), IAA-CSIC (Spain), and UPM (Spain). The instrument is currently finishing AIV and will be sent to GTC on November 2016 for its on-sky commissioning on April 2017. The MEGARA IFU fiber bundle (LCB) covers 12.5x11.3 arcsec(2) with a spaxel size of 0.62 arcsec while the MEGARA MOS mode allows observing up to 92 objects in a region of 3.5x3.5 arcmin(2) around the IFU. The IFU and MOS modes of MEGARA will provide identical intermediate-to-high spectral resolutions (R-FWHM similar to 6,000, 12,000 and 18,700, respectively for the low-, mid-and high-resolution Volume Phase Holographic gratings) in the range 3700-9800 angstrom angstrom. An x-y mechanism placed at the pseudo-slit position allows (1) exchanging between the two observing modes and (2) focusing the spectrograph for each VPH setup. The spectrograph is a collimator-camera system that has a total of 11 VPHs simultaneously available (out of the 18 VPHs designed and being built) that are placed in the pupil by means of a wheel and an insertion mechanism. The custom-made cryostat hosts a 4kx4k 15-mu m CCD. The unique characteristics of MEGARA in terms of throughput and versatility and the unsurpassed collecting are of GTC make of this instrument the most efficient tool to date to analyze astrophysical objects at intermediate spectral resolutions. In these proceedings we present a summary of the instrument characteristics and the results from the AIV phase. All subsystems have been successfully integrated and the system-level AIV phase is progressing as expected., Depto. de Física de la Tierra y Astrofísica, Fac. de Ciencias Físicas, TRUE, pub

[Resumen] Los vehículos autónomos o tripulados de forma remota hacen necesaria una estación de control de tierra que permita visualizar y, en determinadas situaciones, controlar o enviar instrucciones a dichos vehículos. Cuando estas tareas se vuelven más complejas y requieren varios vehículos en colaboración o incluso que el número o naturaleza de los mismos varíe en base a sus necesidades, el manejo de datos y su visualización se vuelve complicado. Este artículo plantea una posible solución al problema del manejo de datos, control y visualización de un equipo de vehículos autónomos o tripulados de forma remota y a los ocasionados por variaciones en el número y naturaleza de los vehículos o al entorno cambiante de la misión. Si se contempla además la relevancia del flujo de datos en el rendimiento del operador, añadimos una nueva dimensión al problema. También, analizaremos los aspectos relevantes que deben desarrollarse en el centro de control para que pueda adaptarse y aprender en tiempo de ejecución cómo cambiar la configuración del entorno gráfico de la forma más beneficiosa posible en base a los datos recopilados y las características del operador.

This paper presents a new nonlinear path-following guidance method for autonomous vehicles, which integrates two guidance laws that have given good results independently in applications in autonomous ground, marine, and air vehicles. This new technique retains the best aspects of its two supporting methods, whereas it overcomes some of their drawbacks. It uses the control law by Park et al. to command the vehicle position towards a reference point. However, the position of the reference point is controlled in a different way: instead of being calculated to stay at a fixed distance forward of the vehicle, we use a strategy, inspired in the works by other authors, that controls the speed of the reference point to maintain its position at the given distance. This change does not increment the number of parameters to tune the algorithm and makes it applicable to any initial conditions and parameterized paths. The paper also analyzes the stability of this new nonlinear guidance control law and shows its effectiveness under different simulations.