Esteban E.,Centro Universitario Of La Defensa |
Dinar A.,University of California at Riverside
Environmental and Resource Economics | Year: 2013
This paper investigates how cooperation among users can achieve a better management of groundwater in the presence of environmental externalities. Cooperation allows users to internalize the damages caused by their activities and reduce extractions. The paper develops a game theoretical framework to assess the value of cooperation in an aquifer that is divided into three sub-aquifers that are being overly exploited. Two types of externalities are modeled: first, water extractions in each sub-aquifer impact water levels in neighboring sub-aquifers (extraction externality). Second, the three sub-aquifers are also connected to an ecosystem and thus decisions in each sub-aquifer affect the health of the ecosystem (environmental externality). A cooperative game theory model is applied. The model empirically shows how the uncontrolled extractions in each sub-aquifer affects neighboring groundwater users but also cause severe impacts to the linked ecosystem. The model is tested empirically in one of the most important aquifers in Spain, the Eastern la Mancha aquifer. The results illustrate how both extraction and environmental externalities interact in affecting the likelihood of cooperation among the users. The paper estimates the value of cooperation and its stability with and without the environmental externality. © 2012 Springer Science+Business Media B.V.
Bernardi S.,Centro Universitario Of La Defensa |
Merseguer J.,University of Zaragoza |
Petriu D.C.,Carleton University
ACM Computing Surveys | Year: 2012
The goal is to survey dependability modeling and analysis of software and systems specified with UML, with focus on reliability, availability, maintainability, and safety (RAMS). From the literature published in the last decade, 33 approaches presented in 43 papers were identified. They are evaluated according to three sets of criteria regarding UML modeling issues, addressed dependability characteristics, and quality assessment of the surveyed approaches. The survey shows that more works are devoted to reliability and safety, fewer to availability and maintainability, and none to integrity. Many methods support early life-cycle phases (from requirements to design). More research is needed for tool development to automate the derivation of analysis models and to give feedback to designers. © 2012 ACM.
Montijano E.,Centro Universitario Of La Defensa |
Aragues R.,CNRS Pascal Institute |
Sagues C.,Institute Investigacion En Ingenieria Of Aragon
IEEE Transactions on Robotics | Year: 2013
We address the data association problem of features that are observed by a robotic network. Every robot in the network has limited communication capabilities and can only exchange localmatches with its neighbors.We propose a distributed algorithm that takes these local matches and, by their propagation in the network, computes global correspondences. When the algorithm finishes, each robot knows the correspondences between its features and the features of all the other robots, even if they cannot directly communicate. The presence of spurious local correspondences may produce inconsistent global correspondences,which are association paths between features observed by the same robot. The contributions of this study are the propagation of the local matches and the detection and resolution of these inconsistencies. We formally prove that after executing the algorithm, all the robots finish with a data association that is free of inconsistencies.We provide a fully decentralized solution to the problem that is valid for any fixed communication topology and with bounded communications between the robots. Simulations and experimental results with real images show the performance of the method considering different features, matching functions, and robotic applications. © 2013 IEEE.
Cucinotta G.,University of Florence |
Perfetti M.,University of Florence |
Luzon J.,University of Zaragoza |
Luzon J.,Centro Universitario Of La Defensa |
And 6 more authors.
Angewandte Chemie - International Edition | Year: 2012
Magnetic moments: The orientation of the title single-molecule magnet was investigated by magnetic single crystal and luminescence characterization, supported by ab initio calculations, and was found to be governed by the position of the hydrogen atoms of the apical water molecules. This finding suggests that simple magneto-structural correlations can give misleading clues for research in molecular magnetism as well as in the design of MRI contrast agents. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Luzon J.,Centro Universitario Of La Defensa |
Luzon J.,University of Zaragoza |
Sessoli R.,University of Florence
Dalton Transactions | Year: 2012
Due to their usual large magnetic moments and large magnetic anisotropy lanthanide ions are investigated for the search of Single Molecule Magnets with high blocking temperature. However, the low symmetry crystal environment, the complexity of the electronic states or the non-collinearity of the magnetic anisotropy easy-axes in polynuclear systems make the rationalization of the magnetic behaviour of lanthanide based molecular systems difficult. In this perspective article we expose a methodology in which the use of additional characterization techniques, like single crystal magnetic measurements or luminescence experiments, complemented by relativistic ab initio calculations and a suitable choice of spin Hamiltonian models, can be of great help in order to overcome such difficulties, representing an essential step for the rational design of lanthanide based Single Molecule Magnets with enhanced physical properties. © The Royal Society of Chemistry 2012.
Costa-Montenegro E.,University of Vigo |
Barragans-Martinez A.B.,Centro Universitario Of La Defensa |
Rey-Lopez M.,Conselleria de Educacion e O.U.
Expert Systems with Applications | Year: 2012
Users face the information overload problem when downloading applications in markets. This is mainly due to (i) the increasing unmanageable number of applications and (ii) the lack of an accurate and fine-grained categorization of the applications in the markets. To address this issue, we present an integrated solution which recommends to the users applications by considering a big amount of information: that is, according to their previously consumed applications, use pattern, tags used to annotate resources and history of ratings. We focus this paper on the service for monitoring users' interaction. © 2012 Elsevier Ltd. All rights reserved.
De Leon M.,Institute Ciencias Matematicas CSIC UAM UC3M UCM |
Vilarino S.,Centro Universitario Of La Defensa
International Journal of Geometric Methods in Modern Physics | Year: 2014
In this paper, we extend the geometric formalism of the Hamilton-Jacobi theory for time-dependent Mechanics to the case of classical field theories in the k-cosymplectic framework. © 2014 World Scientific Publishing Company.
Javierre E.,Centro Universitario Of La Defensa
Medical Engineering and Physics | Year: 2016
This work focuses on the transport kinetics of chemical and cellular species during wound healing. Anomalous transport kinetics, coupling sub- and superdiffusion with chemotaxis, and fractional viscoelasticity of soft tissues are analyzed from a modeling point of view. The paper presents a generalization of well stablished mechano-chemical models of wound contraction (Murphy et al., 2012; Valero et al., 2014) to include the previously mentioned anomalous effects by means of partial differential equations of fractional order. Results show the effect that anomalous dynamics have on the contraction rate and extension and on the distribution of biological species, and indicators of fibroproliferative disorders are identified. © 2016 IPEM.
Martinez-Cantin R.,Centro Universitario Of La Defensa
Journal of Machine Learning Research | Year: 2014
BayesOpt is a library with state-of-the-art Bayesian optimization methods to solve nonlin-ear optimization, stochastic bandits or sequential experimental design problems. Bayesian optimization characterized for being sample efficient as it builds a posterior distribution to capture the evidence and prior knowledge of the target function. Built in standard C++, the library is extremely efficient while being portable and exible. It includes a common interface for C, C++, Python, Matlab and Octave. © 2014 Ruben Martinez-Cantin
Martin J.,Centro Universitario Of La Defensa |
Grossard M.,French Atomic Energy Commission
International Journal of Robotics Research | Year: 2014
This paper presents the mechatronic design of a new anthropomorphic hand. It has been developed in the context of a multidisciplinary project which aims at understanding how humans perform the manipulation of objects in order to replicate grasping and in-hand movements with an artificial hand. This has required the development of a new hand with a high level of both anthropomorphism and dexterity. The hand must exactly replicate the kinematics of the human hand, adding up to 24 degrees of mobility and 20 degrees of freedom, which is a design challenge if a high level of dexterity must be guaranteed. Three key concepts have guided the mechanical design: modularity, backdrivability and mechanical simplicity. A modular approach simplifies the complex hand assembly and permits us to concentrate our efforts on one basic unit which will be replicated throughout the hand. Mechanical simplicity and backdrivability ensure a good natural mechanical behavior, essential for stable control of contact forces. Likewise, a better controllability will enhance the dexterity of the hand. A thorough mechanical design assures backdrivability through the whole mechanism, including actuators and transmission of movement to the joints. Experimental results confirm the validity of the design approach and will open new lines of research into robotic hands. © The Author(s) 2014.