Publications

Displaying 1026 - 1050 of 1227

Publication	Date
A two-dimensional self-adaptive hp finite element method for the characterization of waveguide discontinuities. Part II: Goal-oriented hp-adaptivity Authors: Carlos Torres-Verdín,David Pardo,Leszek Demkowicz,Luis E. Garcia-Castillo Abstract This is the second part of the work on the analysis of different types of rectangular waveguide discontinuities by using a fully automatic hp -adaptive finite element method. In this paper, we describe a fully automatic goal-oriented hp -adaptive Finite Element (FE) strategy. The… Elsevier BV	2007-11-01
Hardy-type estimates for Dirac operators Authors: Dolbeault, Jean,Duoandikoetxea, Javier,Esteban, Maria J.,Vega, Luis International audience; We prove some Hardy type inequalities related to the Dirac operator by elementary methods, for a large class of potentials, which even includes measure valued potentials. Optimality is achieved by the Coulomb potential. When potentials are smooth enough, our estimates… Societe Mathematique de France	2007-11-01
Combining variable neighborhood search and estimation of distribution algorithms in the protein side chain placement problem Authors: Santana, Roberto,Larrañaga Múgica, Pedro María,Lozano, Jose Antonio The aim of this work is to introduce several proposals for combining two metaheuristics: variable neighborhood search (VNS) and estimation of distribution algorithms (EDAs). Although each of these metaheuristics has been previously hybridized in several ways, this paper constitutes the first… Springer Science and Business Media LLC	2007-10-23
The perspective: a panorama of the Solar System Authors: Agustín Sánchez-Lavega Cambridge University Press (CUP)	2007-10-18
A reanalysis of Venus winds at two cloud levels from Galileo SSI images Authors: Ricardo Hueso,Agustín Sánchez-Lavega,Javier Peralta Abstract The global circulation of the Venus atmosphere is characterized at cloud level by a zonal super rotation studied over the years with data from a battery of spacecrafts: orbiters, balloons and probes. Among them, the Galileo spacecraft monitored the Venus atmosphere in a flyby in February… Elsevier BV	2007-10-01
On Combining Distributed Joint Source-Channel-Network Coding and Turbo Equalization in Multiple Access Relay Networks Authors: Pedro M. Crespo,B.H. Khalaj,Jesús Gutiérrez-Gutiérrez,J. Del Ser We consider a multiple access relay channel where two sources S1 and S2 send their data to a common destination node aided by a shared relay node. In this paper we extend previous work on this topic by assuming that the output of both information sources are correlated with memory. Furthermore, we… IEEE	2007-10-01
Diversity Gain Analysis of a Novel Dual-Frequency Multiple Access Relay Transmission Scheme Authors: J. Del Ser,Pedro M. Crespo,B.H. Khalaj,Jesús Gutiérrez-Gutiérrez In this paper, we will present diversity gain analysis of a novel channel assignment scheme at the relay for the case in which two non-cooperative independent users communicate with their destination through a single relay and by using only two frequency channels. The analysis of two main relay… IEEE	2007-10-01
Sequential VT/VF discrimination algorithm based on wave mode sample entropy for adult and pediatric patients Authors: Elisabete Aramendi,S.R. de Gauna,Unai Irusta,Jesus Ruiz The two fatal ventricular arrhythmias, Ventricular Fibrillation (VF) and Ventricular Tachycardia (VT), are better treated using different electrical therapies: a lower energy cardioversion for VT and a defibrillation shock for VF. Automated External Defibrillators (AED), whose use for children is… IEEE	2007-09-01
Comparative analysis of the parameters affecting AED rhythm analysis algorithm applied to pediatric and adult Ventricular Tachycardia Authors: S. Ruiz de Gauna,Elisabete Aramendi,Unai Irusta,Jesus Ruiz In this study pediatric and adult Ventricular Tachycardia (VT) are used to test the efficiency of an AED analysis algorithm. Statistical assessment of the four significant parameters that define the shock-noshock classification algorithm has been performed. The following parameters are considered:… IEEE	2007-09-01
Validation of a screening questionnaire for hip and knee osteoarthritis in old people Authors: Quintana López, José María,Arostegui Madariaga, Inmaculada,Escobar, Antonio,Lafuente Guerrero, Iratxe,Arenaza Merino, Juan Carlos,García, Isidoro,Aguirre, Urko To develop a sensitive and specific screening tool for knee and hip osteoarthritis in the general population of elderly people.The Knee and Hip OsteoArthritis Screening Questionnaire (KHOA-SQ) was developed based on previous studies and observed data and sent to 11,002 people aged 60 to 90 years,… Springer Science and Business Media LLC	2007-08-23
A self-adaptive goal-oriented hp-finite element method with electromagnetic applications. Part II: Electrodynamics Authors: Leszek Demkowicz,Carlos Torres-Verdín,Maciej Paszyński,David Pardo Abstract We present the formulation, implementation, and applications of a self-adaptive, goal-oriented, hp-Finite Element (FE) Method for Electromagnetic (EM) problems. The algorithm delivers (without any user interaction) a sequence of optimal hp-grids. This sequence of grids minimizes the… Elsevier BV	2007-08-01
A parallel framework for loopy belief propagation Authors: Alexander Mendiburu,Endika Bengoetxea,Jose A. Lozano,Roberto Santana There are many innovative proposals introduced in the literature under the evolutionary computation field, from which estimation of distribution algorithms (EDAs) is one of them. Their main characteristic is the use of probabilistic models to represent the (in) dependencies between the variables of… ACM	2007-07-07
Cloud brightness distribution and turbulence in Venus using Galileo violet images Authors: Agustín Sánchez-Lavega,Javier Peralta,Ricardo Hueso Venus cloud covered atmosphere offers a well-suited framework to study the coupling between the atmospheric dynamics and the structure of the cloud field. Violet images obtained during the Galileo flyby from 12 to 17 February 1990 have been analyzed to retrieve the zonal power spectra of the cloud… Elsevier BV	2007-06-01
Source Controlled Modulation Scheme for Sources with Memory Authors: Pedro M. Crespo,E. Loyo,C.J. Mitchell,J. Del Ser Given an AWGN channel, we look at the problem of designing a source controlled binary antipodal signaling system for transmitting blocks of binary symbols generated either by a Markov chain source (MC) or by a hidden Markov model source (HMM). The goal is to minimize the average SNR required for… IEEE	2007-06-01
Feasibility study for 2D frequency-dependent electromagnetic sensing through casing Authors: Leszek Demkowicz,Carlos Torres-Verdín,David Pardo We perform a numerical-sensitivity study of various physical phenomena of interest for borehole resistivity logging applications in steel-cased wells. Specifically, we analyze the sensitivity of through-casing measurements for detecting water invasion, shale-laminated sands, and electrical… Society of Exploration Geophysicists	2007-05-01
Improving the performance of perfectly matched layers by means of hp‐adaptivity Authors: Christian Michler,Jason Kurtz,David Pardo,Leszek Demkowicz AbstractWe improve the performance of the Perfectly Matched Layer (PML) by using an automatic hp‐adaptive discretization. By means of hp‐adaptivity, we obtain a sequence of discrete solutions that converges exponentially to the continuum solution. Asymptotically, we thus recover the property of the… Wiley	2007-04-26
Self-similar planar curves related to modified Korteweg–de Vries equation Authors: Perelman, G.,Vega, L. We exhibit a time reversible geometric flow of planar curves which can develop singularities in finite time within the uniform topology. The example is based on the construction of selfsimilar solutions of modified Korteweg–de Vries equation of a given (small) mean. Elsevier BV	2007-04-01
The three-dimensional structure of Saturn's equatorial jet at cloud level Authors: Agustín Sánchez-Lavega,Ricardo Hueso,Santiago Pérez-Hoyos Abstract The three-dimensional structure of Saturn's intense equatorial jet from latitudes 8° N to 20° S is revealed from detailed measurements of the motions and spectral reflectivity of clouds at visible wavelengths on high resolution images obtained by the Cassini Imaging Science Subsystem (… Elsevier BV	2007-04-01
On uniqueness properties of solutions of the k-generalized KdV equations Authors: Escauriaza, L.,Kenig, C.E.,Ponce, G.,Vega, L. In this paper we study uniqueness properties of solutions of the k-generalized Korteweg-de Vries equation. Our goal is to obtain sufficient conditions on the behavior of the difference $u_1-u_2$ of two solutions $u_1, u_2$ of the equation at two different times $t_0=0$ and $t_1=1$ which guarantee… Elsevier BV	2007-03-01
Some weighted Gagliardo-Nirenberg inequalities and applications Authors: Javier Duoandikoetxea,Luis Vega We obtain conditions on the measure μ \mu so that the L 2 ( μ ) L^2(\mu ) -norm of a function is controlled by the L 2 L^2 -norms of the function and its gradient.… American Mathematical Society (AMS)	2007-02-09
A Novel Dual-Frequency Multiple Access Relay Transmission Scheme Authors: B.H. Khalaj,Jesús Gutiérrez-Gutiérrez,Pedro M. Crespo,J. Del Ser As data rates are increasing continuously in wireless networks, additional ways of improving system performance and providing higher rates is needed. One scheme that has recently attracted a lot of attention, is using relays in order to provide additional diversity, especially in scenarios that use… IEEE	2007-01-01
Detection of ventricular fibrillation in the presence of cardiopulmonary resuscitation artefacts Authors: Elisabete Aramendi,Unai Irusta,Jesus Ruiz,Mª Fe Arcocha,Sofía Ruiz de Gauna,Jose Miguel Ormaetxe Providing cardiopulmonary resuscitation (CPR) to a patient in cardiac arrest introduces artefacts into the electrocardiogram (ECG), corrupting the diagnosis of the underlying heart rhythm. CPR must therefore be discontinued for reliable shock advice analysis by an automated external defibrillator (… Elsevier BV	2007-01-01
On the local smoothing for a class of conformally invariant Schrodinger equations Authors: VEGA L,VISCIGLIA, NICOLA We present some a - priori bounds from above and from below for solutions to a class of conformally invariant Schroedinger equations. As a by - product we deduce some new uniqueness results. Indiana University Mathematics Journal	2007-01-01
Numerical simulation of 3D EM borehole measurements using an hp‐adaptive goal‐oriented finite‐element formulation Authors: Maciej Paszyński,Carlos Torres-Verdín,David Pardo We describe two different algorithms for automatic generation (without any user interaction) of optimal goal-oriented grids within a 3D higher-order Finite Element (FE) package, in context of simulation of electromagnetic borehole resistivity measurements for the assessment of rock formation… Society of Exploration Geophysicists	2007-01-01
SemEval-2007 task 01 Authors: Agirre, E.,Lopez de Lacalle, O.,Magnini, B.,Otegi, A.,Rigau, G.,Vossen, P.T.J.M. This paper presents a first attempt of an application-driven evaluation exercise of WSD. We used a CLIR testbed from the Cross Lingual Evaluation Forum. The expansion, indexing and retrieval strategies where fixed by the organizers. The participants had to return both the topics and documents… Association for Computational Linguistics (ACL)	2007-01-01