Publications

Displaying 1051 - 1075 of 1307

Publication	Date
Sensitivity study of borehole-to-surface and crosswell electromagnetic measurements acquired with energized steel casing to water displacement in hydrocarbon-bearing layers Authors: Pardo, D.,Torres-Verdin, C.,Zhang, Z. We study the theoretical response of electromagnetically energized steel casing in the presence of subsurface variations of electrical resistivity. Casing is energized with a finite-size solenoid antenna located along the axis of the borehole. Measurements consist of the azimuthal component of the… Society of Exploration Geophysicists	2008-11-01
Optimizing the number of classes in automated zooplankton classification Authors: Jose A. Fernandes,Jose A. Lozano,Xabier Irigoien,Guillermo Boyra,Iñaki Inza Zooplankton biomass and abundance estimation, based on surveys or time-series, is carried out routinely. Automated or semi-automated image analysis processes, combined with machine-learning techniques for the identification of plankton, have been proposed to assist in sample analysis. A difficulty… Oxford University Press (OUP)	2008-10-22
Design, Simulation and Implementation of a Channel Equalizer for DVB-T On-channel Repeaters Authors: Iker Sobron,Pablo Prieto,J. Del Ser,R. Isasi,Mikel Mendicute This article describes the design and implementation of a channel equalizer for a terrestrial digital television (digital video broadcasting-terrestrial, DVB-T) on-channel repeater, namely gap-filler. Two are the benefits of including this equalizer in a repeater setup: on one hand, the transmitted… IEEE	2008-10-01
A review of estimation of distribution algorithms in bioinformatics Authors: Armañanzas, Rubén,Inza, Iñaki,Santana, Roberto,Saeys, Yvan,Flores, Jose Luis,Lozano, Jose Antonio,Van de Peer, Yves,Blanco, Rosa,Robles, Victor,Bielza, Concha,Larrañaga, Pedro Evolutionary search algorithms have become an essential asset in the algorithmic toolbox for solving high-dimensional optimization problems in across a broad range of bioinformatics problems. Genetic algorithms, the most well-known and representative evolutionary search technique, have been the… Springer Science and Business Media LLC	2008-09-11
A pediatric shock advice algorithm based on the regularity of the detected beats Authors: Unai Irusta,Jesus Ruiz,S. Ruiz de Gauna,Elisabete Aramendi Automated external defibrillators (AED) detect fatal ventricular arrhythmias: ventricular fibrillation (VF) and ventricular tachycardia (VT). We have developed an algorithm based on the regularity of the detected beats to accurately discriminate VF from nonshockable rhythms in pediatric patients.… IEEE	2008-09-01
Multi-Objective Learning of Multi-Dimensional Bayesian Classifiers Authors: J.D. Rodriguez,Jose A. Lozano Multi-dimensional classification is a generalization of supervised classification that considers more than one class variable to classify. In this paper we review the existing multi-dimensional Bayesian classifiers and introduce a new one: the KDB multi-dimensional classifier. Then we define… IEEE	2008-09-01
Parameters affecting shock decision in pediatric automated defibrillation Authors: S.R. de Gauna,Elisabete Aramendi,Unai Irusta,Jesus Ruiz There are important differences between adult and pediatric ECG. To approve their use in children, the adaptation of automated external defibrillator (AED) shock advice algorithms require a specific analysis of the particular pediatric ECG characteristics. In this study, we measured several… IEEE	2008-09-01
Uncoded optimal binary communication for sources with memory using the Burrows Wheeler Transform Authors: Javier Del Ser,Estíbaliz Loyo,Pedro M. Crespo Abstract Given an AWGN channel, we look at the problem of designing an optimal binary uncoded communication system for transmitting blocks of binary symbols generated by a stationary source with memory modelled by a Markov chain (MC) or a hidden Markov model (HMM). The goal is to minimize the… Elsevier BV	2008-09-01
An algorithm to discriminate SVT from VT in pediatric AED based on spectral parameters Authors: Elisabete Aramendi,Unai Irusta,S.R. de Gauna,Jesus Ruiz Supraventricular tachycardia (SVT) often has very high heart rates in children. Automated external defibrillators (AED), whose use for children is recommended since 2003, could misinterpret high rate SVT as ventricular tachycardia (VT) producing an incorrect shock diagnosis. The objective of this… IEEE	2008-09-01
Protein Folding in Simplified Models With Estimation of Distribution Algorithms Authors: Santana, Roberto,Larrañaga Múgica, Pedro María,Lozano, Jose Antonio Simplified lattice models have played an important role in protein structure prediction and protein folding problems. These models can be useful for an initial approximation of the protein structure, and for the investigation of the dynamics that govern the protein folding process. Estimation of… Institute of Electrical and Electronics Engineers (IEEE)	2008-08-01
On the Dirac delta as initial condition for nonlinear Schrödinger equations Authors: Banica, Valeria,Vega, Luis In this article we will study the initial value problem for some Schrödinger equations with Dirac-like initial data and therefore with infinite L^{2} mass, obtaining positive results for subcritical nonlinearities. In the critical… European Mathematical Society - EMS - Publishing House GmbH	2008-08-01
On the equipartition of energy for the critical NLW Authors: VEGA L,VISCIGLIA, NICOLA AbstractWe study some qualitative properties of global solutions to the following focusing and defocusing critical NLW:□u+λu\|u\|2∗−2=0,λ∈R,u(0)=f∈H˙1(Rn),∂tu(0)=g∈L2(Rn) on R×Rn for n⩾3, where 2∗≡2nn−2. We will consider the global solutions of the defocusing NLW whose existence and scattering… Elsevier BV	2008-08-01
Fourier series expansion in a non-orthogonal system of coordinates for the simulation of 3D alternating current borehole resistivity measurements Authors: Carlos Torres-Verdín,Victor M. Calo,Maciej Paszyński,Myung Jin Nam,David Pardo Abstract We describe a method to simulate 3D resistivity borehole measurements acquired with alternating current (AC) logging instruments. It combines the use of a Fourier series expansion in a non-orthogonal system of coordinates with an existing 2D goal-oriented higher-order self-adaptive hp-… Elsevier BV	2008-08-01
Scaling-sharp dispersive estimates for the Korteweg–de Vries group Authors: Côte, Raphaël,Vega, Luis We prove weighted estimates on the linear KdV group, which are scaling sharp. This kind of estimates are in the spirit of that used to prove small data scattering for the generalized KdV equations. Cellule MathDoc/Centre Mersenne	2008-08-01
Prevalence of Knee and Hip Osteoarthritis and the Appropriateness of Joint Replacement in an Older Population Authors: J. Ignacio Goenaga,José M. Quintana,Iratxe Lafuente,Inmaculada Arostegui,Antonio Escobar,Jesús Azkarate Relatively little is known about the prevalence of knee and hip osteoarthritis in the general population.To estimate the prevalence of knee and hip osteoarthritis and the appropriateness of joint replacement in a general population of older individuals, the validated Knee and Hip OsteoArthritis… American Medical Association (AMA)	2008-07-28
Vertical structure of Jupiter's troposphere from nonlinear simulations of long-lived vortices Authors: Agustín Sánchez-Lavega,Jon Legarreta Abstract Numerical simulations of jovian vortices at tropical and temperate latitudes, under different atmospheric conditions, have been performed using the EPIC code [Dowling, T.E., Fisher, A.S., Gierasch, P.J., Harrington, J., LeBeau, R.P., Santori, C.M., 1998. Icarus 132, 221–238] to simulate… Elsevier BV	2008-07-01
A multi-objective approach to the Channel Assignment Problem Authors: Jayrani Cheeneebash,Jose A. Lozano,Harry Coomar Shumsher Rughooputh With the rapid growth of mobile communications, solving the channel assignment problem has now become a new challenge in research. In this paper, we present the channel assignment problem (CAP) from a multi-objective approach. From this new idea, the communication system can be easily managed in… IEEE	2008-06-01
Morphology and dynamics of Venus oxygen airglow from Venus Express/Visible and Infrared Thermal Imaging Spectrometer observations Authors: Hueso, R.,Sánchez-Lavega, Agustín,Piccioni, Giuseppe,Drossart, Pierre,Gérard, Jean-Claude,Khatuntsev, Igor V.,Zasova, Ludmilla,Migliorini, Alessandra Images obtained by the Visible and Infrared Thermal Imaging Spectrometer (VIRTIS)‐M channel instrument onboard Venus Express have been used to retrieve maps and apparent motions of the O2 (1Δ) infrared nightglow on Venus at 1.27 μm. The nightglow distribution is highly inhomogeneous with the… American Geophysical Union (AGU)	2008-05-01
GSHMC: An efficient method for molecular simulation Authors: Elena Akhmatskaya,Sebastian Reich The hybrid Monte Carlo (HMC) method is a popular and rigorous method for sampling from a canonical ensemble. The HMC method is based on classical molecular dynamics simulations combined with a Metropolis acceptance criterion and a momentum resampling step. While the HMC method completely resamples… Elsevier BV	2008-05-01
Characterization of mesoscale gravity waves in the upper and lower clouds of Venus from VEX‐VIRTIS images Authors: Peralta, Javier,Hueso, R.,Sánchez-Lavega, Agustín,Piccioni, Giuseppe,Lanciano, O.,Drossart, Pierre Images obtained from the Visible and InfraRed Thermal Imaging Spectrometer (VIRTIS)‐M instrument onboard Venus Express present visible trains of alternating bands of cloud brightness in two different layers: at the upper cloud tops (∼66 km altitude) observed in the dayside hemisphere using… American Geophysical Union (AGU)	2008-05-01
Improved Sampling for Simulations of Interfacial Membrane Proteins: Application of Generalized Shadow Hybrid Monte Carlo to a Peptide Toxin/Bilayer System Authors: Wee, C,Sansom, MS,Reich, S,Akhmatskaya, E The computational costs associated with performing molecular dynamics (MD) simulations are still somewhat prohibitive and therefore limit the time and length scales that can be currently achieved. One approach to overcoming the limited size and duration of a simulation is to reduce the amount of… American Chemical Society (ACS)	2008-04-16
Fourier series expansion in a non-orthogonal system of coordinates for the simulation of 3D-DC borehole resistivity measurements Authors: Myung Jin Nam,Carlos Torres-Verdín,David Pardo,Victor M. Calo Abstract We describe a new method to simulate 3D borehole resistivity measurements at zero frequency (DC). The method combines the use of a Fourier series expansion in a non-orthogonal system of coordinates with an existing 2D goal-oriented higher-order self-adaptive hp -finite element algorithm… Elsevier BV	2008-04-01
The Effect of Surface Tension on the Moore Singularity of Vortex Sheet Dynamics Authors: F. de la Hoz,Marco A. Fontelos,Luis Vega We investigate the regularization of Moore’s singularities by surface tension in the evolution of vortex sheets and its dependence on the Weber number (which is inversely proportional to surface tension coefficient). The curvature of the vortex sheet, instead of blowing up at finite time t0, grows… Springer Science and Business Media LLC	2008-04-01
On linearization of Morison force given by high three-dimensional sea wave groups Authors: Vincenzo Nava,Felice Arena Abstract In-line loading on slender marine structures may be computed by means of the Morison equation, which includes the inertia term (depending on wave acceleration) and the drag term (depending on square velocity). In the presence of random sea waves (either two- or three-dimensional waves),… Elsevier BV	2008-04-01
Inference of Population Structure Using Genetic Markers and a Bayesian Model Averaging Approach for Clustering Authors: Santafé, Guzmán,Lozano, Jose Antonio,Larrañaga Múgica, Pedro María The analysis of the structure of populations on the basis of genetic data is essential in population genetics. It is used, for instance, to study the evolution of species or to correct for population stratification in association studies. These genetic data, normally based on DNA polymorphisms, may… Mary Ann Liebert Inc	2008-03-01