Publications

Displaying 976 - 1000 of 1227

Publication	Date
Coupled Surge-Heave-Pitch Dynamic Modeling of Spar-Moonpool-Riser Interaction Authors: Vincenzo Nava,Pol D. Spanos,Felice Arena Due to the rather intense ongoing development of deep water gas and oil fields, the technical community has devoted considerable attention to the dynamic behavior of Spar floating systems. Spar dynamics exhibits a highly nonlinear behavior due to the presence of various components such as mooring… ASME International	2009-01-01
Simulation of DC dual-laterolog measurements in complex formations: A Fourier-series approach with nonorthogonal coordinates and self-adapting finite elements Authors: Nam, M.J.,Pardo, D.,Torres-Verdin, C. Dual laterolog (DLL) makes use of a galvanic conduction principle to focus electrical currents into rock formations, thereby minimizing shoulder and borehole effects in the measurement of formation resistivity. The tool includes two separate focusing systems: deep-sensing (LLd) and shallow-sensing… Society of Exploration Geophysicists	2009-01-01
Performance Analysis of a Novel Dual-Frequency Multiple Access Relay Transmission Scheme Authors: Babak Hossein Khalaj,Javier Del Ser In this paper we present the performance analysis of a novel channel assignment scheme where two non-cooperative independent users simultaneously communicate with their destination through a single relay by using only two frequency channels. The analytic derivation of the probability of symbol… Scientific Research Publishing, Inc.	2009-01-01
Overview of the Clef 2008 Multilingual Question Answering Track Authors: Paulo Rocha,Anselmo Peñas,Eneko Agirre,Nicolas Moreau,Pamela Forner,Bogdan Sacaleanu,Erik Tjong Kim Sang,Corina Forascu,Petya Osenova,Iñaki Alegria,Prokopis Prokopidis,Richard F. E. Sutcliffe The QA campaign at CLEF 2008 [1], was mainly the same as that proposed last year. The results and the analyses reported by last year's participants suggested that the changes introduced in the previous campaign had led to a drop in systems' performance. So for this year's competition it has been… Springer Berlin Heidelberg	2009-01-01
Joint Source-Channel-Network Decoding and Blind Estimation of Correlated Sensors Using Concatenated Zigzag Codes Authors: Pedro M. Crespo,Ignacio Olabarrieta,Javier Del Ser,Mikel Mendicute,Sergio Gil-Lopez Focusing on densely deployed wireless sensor networks, this paper presents a novel method for joint source-channel-network coding of distributed correlated sources through multiple access relay channels. In such networks, the role of intermediate sensors as relay nodes permits to achieve enhanced… Springer Berlin Heidelberg	2009-01-01
Magnetic virial identities, weak dispersion and Strichartz inequalities Authors: Luis Vega,Luca Fanelli 23 pages, misprint in the title of the previous version Springer Science and Business Media LLC	2008-12-13
Energy-Norm-Based and Goal-Oriented Automatic $hp$ Adaptivity for Electromagnetics: Application to Waveguide Discontinuities Authors: Garcia-Castillo, L.E.,Pardo, D.,Demkowicz, L. The finite-element method (FEM) enables the use of adapted meshes. The simultaneous combination of h (local variations in element size) and p (local variations in the polynomial order of approximation) refinements, i.e., hp-adaptivity, is the most powerful and flexible type of adaptivity. In this… Institute of Electrical and Electronics Engineers (IEEE)	2008-12-01
Three-dimensional nonlinear random wave groups in intermediate water depth Authors: Diego Pavone,Diego Pavone,Vincenzo Nava,Vincenzo Nava,Felice Arena,Alessandra Romolo,Alfredo Ascanelli Abstract High waves at ocean occur during a complex space–time evolution of wave groups. In this paper the nonlinear structure of three-dimensional sea wave groups at intermediate water depth is investigated. To this purpose, the Boccotti's Quasi-Determinism theory is firstly applied to describe… Elsevier BV	2008-12-01
On the Stability of a Singular Vortex Dynamics Authors: Banica, Valeria,Vega, Luis In this paper we address the question of the singular vortex dynamics exhibited in [15], which generates a corner in finite time. The purpose is to prove that under some appropriate small regular perturbation the corner still remains. Our approach uses the Hasimoto transform and deals with the long… Springer Science and Business Media LLC	2008-11-19
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 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
On the Dirac delta as initial condition for nonlinear Schrödinger equations Authors: Banica, Valeria,Vega, Luis 17 pages, to appear in in AnIHP Ann Non Lin European Mathematical Society - EMS - Publishing House GmbH	2008-08-01
On the equipartition of energy for the critical NLW Authors: VEGA L,VISCIGLIA, NICOLA We 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
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
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