Publications

Displaying 1001 - 1025 of 1227

Publication	Date
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: Mark S.P. Sansom,Chze Ling Wee,Sebastian Reich,Elena Akhmatskaya 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
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
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
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
Jupiter's polar clouds and waves from Cassini and HST images: 1993–2006 Authors: Agustín Sánchez-Lavega,Ricardo Hueso,N. Barrado-Izagirre,Santiago Pérez-Hoyos Abstract For a variety of reasons, Jupiter's polar areas are probably the less observed regions of the planet. To study the dynamics and cloud vertical structure in the polar regions of the planet (latitudes 50° to 80° in both hemispheres) we have used images of Jupiter obtained from the… Elsevier BV	2008-03-01
Asymptotic Lower Bounds for a Class of Schrödinger Equations Authors: VEGA L,VISCIGLIA, NICOLA 24 pages. to appear on Comm. Math. Phys Springer Science and Business Media LLC	2008-02-22
A Preliminary Study on the Robustness and Generalization of Role Sets for Semantic Role Labeling Authors: Beñat Zapirain,Eneko Agirre,Lluís Màrquez Most Semantic Role Labeling (SRL) systems rely on available annotated corpora, being PropBank the most widely used corpus so far. Propbank role set is based on theory-neutral numbered arguments, which are linked to fine grained verb-dependant semantic roles through the verb framesets. Recently,… Springer Berlin Heidelberg	2008-02-09
A method to remove CPR artefacts from human ECG using only the recorded ECG Authors: Elisabete Aramendi,Sofía Ruiz de Gauna,Jo Kramer-Johansen,Trygve Eftestøl,Unai Irusta,Jesus Ruiz To show the possibility of using cardiopulmonary resuscitation (CPR) artefact suppression methods that do not need additional reference signals to model CPR artefacts.A CPR suppression method based on a Kalman filter was designed. The artefact was modelled using the fundamental frequency of the… Elsevier BV	2008-02-01
Improved dual frequency multiple access relay scheme for spatially correlated sources Authors: Pedro M. Crespo,Jose Angel Esteban,Javier Del Ser,Babak Hossein Khalaj We consider the non-cooperative multiple access relay channel, where N users transmit their information to a common receiver with the assistance of a shared relay. For N = 2 independent sources and dual-frequency operation (i.e. two separate frequency channels are available for transmission), it… IEEE	2008-02-01
Bounds for the maximal function associated to periodic solutions of one-dimensional dispersive equations Authors: Luis Vega,A. Moyua We give bounds on sup t \|u(x, t)\| for solutions u of dispersive equations on the one-dimensional torus. They are obtained from some improvements on bilinear types of estimate. Wiley	2008-02-01
Erratum: Depth of a strong jovian jet from a planetary-scale disturbance driven by storms Authors: G. S. Orton,Santiago Pérez-Hoyos,M. Valimberti,P. Yanamandra-Fisher,Ricardo Hueso,M. H. Wong,M. Salway,Noemi Pinilla-Alonso,Zac Pujic,Joseph L. Hora,F. Carvalho,J. Joels,Leigh Fletcher,A. Sánchez-Lavega,Enrique Garcia-Melendo,I. de Pater,J. Kemerer,D.… Springer Science and Business Media LLC	2008-02-01
Depth of a strong jovian jet from a planetary-scale disturbance driven by storms Authors: Michael H. Wong,J. Joels,I. de Pater,Santiago Pérez-Hoyos,Noemi Pinilla-Alonso,Jose Félix Rojas,M. Valimberti,Agustín Sánchez-Lavega,Joseph L. Hora,F. Carvalho,D. Parker,M. Salway,Amy A. Simon-Miller,Ricardo Hueso,A. Wesley,J. Kemerer,J. M. Gomez,Leigh N… The atmospheres of the gas giant planets (Jupiter and Saturn) contain jets that dominate the circulation at visible levels. The power source for these jets (solar radiation, internal heat, or both) and their vertical structure below the upper cloud are major open questions in the atmospheric… Springer Science and Business Media LLC	2008-01-24
DYNAMIC SEARCH SPACE TRANSFORMATIONS FOR SOFTWARE TEST DATA GENERATION Authors: Ramón Sagarna,Jose A. Lozano Among the tasks in software testing, test data generation is particularly difficult and costly. In recent years, several approaches that use metaheuristic search techniques to automatically obtain the test inputs have been proposed. Although work in this field is very active, little attention has… Wiley	2008-01-21
Distribution of the O₂ infrared nightglow observed with VIRTIS on board Venus Express Authors: Gérard, Jean-Claude,Saglam, Adem,Piccioni, Giuseppe,Drossart, Pierre,Cox, Cedric,Erard, Stéphane,Hueso, R.,Sánchez-Lavega, Agustín We present characteristics of the statistical horizontal distribution of the O2 infrared nightglow over most of the southern hemisphere observed with the VIRTIS instrument over a period spanning nearly 11 months of low solar activity. We show that the distribution is inhomogeneous with the regions… American Geophysical Union (AGU)	2008-01-01
Software Metrics Mining to Predict the Performance of Estimation of Distribution Algorithms in Test Data Generation Authors: Ramón Sagarna,Jose A. Lozano Springer Berlin Heidelberg	2008-01-01
Determination of Riser Tensioner Properties From Full-Scale Data Authors: Himanshu Gupta,Pol D. Spanos,Vincenzo Nava,Vasileios Gkaras,Hugh Banon Tensioners are used for supporting various kinds of production and drilling risers on offshore platforms. All permanent production facilities (such as TLP’s and Spar’s) have employed tensioners to support their dry tree production risers. The key design parameters for the tensioners design are… ASMEDC	2008-01-01
PML Enhanced with a Self-Adaptive Goal-Oriented $hp$-Finite Element Method: Simulation of Through-Casing Borehole Resistivity Measurements Authors: David Pardo,Carlos Torres-Verdín,Leszek Demkowicz,Christian Michler We describe the application of a perfectly matched layer (PML) combined with a self-adaptive goal-oriented $hp$-finite element (FE) method to the simulation of borehole resistivity measurements. The adaptive refinements and fast convergence of the self-adaptive $hp$-FE method enhance the… Society for Industrial & Applied Mathematics (SIAM)	2008-01-01
Simulations of 3D DC borehole resistivity measurements with a goal-oriented hp finite-element method. Part II: through-casing resistivity instruments Authors: Carlos Torres-Verdín,Maciej Paszyński,David Pardo We simulate direct current (DC) borehole resistivity measurements acquired in steel-cased deviated wells for the assessment of rock formation properties. The assumed data acquisition configuration considers one current (emitter) and three voltage (collector) electrodes that are utilized to measure… Springer Science and Business Media LLC	2007-12-06
Energy Concentration and Sommerfeld Condition for Helmholtz Equation with Variable Index at Infinity Authors: Luis Vega,Benoît Perthame,Benoît Perthame We consider the Helmholtz equation with a variable index of refraction $n(x)$, which is not necessarily constant at infinity but can have an angular dependency like $n(x)\to n\_\infty(x/\|x \|)$ as $\|x \|\to \infty$. Under some appropriate assumptions on this convergence and on $n\_\infty$ we prove… Springer Science and Business Media LLC	2007-11-26
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
A two-dimensional self-adaptive hp finite element method for the characterization of waveguide discontinuities. Part I: Energy-norm based automatic hp-adaptivity Authors: Luis E. Garcia-Castillo,Leszek Demkowicz,Ignacio Gomez-Revuelto,David Pardo Abstract The accurate analysis and characterization of waveguide discontinuities is an important issue in microwave engineering. In some cases, the discontinuities are an unavoidable result of mechanical or electric transitions which effects have to be minimized; in other cases, the… Elsevier BV	2007-11-01