Publications

Displaying 1176 - 1200 of 1351

Publication	Date
Some dispersive estimates for Schrödinger equations with repulsive potentials Authors: Juan Antonio Barceló,Luis Vega,Alberto Ruiz AbstractWe prove the local smoothing effect for Schrödinger equations with repulsive potentials for n⩾3. The estimates are global in time and are proved using a variation of Morawetz multipliers. As a consequence we give sharp constants to measure the attractive part of the potential and its rate… Elsevier BV	2006-07-01
Fully automatic hp-adaptivity in three dimensions Authors: David Pardo,Waldemar Rachowicz,Leszek Demkowicz The paper presents a three-dimensional implementation of the fully automatic hp-adaptive mesh refinement strategy proposed in [L. Demkowicz, W. Rachowicz, Ph. Devloo, A fully automatic hp-adaptivity, J. Sci. Comput. 17 (1–3) (2002) 127–155]. The methodology is based on a minimization of the… Elsevier BV	2006-07-01
Methane storms on Saturn's moon Titan Authors: Agustín Sánchez-Lavega,Ricardo Hueso The presence of dry fluvial river channels and the intense cloud activity in the south pole of Titan over the past few years suggest the presence of methane rain. The nitrogen atmosphere of Titan therefore appears to support a methane meteorological cycle that sculptures the surface and controls… Springer Science and Business Media LLC	2006-07-01
Analysis of the short form‐36 (SF‐36): the beta‐binomial distribution approach Authors: Vicente Núñez-Antón,Inmaculada Arostegui,José M. Quintana AbstractHealth‐related quality of life (HRQoL) is an important indicator of health status and the Short Form‐36 (SF‐36) is a generic instrument to measure it. Multiple linear regression (MLR) is often used to study the relationship of HRQoL with patients' characteristics, though HRQoL outcomes tend… Wiley	2006-06-23
A Two-Dimensional Self-Adaptive $hp$ Finite Element Method for the Analysis of Open Region Problems in Electromagnetics Authors: David Pardo,Leszek Demkowicz,Ignacio Gomez-Revuelto,Luis E. Garcia-Castillo A two-dimensional self-adaptive hp finite element method (FEM) for the analysis of open region problems in electromagnetics is described. The method incorporates an iterative procedure for solving open region problems. More precisely, solution of the open problem is achieved by solving a low number… Institute of Electrical and Electronics Engineers (IEEE)	2006-05-25
A Two-Dimensional Self-Adaptive hp Finite Element Method for the Analysis of Open Region Problems in Electromagnetics Authors: David Pardo,Leszek Demkowicz,Ignacio Gomez-Revuelto,Luis E. Garcia-Castillo A two-dimensional self-adaptive hp finite element method (FEM) for the analysis of open region problems in electromagnetics is described. The method incorporates an iterative procedure for solving open region problems. More precisely, solution of the open problem is achieved by solving a low number… IEEE	2006-05-25
‘Planetodiversity’: the variety of planets and planetary systems in the Universe Authors: Agustín Sánchez-Lavega ‘Planetodiversity’ is a composite word from planetary diversity. This denomination wants to parallel the common use of the term biodiversity employed in biology but translated here to the context of planetary sciences due to the proliferating variety of planets discovered outside the Solar System… Informa UK Limited	2006-05-01
Integration of hp-adaptivity and a two grid solver for electromagnetic problems Authors: Leszek Demkowicz,David Pardo,Jay Gopalakrishnan We present implementation details and analyze convergence of a two grid solver forming the core of a fully automatic hp-adaptive strategy for electromagnetic problems. The solver delivers a solution for a fine grid obtained from an arbitrary coarse hp grid by a global hp-refinement. The classical V… Elsevier BV	2006-04-01
IMPLEMENTATION AND PERFORMANCE EVALUATION OF A PARALLELIZATION OF ESTIMATION OF BAYESIAN NETWORK ALGORITHMS Authors: Alexander Mendiburu,Jose Miguel-Alonso,Jose A. Lozano This paper presents, discusses and evaluates parallel implementations of a set of algorithms designed for optimization tasks: Estimation of Bayesian Network Algorithms (EBNAs). These algorithms belong to the family of Evolutionary Computation. Two different APIs have been combined: message passing… World Scientific Pub Co Pte Lt	2006-03-01
Scatter Search in software testing, comparison and collaboration with Estimation of Distribution Algorithms Authors: Ramón Sagarna,Jose A. Lozano Abstract One of the main tasks software testing includes is the generation of the test cases to be used during the test. Due to its expensive cost, the automatization of this task has become one of the key issues in the area. The field of Evolutionary Testing deals with this problem by means of… Elsevier BV	2006-03-01
A goal-orientedhp-adaptive finite element method with electromagnetic applications. Part I: electrostatics Authors: Carlos Torres-Verdín,L. Tabarovsky,Leszek Demkowicz,David Pardo We describe the development and application of a finite element (FE) self-adaptive hp goal-oriented algorithm for elliptic problems. The algorithm delivers (without any user interaction) a sequence of optimal hp-grids. This sequence of grids minimizes the error of a prescribed quantity of interest… Wiley	2006-02-19
Solar flux in Saturn's atmosphere: Penetration and heating rates in the aerosol and cloud layers Authors: Agustín Sánchez-Lavega,Santiago Pérez-Hoyos Abstract In this work, we describe an analysis of the internal solar radiation fields in Saturn's atmosphere. The aim of this paper is to study how the solar radiation flux in optical wavelengths (0.25–1.0 μm) is attenuated, primarily by the effect of the aerosols located close to the tropopause… Elsevier BV	2006-02-01
Health-Related Quality of Life and Appropriateness of Knee or Hip Joint Replacement Authors: Juan Carlos Arenaza,Antonio Escobar,Inmaculada Arostegui,Amaia Bilbao,Jesús Azkarate,J. Ignacio Goenaga,José M. Quintana We studied the association between explicit appropriateness criteria for total hip joint replacement (THR) and total knee replacement (TKR) with changes in health-related quality of life of patients undergoing these procedures.Prospective observational study of 1576 consecutive patients with… American Medical Association (AMA)	2006-01-23
Evaluating and optimizing the parameters of an unsupervised graph-based WSD algorithm Authors: Oier Lopez de Lacalle,Aitor Soroa,Eneko Agirre,David Martinez Veronis (2004) has recently proposed an innovative unsupervised algorithm for word sense disambiguation based on small-world graphs called HyperLex. This paper explores two sides of the algorithm. First, we extend Veronis' work by optimizing the free parameters (on a set of words which is different… Association for Computational Linguistics (ACL)	2006-01-01
Pointwise convergence of solutions to the nonelliptic Schr\"odinger equation Authors: Keith M. Rogers,Luis Vega González,Ana María Vargas Rey It is conjectured that the solution to the Schrodinger equation in R n+1 converges almost everywhere to its initial datum f, for all f ∈ H s (R n ), if and only if s ≥ 1 4. It is known that there is an s < 1 2 for which the solution converges for all f ∈ H s (R 2 ). We show that the solution… Indiana University Mathematics Journal	2006-01-01
Two‐Dimensional High‐Accuracy Simulation of Resistivity Log ging‐While‐Drilling (LWD) Measurements Using a Self‐Adaptiv e Goal‐Oriented $hp$ Finite Element Method Authors: Maciej Paszyński,Maciej Paszyński,Carlos Torres-Verdín,David Pardo,Leszek Demkowicz We simulate electromagnetic (EM) measurements acquired with a logging‐while‐drilling (LWD) instrument in a borehole environment. The measurements are used to assess electrical properties of rock formations. Logging instruments as well as rock formation properties are assumed to exhibit axial… Society for Industrial & Applied Mathematics (SIAM)	2006-01-01
Non-Linear Random Wave Groups With a Superimposed Current Authors: Nava V.,Arena F.,Romolo A. In this paper a new solution for non-linear random wave groups in the presence of a uniform current is obtained, by extending to the second-order the Boccotti’s ‘Quasi-Determinism’ (QD) theory. The second formulation of the QD theory gives the mechanics of linear random wave groups when a large… ASMEDC	2006-01-01
On the vertical wind shear of Saturn's Equatorial Jet at cloud level Authors: Agustín Sánchez-Lavega,Santiago Pérez-Hoyos Abstract In this work we analyze and compare the vertical cloud structure of Saturn's Equatorial Zone in two different epochs: the first one close to the Voyagers flybys (1979–1981) and the second one in 2004, when the Cassini spacecraft entered its orbit around the planet. Our goal is to… Elsevier BV	2006-01-01
A 2D and 3D hp-Finite Element Method for Simulation of Through Casing Resistivity Logging Instruments Authors: Carlos Torres-Verdín,Leszek Demkowicz,David Pardo In order to avoid collapse of wells in oil fields, the use of steel casing has been a common technique throughout the last decades. However, the casing of a well with a steel pipe has some undesired effects. For instance, the assessment of electrical properties of the rock formation becomes more… IEEE	2006-01-01
Integration of hp-adaptivity and a two-grid solver for elliptic problems Authors: David Pardo,Leszek Demkowicz We present implementation details and analyze convergence of a two-grid solver forming the core of the fully automatic hp-adaptive strategy for elliptic problems. The solver delivers a solution for a fine grid obtained from an arbitrary coarse hp-grid by a global hp-refinement. The classical V-… Elsevier BV	2006-01-01
Responsiveness and clinically important differences for the WOMAC and SF-36 after hip joint replacement Authors: Amaia Bilbao,Antonio Escobar,José M. Quintana,I. Vidaurreta,Inmaculada Arostegui,Iratxe Lafuente To study responsiveness and establish the minimal clinically important differences (MCID) and minimal detectable change (MDC) in patients undergoing total hip replacement (THR) using the Short Form 36 (SF-36) and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC).We… Elsevier BV	2005-12-01
Verification of goal-oriented HP-adaptivity Authors: M. Paszyski,David Pardo,Leszek Demkowicz AbstractThe paper presents calculations for the radiation of a loop antenna wrapped around a metallic cylinder into a conductive medium. The problem has been solved analytically by using Fourier transform and Bessel functions. The analytical solution has been used to verify a goal-oriented hp… Elsevier BV	2005-10-01
Variable coefficient Schrödinger flows for ultrahyperbolic operators Authors: Luis Vega,Gustavo Ponce,C. Rolvung,Carlos E. Kenig In this paper we study the local solvability of nonlinear Schr��dinger equations of the form $$\p_t u = i {\cal L}(x) u + \vec b_1(x)\cdot \nabla_x u + \vec b_2(x)\cdot \nabla_x \bar u + c_1(x)u+c_2(x)\bar u +P(u,\bar u,\nabla_x u, \nabla_x\bar u), where $x\in\mathbb R^n$, $t>0$, $\displaystyle… Elsevier BV	2005-10-01
Asymmetric Joint Source-Channel Coding for Correlated Sources with Blind HMM Estimation at the Receiver Authors: Olaia Galdos,Pedro M. Crespo,Javier Del Ser We consider the case of two correlated sources, S 1 and S 2 . The correlation between them has memory, and it is modelled by a hidden Markov chain. The paper studies the problem of reliable communication of the information sent by the source S 1 over an additive white Gaussian noise (AWGN… Springer Science and Business Media LLC	2005-09-08
Parallel and Multi-Objective EDAs to Create Multivariate Calibration Models for Quantitative Chemical Applications Authors: Jose Miguel-Alonso,C. Ubide,Jose A. Lozano,Alexander Mendiburu,M. Ostra This paper describes the application of several data mining approaches to solve a calibration problem in a quantitative chemistry environment. Experimental data obtained from reactions which involve known concentrations of two or more components are used to calibrate a model that, later, will be… IEEE	2005-08-03