Publications

Displaying 876 - 900 of 1227

Publication	Date
Architecture and Approach for Obtaining Spectrum Availability Information Authors: Matinmikko, Marja,Rauma, Tapio,Mustonen, Miia,Del Ser, Javier This paper presents a novel architecture and approach for obtaining spectrum availability information in future cognitive radio systems (CRS). CRS can opportunistically access spectrum by identifying unoccupied channels while keeping higher priority systems on the same channel free from harmful… IEEE	2011-05-01
On the Application of a Novel Hybrid Harmony Search Algorithm to the Radar Polyphase Code Design Problem Authors: Sancho Salcedo-Sanz,Javier Del Ser,Jose A. Portilla-Figueras,Ángel M. Pérez-Bellido,Sergio Gil-Lopez Polyphase codes are widely used in radar systems as a pulse compression approach due to the fact that they produce lower side-lobes in the compressed signal than other methods. Unfortunately, the efficient design of such codes comprises by itself a non-linear n-dimensional NP-hard optimization… IEEE	2011-05-01
Modeling of bone conduction of sound in the human head using hp-finite elements: Code design and verification Authors: Demkowicz, L.,Gatto, P.,Kurtz, J.,Paszynski, M.,Rachowicz, W.,Bleszyński, E.,Bleszyński, M.,Hamilton, M.,Champlin, C.,Pardo, D. We focus on the development of a reliable numerical model for investigating the bone-conduction of sound in the human head. The main challenge of the problem is the lack of fundamental knowledge regarding the transmission of acoustic energy through non-airborne pathways to the cochlea. A fully… Elsevier BV	2011-05-01
Joint Non-Binary LDPC-BICM and Network Coding with Iterative Decoding for the Multiple Access Relay Channel Authors: Javier Del Ser,Mikel Hernaez,Pedro M. Crespo In this paper we present a novel joint network-channel coding scheme for the time-division Multiple Access Relay Channel (MARC), which combines Bit-Interleaved Coded Modulation with iterative decoding (BICM-ID) based on nonbinary Low-Density Parity Check (LDPC) codes, along with the linear… IEEE	2011-05-01
An interactive optimization approach to a real-world oceanographic campaign planning problem Authors: Maria Santos,Alexander Mendiburu,Jose A. Lozano,Izaskun Ibarbia In this paper we deal with a real-world routing problem that consists of finding the best route for an oceanographic campaign. The planning task involves setting up the initial route and managing the route variations along the way. Bearing in mind the idea of building an experimental tool to… Springer Science and Business Media LLC	2011-04-26
A study on the complexity of TSP instances under the 2-exchange neighbor system Authors: Jose Antonio Pascual,Alexander Mendiburu,Jose A. Lozano,Leticia Hernando This work is related to the search of complexity measures for instances of combinatorial optimization problems. Particularly, we have carried out a study about the complexity of random instances of the Traveling Salesman Problem under the 2-exchange neighbor system. We have proposed two descriptors… IEEE	2011-04-01
A class of discontinuous Petrov–Galerkin methods. Part IV: The optimal test norm and time-harmonic wave propagation in 1D Authors: J. Zitelli,Jay Gopalakrishnan,Leszek Demkowicz,Ignacio Muga,David Pardo,Victor M. Calo The phase error, or the pollution effect in the finite element solution of wave propagation problems, is a well known phenomenon that must be confronted when solving problems in the high-frequency range. This paper presents a new method with no phase errors for one-dimensional (1D) time-harmonic… Elsevier BV	2011-04-01
On the existence of maximizers for a family of restriction theorems Authors: FANELLI, Luca,L. Vega,N. Visciglia We prove the existence of maximizers for a general family of restrictions operators, up to the end-point. We also provide some counterxamples in the end-point case. Wiley	2011-03-22
Extracting S-matrix poles for resonances from numerical scattering data: Type-II Padé reconstruction Authors: Elena Akhmatskaya,Elena Akhmatskaya,S. K. Sen,Dmitri Sokolovski,Dmitri Sokolovski,Dmitri Sokolovski We present a FORTRAN 77 code for evaluation of resonance pole positions and residues of a numerical scattering matrix element in the complex energy (CE) as well as in the complex angular momentum (CAM) planes. Analytical continuation of the S-matrix element is performed by constructing a type-II… Elsevier BV	2011-02-01
Resource allocation in rate-limited OFDMA Systems: A hybrid heuristic approach Authors: Sancho Salcedo-Sanz,Marja Matinmikko,Sergio Gil-Lopez,Javier Del Ser,Miren Nekane Bilbao This paper presents a novel resource allocation procedure for OFDMA downlinks, which stems from an hybridization of the Harmony Search and the Differential Evolution heuristic algorithms. In this setup it is known that optimum subcarrier and power allocation is achieved through 1) assigning each… IEEE	2011-02-01
Dynamics of Jupiter’s equatorial region at cloud top level from Cassini and HST images Authors: Jose Félix Rojas,Ricardo Hueso,Agustín Sánchez-Lavega,N. Barrado-Izagirre,J. M. Gómez-Forrellad,Santiago Pérez-Hoyos,J. F. Sanz-Requena,J. Arregi,Enrique Garcia-Melendo Abstract We present a study of the equatorial region of Jupiter, between latitudes ∼15°S and ∼15°N, based on Cassini ISS images obtained during the Jupiter flyby at the end of 2000, and HST images acquired in May and July 2008. We examine the structure of the zonal wind profile and report the… Elsevier BV	2011-02-01
Iterative Fusion of Distributed Decisions over the Gaussian Multiple-Access Channel Using Concatenated BCH-LDGM Codes Authors: Del Ser, Javier,Manjarres, Diana,Crespo, Pedro M.,Gil-Lopez, Sergio,Garcia-Frias, Javier This paper focuses on the data fusion scenario where nodes sense and transmit the data generated by a source to a common destination, which estimates the… Springer Science and Business Media LLC	2011-01-27
Response of a Spar Platform Under the Occurrence of Extreme Waves Authors: Vincenzo Nava,Felice Arena In this note, the response of a Spar Platform is studied when subject to very high waves. The novelty of this paper consists in adopting the Quasi Determinism (QD) theory in its first formulation for the determination of the response of the structure. In fact, one of the peculiarities of QD theory… ASMEDC	2011-01-01
Computational complexity and memory usage for multi-frontal direct solvers used in p finite element analysis Authors: Calo, Victor M.,Collier, Nathaniel O.,Pardo, David,Paszyński, Maciej R. The multi-frontal direct solver is the state of the art for the direct solution of linear systems. This paper provides computational complexity and memory usage estimates for the application of the multi-frontal direct solver algorithm on linear systems resulting from p finite elements.… Elsevier BV	2011-01-01
Anisotropic 2D mesh adaptation in hp-adaptive FEM Authors: Szymczak, Arkadiusz,Paszýnska, Anna,Paszýnski, Maciej,Pardo, David Abstract The paper presents a grammar for anisotropic two-dimensional mesh adaptation in hp-adaptive Finite Element Method with rectangular elements. It occurs that a straightforward approach to modeling this process via grammar productions leads to potential deadlock in h-adaptation of the mesh… Elsevier BV	2011-01-01
Out-of-core multi-frontal solver for multi-physics hp adaptive problems Authors: Paszyński, Maciej,Pardo, David,Paszyńska, Anna,Demkowicz, Leszek Abstract In this paper we present the out-of-core solver algorithm for three dimensional (3D) multi-physics problems solved by the Finite Element Method (FEM). The solver is able to solve problems where 3D meshes contain finite elements of different kind (tetrahedral, prism and pyramid elements)… Elsevier BV	2011-01-01
Goal-Oriented Self-Adaptive hp Finite Element Simulation of 3D DC Borehole Resistivity Simulations Authors: Calo, Victor M.,Pardo, David,Paszyński, Maciej R. Abstract In this paper we present a goal-oriented self-adaptive hp Finite Element Method ( hp -FEM ) with shared data structures and a parallel multi-frontal direct solver. The algorithm automatically generates (without any user interaction) a sequence of meshes delivering exponential… Elsevier BV	2011-01-01
KYOTO Authors: Marchetti A.,Ronzano F.,Tesconi M.,Vossen P.,Agirre E.,Bond F.,Bosma W.,Herold A.,Hicks A.,Hsieh S.,Isahara H.,Huang C.,Kanzaki K.,Rigau G.,Segers R. KYOTO is an Asian-European project developing a community platform for modeling knowledge and finding facts across languages and cultures. The platform operates as a Wiki system that multilingual and multi-cultural communities can use to agree on the meaning of terms in specific domains. The Wiki… IGI Global	2011-01-01
A Novel Grouping Heuristic Algorithm for the Switch Location Problem Based on a Hybrid Dual Harmony Search Technique Authors: Itziar Landa-Torres,Sancho Salcedo-Sanz,Javier Del Ser,Sergio Gil-Lopez,Diana Manjarres,Jose A. Portilla-Figueras This manuscript proposes a novel iterative approach for the so-called Switch Location Problem (SLP) based on the hybridization of a group-encoded Harmony Search combinatorial heuristic (GHS) with local search and repair methods. Our contribution over other avantgarde techniques lies on the dual… Springer Berlin Heidelberg	2011-01-01
Introducing the Mallows Model on Estimation of Distribution Algorithms Authors: Jose A. Lozano,Alexander Mendiburu,Josu Ceberio Estimation of Distribution Algorithms are a set of algorithms that belong to the field of Evolutionary Computation. Characterized by the use of probabilistic models to learn the (in)dependencies between the variables of the optimization problem, these algorithms have been applied to a wide set of… Springer Berlin Heidelberg	2011-01-01
The atmospheric influence, size and possible asteroidal nature of the July 2009 Jupiter impactor Authors: Ricardo Hueso,P. Yanamandra-Fisher,H. B. Hammel,Tom Momary,Franck Marchis,Franck Marchis,N. Reshetnikov,Andrew P. Ingersoll,G. S. Orton,Agustín Sánchez-Lavega,S. Lai,Olivier Mousis,Carey M. Lisse,W. Golisch,I. de Pater,G. Villar,Michael H. Wong,Santiago… International audience Elsevier BV	2011-01-01
Meso-GSHMC: A stochastic algorithm for meso-scale constant temperature simulations Authors: Akhmatskaya, E.,Reich, S. We consider the problem of time-stepping/sampling for molecular and meso-scale particle dynamics. The aim of the work is to derive numerical time-stepping methods that generate samples exactly from the desired target temperature distribution. The numerical methods proposed in this paper rely on the… Elsevier BV	2011-01-01
Uncertainty principle of Morgan type and Schrödinger evolutions Authors: Carlos E. Kenig,Gustavo Ponce,Luis Vega,Luis Escauriaza We prove unique continuation properties for solutions of evolution Schr��dinger equation with time dependent potentials. In the case of the free solution these correspond to uncertainly principles referred to as being of Morgan type. As an application of our method we also obtain results concerning… Wiley	2010-12-20
A multi-wavelength study of the 2009 impact on Jupiter: Comparison of high resolution images from Gemini, Keck and HST Authors: Michael H. Wong,Santiago Pérez-Hoyos,Statia Luszcz-Cook,Glenn S. Orton,Mark Boslough,Agustín Sánchez-Lavega,Heidi B. Hammel,Leigh N. Fletcher,Imke de Pater Within several days of A. Wesley's announcement that Jupiter was hit by an object on UT 19 July 2009, we observed the impact site with (1) the Hubble Space Telescope (HST) at UV through visible (225-924nm) wavelengths, (2) the 10-m W.M. Keck II telescope in the near-infrared (1-5μm), and (3) the 8-… Elsevier BV	2010-12-01
The Planetary Laboratory for Image Analysis (PLIA) Authors: Jose Félix Rojas,Agustín Sánchez-Lavega,Javier Peralta,Ricardo Hueso,Santiago Pérez-Hoyos,T. del Río-Gaztelurrutia,Jon Legarreta The observation, characterization, and understanding of planetary atmospheres are key components of Solar System exploration. Their study requires, among other observations, the use of image data acquired from spacecrafts. The basic tasks that are generally used to work with planetary image data… Elsevier BV	2010-11-01