Ponències/Comunicacions de congressos
http://hdl.handle.net/2117/3335
2016-05-02T20:42:37ZFiltrado transversal adaptativo de varianza constante para la ecualización de canal
http://hdl.handle.net/2117/86209
Filtrado transversal adaptativo de varianza constante para la ecualización de canal
Vázquez Grau, Gregorio; Gasull Llampallas, Antoni; Sánchez Umbría, Juan; Oliveras Vergés, Albert
This paper describes the problem of lineal filtering of noisy data under a Maximum Likelihood objective. In this sense, the paper shows that a weighted square error cost function deals and it is necessary to weight the filtering error sequence by a factor that, basically, depends the probability density function of the error sequence and on its first derivate. As it is well known, this information used to be not available and other proposals must be made. For this purpose, going around this problem, the paper discusses the design of this weighting factor for including sorne kind of data-selection mechanism for the final filter weight-vector solution design. The underlying of the proposal is the development of a recursive algorithm in such a way that for any measure or observation, its associated
2016-04-26T14:37:29ZVázquez Grau, GregorioGasull Llampallas, AntoniSánchez Umbría, JuanOliveras Vergés, AlbertThis paper describes the problem of lineal filtering of noisy data under a Maximum Likelihood objective. In this sense, the paper shows that a weighted square error cost function deals and it is necessary to weight the filtering error sequence by a factor that, basically, depends the probability density function of the error sequence and on its first derivate. As it is well known, this information used to be not available and other proposals must be made. For this purpose, going around this problem, the paper discusses the design of this weighting factor for including sorne kind of data-selection mechanism for the final filter weight-vector solution design. The underlying of the proposal is the development of a recursive algorithm in such a way that for any measure or observation, its associatedProcesado digital de imágenes para la detección y seguimiento de células
http://hdl.handle.net/2117/86207
Procesado digital de imágenes para la detección y seguimiento de células
Sayrol Clols, Elisa; Gasull Llampallas, Antoni
A new computerized methodology is described in which detection and tracking of human spermatozoa in semen are analized using a personal computer. Several aproaches are studied in order to quantify the number of spermatozoa and to characterize the swimming motion.
2016-04-26T14:20:20ZSayrol Clols, ElisaGasull Llampallas, AntoniA new computerized methodology is described in which detection and tracking of human spermatozoa in semen are analized using a personal computer. Several aproaches are studied in order to quantify the number of spermatozoa and to characterize the swimming motion.Measuring true spectral density from ML filters (NMLM and q-NMLM spectral estimates)
http://hdl.handle.net/2117/86197
Measuring true spectral density from ML filters (NMLM and q-NMLM spectral estimates)
Lagunas Hernandez, Miguel A.; Gasull Llampallas, Antoni
Starting from the classical procedure reported by Capon for power level estimation from ML filters, the authors present how this method can be modifyed in order to obtain a power spectral density estimate. The basic idea is to compute the effective bandwidth of the ML filter, and normalize the power level estimate, at the output of a quadratic detector following the filter, with it. The effective bandwidth has been obtained by an equal area constraint criteria. Furthermore, the above mentioned estimate, we called NMLM, converges in the distributional sense to the true spectral power density. This suggest the use of new estimates, denoted in the text as q-MLM, which improves the mentioned convergence both in 1-D as well as 2-D problems of SPA.
2016-04-26T12:42:25ZLagunas Hernandez, Miguel A.Gasull Llampallas, AntoniStarting from the classical procedure reported by Capon for power level estimation from ML filters, the authors present how this method can be modifyed in order to obtain a power spectral density estimate. The basic idea is to compute the effective bandwidth of the ML filter, and normalize the power level estimate, at the output of a quadratic detector following the filter, with it. The effective bandwidth has been obtained by an equal area constraint criteria. Furthermore, the above mentioned estimate, we called NMLM, converges in the distributional sense to the true spectral power density. This suggest the use of new estimates, denoted in the text as q-MLM, which improves the mentioned convergence both in 1-D as well as 2-D problems of SPA.Cross spectrum ML estimate
http://hdl.handle.net/2117/86195
Cross spectrum ML estimate
Lagunas Hernandez, Miguel A.; Santamaría Pérez, María Eugenia; Gasull Llampallas, Antoni; Moreno Bilbao, M. Asunción
This work reports how to include general concepts of the one-dimensional MLM procedure in a two-channel problem of cross-spectrum estimation. It is shown in the sequel that there is no any problem in extrapolating the well-known procedures for auto-spectrum estimation to the cross-spectrum, if the original procedure can be explained as a filter bank analysis procedure. The resulting cross-spectrum estimate looks formally to satisfy the excellent features which the normalized maximum likelihood procedure, reported previously by the authors, does in the auto-spectrum problem as concerns with resolution a low-side lobe behavior.
2016-04-26T12:35:55ZLagunas Hernandez, Miguel A.Santamaría Pérez, María EugeniaGasull Llampallas, AntoniMoreno Bilbao, M. AsunciónThis work reports how to include general concepts of the one-dimensional MLM procedure in a two-channel problem of cross-spectrum estimation. It is shown in the sequel that there is no any problem in extrapolating the well-known procedures for auto-spectrum estimation to the cross-spectrum, if the original procedure can be explained as a filter bank analysis procedure. The resulting cross-spectrum estimate looks formally to satisfy the excellent features which the normalized maximum likelihood procedure, reported previously by the authors, does in the auto-spectrum problem as concerns with resolution a low-side lobe behavior.Método MLNq para arrays de alta resolución
http://hdl.handle.net/2117/86149
Método MLNq para arrays de alta resolución
Gasull Llampallas, Antoni; Lagunas Hernandez, Miguel A.; Fernández Rubio, Juan Antonio; Moreno Bilbao, M. Asunción
Spectral analysis techniques are used to bearing estimation problem. Each one of this gives a different array beamforming. We show here a generalized normalized Maximum Likehood Method which present a high resolution comparable to the singular value decomposition methods, but with a smaller computational load .
2016-04-25T13:36:49ZGasull Llampallas, AntoniLagunas Hernandez, Miguel A.Fernández Rubio, Juan AntonioMoreno Bilbao, M. AsunciónSpectral analysis techniques are used to bearing estimation problem. Each one of this gives a different array beamforming. We show here a generalized normalized Maximum Likehood Method which present a high resolution comparable to the singular value decomposition methods, but with a smaller computational load .Data pre-processing for high-resolution adaptive algorithms
http://hdl.handle.net/2117/86134
Data pre-processing for high-resolution adaptive algorithms
Vázquez Grau, Gregorio; Gasull Llampallas, Antoni
The inclusion of adaptive methods in high-resolution spectral estimation algorithms is considered. The generation of a complete family of spectral estimators from the normalized maximum-likelihood method (MLM) is discussed. It is shown how the generalized power MLM can be used to generate adaptive schemes for improving resolution. The authors propose the substitution of the conventional mean-square filtering error by quadratic objectives built as inner products of the coefficient error vector of the estimator filter
2016-04-25T12:34:14ZVázquez Grau, GregorioGasull Llampallas, AntoniThe inclusion of adaptive methods in high-resolution spectral estimation algorithms is considered. The generation of a complete family of spectral estimators from the normalized maximum-likelihood method (MLM) is discussed. It is shown how the generalized power MLM can be used to generate adaptive schemes for improving resolution. The authors propose the substitution of the conventional mean-square filtering error by quadratic objectives built as inner products of the coefficient error vector of the estimator filterData pre-processing for high-resolution adaptive algorithms
http://hdl.handle.net/2117/86074
Data pre-processing for high-resolution adaptive algorithms
Vázquez Grau, Gregorio; Gasull Llampallas, Antoni
The inclusion of adaptive methods in high-resolution spectral estimation algorithms is considered. The generation of a complete family of spectral estimators from the normalized maximum-likelihood method (MLM) is discussed. It is shown how the generalized power MLM can be used to generate adaptive schemes for improving resolution. The authors propose the substitution of the conventional mean-square filtering error by quadratic objectives built as inner products of the coefficient error vector of the estimator filter
2016-04-21T14:41:58ZVázquez Grau, GregorioGasull Llampallas, AntoniThe inclusion of adaptive methods in high-resolution spectral estimation algorithms is considered. The generation of a complete family of spectral estimators from the normalized maximum-likelihood method (MLM) is discussed. It is shown how the generalized power MLM can be used to generate adaptive schemes for improving resolution. The authors propose the substitution of the conventional mean-square filtering error by quadratic objectives built as inner products of the coefficient error vector of the estimator filterAlgoritmo para la estimación óptima de la fase instantánea
http://hdl.handle.net/2117/85976
Algoritmo para la estimación óptima de la fase instantánea
Lagunas Hernandez, Miguel A.; Gasull Llampallas, Antoni; Figueiras Vidal, Aníbal R.; Carol Vilanova, Antonio
A new approach in the problem of phase detectors is presented. The procedure is started from the optimum design of digital phase locked loop (DPLL) and some fundamental aspects as the state equations for the communication model are preserved. The purpose of this paper is to point out the relationships between MAP and optimum estimators. We also show how previous adaptative linear filter of the signal error can be introduced to achieve high levels of quality on the estimate without great computational load. This preprocessing can be interpreted in terms of dissimilarity between input signal and noise spectrum. Finally, we give a heuristic exposition which sacrifices some amount of rigor in order to gain insight into the basic ideas involved.
2016-04-20T13:00:39ZLagunas Hernandez, Miguel A.Gasull Llampallas, AntoniFigueiras Vidal, Aníbal R.Carol Vilanova, AntonioA new approach in the problem of phase detectors is presented. The procedure is started from the optimum design of digital phase locked loop (DPLL) and some fundamental aspects as the state equations for the communication model are preserved. The purpose of this paper is to point out the relationships between MAP and optimum estimators. We also show how previous adaptative linear filter of the signal error can be introduced to achieve high levels of quality on the estimate without great computational load. This preprocessing can be interpreted in terms of dissimilarity between input signal and noise spectrum. Finally, we give a heuristic exposition which sacrifices some amount of rigor in order to gain insight into the basic ideas involved.Remote sensing image processing with graph cut of binary partition trees
http://hdl.handle.net/2117/85904
Remote sensing image processing with graph cut of binary partition trees
Salembier Clairon, Philippe Jean; Foucher, Samuel
This paper discusses the interest of hierarchical region-based
representations of images such as Binary Partition Trees (BPTs) and the usefulness of graph cut to process them. BPTs can be considered as an initial abstraction from the signal in which raw pixels are grouped by similarity to form regions, which are hierarchically structured by inclusion in a tree. They provide multiple resolutions of description and easy access to subsets of regions. Their construction is often based on an iterative region-merging algorithm. Once constructed, BPTs can be used for many applications including filtering, segmentation, classification and object detection. Many processing strategies consist in populating the tree with features of interest for the application and in applying a specific graph cut called pruning. Different graph cut approaches are discussed and analyzed in the context of Polarimetric Synthetic Aperture Radar (PolSAR) images.
2016-04-19T12:55:47ZSalembier Clairon, Philippe JeanFoucher, SamuelThis paper discusses the interest of hierarchical region-based
representations of images such as Binary Partition Trees (BPTs) and the usefulness of graph cut to process them. BPTs can be considered as an initial abstraction from the signal in which raw pixels are grouped by similarity to form regions, which are hierarchically structured by inclusion in a tree. They provide multiple resolutions of description and easy access to subsets of regions. Their construction is often based on an iterative region-merging algorithm. Once constructed, BPTs can be used for many applications including filtering, segmentation, classification and object detection. Many processing strategies consist in populating the tree with features of interest for the application and in applying a specific graph cut called pruning. Different graph cut approaches are discussed and analyzed in the context of Polarimetric Synthetic Aperture Radar (PolSAR) images.Known Input Power Spectrum in Adaptive L.M.S. and A. G. Algorithms
http://hdl.handle.net/2117/85856
Known Input Power Spectrum in Adaptive L.M.S. and A. G. Algorithms
Vázquez Grau, Gregorio; Gasull Llampallas, Antoni; Lagunas Hernandez, Miguel A.
This work deals with the use of previous or colateral information to improve the behaviour of adaptive algorithms. The study is made on gradient-baseq methods due te the relatively simple and good performances that they use to exhibit. This paper shows that the complete knowledge of the data at the input of the adaptive filter (and in consequence of its autocorrelation matrix and its inverse) can be used to modify the classic L.M.S. algorithm leading to new expressions for the gradient and for the optimum 1step size 1 , alternative, in sorne cases, to the Powell expression. Finally, the description is completed with the comparison between the variation ranges and VLSI implementation cost for this two optimum 'step size' values anda natural generalization set of parameter is obtained.
2016-04-19T07:34:25ZVázquez Grau, GregorioGasull Llampallas, AntoniLagunas Hernandez, Miguel A.This work deals with the use of previous or colateral information to improve the behaviour of adaptive algorithms. The study is made on gradient-baseq methods due te the relatively simple and good performances that they use to exhibit. This paper shows that the complete knowledge of the data at the input of the adaptive filter (and in consequence of its autocorrelation matrix and its inverse) can be used to modify the classic L.M.S. algorithm leading to new expressions for the gradient and for the optimum 1step size 1 , alternative, in sorne cases, to the Powell expression. Finally, the description is completed with the comparison between the variation ranges and VLSI implementation cost for this two optimum 'step size' values anda natural generalization set of parameter is obtained.