Ponències/Comunicacions de congressos
http://hdl.handle.net/2117/3749
2016-05-29T15:39:45ZInclusion of gradient-based schemes in high resolution method
http://hdl.handle.net/2117/87368
Inclusion of gradient-based schemes in high resolution method
Vázquez Grau, Gregorio; Vallverdú Bayés, Francesc
This paper deals with the inclusion of adaptive schemes in high-resolution methods. Past works refer gradient and conjugated gradient approaches of Pisarenko’s spectral line decomposition method for sinusoidal in white noise modelling. The proposal is more general in the objective definition. It is well known that it is possible to generate a complete family of spectral estimators from a Normalized Maximum Likelihood Method, with a structure of power Rayleigh quotien.
2016-05-26T13:46:26ZVázquez Grau, GregorioVallverdú Bayés, FrancescThis paper deals with the inclusion of adaptive schemes in high-resolution methods. Past works refer gradient and conjugated gradient approaches of Pisarenko’s spectral line decomposition method for sinusoidal in white noise modelling. The proposal is more general in the objective definition. It is well known that it is possible to generate a complete family of spectral estimators from a Normalized Maximum Likelihood Method, with a structure of power Rayleigh quotien.Parametric envelope in LPC speech coders
http://hdl.handle.net/2117/87288
Parametric envelope in LPC speech coders
Moreno Bilbao, M. Asunción; Lagunas Hernandez, Miguel A.; Vallverdú Bayés, Francesc
During the last decade, many efforts have been devoted to the relative importance of associated functions like magnitude and phase of Fourier Transforms in image and signal bandwidth reduction. The reported work deals with the importance of the real envelope and instantaneous frequency in signal analysis/sintesis problems. In this paper authors show a method to parametrize the envelope and instantaneous frequency of a real signal. This method is very closed to spectral analysis methods in the sense that with an appropiate study, time domain and frequency domain can be analyced in a similar way.
2016-05-24T15:20:00ZMoreno Bilbao, M. AsunciónLagunas Hernandez, Miguel A.Vallverdú Bayés, FrancescDuring the last decade, many efforts have been devoted to the relative importance of associated functions like magnitude and phase of Fourier Transforms in image and signal bandwidth reduction. The reported work deals with the importance of the real envelope and instantaneous frequency in signal analysis/sintesis problems. In this paper authors show a method to parametrize the envelope and instantaneous frequency of a real signal. This method is very closed to spectral analysis methods in the sense that with an appropiate study, time domain and frequency domain can be analyced in a similar way.The normalized backpropagation and some experiments on speech recognition
http://hdl.handle.net/2117/87286
The normalized backpropagation and some experiments on speech recognition
Monte Moreno, Enrique; Mariño Acebal, José Bernardo
In the paper we present the theoretical development of the normalized backpropagation, and we compare it with other algorithms that have been presented in the literature.
The algorithm that we propose is based on the idea of normalizing the adaptation step in the gradient search by the variance of the input. This algorithm is simple and gives good results in comparison with other algorithms that accelerate the learning and has the additional advantage that the parameters are calculated by the algorithm, so the user does not have to make several trials in order to trim the adaptation step and the momentum until the best combination is found.
The task which we have designed in order to compare the algorithms is the recognition of digits in the Catalan language, with a data base of 1000 items, spoken by 10 speakers. The algorithms that we have compared with the normalized back propagation are: D.E.Rumelhart and J .L. McCielland, Franzini, Suddhard, Fahlman, Monte.
2016-05-24T15:13:08ZMonte Moreno, EnriqueMariño Acebal, José BernardoIn the paper we present the theoretical development of the normalized backpropagation, and we compare it with other algorithms that have been presented in the literature.
The algorithm that we propose is based on the idea of normalizing the adaptation step in the gradient search by the variance of the input. This algorithm is simple and gives good results in comparison with other algorithms that accelerate the learning and has the additional advantage that the parameters are calculated by the algorithm, so the user does not have to make several trials in order to trim the adaptation step and the momentum until the best combination is found.
The task which we have designed in order to compare the algorithms is the recognition of digits in the Catalan language, with a data base of 1000 items, spoken by 10 speakers. The algorithms that we have compared with the normalized back propagation are: D.E.Rumelhart and J .L. McCielland, Franzini, Suddhard, Fahlman, Monte.Medium Rate Speech Coding with Vector Quantization
http://hdl.handle.net/2117/86212
Medium Rate Speech Coding with Vector Quantization
Masgrau Gómez, Enrique José; Mariño Acebal, José Bernardo; Moreno Bilbao, M. Asunción
2016-04-26T15:40:05ZMasgrau Gómez, Enrique JoséMariño Acebal, José BernardoMoreno Bilbao, M. AsunciónAdaptive spectrum estimation with linear constrains
http://hdl.handle.net/2117/86201
Adaptive spectrum estimation with linear constrains
Vázquez Grau, Gregorio; Vallverdú Bayés, Francesc
A general constrained adaptive metbod is developed to be applied to the spectral estimation problem. The method presented can be used in a wide range of situatious, this is, we can get different estimators wíth it. The algorithm is formulated in a varíational approach context,and tbe non linear system obtained is solved with a constrained adaptive method applied to a digitized version of the spedrum. The set of constraínts is considered to be a set of known correlation values, and they can be located in non consecutíve lags. A generalization of the method is done, so it can be used in a rnu lt idimensional framework. As an example, a bidimensional ma.ximum entropy spectrum is presented.
2016-04-26T13:05:44ZVázquez Grau, GregorioVallverdú Bayés, FrancescA general constrained adaptive metbod is developed to be applied to the spectral estimation problem. The method presented can be used in a wide range of situatious, this is, we can get different estimators wíth it. The algorithm is formulated in a varíational approach context,and tbe non linear system obtained is solved with a constrained adaptive method applied to a digitized version of the spedrum. The set of constraínts is considered to be a set of known correlation values, and they can be located in non consecutíve lags. A generalization of the method is done, so it can be used in a rnu lt idimensional framework. As an example, a bidimensional ma.ximum entropy spectrum is presented.On the Use of Higher Order Information in SVD Based Methods
http://hdl.handle.net/2117/86199
On the Use of Higher Order Information in SVD Based Methods
Vázquez Grau, Gregorio; Vallverdú Bayés, Francesc
2016-04-26T12:50:19ZVázquez Grau, GregorioVallverdú Bayés, FrancescCross 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 .A direct approximation technique for designing digital equalizers with simultaneous specification of magnitude and phase
http://hdl.handle.net/2117/86137
A direct approximation technique for designing digital equalizers with simultaneous specification of magnitude and phase
Mariño Acebal, José Bernardo; Figueiras Vidal, Aníbal R.
A new direct method for designing nonrecursive and recursive digital equalizers approximating specified attenuation and phase responses is introduced . This method allows to control both magnitude and phase characteristics independently; to the authors' knowledge, this is the only direct method proposed in the literature which allows this independent control in nonrecursive designs without using sucessive equalization.
2016-04-25T12:38:22ZMariño Acebal, José BernardoFigueiras Vidal, Aníbal R.A new direct method for designing nonrecursive and recursive digital equalizers approximating specified attenuation and phase responses is introduced . This method allows to control both magnitude and phase characteristics independently; to the authors' knowledge, this is the only direct method proposed in the literature which allows this independent control in nonrecursive designs without using sucessive equalization.Randomizing ties in a sign radar detector
http://hdl.handle.net/2117/86104
Randomizing ties in a sign radar detector
Figueiras Vidal, Aníbal R.; Mariño Acebal, José Bernardo; Lagunas Hernandez, Miguel A.; García Gómez, Ramón; Martín Funke, Enrique
A general formulation to consider the effects of typical randomization methods (RMs) for a digital application of Generalized Sign Test (GST) detector in Radar is introduced. A first approximation leads us to some basic restrictions to be imposed to RMs. Introducing them, when the approximation is acceptable, our formulation allows to evaluate easily the false alarm and detection probabilities (PFA and PD ) obtainable with the use of each RM in fuction of the quantizing step (q) of the video samples, and, then, to select the most appropriate among them. Besides this, by considering the values of PFA and PD with respect to continuous situations, we can determine the maximum q to obtain small enough variations due to quantization (which has parametric effects). In such a way, a maximum dynamic range and a basically nonparametric behaviour are achieved. An example illustrates the application of the theory.
2016-04-22T13:44:15ZFigueiras Vidal, Aníbal R.Mariño Acebal, José BernardoLagunas Hernandez, Miguel A.García Gómez, RamónMartín Funke, EnriqueA general formulation to consider the effects of typical randomization methods (RMs) for a digital application of Generalized Sign Test (GST) detector in Radar is introduced. A first approximation leads us to some basic restrictions to be imposed to RMs. Introducing them, when the approximation is acceptable, our formulation allows to evaluate easily the false alarm and detection probabilities (PFA and PD ) obtainable with the use of each RM in fuction of the quantizing step (q) of the video samples, and, then, to select the most appropriate among them. Besides this, by considering the values of PFA and PD with respect to continuous situations, we can determine the maximum q to obtain small enough variations due to quantization (which has parametric effects). In such a way, a maximum dynamic range and a basically nonparametric behaviour are achieved. An example illustrates the application of the theory.