Hilda Larrondo | Universidad Nacional de Mar del Plata (original) (raw)
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Papers by Hilda Larrondo
Nonlinear Dynamics
ABSTRACT
Entropy, 2018
In this paper we investigate the degradation of the statistic properties of chaotic maps as conse... more In this paper we investigate the degradation of the statistic properties of chaotic maps as consequence of their implementation in a digital media such as Digital Signal Processors (DSP), Field Programmable Gate Arrays (FPGA) or Application-Specific Integrated Circuits (ASIC). In these systems, binary floating-and fixed-point are the numerical representations available. Fixed-point representation is preferred over floating-point when speed, low power and/or small circuit area are necessary. Then, in this paper we compare the degradation of fixed-point binary precision version of chaotic maps with the one obtained by using floating point 754-IEEE standard, to evaluate the feasibility of their FPGA implementation. The specific period that every fixed-point precision produces was investigated in previous reports. Statistical characteristics are also relevant, it has been recently shown that it is convenient to describe the statistical characteristic using both, causal and non-causal quantifiers. In this paper we complement the period analysis by characterizing the behavior of these maps from an statistical point of view using cuantifiers from information theory. Here, rather than reproducing an exact replica of the real system, the aim is to meet certain conditions related to the statistics of systems.
CONICET Resumen— En este trabajo se investiga el uso de muestreo caótico para adquirir s nales de... more CONICET Resumen— En este trabajo se investiga el uso de muestreo caótico para adquirir s nales de baja frecuencia inmersas en ruido de alta frecuencia. El método reduce el aliasing sin utilizar los típicos filtros antialiasing. Se realizan simulaciones con varios ma-pas caóticos que poseen diferente función densidad de probabilidad invariante (IPDF) y diferente constante de tiempo de evolución en el espacio de las funciones densidad de probabilidad (PDF). Se reportan resulta-dos con diferentes tipos de filtros de respuesta finita al impulso (FIR) y se los compara con los obtenidos en trabajos previos con muestreo aleatorio. P alabras Clave— caos, mapas iterados, gener-adores pseudoaleatorios, jitter random sampling. I. INTRODUCC ON Varios autores han tratado el tema del muestreo no periódico como por ejemplo Beutler (1970); Bilinskis y Mikelsons (1992); Carrica et al. (2001, 2007); Balakr-ishnan (1962); Tarczynski (2001); Mirri et al. (1998); DaDalt et al. (2002). En especial el mue...
AIP Conference Proceedings, 2007
Literature on the use of electroencephalogram (EEG) is not extensive. Research efforts have large... more Literature on the use of electroencephalogram (EEG) is not extensive. Research efforts have largely concerned the use of the EEG either as an indicator of the general integrity of the nervous system or as a measure of specific brain states, such as sleep cycles and other EEG rhythm defined states.
Ocean Engineering, 1995
ABSTRACT
Journal of Sound and Vibration, 1993
ABSTRACT
Journal of Sound and Vibration, 1993
Journal of Sound and Vibration, 1994
Journal of Sound and Vibration, 1997
Journal of Sound and Vibration, 1998
Journal of Sound and Vibration, 1999
Journal of Sound and Vibration, 2000
Spread-spectrum techniques for improving Electromagnetic Compatibilities are investigated. This r... more Spread-spectrum techniques for improving Electromagnetic Compatibilities are investigated. This requires generating Constant Envelope Wideband signals. We produce them via chaotic maps that yield pseudo random time series, used afterwards to modulate sinusoidal waves in frequency. How to assess a maps’s suitability for such task is also discussed.
Revista De Ensenanza De La Fisica, Nov 13, 2010
By appealing to a long list of different nonlinear maps we review the characterization of time se... more By appealing to a long list of different nonlinear maps we review the characterization of time series arising from chaotic maps. The main tool for this characterization is the permutation Bandt-Pompe probability distribution function. We focus attention on both local and global characteristics of the components of this probability distribution function. We show that forbidden ordinal patterns (local quantifiers) exhibit an exponential growth for pattern-length range 3 ≤ D ≤ 8, in the case of finite time series data. Indeed, there is a minimum Dmin-value such that forbidden patterns cannot appear for D < Dmin. The system's localization in an entropy-complexity plane (global quantifier) displays typical specific features associated with its dynamics' nature. We conclude that a more "robust" distinction between deterministic and stochastic dynamics is achieved via the present time series' treatment based on the global characteristics of the permutation Bandt-Pompe probability distribution function.
Applied Acoustics, 1989
The present note deals with an approximate solution of the title problem in the case where a port... more The present note deals with an approximate solution of the title problem in the case where a portion of the plate is subject to a Po cos ogt-type excitation. The lower natural frequency coefficients and dimensionless values of displacements and stress resultants are determined for several combinations of the mechanical parameters coming into play.
Nonlinear Dynamics
ABSTRACT
Entropy, 2018
In this paper we investigate the degradation of the statistic properties of chaotic maps as conse... more In this paper we investigate the degradation of the statistic properties of chaotic maps as consequence of their implementation in a digital media such as Digital Signal Processors (DSP), Field Programmable Gate Arrays (FPGA) or Application-Specific Integrated Circuits (ASIC). In these systems, binary floating-and fixed-point are the numerical representations available. Fixed-point representation is preferred over floating-point when speed, low power and/or small circuit area are necessary. Then, in this paper we compare the degradation of fixed-point binary precision version of chaotic maps with the one obtained by using floating point 754-IEEE standard, to evaluate the feasibility of their FPGA implementation. The specific period that every fixed-point precision produces was investigated in previous reports. Statistical characteristics are also relevant, it has been recently shown that it is convenient to describe the statistical characteristic using both, causal and non-causal quantifiers. In this paper we complement the period analysis by characterizing the behavior of these maps from an statistical point of view using cuantifiers from information theory. Here, rather than reproducing an exact replica of the real system, the aim is to meet certain conditions related to the statistics of systems.
CONICET Resumen— En este trabajo se investiga el uso de muestreo caótico para adquirir s nales de... more CONICET Resumen— En este trabajo se investiga el uso de muestreo caótico para adquirir s nales de baja frecuencia inmersas en ruido de alta frecuencia. El método reduce el aliasing sin utilizar los típicos filtros antialiasing. Se realizan simulaciones con varios ma-pas caóticos que poseen diferente función densidad de probabilidad invariante (IPDF) y diferente constante de tiempo de evolución en el espacio de las funciones densidad de probabilidad (PDF). Se reportan resulta-dos con diferentes tipos de filtros de respuesta finita al impulso (FIR) y se los compara con los obtenidos en trabajos previos con muestreo aleatorio. P alabras Clave— caos, mapas iterados, gener-adores pseudoaleatorios, jitter random sampling. I. INTRODUCC ON Varios autores han tratado el tema del muestreo no periódico como por ejemplo Beutler (1970); Bilinskis y Mikelsons (1992); Carrica et al. (2001, 2007); Balakr-ishnan (1962); Tarczynski (2001); Mirri et al. (1998); DaDalt et al. (2002). En especial el mue...
AIP Conference Proceedings, 2007
Literature on the use of electroencephalogram (EEG) is not extensive. Research efforts have large... more Literature on the use of electroencephalogram (EEG) is not extensive. Research efforts have largely concerned the use of the EEG either as an indicator of the general integrity of the nervous system or as a measure of specific brain states, such as sleep cycles and other EEG rhythm defined states.
Ocean Engineering, 1995
ABSTRACT
Journal of Sound and Vibration, 1993
ABSTRACT
Journal of Sound and Vibration, 1993
Journal of Sound and Vibration, 1994
Journal of Sound and Vibration, 1997
Journal of Sound and Vibration, 1998
Journal of Sound and Vibration, 1999
Journal of Sound and Vibration, 2000
Spread-spectrum techniques for improving Electromagnetic Compatibilities are investigated. This r... more Spread-spectrum techniques for improving Electromagnetic Compatibilities are investigated. This requires generating Constant Envelope Wideband signals. We produce them via chaotic maps that yield pseudo random time series, used afterwards to modulate sinusoidal waves in frequency. How to assess a maps’s suitability for such task is also discussed.
Revista De Ensenanza De La Fisica, Nov 13, 2010
By appealing to a long list of different nonlinear maps we review the characterization of time se... more By appealing to a long list of different nonlinear maps we review the characterization of time series arising from chaotic maps. The main tool for this characterization is the permutation Bandt-Pompe probability distribution function. We focus attention on both local and global characteristics of the components of this probability distribution function. We show that forbidden ordinal patterns (local quantifiers) exhibit an exponential growth for pattern-length range 3 ≤ D ≤ 8, in the case of finite time series data. Indeed, there is a minimum Dmin-value such that forbidden patterns cannot appear for D < Dmin. The system's localization in an entropy-complexity plane (global quantifier) displays typical specific features associated with its dynamics' nature. We conclude that a more "robust" distinction between deterministic and stochastic dynamics is achieved via the present time series' treatment based on the global characteristics of the permutation Bandt-Pompe probability distribution function.
Applied Acoustics, 1989
The present note deals with an approximate solution of the title problem in the case where a port... more The present note deals with an approximate solution of the title problem in the case where a portion of the plate is subject to a Po cos ogt-type excitation. The lower natural frequency coefficients and dimensionless values of displacements and stress resultants are determined for several combinations of the mechanical parameters coming into play.