Noise on resistive switching: a Fokker–Planck approach

We study the effect of internal and external noise on the phenomenon of resistive switching. We consider a non-harmonic external driving signal and provide a theoretical framework to explain the observed behavior in terms of the related Fokker–Planck equations. It is found that internal noise causes an enhancement of the resistive contrast and that noise proves to be advantageous when considering short driving pulses. In the case of external noise, however, noise only has the effect of degrading the resistive contrast. Furthermore, we find a relationship between the noise amplitude and the driving signal pulsewidth that constrains the persistence of the resistive state. In particular, results suggest that strong and short driving pulses favor a longer persistence time, an observation that may find applications in the field of high-integration high-speed resistive memory devices.Fil: Patterson, Germán Agustín. Instituto Tecnológico de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Grosz, Diego Fernando. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Fierens, Pablo Ignacio. Instituto Tecnológico de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

A geometrical view of scalar modulation instability in optical fibers

Full models of scalar modulation instability (MI) in optical fibers available in the literature usually involve complex formulations. In this paper, we present a novel approach to the analysis of MI in optical fibers by means of a simple geometrical description in the power vs. frequency plane. This formulation allows to relate the shape of the MI gain to any arbitrary dispersion profile of the medium, thus providing a simple insight. As a result, we derive a straightforward explanation of the non-trivial dependence of the cutoff power on high-order dispersion and derive explicitly the power that maximizes the gain. Our approach puts forth a tool to synthesize a desired MI gain with the potential application to a number of parametric-amplification and supercontinuum-generation devices whose initial-stage dynamics rely upon modulation instability.Fil: Hernandez, Santiago Martin. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; ArgentinaFil: Fierens, Pablo Ignacio. Instituto Tecnológico de Buenos Aires; ArgentinaFil: Bonetti, Juan Ignacio. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; ArgentinaFil: Sánchez, Alfredo Daniel. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; ArgentinaFil: Grosz, Diego Fernando. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentina. Instituto Tecnológico de Buenos Aires; Argentin

A higher-order perturbation analysis of the nonlinear Schrödinger equation

A well-known and thoroughly studied phenomenon in nonlinear wave propagation is that of modulation instability (MI). MI is usually approached as a perturbation to a pump, and its analysis is based on preserving only terms which are linear on the perturbation, discarding those of higher order. In this sense, the linear MI analysis is relevant to the understanding of the onset of many other nonlinear phenomena, such as supercontinuum generation, but it has limitations as it can only be applied to the propagation of the perturbation over short distances. In this work, we propose approximations to the propagation of a perturbation, consisting of additive white noise, that go beyond the linear modulation instability analysis, and show them to be in excellent agreement with numerical simulations and experimental measurements.Fil: Bonetti, Juan Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; ArgentinaFil: Hernandez, Santiago Martin. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; ArgentinaFil: Fierens, Pablo Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Tecnológico de Buenos Aires; ArgentinaFil: Grosz, Diego Fernando. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentin

Encrypted CDMA audio network

We present a secure LAN using sound as the physical layer for low speed applications. In particular, we show a real implementation of a point-to-point or point-to-multipoint secure acoustic network, having a short range, consuming a negligible amount of power, and requiring no specific hardware on mobile clients. The present acoustic network provides VPN-like private channels to multiple users sharing the same medium. It is based on Time-hopping CDMA, and makes use of an encrypted Bloom filter. An asymmetrical error-correction is used to supply data integrity, even in the presence of strong interference. Simulations and real experiments show its feasibility. We also provide some theoretical analysis on the principle of operation.Fil: Ortega, Alfredo A.. Instituto Tecnológico de Buenos Aires; ArgentinaFil: Bettachini, Victor. Instituto Tecnológico de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Fierens, Pablo Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Tecnológico de Buenos Aires; ArgentinaFil: Alvarez Hamelin, Jose Ignacio. Instituto Tecnológico de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Guest editorial special issue on embedded systems

Los sistemas integrados encuentran aplicación en una amplia variedad de áreas. En esta editorial, revisamos brevemente los artículos de este número especial sobre sistemas integrados. Estos artículos presentan aplicaciones de los sistemas integrados en campos como las comunicaciones, los satélites, el transporte, la visión por computadora, la energía y la educación.Embedded Systems (ES) find application in a wide variety of areas. In this Editorial, we briefly review the papers in this Special Issue on Embedded Systems. These papers present applications of ES in fields such as communications, satellites, transportation, computer vision, energy and education.Fil: de Micco, Luciana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Científicas y Tecnológicas en Electrónica. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones Científicas y Tecnológicas en Electrónica; ArgentinaFil: Vargas, F.. Pontificia Universidade Católica do Rio Grande do Sul; BrasilFil: Fierens, Pablo Ignacio. Instituto Tecnológico de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Measuring self-steepening with the photon-conserving nonlinear Schrödinger equation

We propose an original, simple, and direct method to measure self-steepening (SS) in nonlinear waveguides. Our proposal is based on results derived from the recently introduced photon-conserving nonlinear Schrödinger equation (NLSE) and relies on the time shift experienced by soliton-like pulses due to SS upon propagation. In particular, a direct measurement of this time shift allows for a precise estimation of the SS parameter. Furthermore, we show that such an approach cannot be tackled by resorting to the NLSE. The proposed method is validated through numerical simulations, in excellent agreement with the analytical model, and results are presented for relevant spectral regions in the near infrared, the telecommunication band, and the mid infrared, and for realistic parameters of available laser sources and waveguides. Finally, we demonstrate the robustness of the proposed scheme against deviations expected in real-life experimental conditions, such as pulse shape, pulse peak power, pulsewidth, and/or higher-order linear and nonlinear dispersion.Fil: Linale, Nicolás Martín. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Comision Nacional de Energia Atomica. Gerencia D/area Invest y Aplicaciones No Nucleares. Gerencia de Des. Tec. y Proyectos Especiales. Departamento de Ingenieria En Telecomunicaciones; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; ArgentinaFil: Fierens, Pablo Ignacio. Instituto Tecnológico de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Bonetti, Juan Ignacio. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Comision Nacional de Energia Atomica. Gerencia D/area Invest y Aplicaciones No Nucleares. Gerencia de Des. Tec. y Proyectos Especiales. Departamento de Ingenieria En Telecomunicaciones; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; ArgentinaFil: Sánchez, Alfredo Daniel. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Comision Nacional de Energia Atomica. Gerencia D/area Invest y Aplicaciones No Nucleares. Gerencia de Des. Tec. y Proyectos Especiales. Departamento de Ingenieria En Telecomunicaciones; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; ArgentinaFil: Hernandez, Santiago Martin. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentina. Universidad Nacional de Cuyo; ArgentinaFil: Grosz, Diego Fernando. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Comision Nacional de Energia Atomica. Gerencia D/area Invest y Aplicaciones No Nucleares. Gerencia de Des. Tec. y Proyectos Especiales. Departamento de Ingenieria En Telecomunicaciones; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentin

Joint position and clock tracking of wireless nodes under mixed LOS-NLOS conditions

We propose an algorithm for the simultaneous position and clock tracking of a wireless mobile node by a set of reference nodes. Based on a protocol similar to that of two-way ranging, our algorithm efficiently estimates the position and velocity of the mobile, and the skew and offset of its clock. We take into account that the propagation conditions between each reference node and the mobile change as the latter moves. In particular, changes between line-of-sight (LOS) and several non-line-of-sight (NLOS) scenarios are considered. We study the performance of our algorithm and compare it to other relevant proposals in the literature by means of simulations, showing that our proposed method improves localization accuracy.Fil: Grisales Campeón, Juan Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Tecnológico de Buenos Aires; ArgentinaFil: Fierens, Pablo Ignacio. Instituto Tecnológico de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Joint position and clock tracking of wireless nodes

In this paper we consider the problem of joint position and clock tracking of a mobile wireless node by a set of reference nodes. Imperfections of the mobile clock are characterized by its skew and offset, which are assumed to change with time according to simple random walk models. We put forth a measurement protocol, similar to that used in two-way ranging, and apply extended and unscented Kalman filters to estimate the position and the velocity of the mobile, and the skew and offset of its clock. We analyze the performance of the algorithms by means of extensive simulations, where the mobile's velocity is assumed to follow a random walk. Simulation results are compared to the Cramér–Rao bound for a simplified model of a mobile with constant velocity. We show that estimation errors are largely independent of the mean values of the offset and the skew, but they increase with the mean speed. We also study how estimation errors are influenced by other factors such as the number of reference nodes. We believe these results to be of relevance, specially, in indoor positioning applications.Fil: Grisales Campeón, Juan Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Tecnológico de Buenos Aires; ArgentinaFil: Fierens, Pablo Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Tecnológico de Buenos Aires; Argentin