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  • Ítem
    On the spectral dynamics of noise-seeded modulation instability in optical fibers
    (2017) Fierens, Pablo Ignacio; Hernández, Santiago M.; Bonetti, Juan I.; Grosz, Diego
    We revisit modulation instability in optical fibers, including all relevant effects, such as higher-order dispersion terms, self-steepening, and the Raman response. Our analysis allows us to calculate the spectral evolution of a small perturbation to a continuous pump, and thus obtain an analytical expression for the small-signal spectral dynamics, showing excellent agreement with numerical simulations. We apply the expression for the spectral evolution to the case of white Gaussian noise and calculate some relevant metrics of the resulting signal, such as its coherence and signal-to-noise ratio. These calculations might shed some light on the nonlinear phenomena of supercontinuum generation.
  • Ítem
    Dispersive waves in optical fibers with a zero-nonlinearity wavelength
    (2021-08) Sparapani, Alexis; Linale, N.; Grosz, Diego; Bonetti, Juan I.; Fierens, Pablo Ignacio; Hernández, Santiago M.
    "We present results on dispersive waves radiated by solitons in the context of fibers with arbitrary frequency-dependent nonlinearities. In particular, we focus on the effect of a zero-nonlinearity wavelength within the spectral region of interest."
  • Ítem
    Data-driven simulation for pedestrian avoiding a fixed obstacle
    (2019-07) Martin, Rafael F.; Parisi, Daniel
    "Data-driven simulation of pedestrian dynamics is an incipient and promising approach for building reliable microscopic pedestrian models. We propose a methodology based on generalized regression neural networks, which does not have to deal with a huge number of free parameters as in the case of multilayer neural networks. Although the method is general, we focus on the one pedestrian—one obstacle problem. The proposed model allows us to simulate the trajectory of a pedestrian avoiding an obstacle from any direction."
  • Ítem
    PCF-based tunable source of femtosecond pulses in the visible region
    (2010-06) Rieznik, Andrés; Bettachini, Víctor A.; König, Pablo; Grosz, Diego; Masip, Martin Eduardo; Caldarola, Martín; Bragas, Andrea
    "Blue-shifting dispersive waves and soliton trapping in a PCF pumped with a Ti:Sa laser are shown to produce tunable femtosecond pulses in the visible region, with a central wavelength depending upon the input pump power."
  • Ítem
    Set-up of a method for people-counting using images from a UAV
    (2019-07-02) Parisi, Daniel; Giribet, Juan I.; Pose, Claudio D.; Mas, Ignacio
    "We present a new method for obtaining the positions of each person attending an outdoor gathering. From this information it is possible to calculate the density field and the number of people. A dual-camera (visible + infrared (IR)) is mounted on an unmanned aerial vehicle (UAV). In this work, we only use the IR channel and present an initial set-up and calibration of the system along with the characterization of a small group of people."