2026-04-18T07:33:47Zhttps://recercat.cat/oai/request

oai:recercat.cat:2117/4494402026-01-16T04:10:54Zcom_2072_1033col_2072_452950

A Single-neuron-per-class Readout for image-encoded sensor time series Bernal Casas, David Gallego Vila, Jaime Universitat Politècnica de Catalunya. Departament de Ciències de la Computació Universitat Politècnica de Catalunya. ViRVIG - Grup de Recerca en Visualització, Realitat Virtual i Interacció Gràfica Àrees temàtiques de la UPC::Informàtica End-to-end learning Single-neuron-per-class readout Neuromorphic computing Image-encoded time series Neural networks Spiking neural networks Resonate-and-fire (RAF) neuron Noisy environments We introduce an ultra-compact, single-neuron-per-class end-to-end readout for binary classification of noisy, image-encoded sensor time series. The approach compares a linear single-unit perceptron (E2E-MLP-1) with a resonate-and-fire (RAF) neuron (E2E-RAF-1), which merges feature selection and decision-making in a single block. Beyond empirical evaluation, we provide a mathematical analysis of the RAF readout: starting from its subthreshold ordinary differential equation, we derive the transfer function H(j¿), characterize the frequency response, and relate the output signal-to-noise ratio (SNR) to |H(j¿)|2 and the noise power spectral density Sn(¿)¿¿a (brown, pink, and blue noise). We present a stable discrete-time implementation compatible with surrogate gradient training and discuss the associated stability constraints. As a case study, we classify walk-in-place (WIP) in a virtual reality (VR) environment, a vision-based motion encoding (72 × 56 grayscale) derived from 3D trajectories, comprising 44,084 samples from 15 participants. On clean data, both single-neuron-per-class models approach ceiling accuracy. At the same time, under colored noise, the RAF readout yields consistent gains (typically +5–8% absolute accuracy at medium/high perturbations), indicative of intrinsic band-selective filtering induced by resonance. With ~8 k parameters and sub-2 ms inference on commodity graphical processing units (GPUs), the RAF readout provides a mathematically grounded, robust, and efficient alternative for stochastic signal processing across domains, with virtual reality locomotion used here as an illustrative validation. Peer Reviewed Postprint (published version) 2025-12-05 Article Bernal-Casas, D.; Gallego, J. A Single-neuron-per-class Readout for image-encoded sensor time series. «Mathematics», 5 Desembre 2025, vol. 13, núm. 24, article 3893. 2227-7390 https://hdl.handle.net/2117/449440 10.3390/math13243893 eng https://www.mdpi.com/2227-7390/13/24/3893 http://creativecommons.org/licenses/by/4.0/ Open Access Attribution 4.0 International application/pdf Multidisciplinary Digital Publishing Institute (MDPI)