Dal modello conoscitivo e computazionale al controllo associativo della memoria

Implementazione del modello di ippocampo per la realizzazione di un sistema bioispirato di ricordo e memoria associativ

New generation of wearable goniometers for motion capture systems

Background Monitoring joint angles through wearable systems enables human posture and gesture to be reconstructed as a support for physical rehabilitation both in clinics and at the patient's home. A new generation of wearable goniometers based on knitted piezoresistive fabric (KPF) technology is presented. Methods KPF single-and double-layer devices were designed and characterized under stretching and bending to work as strain sensors and goniometers. The theoretical working principle and the derived electromechanical model, previously proved for carbon elastomer sensors, were generalized to KPF. The devices were used to correlate angles and piezoresistive fabric behaviour, to highlight the differences in terms of performance between the single layer and the double layer sensors. A fast calibration procedure is also proposed. Results The proposed device was tested both in static and dynamic conditions in comparison with standard electrogoniometers and inertial measurement units respectively. KPF goniometer capabilities in angle detection were experimentally proved and a discussion of the device measurement errors of is provided. The paper concludes with an analysis of sensor accuracy and hysteresis reduction in particular configurations. Conclusions Double layer KPF goniometers showed a promising performance in terms of angle measurements both in quasi-static and dynamic working mode for velocities typical of human movement. A further approach consisting of a combination of multiple sensors to increase accuracy via sensor fusion technique has been presented

The Digital Signal Processing Platform for the Low Frequency Aperture Array: Preliminary Results on the Data Acquisition Unit

A signal processing hardware platform has been developed for the Low Frequency Aperture Array component of the Square Kilometre Array (SKA). The processing board, called an Analog Digital Unit (ADU), is able to acquire and digitize broadband (up to 500MHz bandwidth) radio-frequency streams from 16 dual polarized antennas, channel the data streams and then combine them flexibly as part of a larger beamforming system. It is envisaged that there will be more than 8000 of these signal processing platforms in the first phase of the SKA, so particular attention has been devoted to ensure the design is low-cost and low-power. This paper describes the main features of the data acquisition unit of such a platform and presents preliminary results characterizing its performance

The Signal Processing Firmware for the Low Frequency Aperture Array

The signal processing firmware that has been developed for the Low Frequency Aperture Array component of the Square Kilometre Array is described. The firmware is implemented on a dual FPGA board, that is capable of processing the streams from 16 dual polarization antennas. Data processing includes channelization of the sampled data for each antenna, correction for instrumental response and for geometric delays and formation of one or more beams by combining the aligned streams. The channelizer uses an oversampling polyphase filterbank architecture, allowing a frequency continuous processing of the input signal without discontinuities between spectral channels. Each board processes the streams from 16 antennas, as part of larger beamforming system, linked by standard Ethernet interconnections. There are envisaged to be 8192 of these signal processing platforms in the first phase of the Square Kilometre array so particular attention has been devoted to ensure the design is low cost and low power

Has music a specific effect on temporal control of movements? An auditory-motor task of synchronization.

The timing of action is analyzed by studying a repetitive task in which participants are required to execute simple isochronous repetitive movements (IRMs) avoiding prerequisites for explicit temporal representation. Movements are performed in free condition and accompanying predictable time-based auditory stimuli such as metronome clicks and robustly timed musical excerpts

Event Related Biometrics: Towards an Unobtrusive Sensing Seat System for Continuous Human Authentication

The present work is focused on the improvement of a Sensing Seat system previously developed by the authors for the initial authentication purpose in office and car scenarios. The goal is to obtain an event-related continuous authentication system, where the human subject should not take care of the system itself so that he is free to perform his normal actions. The system is realized by means of a sensing cover where conductive elastomers are used as strain sensors. The deformation of the cover caused by the body shape while actions are performed by the subject are used to obtain time-dependent relevant features. Such information are then analyzed by suitable classifiers that are able to perform the real-time continuous authentication task. A measurement campaign was carried out using data from 24 human subjects employed in an office scenario while a set of 22 actions were performed. The authentication capabilities of the system are reported in terms of acceptance and rejection rates, showing a high degree of correct classification

Isochronous sounds for isochronous movements: The multiplex control of timing in human subjects

The ability to perform isochronous movements when listening to rhythmic auditory input requires a foremost and flexible process to manage timing information. We tested whether isochronic movement is result of a multifaceted control process of timing whose individual elements are sensitive or variously resistant to auditory input. We recorded kinematic parameters of movement while participants, free from visual and touch information, performed repeated isochronous wrist's flexion-extensions in silence, driven by streams of beats or excerpts of music, and during auditory recall. Our study on the temporal behavior of isochronous wrist movements reveals composite interrelations between auditory input and motor performance. Some elements of timing are insensitive to auditory information. Other elements of timing are sensitive to auditory input, but only as regarding rhythmic information. Interestingly, the nature of the auditory input is not real-time influential, comes into play only during recall, and for a comprehensive characteristic of rhythmic motor performance: the tempo. Our results provide evidence of a multiplex control of timing in audio-motor coupling for isochronous movements. This intricate framework to control movement offers unique opportunities for the functional exploration of then normal and diseased human brain