75 research outputs found
A spiking neural network for real-time Spanish vowel phonemes recognition
This paper explores neuromorphic approach capabilities applied to real-time speech processing. A spiking
recognition neural network composed of three types of neurons is proposed. These neurons are based on an
integrative and fire model and are capable of recognizing auditory frequency patterns, such as vowel phonemes;
words are recognized as sequences of vowel phonemes. For demonstrating real-time operation, a complete
spiking recognition neural network has been described in VHDL for detecting certain Spanish words, and it has
been tested in a FPGA platform. This is a stand-alone and fully hardware system that allows to embed it in a
mobile system. To stimulate the network, a spiking digital-filter-based cochlea has been implemented in VHDL.
In the implementation, an Address Event Representation (AER) is used for transmitting information between
neurons.Ministerio de Economía y Competitividad TEC2012-37868-C04-02/0
Ionogram inversion F1-layer treatment effect in raytracing
This paper shows the importance of the F1-layer shape in the electron density profiles obtained from ionograms
with different inversion techniques when the profiles are used in ray tracing. This layer often controls the propagation
on the path with ranges less than about 2000 km, particularly for spring and summer periods. Ionograms
from two different stations, Hainan (19.4N, 109E) and El Arenosillo (37.1N, -6.7E), obtained during the month
of July 2002 (average sunspot number: 99.6) during geomagnetic quiet conditions (Ap-index between 9 and 15)
are analyzed. The profiles obtained with two different inversion techniques with different options are used together
with the ray tracing program of the Proplab-Pro software. This program calculates the features of the received signal
as angle of arrival, path length, height of reflection and range for each given profile assumed to define a spherically
symmetric ionosphere in the region along the path. For each ionospheric condition (location, day, hour) the
difference between range values obtained with Proplab-Pro program using profiles from the two techniques and
the different options (POLAN no valley, POLAN valley, POLAN1-layer and NHPC) are considered
Validation of a method for ionospheric electron density reconstruction by means of vertical incidence data during quiet and storm periods
A preliminary validation of the technique developed using the NeQuick ionospheric model and the «effective ionization parameter» Az, based on vertical total electron content data ingestion, was carried out in a previous study. The current study was performed to extend the analyzed conditions and confirm the results. The method to validate this technique is based on a comparison between hourly F2 peak values measured with Vertical Incidence (VI) soundings and those calculated with the new technique. Data corresponding to different hours and seasons (equinox, summer solstice, and winter solstice) during the period 2000-2003 (high and medium solar activity conditions) were compared for all available ionosonde stations. The results show a good agreement between foF2 and hmF2 values obtained with the new technique and measurements from vertical incidence soundings during quiet and storms conditions.European Community Fifth Framework Programm
Augmented and virtual reality evolution and future tendency
Augmented reality and virtual reality technologies are increasing in popularity. Augmented reality has thrived to date mainly on mobile applications, with games like Pokémon Go or the new Google Maps utility as some of its ambassadors. On the other hand, virtual reality has been popularized mainly thanks to the videogame industry and cheaper devices. However, what was initially a failure in the industrial field is resurfacing in recent years thanks to the technological improvements in devices and processing hardware. In this work, an in-depth study of the different fields in which augmented and virtual reality have been used has been carried out. This study focuses on conducting a thorough scoping review focused on these new technologies, where the evolution of each of them during the last years in the most important categories and in the countries most involved in these technologies will be analyzed. Finally, we will analyze the future trend of these technologies and the areas in which it is necessary to investigate to further integrate these technologies into society.Universidad de Sevilla, Spain Telefonica Chair “Intelligence in Networks
Validation of a method for ionospheric electron density reconstruction by means of vertical incidence data during quiet and storm periods
A preliminary validation of the technique developed using the NeQuick ionospheric model and the «effective ionization
parameter» Az, based on vertical total electron content data ingestion, was carried out in a previous study. The
current study was performed to extend the analyzed conditions and confirm the results. The method to validate this
technique is based on a comparison between hourly F2 peak values measured with Vertical Incidence (VI) soundings
and those calculated with the new technique. Data corresponding to different hours and seasons (equinox, summer
solstice, and winter solstice) during the period 2000-2003 (high and medium solar activity conditions) were compared
for all available ionosonde stations. The results show a good agreement between foF2 and hmF2 values obtained with
the new technique and measurements from vertical incidence soundings during quiet and storms conditions
Smart Footwear Insole for Recognition of Foot Pronation and Supination Using Neural Networks
Abnormal foot postures during gait are common sources of pain and pathologies of the
lower limbs. Measurements of foot plantar pressures in both dynamic and static conditions can detect
these abnormal foot postures and prevent possible pathologies. In this work, a plantar pressure
measurement system is developed to identify areas with higher or lower pressure load. This system
is composed of an embedded system placed in the insole and a user application. The instrumented
insole consists of a low-power microcontroller, seven pressure sensors and a low-energy bluetooth
module. The user application receives and shows the insole pressure information in real-time and,
finally, provides information about the foot posture. In order to identify the different pressure states
and obtain the final information of the study with greater accuracy, a Deep Learning neural network
system has been integrated into the user application. The neural network can be trained using a
stored dataset in order to obtain the classification results in real-time. Results prove that this system
provides an accuracy over 90% using a training dataset of 3000+ steps from 6 different users.Ministerio de Economía y Competitividad TEC2016-77785-
Two Hardware Implementations of the Exhaustive Synthetic AER Generation Method
Address-Event-Representation (AER) is a communications protocol
for transferring images between chips, originally developed for bio-inspired
image processing systems. In [6], [5] various software methods for synthetic
AER generation were presented. But in neuro-inspired research field, hardware
methods are needed to generate AER from laptop computers. In this paper two
real time implementations of the exhaustive method, proposed in [6], [5], are
presented. These implementations can transmit, through AER bus, images
stored in a computer using USB-AER board developed by our RTCAR group
for the CAVIAR EU project.Commission of the European Communities IST-2001-34124 (CAVIAR)Comisión Interministerial de Ciencia y Tecnología TIC-2003-08164-C03-0
A model assisted ionospheric electron density reconstruction method based on vertical TEC data ingestion
A technique to reconstruct the electron density of the ionosphere starting from total electron content values has
been developed using the NeQuick ionospheric electron density model driven by its effective ionization parameter
Az. The technique is based on the computation of Az values for a suitable worldwide grid of points. A simple
way to obtain relevant Az grids is to use global vertical Total Electron Content (TEC) maps to define for each
grid point as Az value, the one that minimizes the difference between the experimental and the modeled vertical
TEC. Having a global grid of Az values it is possible to compute the electron density at any point in the ionosphere
using NeQuick. As a consequence, slant TEC values for specific ground station to satellite links or ionosphere
peak parameter values at any location can be calculated. The results of the comparisons between experimental
and reconstructed slant TEC as well as experimental and reconstructed peak parameters values indicate
that the proposed reconstruction method can be used to reproduce the observed ionosphere in a realistic way
Worst cases for a one-hop high frequency link
The characterisation of a HF channel by means of monthly electron density profiles can be complemented with a detailed study of radio propagation «worst cases» on situations with extremes conditions of radiopropagation for a given period. These «worst cases» correspond to conditions that can be identified by means of cumulative distributions of the key parameter f0F2. This paper analyses the main parameters of the HF channel: time delay, apogee, elevation angle and transmission frequency with mean and extreme conditions. The method used to characterise the ionospheric channel is based on ray-tracing techniques.National Institute of Aerospace Technology (INTA)Dr. Moorhead of Neptune Radar Ltd.Gloucester U.
Introducción : #DIenlínea UNIA: guía para una docencia innovadora en red
págs. 9-14Capítulo incluido en el libro: #DIenlínea UNIA: guía para una docencia innovadora en red. María Sánchez González (coord.). Sevilla, Universidad Internacional de Andalucía, 2021. ISBN 978-84-7993-365-4. Enlace: http://hdl.handle.net/10334/598
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