61 research outputs found
Una aportación a los sistemas de procesamiento de la información basados en modelos neuronales pulsantes
En este trabajo se propone e implementa un nuevo sistema de reconocimiento de sonidos basado en una cóclea artificial pulsante innovadora.
Inicialmente se estudian los mecanismos clásicos de procesamiento de audio para el reconocimiento de sonidos; así como el funcionamiento del sistema auditivo humano en conjunción con los procesos neuronales del cerebro. A partir de dichos estudios, es como se proponen nuevos sistemas en lo que respecta al procesamiento de audio y reconocimiento de sonidos automático.
En trabajos de investigación recientes se han desarrollado una serie de elementos neuromórficos hardware pulsantes basados en codificación AER (Address Event Representation), en esta tesis estos bloques sirven de punto de partida para la implementación de nuestro sistema de reconocimiento de sonidos.
Se proponen e implementan dos sistemas: por una parte, una cóclea artificial para la obtención de las componentes de frecuencia del sonido, imitando el funcionamiento del aparato auditivo. Y por otra, un sistema de reconocimiento de patrones sonoros, obtenidos a partir de la salida generada por la cóclea artificial, inspirado en el comportamiento de las neuronas y las conexiones entre ellas.
Por último, en este trabajo, se realiza un estudio exhaustivo para evaluar la eficiencia de los sistemas implementados y compararlos con los desarrollos previos
Análisis de usabilidad y utilidad de las herramientas GDUS+ y LAMS para el diseño pedagógico en un entorno de enseñanza semipresencial universitario
IMS Learning Design is a pedagogically neutral specification that allows the creation of environments and educational contents and that promotes the reusability. Furthermore, this specification allows a large range of didactic approaches. IMS Learning is particularly suitable for distance learning through electronic platforms. In addition, there is great interest in using these types of standards in face-to-face and blended learning at universities. However, there are some difficulties that must be overcome when considering these solutions in universities, for example, those related to the computing skills of potential uses, those associated to the usability of editing tools for Learning Units creation, or those linked to human resource costs… This article deals with these issues by analysing the usefulness and usability of two tools based on Learning Design, GDUS + and LAMS, to create virtual Learning Units according to specific pedagogical design approaches.IMS-Learning Design es una especificación pedagógicamente neutral que permite la creación de escenarios y contenidos educativos promoviendo la reusabilidad y permitiendo un amplio abanico de enfoques didácticos. No obstante, aún siendo especialmente adecuada para el ámbito de la educación a distancia mediante plataforma electrónica, existe también gran interés en emplear este tipo de estándares en entornos universitarios de enseñanza presencial y semi-presencial. Sin embargo, existen una serie de dificultades que deben ser superadas a la hora de plantear este tipo de soluciones en dichos entornos, entre otras de tipo cultural, asociadas con la usabilidad de herramientas de edición de Unidades de Aprendizaje, de coste en recursos humanos... En el presente artículo se van a abordar estas cuestiones mediante el análisis de la utilidad y usabilidad de dos herramientas basadas en Learning Desing, GDUS+ y LAMS, para la creación de Unidades de Aprendizaje virtuales según determinados enfoques de diseño pedagógico
Live Demonstration: Real-time neuro-inspired sound source localization and tracking architecture applied to a robotic platform
This live demonstration presents a sound source
localization and tracking system implemented with Spike Signal
Processing (SSP) building blocks on FPGA devices. The system
architecture is based on the ability of the mammalian auditory
system to locate the direction of a sound in the horizontal plane
using the interaural intensity difference. We used a binaural
Neuromorphic Auditory Sensor to obtain spike rates similar to
those generated by the inner hair cells of the human auditory
system and the component that obtains the interaural intensity
difference is inspired by the lateral superior olive. The spike
stream that represents the interaural intensity difference is used
to turn a robotic platform towards the sound source direction.
The system was tested with pure tones (1-kHz, 2.5-kHz and 5-
kHz sounds) with an average error of 2.32 degrees.Ministerio de Economía y Competitividad TEC2016-77785-
Spikes Monitors for FPGAs, an Experimental Comparative Study
In this paper we present and analyze two VHDL components for
monitoring internal activity of spikes fired by silicon neurons inside FPGAs.
These spikes monitors encode each spike according to the Address-Event Representation,
sending them through a time multiplexed digital bus as discrete
events, using different strategies. In order to study and analyze their behavior
we have designed an experimental scenario, where diverse AER systems have
been used to stimulate the spikes monitors and collect the output AER events,
for later analysis. We have applied a battery of tests on both monitors in order
to measure diverse features such as maximum spike load and AER event loss
due to collisions.Ministerio de Ciencia e Innovación TEC2009-10639-C04-02Ministerio de Economía y Competitividad TEC2012-37868-C04-0
On the Designing of Spikes Band-Pass Filters for FPGA
In this paper we present two implementations of spike-based bandpass
filters, which are able to reject out-of-band frequency components in the
spike domain. First one is based on the use of previously designed spike-based
low-pass filters. With this architecture the quality factor, Q, is lower than 0.5.
The second implementation is inspired in the analog multi-feedback filters
(MFB) topology, it provides a higher than 1 Q factor, and ideally tends to
infinite. These filters have been written in VHLD, and synthesized for FPGA.
Two spike-based band-pass filters presented take advantages of the spike rate
coded representation to perform a massively parallel processing without complex
hardware units, like floating point arithmetic units, or a large memory. These low
requirements of hardware allow the integration of a high number of filters inside
a FPGA, allowing to process several spike coded signals fully in parallel.Ministerio de Ciencia e Innovación TEC2009-10639-C04-0
On the AER Stereo-Vision Processing: A Spike Approach to Epipolar Matching
Image processing in digital computer systems usually considers
visual information as a sequence of frames. These frames are from cameras that
capture reality for a short period of time. They are renewed and transmitted at a
rate of 25-30 fps (typical real-time scenario). Digital video processing has to
process each frame in order to detect a feature on the input. In stereo vision,
existing algorithms use frames from two digital cameras and process them pixel
by pixel until it finds a pattern match in a section of both stereo frames. To
process stereo vision information, an image matching process is essential, but it
needs very high computational cost. Moreover, as more information is
processed, the more time spent by the matching algorithm, the more inefficient
it is. Spike-based processing is a relatively new approach that implements
processing by manipulating spikes one by one at the time they are transmitted,
like a human brain. The mammal nervous system is able to solve much more
complex problems, such as visual recognition by manipulating neuron’s spikes.
The spike-based philosophy for visual information processing based on the
neuro-inspired Address-Event- Representation (AER) is achieving nowadays
very high performances. The aim of this work is to study the viability of a
matching mechanism in a stereo-vision system, using AER codification. This
kind of mechanism has not been done before to an AER system. To do that,
epipolar geometry basis applied to AER system are studied, and several tests
are run, using recorded data and a computer. The results and an average error
are shown (error less than 2 pixels per point); and the viability is proved
Musical notes classification with Neuromorphic Auditory System using FPGA and a Convolutional Spiking Network
In this paper, we explore the capabilities of a sound
classification system that combines both a novel FPGA cochlear
model implementation and a bio-inspired technique based on a
trained convolutional spiking network. The neuromorphic
auditory system that is used in this work produces a form of
representation that is analogous to the spike outputs of the
biological cochlea. The auditory system has been developed using
a set of spike-based processing building blocks in the frequency
domain. They form a set of band pass filters in the spike-domain
that splits the audio information in 128 frequency channels, 64
for each of two audio sources. Address Event Representation
(AER) is used to communicate the auditory system with the
convolutional spiking network. A layer of convolutional spiking
network is developed and trained on a computer with the ability
to detect two kinds of sound: artificial pure tones in the presence
of white noise and electronic musical notes. After the training
process, the presented system is able to distinguish the different
sounds in real-time, even in the presence of white noise.Ministerio de Economía y Competitividad TEC2012-37868-C04-0
Simulating Building Blocks for Spikes Signals Processing
In this paper we will explain in depth how we have used Simulink
with the addition of Xilinx System Generation to design a simulation
framework for testing and analyzing neuro-inspired elements for spikes rate
coded signals processing. Those elements have been designed as building
blocks, which represent spikes processing primitives, combining them we have
designed more complex blocks, which behaves like analog frequency filter
using digital circuits. This kind of computation performs a massively parallel
processing without complex hardware units. Spikes processing building blocks
have been written in VHDL to be implemented for FPGA. Xilinx System
Generator allows co-simulating VHDL entities together with Simulink
components, providing an easy interface for presented building block
simulations and analysis.Ministerio de Ciencia e Innovación TEC2009-10639-C04-0
Real-time motor rotation frequency detection with event-based visual and spike-based auditory AER sensory integration for FPGA
Multisensory integration is commonly
used in various robotic areas to collect more
environmental information using different and
complementary types of sensors. Neuromorphic
engineers mimics biological systems behavior to
improve systems performance in solving engineering
problems with low power consumption. This work
presents a neuromorphic sensory integration scenario
for measuring the rotation frequency of a motor using
an AER DVS128 retina chip (Dynamic Vision Sensor)
and a stereo auditory system on a FPGA completely
event-based. Both of them transmit information with
Address-Event-Representation (AER). This
integration system uses a new AER monitor hardware
interface, based on a Spartan-6 FPGA that allows two
operational modes: real-time (up to 5 Mevps through
USB2.0) and data logger mode (up to 20Mevps for
33.5Mev stored in onboard DDR RAM). The sensory
integration allows reducing prediction error of the
rotation speed of the motor since audio processing
offers a concrete range of rpm, while DVS can be
much more accurate.Ministerio de Economía y Competitividad TEC2012-37868-C04-02/0
Live Demonstration: Real-time motor rotation frequency detection by spike-based visual and auditory AER sensory integration for FPGA
Multisensory integration is commonly used in
various robotic areas to collect much more information from an
environment using different and complementary types of sensors.
This demonstration presents a scenario where the motor rotation
frequency is obtained using an AER DVS128 retina chip
(Dynamic Vision Sensor) and a frequency decomposer auditory
system on a FPGA that mimics a biological cochlea. Both of them
are spike-based sensors with Address-Event-Representation
(AER) outputs. A new AER monitor hardware interface, based
on a Spartan-6 FPGA, allows two operational modes: real-time
(up to 5 Mevps through USB2.0) and off-line mode (up to
20Mevps and 33.5Mev stored in DDR RAM). The sensory
integration allows the bio-inspired cochlea limit to provide a
concrete range of rpm approaches, which are obtained by the
silicon retina.Ministerio de Economía y Competitividad TEC2012-37868-C04-02/0
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