165 research outputs found
Performance evaluation over HW/SW co-design SoC memory transfers for a CNN accelerator
Many FPGAs vendors have recently included embedded
processors in their devices, like Xilinx with ARM-Cortex
A cores, together with programmable logic cells. These devices
are known as Programmable System on Chip (PSoC). Their ARM
cores (embedded in the processing system or PS) communicates
with the programmable logic cells (PL) using ARM-standard AXI
buses. In this paper we analyses the performance of exhaustive
data transfers between PS and PL for a Xilinx Zynq FPGA
in a co-design real scenario for Convolutional Neural Networks
(CNN) accelerator, which processes, in dedicated hardware, a
stream of visual information from a neuromorphic visual sensor
for classification. In the PS side, a Linux operating system is
running, which recollects visual events from the neuromorphic
sensor into a normalized frame, and then it transfers these
frames to the accelerator of multi-layered CNNs, and read results,
using an AXI-DMA bus in a per-layer way. As these kind of
accelerators try to process information as quick as possible, data
bandwidth becomes critical and maintaining a good balanced
data throughput rate requires some considerations. We present
and evaluate several data partitioning techniques to improve the
balance between RX and TX transfer and two different ways
of transfers management: through a polling routine at the userlevel
of the OS, and through a dedicated interrupt-based kernellevel
driver. We demonstrate that for longer enough packets,
the kernel-level driver solution gets better timing in computing a
CNN classification example. Main advantage of using kernel-level
driver is to have safer solutions and to have tasks scheduling in
the OS to manage other important processes for our application,
like frames collection from sensors and their normalization.Ministerio de Economía y Competitividad TEC2016-77785-
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
A Sensor Fusion Horse Gait Classification by a Spiking Neural Network on SpiNNaker
The study and monitoring of the behavior of wildlife has always been
a subject of great interest. Although many systems can track animal positions
using GPS systems, the behavior classification is not a common task. For this
work, a multi-sensory wearable device has been designed and implemented to be
used in the Doñana National Park in order to control and monitor wild and semiwild
life animals. The data obtained with these sensors is processed using a
Spiking Neural Network (SNN), with Address-Event-Representation (AER)
coding, and it is classified between some fixed activity behaviors. This works
presents the full infrastructure deployed in Doñana to collect the data, the wearable
device, the SNN implementation in SpiNNaker and the classification
results.Ministerio de Economía y Competitividad TEC2012-37868-C04-02Junta de Andalucía P12-TIC-130
Embedded neural network for real-time animal behavior classification
Recent biological studies have focused on understanding animal interactions and welfare. To help biolo- gists to obtain animals’ behavior information, resources like wireless sensor networks are needed. More- over, large amounts of obtained data have to be processed off-line in order to classify different behaviors.There are recent research projects focused on designing monitoring systems capable of measuring someanimals’ parameters in order to recognize and monitor their gaits or behaviors. However, network unre- liability and high power consumption have limited their applicability.In this work, we present an animal behavior recognition, classification and monitoring system based ona wireless sensor network and a smart collar device, provided with inertial sensors and an embeddedmulti-layer perceptron-based feed-forward neural network, to classify the different gaits or behaviorsbased on the collected information. In similar works, classification mechanisms are implemented in aserver (or base station). The main novelty of this work is the full implementation of a reconfigurableneural network embedded into the animal’s collar, which allows a real-time behavior classification andenables its local storage in SD memory. Moreover, this approach reduces the amount of data transmittedto the base station (and its periodicity), achieving a significantly improving battery life. The system hasbeen simulated and tested in a real scenario for three different horse gaits, using different heuristics andsensors to improve the accuracy of behavior recognition, achieving a maximum of 81%.Junta de Andalucía P12-TIC-130
Accuracy Improvement of Neural Networks Through Self-Organizing-Maps over Training Datasets
Although it is not a novel topic, pattern recognition has
become very popular and relevant in the last years. Different classification
systems like neural networks, support vector machines or even
complex statistical methods have been used for this purpose. Several
works have used these systems to classify animal behavior, mainly in an
offline way. Their main problem is usually the data pre-processing step,
because the better input data are, the higher may be the accuracy of the
classification system. In previous papers by the authors an embedded
implementation of a neural network was deployed on a portable device
that was placed on animals. This approach allows the classification to
be done online and in real time. This is one of the aims of the research
project MINERVA, which is focused on monitoring wildlife in Do˜nana
National Park using low power devices. Many difficulties were faced when
pre-processing methods quality needed to be evaluated. In this work, a
novel pre-processing evaluation system based on self-organizing maps
(SOM) to measure the quality of the neural network training dataset is
presented. The paper is focused on a three different horse gaits classification
study. Preliminary results show that a better SOM output map
matches with the embedded ANN classification hit improvement.Junta de Andalucía P12-TIC-1300Ministerio de Economía y Competitividad TEC2016-77785-
Event-based Row-by-Row Multi-convolution engine for Dynamic-Vision Feature Extraction on FPGA
Neural networks algorithms are commonly used to
recognize patterns from different data sources such as audio or
vision. In image recognition, Convolutional Neural Networks are
one of the most effective techniques due to the high accuracy they
achieve. This kind of algorithms require billions of addition and
multiplication operations over all pixels of an image. However,
it is possible to reduce the number of operations using other
computer vision techniques rather than frame-based ones, e.g.
neuromorphic frame-free techniques. There exists many neuromorphic
vision sensors that detect pixels that have changed
their luminosity. In this study, an event-based convolution engine
for FPGA is presented. This engine models an array of leaky
integrate and fire neurons. It is able to apply different kernel
sizes, from 1x1 to 7x7, which are computed row by row, with a
maximum number of 64 different convolution kernels. The design
presented is able to process 64 feature maps of 7x7 with a latency
of 8.98 s.Ministerio de Economía y Competitividad TEC2016-77785-
Production of 4-ethylphenol in alperujo by Lactobacillus pentosus
© 2014 Society of Chemical Industry. BACKGROUND: Alperujo is the paste generated from the two-phase extraction system of olive oil. This wet pomace must be stored for several months and, during this period, the formation of 4-ethyphenol provokes a strong off-odour. The aim of this work was to identify the microorganisms able to produce this volatile phenol. RESULTS: Yeast and bacterial strains were isolated from stored alperujo and tested for their ability to metabolize p-coumaric acid and form 4-ethylphenol. Among them, Lactobacillus pentosus was the microorganism that both in synthetic medium and alperujo gave rise to 4-ethylphenol formation. This microorganism did not grow in alperujo acidified to pH 2, thereby confirming that acidification as the best method to control odour emissions during alperujo storage. CONCLUSION: Lactic acid bacteria, particularly Lactobacillus pentosus, can be responsible for the formation of the off-odour caused by 4-ethylphenol during the storage of alperujo. This odour can be prevented by acidifying the alperujo.This research was supported by the Spanish Government and the European Union FEDER funds through the project AGL-2009-07512. The authors are grateful to Irene de la Rosa for technical help and Oleícola el Tejar SCA for providing the alperujo samples.Peer Reviewe
Fall-back time for photo-ionized Cs atoms attached to superfluid He-4 nanodroplets
We have studied the dynamic evolution of a Cs atom photo-excited from 6s to 6p and 7s states on a helium droplet using time-dependent 4He-DFT simulations. Depending on the excited electronic state, the Cs impurity remains on the droplet surface or it is ejected. Upon subsequent photo-ionization of the excited Cs atom the resulting Cs+ cation may either be ejected or come back to the droplet, depending on the time delay between photo-excitation and photo-ionization. We have calculated the critical time delay separating these two different behaviors, as well as final ion velocities. These observables will be used for future comparison with planned pump-probe experiments
Self-Assembled Lanthanide Antenna Glutathione Sensor for the Study of Immune Cells
This work was supported by grants CTQ2017-85658-R, BFU2015-67284-R, and PID2019-104366RB-C22 funded by MCIN/AEI/10.13039/501100011033/FEDER "Una manera de hacer Europa"; grant PID2020-114256RB-I00 funded by MCIN/AEI/10.13039/501100011033; grant A-FQM-386-UGR20 funded by FEDER/Junta de Andalucia-Consejeria de Transformacion Economica, Industria, Conocimiento y Universidades, and the CSIC grant 201580E073. Funding for open access charge: Universidad de Granada/CBUA.The small molecule 8-methoxy-2-oxo-1,2,4,5-
tetrahydrocyclopenta[de]quinoline-3-carboxylic acid (2b) behaves
as a reactive non-fluorescent Michael acceptor, which after reaction
with thiols becomes fluorescent, and an efficient Eu3+ antenna,
after self-assembling with this cation in water. This behavior makes
2b a highly selective GSH biosensor, which has demonstrated high
potential for studies in murine and human cells of the immune
system (CD4+ T, CD8+ T, and B cells) using flow cytometry. GSH
can be monitored by the fluorescence of the product of addition to
2b (445 nm) or by the luminescence of Eu3+ (592 nm). 2b was
able to capture baseline differences in GSH intracellular levels
among murine and human CD4+ T, CD8+ T, and B cells. We also
successfully used 2b to monitor intracellular changes in GSH associated with the metabolic variations governing the induction of
CD4+ naiv̈ e T cells into regulatory T cells (TREG).MCIN/AEI/FEDER "Una manera de hacer Europa" CTQ2017-85658-R
BFU2015-67284-R
PID2019-104366RB-C22MCIN/AEI PID2020-114256RB-I00FEDER/Junta de Andalucia-Consejeria de Transformacion Economica, Industria, Conocimiento y Universidades A-FQM-386-UGR20CSIC grant 201580E073Universidad de Granada/CBU
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