Live Demonstration: On the distance estimation of moving targets with a Stereo-Vision AER system

Distance calculation is always one of the most important goals in a digital stereoscopic vision system. In an AER system this goal is very important too, but it cannot be calculated as accurately as we would like. This demonstration shows a first approximation in this field, using a disparity algorithm between both retinas. The system can make a distance approach about a moving object, more specifically, a qualitative estimation. Taking into account the stereo vision system features, the previous retina positioning and the very important Hold&Fire building block, we are able to make a correlation between the spike rate of the disparity and the distance.Ministerio de Ciencia e Innovación TEC2009-10639-C04-0

A multimode gray-scale CMOS optical sensor for visual computers

This paper presents a new multimode optical sensor architecture for the optical interface of Visual CNN (cellular neural net) chips. The sensor offers to the user the possibility of choosing the photo-sensitive device as well as the mechanism for transducing the photogenerated charges into the correspondent pixel voltage. Both linear or logarithmic compression acquisition modes are available. This makes the sensor very suitable to be used in very different illumination conditions.Office of Naval Research (USA) N0014-WC-0295Comisión Interministerial de Ciencia y Tecnología TIC 1999-082

A versatile sensor interface for programmable vision systems-on-chip

This paper describes an optical sensor interface designed for a programmable mixed-signal vision chip. This chip has been designed and manufactured in a standard 0.35μm n-well CMOS technology with one poly layer and five metal layers. It contains a digital shell for control and data interchange, and a central array of 128 × 128 identical cells, each cell corresponding to a pixel. Die size is 11.885 × 12.230mm2 and cell size is 75.7μm × 73.3μm. Each cell contains 198 transistors dedicated to functions like processing, storage, and sensing. The system is oriented to real-time, single-chip image acquisition and processing. Since each pixel performs the basic functions of sensing, processing and storage, data transferences are fully parallel (image-wide). The programmability of the processing functions enables the realization of complex image processing functions based on the sequential application of simpler operations. This paper provides a general overview of the system architecture and functionality, with special emphasis on the optical interface.European Commission IST-1999-19007Office of Naval Research (USA) N00014021088

Mixed-signal CNN array chips for image processing

Due to their local connectivity and wide functional capabilities, cellular nonlinear networks (CNN) are excellent candidates for the implementation of image processing algorithms using VLSI analog parallel arrays. However, the design of general purpose, programmable CNN chips with dimensions required for practical applications raises many challenging problems to analog designers. This is basically due to the fact that large silicon area means large development cost, large spatial deviations of design parameters and low production yield. CNN designers must face different issues to keep reasonable enough accuracy level and production yield together with reasonably low development cost in their design of large CNN chips. This paper outlines some of these major issues and their solutions

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

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

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

Aprendizaje basado en proyectos: implementación de interfaces gráficas para microcontroladores ARM

Este artículo presenta la metodología empleada para dotar a nuestros alumnos, alumnos de la asignatura Diseño con Microcontroladores en el contexto del Máster de Ingeniería de Computadores y Redes de la Universidad de Sevilla, de la capacidad de diseñar y desarrollar sistemas empotrados integrados con interfaz gráfica. En la actualidad se ha extendido el uso de microcontroladores ARM de 32 bits, existiendo diversas familias y arquitecturas, además se han popularizado las pantallas basadas en la tecnología OLED. Debido a esta popularidad, resulta muy interesante la combinación de ambos dispositivos para la formación de la integración de sistemas empotrados con interfaz gráfica, ya que así se puede proporcionar una interactuación entre este tipo de sistemas y los usuarios. Este módulo didáctico ha sido bien acogido por el alumnado, ya que el manejo de los displays OLED les resulta muy atractivo y se plantean las técnicas de programación necesarias para la implementación de interfaces gráficas más complejas.SUMMARY -- This paper presents the methodology used to provide our students, students of the Design with Microcontrollers subject in the studies of Master of Computer Engineering and Networks at the University of Seville, with the capacity to design and to develop embedded systems with graphical interface. Today, the use of 32-bit ARM microcontrollers has been expanded, giving rise to the evolution of different families and architectures and the popularity of displays based on OLED technology. Because of this popularity, is very interesting the combination of both devices, as this can provide an interaction between these systems and users. This educational module has been well received by students, because the management of OLED displays is very attractive for them, and this module raises the programming techniques necessary for implementing complex graphical interfaces

Estudio paleobotánico e implicaciones paleocimáticas de los restos fósiles vegetales hallados en el cenozoico de la zona surpirenaica central o occidental de la provincia de Huesca

Actualmente, los afloramientos documentados de macroflora cenozoica de Aragón se limitan a los yacimientos de Rubielos de Mora (Teruel), Libros (Teruel) y Épila (Zaragoza), junto a los yacimientos descritos en esta tesis. No obstante, es importante mencionar los numerosos fósiles de plantas citados en los informes de prospección de lignitos terciarios llevados a cabo en la cuenca del Ebro, Pirineo aragonés y en la provincia de Teruel realizados por el Instituto Geológico y Minero de España. Estos restos no están estudiados ni publicados, pero muestran la existencia de otras áreas potenciales para el descubrimiento de nuevosyacimientos paleobotánicos en el Cenozoico.En la paleobotánica española, el estudio de la vegetación del Cenozoico ha estado casi siempre centrado en el Neógeno (Mioceno–Plioceno) y el Cuaternario, estando el Paleógeno (Paleoceno–Eoceno–Oligoceno) poco estudiado, en comparación con las otras Épocas, y focalizado principalmente en el Oligoceno Inferior. El descubrimiento de dos nuevos yacimientos paleobotánicos (Estadilla/La Val, Arguis/Casa Migalón) con suficiente material para estudio en la zona limítrofe entre el Prepirineo y la cuenca del Ebro (provincia deHuesca), así como el interés de su edad (Eoceno Medio y Oligoceno Superior), ha llevado a larealización de esta tesis doctoral. En esta tesis se describen diversos restos de fósiles vegetales (hojas, frutos y endocarpos), incluyendo el primer estudio de las interacciones planta–insecto del OligocenoSuperior de la Península Ibérica en el yacimiento de La Val, Estadilla (Huesca). A su vez, tras la determinación taxonómica y estudio tafonómico, se han obtenido diversas deducciones paleoambientales: paleoclimáticas y paleoecológicas. Este estudio está formado de cuatro publicaciones independientes con una misma unidad temática: tres para el yacimiento de La Val (Estadilla, Huesca, España) y una para el yacimiento de Casa Migalón (Arguis, Huesca, España). La edad del yacimiento de La Val, tanto de su macroflora como de sus interacciones planta–insecto, es Chatiense (Oligoceno Superior), mientras que los endocarpos y frutos de Nypa del yacimiento de Casa Migalón es Bartoniense (Eoceno Medio). Los primeros resultados del estudio del yacimiento de La Val se han plasmado en una primera publicación sobre la macroflora. Estos resultados han incluído aspectos taxonómicos y tafonómicos, así como una primera aproximación paleoecológica y paleoclimática donde se compara la composición de dicha flora con otras floras similares a las del resto de Europa. En el segundo trabajo se completan los datos mostrados en el artículo precedente y se redefine la edad del yacimiento. La segunda publicación recoge además el estudio del medio sedimentario del yacimiento, así como las implicaciones paleoecológicas derivadas de la presencia del helecho Acrostichum lanzaeanum. En el tercer artículo y último relativo al yacimiento de La Val, se describen las primerasinteracciones planta–insecto encontradas sobre las hojas de uno de los niveles fosilíferos, realizando una discusión para determinar sus implicaciones paleoclimáticas, cuyas conclusiones han matizado y completado la paleoclimatología inferida en el primer trabajo. La cuarta y última publicación que conforma esta tesis ha versado sobre los frutos y endocarpos fósiles de Nypa encontrados en el yacimiento de Casa Migalón (Arguis, Huesca). En este trabajo se llevó a cabo un estudio taxonómico, tafonómico y paleoambiental. Es importante destacar que este artículo se centra especialmente en un aspecto tafonómico muy poco conocido como es la duración del tiempo de flotación en el mar de este tipo de restos hasta su depósito definitivo.<br /