Ponencias (Arquitectura y Tecnología de Computadores)
URI permanente para esta colecciónhttps://hdl.handle.net/11441/11294
Examinar
Examinando Ponencias (Arquitectura y Tecnología de Computadores) por Título
Mostrando 1 - 20 de 311
- Resultados por página
- Opciones de ordenación
Ponencia A 20Mevps/32Mev event-based USB framework for neuromorphic systems debugging(IEEE Computer Society, 2016) Ríos Navarro, José Antonio; Domínguez Morales, Juan Pedro; Tapiador Morales, Ricardo; Gutiérrez Galán, Daniel; Jiménez Fernández, Ángel Francisco; Linares Barranco, Alejandro; Universidad de Sevilla. Departamento de Arquitectura y Tecnología de Computadores; Universidad de Sevilla. TEP-108: Robótica y Tecnología de Computadores Aplicada a la RehabilitaciónNeuromorphic systems are engineering solutions that take inspiration from biological neural systems. They use spike-or event-based representation and codification of the information. This codification allows performing complex computations, filters, classifications and learning in a pseudo-simultaneous way. Small incremental processing is done per event, which shows useful results with very low latencies. Therefore, developing this kind of systems requires the use of specialized tools for debugging and testing those flows of events. This paper presents a set of logic implementations for FPGA that assists on the development of event-based systems and their debugging. Address-Event-Representation (AER) is a communication protocol for transferring events/spikes between bio-inspired chips/systems. Real-time monitoring and sequencing, logging and playing back long sequences of events/spikes to and from memory; and several merging and splitting ports are the main requirements when developing these systems. These functionalities and implementations are explained and tested in this work. The logic has been evaluated in an Opal-Kelly XEM6010 acting as a daughter board for the AER-Node platform. It has a peak rate of 20Mevps when logging and a total of 32Mev of logging capacity on DDR when debugging an AER system in the AER-Node or a set of them connected in daisy chain.Ponencia A 5 Meps $100 USB2.0 Address-Event Monitor-Sequencer Interface(IEEE Computer Society, 2007) Berner, Raphael; Delbruck, Tobias; Civit Balcells, Antón; Linares Barranco, Alejandro; Universidad de Sevilla. Departamento de Arquitectura y Tecnología de ComputadoresThis paper describes a high-speed USB2.0 Address- Event Representation (AER) interface that allows simultaneous monitoring and sequencing of precisely timed AER data. This low-cost (<$100), two chip, bus powered interface can achieve sustained AER event rates of 5 megaevents per second (Meps). Several boards can be electrically synchronized, allowing simultaneous synchronized capture from multiple devices. It has three AER ports, one for sequencing, one for monitoring and one for passing through the monitored events. This paper also describes the host software infrastructure that makes the board usable for a heterogeneous mixture of AER devices and that allows recording and playback of recorded data.Ponencia A cellular automaton model of a laser with saturable absorber reproducing laser passive Q-switching(Springer, 2022) Jiménez Morales, Francisco; Guisado Lizar, José Luis; Universidad de Sevilla. Departamento de Arquitectura y Tecnología de ComputadoresIn this paper, we present a cellular automata model for a two-level laser which includes a saturable absorber. We show that the model reproduces laser passive Q-switching, a behavior in which intense short pulses of laser radiation are produced. Depending on the concentration of the absorbent, the automaton model qualitatively reproduces two operating states of the laser: a stable state and another oscillatory or pulsed state.Ponencia A Current Attenuator for Efficient Memristive Crossbars Read-Out(IEEE Computer Society, 2019) Mohan, Charanraj; Rosa, José M. de la; Vianello, Elisa; Perniola, Luca; Reita, Carlo; Linares Barranco, Bernabé; Serrano Gotarredona, María Teresa; Universidad de Sevilla. Departamento de Arquitectura y Tecnología de Computadores; European Union (UE); European Union (UE)This paper presents a new current attenuator circuit to scale down the inference currents in memristor based crossbars that drive integrate-and-fire neurons, which subsequently allows to reduce the size of integrating capacitors by several orders of magnitude, making IC integration possible. The proposed circuit uses a linear switch to divide the inference current and scale it down by a factor of about 104. The proposed attenuator has been designed in 130nm CMOS technology. Simulation results considering noise, process and temperature variations are shown to validate the presented approach.Ponencia A Dynamic Equilibrium View of Caching Systems(IEEE Computer Society, 2009) Díaz del Río, Fernando; Sevillano Ramos, José Luis; Cascado Caballero, Daniel; Rodríguez Corral, José María; Universidad de Sevilla. Departamento de Arquitectura y Tecnología de Computadores; Ministerio de Educación y Ciencia (MEC). España; Junta de Andalucía; Universidad de Sevilla. TEP-108: Robótica y Tecnología de Computadores Aplicada a la RehabilitaciónIn this paper, we present a simple analytical study of caching systems based on the idea of dynamic equilibrium of cache blocks, assuming the Independent Reference Model (IRM) of references. This method allows us to obtain simple closedform expressions for parameters that are usually excluded from cache studies, such as the mean number of reads or writes per cache block while in the cache. We finally present some simulation results in order to validate the analysis.Ponencia A FPGA Spike-Based Robot Controlled with Neuro-inspired VITE(Springer, 2013) Pérez Peña, Fernando; Morgado Estévez, Arturo; Linares Barranco, Alejandro; Jiménez Fernández, Ángel Francisco; López Coronado, Juan; Muñóz Lozano, José Luis; Universidad de Sevilla. Departamento de Arquitectura y Tecnología de Computadores; Universidad de Sevilla. TEP-108: Robótica y Tecnología de Computadores Aplicada a la RehabilitaciónThis paper presents a spike-based control system applied to a fixed robotic platform. Our aim is to take a step forward to a future complete spikes processing architecture, from vision to direct motor actuation. This paper covers the processing and actuation layer over an anthropomorphic robot. In this way, the processing layer uses the neuro-inspired VITE algorithm, for reaching a target, based on PFM taking advantage of spike system information: its frequency. Thus, all the blocks of the system are based on spikes. Each layer is implemented within a FPGA board and spikes communication is codified under the AER protocol. The results show an accurate behavior of the robotic platform with 6-bit resolution for a 130º range per joint, and an automatic speed control of the algorithm. Up to 96 motor controllers could be integrated in the same FPGA, allowing the positioning and object grasping by more complex anthropomorphic robots.Ponencia A General Subthreshold MOS Translinear Theorem(IEEE Computer Society, 1999) Serrano Gotarredona, María Teresa; Linares Barranco, Bernabé; Andreou, Andreas G.; Universidad de Sevilla. Departamento de Arquitectura y Tecnología de ComputadoresThis paper outlines the conditions under which the translinear principle can be fully exploited for MOS transistors operating in subthreshold. Due to the exponential nature of subthreshold MOS transistors the translinear principle applies immediately as long as the source-to-bulk voltages are made equal to zero (or constant). This paper addresses the conditions under which subthreshold MOS transistors still satisfy a translinear principle but without imposing this constraint. It is found that the translinear principle results in a more general formulation than the original for BJTs since now multiple translinear loops can be involved. The constraint of even number of transistors is no longer necessary.Ponencia A generalization of path following for mobile robots(IEEE Computer Society, 1999) Díaz del Río, Fernando; Jiménez Moreno, Gabriel; Sevillano Ramos, José Luis; Vicente Díaz, Saturnino; Civit Balcells, Antón; Universidad de Sevilla. Departamento de Arquitectura y Tecnología de Computadores; Comisión Interministerial de Ciencia y Tecnología (CICYT). España; Universidad de Sevilla. TEP-108: Robótica y Tecnología de Computadores Aplicada a la RehabilitaciónSeveral authors have proposed some methods for applying path following in specific cases to mobile robots. When we try to extend the path following approach to the general problem several difficulties arise. We present a generalized technique to apply path following to a mobile robot with nonholonomic constraints. As an application example, we expose the case of mobile robots with a higher degree of manoeuvrability than the typical car-like robots. In particular we consider a robot that can turn around itself making a zero-radius turn; a case still not resolved as far as we know. Finally we propose a suitable control law for this example that ensures asymptotical convergence.Ponencia A Genetic Algorithm to Study a P3 Non-trivial Collective Task(INSTICC, Institute for Systems and Technologies of Information Control and Communication, 2012) Jiménez-Morales, Francisco de Paula; Guisado Lizar, José Luis; Universidad de Sevilla. Departamento de Arquitectura y Tecnología de Computadores; Universidad de Sevilla. Departamento de Física de la Materia CondensadaHere we report new results of a genetic algorithm (GA) used to evolve one dimensional Cellular Automata (CA) to perform a P3 non-trivial collective behavior task. For this task the goal is to find a CA rule that reaches one final configuration in which the concentration of active cells oscillates among three different values. Though the majority of the best evolved rules belong to the II Wolfram’s class, the GA also finds rules of the III and IV classes. The different computational mechanisms used by each rule to synchronize the entire lattice are analyzed by means of the spatio-temporal patterns generated.Ponencia A Genetic Programming infrastructure profiting from public computation resources(Editorial CIEMAT, 2007) Chávez de la O, F.; Rubio del Solar, Manuel; Guisado Lizar, José Luis; Lombraña González, Daniel; Cárdenas Montes, Miguel; Fernández de Vega, Francisco; Universidad de Sevilla. Departamento de Arquitectura y Tecnología de ComputadoresIn this article an experience of the utilization of PRC (Public Resource Computation) in research projects that needs large quantities of CPU time is presented. We have developed a distributed architecture based on middleware BOINC and LilGP Genetic Programming tool. In order to run LilGP applications under BOINC platforms, some core LilGP functions has been adapted to BOINC requirements. We have used a classic GP problem known as the artificial ANT in Santa Fe Trail. Some computers from a classroom were used acting as clients, proving that they can be used for scientific computation in conjunction with their primary uses.Ponencia A Low-power, Reachable, Wearable and Intelligent IoT Device for Animal Activity Monitoring(ScitePress Digital Library, 2019) Durán López, Lourdes; Gutiérrez Galán, Daniel; Domínguez Morales, Juan Pedro; Ríos Navarro, José Antonio; Tapiador Morales, Ricardo; Jiménez Fernández, Ángel Francisco; Cascado Caballero, Daniel; Linares Barranco, Alejandro; Universidad de Sevilla. Departamento de Arquitectura y Tecnología de Computadores; Universidad de Sevilla. TEP-108: Robótica y Tecnología de Computadores Aplicada a la RehabilitaciónAlong with the proliferation of mobile devices and wireless signal coverage, IoT devices, such as smart wristbands for monitoring its owner’s activity or sleep patterns, get great popularity. Wearable technology in human life has become quite useful due to the information given (sleep hours, heart rate, etc). However, wearables for animals does not give information about behaviour directly: they collect raw data that is sent to a server where, after a post-processing step, the behaviour is known. In this work, we present a smart IoT device that classifies different animal behaviours from the information obtained from on-board sensors using an embedded neural network running in the device. This information is uploaded to a server through a wireless sensor network based on Zigbee communication. The architecture of the device allows an easy assembly in a reduced dimension wearable case. The firmware allows a modular functionality by activating or deactivating modules independently, which improve the power efficiency of the device. The power consumption has been analyzed, allowing the 1Ah battery to work the system during several days. A novel localization and distance estimation technique (for 802.15.4 networks) is presented to recover a lost device in Do˜nana National Park with unidirectional antennas and log-normalization distance estimation over RSSI.Ponencia A LVDS Serial AER Link(IEEE Computer Society, 2007) Miró Amarante, María Lourdes; Jiménez Fernández, Ángel Francisco; Linares Barranco, Alejandro; Gómez Rodríguez, Francisco de Asís; Paz Vicente, Rafael; Jiménez Moreno, Gabriel; Civit Balcells, Antón; Universidad de Sevilla. Departamento de Arquitectura y Tecnología de Computadores; Universidad de Sevilla. TEP-108: Robótica y Tecnología de Computadores Aplicada a la RehabilitaciónAddress-Event-Representation (AER) is a communication protocol for transferring asynchronous events between VLSI chips, originally developed for bio-inspired processing systems (for example, image processing). Such systems may consist of a complicated hierarchical structure with many chips that transmit data among them in real time, while performing some processing (for example, convolutions). The event information is transferred using a high speed digital parallel bus (typically 16 bits and 20ns-40ns per event). This paper presents a testing platform for AER systems that allows to analyse a LVDS Serial AER link. The interface allows up to 0.7 Gbps (~40Mev/s, 16 bits/ev). The eye diagram ensures that the platform could support 1.2 Gbps.Ponencia A Methodology for MOS Transistor Mismatch Parameter Extraction and Mismatch Simulation(IEEE Computer Society, 2000) Serrano Gotarredona, María Teresa; Linares Barranco, Bernabé; Universidad de Sevilla. Departamento de Arquitectura y Tecnología de ComputadoresThis paper presents a methodology for mismatch parameter extraction and mismatch simulation using conventional electrical simulators, like HSpice. A measurement and extraction procedure has been carefully designed to be able to obtain reliable measurements of the mismatch parameters of a given technology. The correctness of this extraction procedure method has been checked through three different validation methods. We also present two methods for performing mismatch simulation with conventional circuit simulators (like HSpice) using the extracted parameters.Ponencia A Microcontroller Based System for Controlling Patient Respiratory Guidelines(Springer, 2017) Morales Trujillo, Leticia; Domínguez Morales, Manuel Jesús; Jiménez Ramírez, Andrés; Escalona Cuaresma, María José; Universidad de Sevilla. Departamento de Lenguajes y Sistemas Informáticos; Universidad de Sevilla. Departamento de Arquitectura y Tecnología de Computadores; Universidad de Sevilla. TIC021: Ingeniería Web y Testing TempranoThe need of making improvements in obtaining (in a non-invasive way) and monitoring the breathing rate parameters in a patient emerges due to (1) the great amount of breathing problems our society suffer, (2) the problems that can be solved, and (3) the methods used so far. Non-specific machines are usually used to carry out these measures or simply calculate the number of inhalations and exhalations within a particular timeframe. These methods lack of effectiveness and precision thus, influencing the capacity of getting a good diagnosis. This proposal focuses on drawing up a technology composed of a mechanism and a user application which allows doctors to obtain the breathing rate parameters in a comfortable and concise way. In addition, such parameters are stored in a database for potential consultation as well as for the medical history of the patients. For this, the current approach takes into account the needs, the capacities, the expectations and the user motivations which have been compiled by means of open interviews, forum discussions, surveys and application uses. In addition, an empirical evaluation has been conducted with a set of volunteers. Results indicate that the proposed technology may reduce cost and improve the reliability of the diagnosis.Ponencia A Mismatch Calibrated Bipolar Spatial Contrast AER Retina with Adjustable Contrast Threshold(IEEE Computer Society, 2009) Leñero Bardallo, Juan Antonio; Serrano Gotarredona, María Teresa; Linares Barranco, Bernabé; Universidad de Sevilla. Departamento de Arquitectura y Tecnología de Computadores; European Union (UE); Ministerio de Educación y Ciencia (MEC). España; Junta de AndalucíaAddress Event Representation (AER) is an emergent technology for assembling modular multi-blocks bio-inspired sensory and processing systems. Visual sensors (retinae) are among the first AER modules to be reported since the introduction of the technology. Spatial contrast AER retinae are of special interest since they provide highly compressed data flow without reducing the relevant information required for performing recognition. Reported AER contrast retinae perform a contrast computation based on the ratio between a pixel’s local light intensity and a spatially weighted average of its neighbourhood. This resulted in compact circuits, but with the penalty of all pixels generating output signals even if they sensed no contrast. In this paper we present a spatial contrast retina with bipolar output: contrast is computed as the relative difference between a pixel’s local light and its weighted spatial average. As a result, contrast includes a sign and the output will be zero if there is no contrast. Furthermore, an adjustable thresholding mechanism has been included, such that pixels remain silent until they sense an absolute contrast above the adjustable threshold. The pixel contrast computation circuit is based on Boahen’s Biharmonic operator contrast circuit, which has been improved to include mismatch calibration and adaptive current based biasing. As a result, the contrast computation circuit shows much less mismatch, is almost insensitive to ambient light illumination, and biasing is much less critical than in the original voltage biasing scheme. A full AER retina version has been submitted for fabrication. In the present paper we provide simulation results.Ponencia A Mobile App to Manage Children Dental Anxiety: Context and Approach(IADIS. International Association for Development of the Information Society, 2017) Romero Ternero, María del Carmen; García Robles, Rocío; Cagigas Muñiz, Daniel; Rivera Romero, Octavio; Universidad de Sevilla. Departamento de Tecnología Electrónica; Universidad de Sevilla. Departamento de Arquitectura y Tecnología de Computadores; Universidad de Sevilla. TIC150: Tecnología Electrónica e Informática Industrial; Universidad de Sevilla. TIC247: Art Science Technology Engineering Research: Innovation, Synergies and Methodologies; Universidad de Sevilla. TEP108: Robótica y Tecnología de Computadores; Universidad de Sevilla. TIC150: Tecnología Electrónica e Informática IndustrialAnxiety and fear related to dentistry interventions have been identified as problems affecting children. This reduces their quality of life and may have a negative impact on aspects such as sleep, self –esteem, mood, social relationships, and other psychological issues.The ARCADE project aims to design and develop a technological solution to manage children dental anxiety. This solution consists on a mobile system co-designed with children. An ecological momentary intervention is proposed using this solution before, during and after dentistry treatments. This paper presents a methodological approach to develop the project.Ponencia A Mobile Memory Game for Patients with Acquired Brain Damage: A Preliminary Usability Study(IEEE Computer Society, 2014) Morón Fernández, María José; Yáñez Gómez, Rosa; Cascado Caballero, Daniel; Suarez Mejias, Cristina; Sevillano Ramos, José Luis; Universidad de Sevilla. Departamento de Arquitectura y Tecnología de Computadores; Ministerio de Ciencia e Innovación (MICIN). España; Universidad de Sevilla. TEP-108: Robótica y Tecnología de Computadores Aplicada a la RehabilitaciónMemory rehabilitation and training is an important activity for patients with Acquired Brain Damage, including Cerebral Vascular Accident (stroke) and Traumatic Brain Injury patients. Although many interactive web-based and computer applications have been developed, the use of mobile devices apps has not been sufficiently studied from the point of view of its usability for these users. In this paper, a preliminary usability and accessibility study of a memory game for mobile devices (developed from scratch under Android OS) is presented. This study, based on the Shadow Expert Technique, allows improving the prototype and provides useful hints for increasing acceptability of Android applications, not only by Acquired Brain Damage patients but also by other people with cognitive disorders.Ponencia A New Strong Inversion 5-Parameter Transistor Mismatch Model(IEEE Computer Society, 2000) Serrano Gotarredona, María Teresa; Linares Barranco, Bernabé; Universidad de Sevilla. Departamento de Arquitectura y Tecnología de ComputadoresA new 5-parameter MOS transistor mismatch model is introduced capable of predicting transistor mismatch with very high accuracy for ohmic and saturation strong inversion regions, including short channel transistors. The new model is based on splitting the contribution of the mobility degradation parameter mismatch into two components, and modulating them as the transistor transitions from ohmic to saturation regions. The model is tested for a wide range of transistor sizes (30), and shows excellent precision, never reported before for such a wide range of transistor sizes, including short channel transistors.Ponencia A Parallel Implementation for Computing the Region-Adjacency-Tree of a Segmentation of a 2D Digital Image(Springer, 2015) Díaz del Río, Fernando; Real Jurado, Pedro; Onchis, Darian M.; Universidad de Sevilla. Departamento de Arquitectura y Tecnología de Computadores; Universidad de Sevilla. Departamento de Matemática Aplicada I (ETSII); Ministerio de Ciencia e Innovación (MICIN). España; Universidad de SevillaA design and implementation of a parallel algorithm for computing the Region-Adjacency Tree of a given segmentation of a 2D digital image is given. The technique is based on a suitable distributed use of the algorithm for computing a Homological Spanning Forest (HSF) structure for each connected region of the segmentation and a classical geometric algorithm for determining inclusion between regions. The results show that this technique scales very well when executed in a multicore processor.Ponencia A parametric formulation of tracking methods: application to chained systems(IEEE Computer Society, 2004) Díaz del Río, Fernando; Jiménez Moreno, Gabriel; Sevillano Ramos, José Luis; Civit Balcells, Antón; Universidad de Sevilla. Departamento de Arquitectura y Tecnología de Computadores; Universidad de Sevilla. TEP-108: Robótica y Tecnología de ComputadoresWhen following a path, there are several possibilities attending to the way in which the actual robot state can be related with the whole path. In this work, we formulate different tracking methods on the base that a memorized path can be described by a single descriptor parameter (the objective point is readily given by this parameter). We classify path tracking according to the way in which we impose or design the progress of descriptor parameter. Benefits and disadvantages of each method are identified. We also summarize how to construct each method. Despite that this classification is generic, application to mobile robots and chained systems is very valuable due to the importance of tracking problem in them and because their desired path is usually memorized