Person: Hermida Correa, Román
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First Name
Román
Last Name
Hermida Correa
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Informática
Department
Arquitectura de Computadores y Automática
Area
Arquitectura y Tecnología de Computadores
Identifiers
7 results
Search Results
Now showing 1 - 7 of 7
Item Low complexity bit-parallel polynomial basis multipliers over binary fields for special irreducible pentanomials(Integration, 2013) Imaña Pascual, José Luis; Hermida Correa, Román; Tirado Fernández, José FranciscoFinite field GF(2m) arithmetic is becoming increasingly important for a variety of different applications including cryptography, error coding theory and computer algebra. Among finite field arithmetic operations, GF(2m) multiplication is of special interest because it is considered the most important building block. GF(2m) multipliers present reduced space and time complexities when the field is generated by some special irreducible polynomials. Among these, irreducible pentanomials of degree m are specially important because they are abundant and there are several eligible candidates for a given m. In this paper, we consider bit-parallel polynomial basis multipliers over the finite field GF(2m) generated using type 2 irreducible pentanomials, for which explicit formulas and algorithms for the computation of the products are given. In this contribution, two new subclasses of type 2 irreducible pentanomials are also introduced. The theoretical complexity analysis proves that the bit-parallel multipliers here presented have the lowest number of XOR gates known to date for similar polynomial basis multipliers based on this type of irreducible pentanomials, while the number of AND gates and the time complexity match the best known results found in the literature.Item Generic Markov Model of the Contention Access Period of IEEE 802.15.4 MAC Layer(Digital Signal Processing, 2014) Recas Piorno, Joaquín; Khaled, Nadia; Del Barrio García, Alberto Antonio; Hermida Correa, RománThe IEEE-802.15.4 standard is poised to become the global standard for low data rate, low energy consumption Wireless Sensor Networks. By assigning the same sets of contention access parameters for all data frames and nodes, the Contention Access Period (CAP) of the slotted IEEE-802.15.4 currently provides an even channel access functionality and no service differentiation. However, some applications may require service differentiation and traffic prioritization support to accommodate high-priority traffic (e.g., alarms). In order to simulate a scenario in which different sets of access parameters for different node classes can be configured, this paper develops a Markov-chainbased model of the CAP of the IEEE-802.15.4-MAC. Our Markov model can be used to evaluate the impact of mixing node classes in important factors like the throughput, energy consumption, probability of delivery and the packet latency. The model has been used to provide traffic differentiation in a high saturation scenario in which a set of nodes can be configured to increase 76% the probability of sending a packet and reduce 58% latency, with a 69% energy penalty, in comparison with a standard scenario. The accuracy of the Markov model is validated by extensive ns-2 simulations.- Project number: 290
Item Arquitecturas dinámica de redes inalámbricas en banda libre para la ejemplificación de conceptos de transmisión en aplicaciones de “Internet Of Things”(2016) Ayala Rodrigo, José Luis; Pagán Ortiz, Josué; Zapater Sancho, Marina; Del Barrio García, Alberto; Hermida Correa, RománEste proyecto de innovación educativa propone una metodología práctica y un equipamiento novedoso para la docencia de la asignatura de Redes y Servicios de Telecomunicación II impartida en tercer curso del Grado en Ingeniería Electrónica de Comunicaciones. Mediante la incorporación de elementos prácticos a la docencia como los recogidos en este proyecto, se pretende ahondar en los conceptos de uso espectral, acceso a un canal compartido, enrutamiento, topología de red, relación consumo vs. potencia de transmisión, etc. desde una perspectiva práctica que facilite el aprendizaje y despierte la curiosidad del alumnado. Para ello, se propondrá un despliegue de nodos inalámbricos, y un entorno de programación de éstos, que permita la evaluación de los contenidos antes descritos. Item Evaluation of blood pressure estimation models based on pulse arrival time(Computers and Electrical Engineering, 2020) Bote Rosado, Jose Manuel; Recas Piorno, Joaquín; Hermida Correa, RománSeveral models in the literature correlate blood pressure (BP) with the electrocardiogram (ECG) and photoplethysmogram (PPG) signals. These studies show substantial differences and have not been adequately compared. The MIMIC database, containing intrusive BP measures collected in a hospital setting, has been used to perform an extensive study of different models and variables extracted from the PPG and ECG signals. The best BP estimator model obtained is α/PAT2 + β HR + δ, where PAT is the Pulse Arrival Time and HR is the heart rate. This model allows the monitoring of fast BP trends and fluctuations. If absolute values of BP were required, the model would have to be calibrated with real BP measures. The model, with periodic recalibrations, meets the Association for the Advancement of Medical Instrumentation (AAMI) requirements for diastolic BP but not for systolic BP, for which the mean error is close to 8 mmHg.- Project number: 18
Item Receptor Software de bajo coste e Interfaz Computerizada para el Estudio Práctico de las Comunicaciones Radioeléctricas(2015) Del Barrio García, Alberto Antonio; Ayala Rodrigo, José Luis; Hermida Correa, RománEn este proyecto se ha desarrollado una plataforma de bajo coste de Software Defined Radio (SDR, Receptor Radio Software) que consta de una componente hardware y otra software, ambas libres. El uso de la interfaz software nos ha permitido modificar distintos parámetros de transmisión de la señal (filtrado de armónicos, frecuencia de muestreo, demodulador, etc.) y estudiar su impacto en la calidad de la señal mediante la síntesis audible a través del altavoz del PC. Item Runtime data center temperature prediction using Grammatical Evolution techniques(Applied soft computing, 2016) Zapater, Marina; Risco Martín, José Luis; Arroba, Patricia; Ayala Rodrigo, José Luis; Moya, José M.; Hermida Correa, RománItem Improving Circuit Performance with Multispeculative Additive Trees in High-Level Synthesis(Microelectronics Journal, 2014) Del Barrio García, Alberto Antonio; Hermida Correa, Román; Ogrenci Memik, Seda; Mendías Cuadros, José Manuel; Molina Prego, María Del CarmenThe recent introduction of Variable Latency Functional Units (VLFUs) has broadened the design space of HighLevel Synthesis (HLS). Nevertheless their use is restricted to only few operators in the datapaths because the number of cases to control grows exponentially. In this work an instance of VLFUs is described, and based on its structure, the average latency of tree structures is improved. Multispeculative Functional Units (MSFUs) are arithmetic Functional Units that operate using several predictors for the carry signal. In spite of utilizing more than a predictor, none or only one additional very short cycle is enough for producing the correct result in the majority of the cases. In this paper our proposal takes advantage of multispeculation in order to increase the performance of tree structures with a negligible area penalty. By judiciously introducing these structures into computation trees, it will only be necessary to predict the carry signals in certain selected nodes, thus minimizing the total number of predictions and the number of operations that can potentially mispredict. Hence, the average latency will be diminished and thus performance will be increased. Our experiments show that it is possible to improve 26% execution time. Furthermore, our flow outperforms previous approaches with Speculative FUs.