396 research outputs found

    Aceleración de algoritmos de estimación de movimiento mediante OpenCL

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    El flujo óptico y la estimación de movimiento es área de conocimiento muy importante usado en otros campos del conocimiento como el de la seguridad o el de la bioinformática. En estos sectores, se demandan aplicaciones de flujo óptico que realicen actividades muy importantes con tiempos de ejecución lo más bajos posibles, llegando a tiempo real si es posible. Debido a la gran complejidad de cálculos que siguen a este tipo de algoritmos como se observará en la sección de resultados, la aceleración de estos es una parte vital para dar soporte y conseguir ese tiempo real tan buscado. Por lo que planteamos como objetivo para este TFG la aceleración de este tipo de algoritmos mediante diversos tipos de aceleradores usando OpenCL y de paso demostrar que OpenCL es una buena herramienta que permite códigos paralelizados con un gran Speedup a la par que funcionar en toda una diversa gama de dispositivos tan distintos como un GPU y una FPGA. Para lo anteriormente mencionado trataremos de desarrollar un código para cada algoritmo y optimizarlo de forma no especifica a una plataforma para posteriormente ejecutarlo sobre las diversas plataformas y medir tiempos y error para cada algoritmo. Para el desarrollo de este proyecto partimos de la teoría de dos algoritmos ya existentes: Lucas&Kanade monoescala y el Horn&Schunck. Además, usaremos estímulos para estos algoritmos muy aceptados por la comunidad como pueden ser el RubberWhale o los Grove, los cuales nos ayudarán a establecer la corrección de estos algoritmos y analizar su precisión, dando así un estudio referencia para saber cual escoger

    Determinant factors of pull up performance in trainedathletes

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    Aim: to investigate the relationship among pull up and lat pull exercises and differentanthropometric dimensions in trained athletes. Methods: twenty-five males were evaluated for maximum number of pull ups, one-repetitionmaximum lat pull (1RM Lat Pull), lat pull repetitions at 80% 1RM (Lat Pull at 80% 1RM), latpull repetitions at a load equivalent to body mass (Lat Pull at BM-load), and differentanthropometric variables. Furthermore, the subjects were divided in higher (HPG, n = 12) andlower pull up performance (LPG, n = 13) to compare the differences in the variables analyzedbetween both levels. Results: pull ups were significantly correlated with Lat Pull at BM-load (r = .62, P < .01) butneither with 1RM Lat Pull (r = .09) nor with Lat Pull at 80% 1RM (r = -.15). Pull ups showed asignificant (P < .05) negative relationship with body mass (BM, r = -.55), lean body mass(LBM, r = -.51), and fat mass (FM, r = -.52), while BM and LBM were significantly correlatedwith 1RM Lat Pull (r = .55, P < .05). HPG showed significantly (P < .05) lower BM (0/3/97%),FM (1/3/97%) and LBM (1/4/95%) than LPG. Furthermore, HPG attained significantly (P < .05– .001) greater performance in Lat Pull at BM-load (100/0/0%) and 1RM Lat Pull•BM-1(96/3/2%) than LPG. Conclusion: these findings suggest that pull up and lat pull exercises have common elements.Moreover, the anthropometric dimensions seem to influence differently on both exercises,depending on the strength indicator evaluated

    Fosfacenos en síntesis heterocíclica preparación de piridotienopirimidinas y ligandos polidentados relacionados mediante procesos tándem/dominó

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    [Resumen] Se ha desarrollado una metodología, muy simple y eficaz, para la síntesis de pirazinotienopirimidinas mediante procesos dominó aza-Witting/adición nucleófila intermolecular/ciclación intramolecular. Se han investigado el efecto de los nucleófilos y de los heterocumulenos empleados en la regioselectividad de la reacción. Esta metodología se ha mostrado muy eficaz para la preparación de bi (pirazinotienopirimidinas), compuestos que no son facilmetnte accesibles por otros procedimientos sintéticos. Se ha estudiado la síntesis en una sola etapa de pirazinotienopirimidinas, mediante reacciones tándem aza-Wittig/electrociclación. Pirazinotienopirimidinas cíclicas, una clase de compuestos particularmente dificiles de obteneer, se han podido preparar adecuadamente mediante reacciones tándem aza-Wittig intramolecular/heterociclación. Se ha comprobado que esta metodología es apropiada para la preparación de otro tipo de sistemas como pirazinotienotriazolopirimidinas y bis(pirazinotienotriazolopirimidinas). Esta estrategia, que implica reacciones dominó en una sola operación sintética, es económica y medioambientalmente muy ventajosa por la sencillez del procedimiento, reducción de las etapas de purificación y aislamiento, y minimización del tiempo, costes y producción de residuos. El sistema de pirazinotienopirimidina es isóstero de la 1,10-fenantrolina y podría ser de interés, por consiguiente, para preparar nuevos ligandos polidentados capaces de autoacoplarse y dar estructuras supramoleculares. Su posible utilidad para la obtención de compuestos con diferente actividad farmacológica parece tambien evidente

    Islanding detection in grid-connected power converters using harmonics due to the non-ideal behavior of the inverter

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    This paper analyzes the use of the voltage distortions in PWM voltage-source-inverters (VSIs) caused by the non-ideal behavior of the inverter for islanding detection purposes. The non-ideal characteristic of the inverters, mainly due to the dead-time needed to have safe commutations, produces fundamental frequency dependent harmonics (-5th, 7th...) in the output voltage. Although these harmonics are in principle an unwanted effect, since they reduce the power quality, they can potentially be used for islanding detection purposes. The physical principles of the method would be the same as for high frequency signal injection methods that have already been proposed but without the need of injecting a high frequency signa

    Sensorless control of doubly-fed induction generators based on stator high frequency signal injection

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    High frequency signal injection based methods have been widely investigated for sensorless position/speed control of induction machines (IMs), permanent magnet synchronous machines (PMSMs) and more recently for doubly fed induction generators (DFIGs). When used with IMs and PMSMs, the high frequency signal is injected in the stator windings, an asymmetric (salient) rotor being required for this case. Contrary to this, both stator and rotor terminals are accessible and sensored in DFIGs, being therefore possible to inject the high frequency signal either in the stator or the rotor terminals. As consequence of this, the method can be used even if the machine is non-salient. In the implementation of the method with DFIGs, the high frequency voltage signal is typically injected in the rotor, the high frequency components (voltages of currents) induced in the stator being used for rotor position estimation. A drawback of this alternative is that the method is sensitive to the grid impedance in the stator side, which will be affected by the grid configuration, and is normally unknown. This paper proposes the sensorless control a DFIG injecting the high frequency voltage in the stator side, and using a high frequency current cancellation strategy in the rotor side. The main advantage of the proposed strategy is that the estimated position is independent of the grid characteristic

    Coordinated operation of parallel-connected inverters for active islanding detection using high frequency signal injection

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    The high frequency impedance measured at the terminals of inverters connected in a microgrid by means of the injection of a small magnitude, high frequency voltage, has been shown to be a reliable metric to detect islanding. While the implementation of this method is simple when only an inverter injects the high frequency signal, this case is of limited applicability. On the other hand, several concerns arise when multiple inverters work in parallel, primarily due to risk interference among inverters. Islanding detection using high frequency signal injection in microgrids with multiple parallel-connected inverters is studied in this paper. A strategy for the coordinated operation of the inverters, without the need of communications or pre-established roles is proposed. Simulation and experimental results will be provided to demonstrate the viability of the concep

    Islanding detection in three-phase and single-phase systems using pulsating high frequency signal injection

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    This paper analyzes the use of pulsating high frequency signal injection for islanding detection purposes. Active islanding detection using high frequency signal injection is an appealing option due to its reduced non-detection zone, reduced cost and ease of implementation. The use of a rotating high frequency signal has been reported and analyzed. However, this method can only be applied to three-phase systems. In this paper, the use of a pulsating high frequency signal injection is proposed. While it uses the same principles as rotating signal injection, it can be applied to both threephase and single-phase system

    Modèles la diversification énergétique en Ibero-Amérique

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    La subida de los precios del petróleo y el accidente nuclear de Fukushima han sacado de nuevo a la palestra un viejo debate acerca del aumento del abastecimiento de energía; en el presente artículo apoyamos que la mejor solución es la diversificación de las fuentes de energía, promoviendo las fuentes alternativas de energía al petróleo y en general las eficiencia energética. A modo comparativo estudiamos la estructura enérgica de ocho países latinoamericanos (Chile, Venezuela, España, Portugal, México, Brasil, Argentina y Colombia) mencionando las características más importantes de cada uno de ellos.p&gt;Rising oil prices and the Fukushima nuclear accident have brought back to the fore an old debate about the supply of energy, in this paper we think the best solution is to diversify energy sources, promoting alternative energy sources to oil and overall energy efficiency. We have studied the energetic structure of eight Latin American countries (Chile, Venezuela, Spain, Portugal, Mexico, Brazil, Argentina and Colombia) and we have compared them, mentioning the most important features of each.La hausse des prix du pétrole et du Fukushima accident nucléaire ont ramené au premier plan un vieux débat sur la fourniture d’énergie, dans cet article Nous pensons que la meilleure solution consiste à diversifier les sources d’énergie, la promotion de sources d’énergie alternatives au pétrole et au rendement énergétique global. Nous avons étudié la structure énergétique de huit pays d’Amérique latine (Chili, Venezuela, Espagne, Portugal, Mexique, Brésil, Argentine et Colombie) et nous les avons comparés, en mentionnant les caractéristiques les plus importantes de chacun

    Sharing Human-Generated Observations by Integrating HMI and the Semantic Sensor Web

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    Current “Internet of Things” concepts point to a future where connected objects gather meaningful information about their environment and share it with other objects and people. In particular, objects embedding Human Machine Interaction (HMI), such as mobile devices and, increasingly, connected vehicles, home appliances, urban interactive infrastructures, etc., may not only be conceived as sources of sensor information, but, through interaction with their users, they can also produce highly valuable context-aware human-generated observations. We believe that the great promise offered by combining and sharing all of the different sources of information available can be realized through the integration of HMI and Semantic Sensor Web technologies. This paper presents a technological framework that harmonizes two of the most influential HMI and Sensor Web initiatives: the W3C’s Multimodal Architecture and Interfaces (MMI) and the Open Geospatial Consortium (OGC) Sensor Web Enablement (SWE) with its semantic extension, respectively. Although the proposed framework is general enough to be applied in a variety of connected objects integrating HMI, a particular development is presented for a connected car scenario where drivers’ observations about the traffic or their environment are shared across the Semantic Sensor Web. For implementation and evaluation purposes an on-board OSGi (Open Services Gateway Initiative) architecture was built, integrating several available HMI, Sensor Web and Semantic Web technologies. A technical performance test and a conceptual validation of the scenario with potential users are reported, with results suggesting the approach is soun

    Influence of Cellulose Characteristics on Pyrolysis Suitability

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    : Cellulose is the most abundant component of biomass and the one that requires the most activation energy (Ea) for pyrolysis. In this study, the dependence of Ea on the intrinsic cellulose characteristics, such as the degree of polymerization (DP), crystallinity, and crystal size, was studied in different cellulose samples, including samples from Eucalyptus globulus, Ulmus minor, Linun usitatissimum, Olea europaea, Robinia pseudoacacia, and Populus alba. Then, to describe the pyrolytic degradation of cellulose, the Ozawa–Flynn–Wall kinetic method was the most appropriate among the isoconversional models studied. An acceptable quadratic relationship of R2 > 0.9 between the Ea values of the different cellulose samples with their corresponding DP, crystallinity index, and crystal size values was found. Therefore, low crystallinity and low-to-medium crystal size values are desired to obtain lower Ea values for cellulose pyrolysis. On the other hand, DP did not present a clear effect on Ea in the studied DP rangeThis research was funded by Comunidad de Madrid and MCIU/AEI/FEDER, EU via Projects SUSTEC-CM S2018/EMT-4348 and RTI2018-096080-B-C22, respectively, and the Regional Ministry of Innovation, Science and Enterprise, Government of the Junta de Andalucía (Operational Programme FEDER Andalusia 2014-2020. Project UHU-1255540), Spain Universidad de Jaén is acknowledged for Olea europaea material. Silviculture and Forest Management Department (Forest Research Center, INIA, CSIC) is acknowledged for Robinia pseudoacacia and Populus alba materials. We thank the personnel at Puerta de Hierro Forest Breeding Centre (Ministerio para la Transición Ecológica y el Reto Demográfico) and the Spanish Elm Breeding Program for providing the Ulmus minor material. Finally, La Montañesa pulp mill (Lecta Group, Spain) and Celesa (Spain) are acknowledged for Eucalyptus globulus and Linun usitatissimum materials, respectivel
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