A dynamic power-aware partitioner with task migration for multicore embedded systems

Nowadays, a key design issue in embedded systems is how to reduce the power consumption, since batteries have a limited energy budget. For this purpose, several techniques such as Dynamic Voltage Scaling (DVS) or task migration can be used. DVS allows reducing power by selecting the optimal voltage supply, while task migration achieves this effect by balancing the workload among cores. This paper first analyzes the impact on energy due to task migration in multicore embedded systems with DVS capability and using the well-known Worst Fit (WF) partitioning heuristic. To reduce overhead, migrations are only performed at the time that a task arrives to and/or leaves the system and, in such a case, only one migration is allowed. The huge potential on energy saving due to task migration, leads us to propose a new dynamic partitioner, namely DP, that migrates tasks in a more efficient way than typical partitioners. Unlike WF, the proposed algorithm examines which is the optimal target core before allowing a migration. Experimental results show that DP can improve energy consumption in a factor up to 2.74 over the typical WF algorithm. © 2011 Springer-Verlag.This work was supported by Spanish CICYT under Grant TIN2009-14475-C04-01, and by Consolider-Ingenio under Grant CSD2006-00046.March Cabrelles, JL.; Sahuquillo Borrás, J.; Petit Martí, SV.; Hassan Mohamed, H.; Duato Marín, JF. (2011). A dynamic power-aware partitioner with task migration for multicore embedded systems. En Euro-Par 2011 Parallel Processing. Springer Verlag (Germany). 2011(6852):218-229. https://doi.org/10.1007/978-3-642-23400-2_21S21822920116852AlEnawy, T.A., Aydin, H.: Energy-Aware Task Allocation for Rate Monotonic Scheduling. In: Proceedings of the 11th Real Time on Embedded Technology and Applications Symposium, March 7-10, pp. 213–223. 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Coalescence preference in surfactant-laden bubbles of equal size

Coalescence preference is the tendency of a bubble merged from two parent bubbles to be placed closer to one of the parents. Coalescence preference has been extensively studied for parent bubbles of different size, but mechanism of coalescence preference in bubbles of equal size have not yet been fully characterized. Here, we use high-fidelity simulations to investigate potential coalescence preference in contaminated bubbles of equal size. Results show that when a clean bubble merges with a surfactant-contaminated bubble of the same size, the merged bubble tends to be closer to the contaminated parent. By analyzing the coalescence events at different surfactant concentrations we also identify a novel preference mechanism characterized by spontaneous self-propulsion of the merged bubble. Elucidating mechanisms of coalescence in surfactant-contaminated bubbles has implications for technological processes involving bubble dispersions in the food and chemical industries where the presence of surfactants is ubiquitous.Fil: Ubal, Sebastian. Universidad Nacional de Entre Ríos. Instituto de Investigación y Desarrollo en Bioingeniería y Bioinformática - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigación y Desarrollo en Bioingeniería y Bioinformática; ArgentinaFil: Lu, J.. University of Massachussets; Estados UnidosFil: Grifoni, R.. Università di Parma; ItaliaFil: Bozzoli, F.. Università di Parma; ItaliaFil: Corvalan, C. M.. Purdue University; Estados Unido

Descriptive study of the use of defensive factors in the highest division of chilean basketball (dimayor)

El objetivo de la presente investigación es analizar diferentes aspectos técnico-tácticos de la fase defensiva del baloncesto chileno. Para ello se analizaron todas las fases de ataque (n=2513) llevadas a cabo a lo largo de 13 partidos de la etapa de playoff del campeonato chileno DIMAYOR jugado el año 2006. En cada fase de ataque se analizaron las siguientes variables en relación con el equipo defensor: (1) tipo de defensa (individual, zonal, mixta, otras); (2) presión en la transición ofensiva; (3) cambios defensivos; (4) ayudas defensivas; (5) pases interiores; (6) grado de oposición al lanzamiento (bajo, medio, alto); (7) puntos recibidos; y (8) rebotes defensivos. Los resultados indicaron que: a) la defensa individual es la más utilizada (56.6%); b) la presión en transición (en 18.0% de fases de ataque), cambios defensivos (0.14 por fase de ataque), y ayudas sobre el hombre con balón (0.52 por fase de ataque), son factores defensivos muy poco utilizados; c) se permiten o se realizan pocos pases interiores (0.17 por fase de ataque); d) el grado de oposición bajo al lanzamiento es el más frecuente (61.4% de los lanzamientos); e) se capturan rebotes defensivos en más del 60% de las oportunidades que se tienen para hacerlo.The objective of the present study was to analyze the various technical and tactical aspects of the defensive phase of Chilean basketball. Therefore, all the attack phases (n=2513) done during 13 play-off games of the 2006 Dimayor Chilean championship were analyzed. In each attack phase the following variables were analyzed in regard to the team on defense: (1) type of defense (man-to-man, zone, combination, other); (2) pressure in the transition offense; (3) defensive switches; (4) defensive help; (5) inside passes; (6) degree of shot opposition (low, medium, high); (7) points allowed; and (8) defensive rebounds. The results indicate that: a) the type of defense that is most used is man-to-man (56.6%); b) defensive factors that are not often used include pressure in transition (in 18.0% of attack phases), defensive switches (0.14 per attack phase), and defensive help to guard the player with the ball (0.52 per attack phase); c) few inside passes are done or allowed (0.17 per attack phase); d) low opposition is the most frequent degree of shot opposition (61.4% of shots); and e) defensive rebounds were made in more than 60% of opportunities.Sin financiaciónNo data 201

A preliminary simulation for the development of an implantable pulsatile blood pump

A preliminary study of a new pulsatile pump, that will work to a frequency greater than 1 Hz, is presented. The fluid-structure interaction between a Newtonian blood flow and a piston drive that moves with periodic speed is simulated. The mechanism is of double effect and has four valves, two at the input flow and two at the output flow; the valves are simulated with specified velocity of closing and reopening. The simulation is made with a finite elements software named COMSOL Multiphysics 3.3 to resolve the flow in a preliminary planar configuration. The geometry is 2D to determine areas of high speeds and high shear stresses that can cause hemolysis and platelet aggregation. The opening and closing valves are modelled by solid structure interacting with flow, the rhythmic opening and closing are synchronized with the piston harmonic movement. The boundary conditions at the input and output areas are only normal traction with reference pressure. On the other hand, the fluid structure interactions are manifested due to the non-slip boundary conditions over the piston moving surfaces, moving valve contours and fix pump walls. The non-physiologic frequency pulsatile pump, from the viewpoint of fluid flow analysis, is predicted feasible and with characteristic of low hemolysis and low thrombogenesis, because the stress tension and resident time are smaller than the limit and the vortices are destroyed for the periodic flow.Fil: Di Paolo, Jose. Universidad Nacional de Entre Ríos. Facultad de Ingeniería. Departamento de Física Química. Laboratorio de Biomecánica Computacional; ArgentinaFil: Insfrán, Jordán Francisco. Universidad Nacional de Entre Ríos. Facultad de Ingeniería. Departamento de Física Química. Laboratorio de Biomecánica Computacional; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Fries, Exequiel R.. Universidad Nacional de Entre Ríos. Facultad de Ingeniería. Departamento de Física Química. Laboratorio de Biomecánica Computacional; ArgentinaFil: Campana, Diego Martin. Universidad Nacional de Entre Ríos. Facultad de Ingeniería. Departamento de Física Química. Laboratorio de Biomecánica Computacional; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Berli, Marcelo Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química (i); Argentina. Universidad Nacional de Entre Ríos. Facultad de Ingeniería. Departamento de Física Química. Laboratorio de Biomecánica Computacional; ArgentinaFil: Ubal, Sebastian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química (i); Argentina. Universidad Nacional de Entre Ríos. Facultad de Ingeniería. Departamento de Física Química. Laboratorio de Biomecánica Computacional; Argentin