3,504 research outputs found

    Simulating the behavior of the human brain on GPUS

    Get PDF
    The simulation of the behavior of the Human Brain is one of the most important challenges in computing today. The main problem consists of finding efficient ways to manipulate and compute the huge volume of data that this kind of simulations need, using the current technology. In this sense, this work is focused on one of the main steps of such simulation, which consists of computing the Voltage on neurons’ morphology. This is carried out using the Hines Algorithm and, although this algorithm is the optimum method in terms of number of operations, it is in need of non-trivial modifications to be efficiently parallelized on GPUs. We proposed several optimizations to accelerate this algorithm on GPU-based architectures, exploring the limitations of both, method and architecture, to be able to solve efficiently a high number of Hines systems (neurons). Each of the optimizations are deeply analyzed and described. Two different approaches are studied, one for mono-morphology simulations (batch of neurons with the same shape) and one for multi-morphology simulations (batch of neurons where every neuron has a different shape). In mono-morphology simulations we obtain a good performance using just a single kernel to compute all the neurons. However this turns out to be inefficient on multi-morphology simulations. Unlike the previous scenario, in multi-morphology simulations a much more complex implementation is necessary to obtain a good performance. In this case, we must execute more than one single GPU kernel. In every execution (kernel call) one specific part of the batch of the neurons is solved. These parts can be seen as multiple and independent tridiagonal systems. Although the present paper is focused on the simulation of the behavior of the Human Brain, some of these techniques, in particular those related to the solving of tridiagonal systems, can be also used for multiple oil and gas simulations. Our studies have proven that the optimizations proposed in the present work can achieve high performance on those computations with a high number of neurons, being our GPU implementations about 4× and 8× faster than the OpenMP multicore implementation (16 cores), using one and two NVIDIA K80 GPUs respectively. Also, it is important to highlight that these optimizations can continue scaling, even when dealing with a very high number of neurons.This project has received funding from the European Union’s Horizon 2020 Research and Innovation Programme under Grant Agreement No. 720270 (HBP SGA1), from the Spanish Ministry of Economy and Competitiveness under the project Computación de Altas Prestaciones VII (TIN2015-65316-P), the Departament d’Innovació, Universitats i Empresa de la Generalitat de Catalunya, under project MPEXPAR: Models de Programació i Entorns d’Execució Parallels (2014-SGR-1051). We thank the support of NVIDIA through the BSC/UPC NVIDIA GPU Center of Excellence, and the European Union’s Horizon 2020 Research and Innovation Program under the Marie Sklodowska-Curie Grant Agreement No. 749516.Peer ReviewedPostprint (published version

    Estimate of social and environmental costs for the urban distribution of goods: practical case for the city of Barcelona

    Get PDF
    The objective of the formulation is to allow to evaluate easily the costs of the urban distribution of goods by means of wheeled vehicles, and to formalize a methodological outline for the mentioned evaluation, which allows its updating and amplification when it was necessary. The sensitivity of the model illustrates the behaviour of the social costs in front of variations of the parameters which intervene in the model. The social costs which are analyzed in this article are the costs of the polluting emissions of the commercial vehicles, the costs of the noise emitted by the same ones, the costs which generate these vehicles in congestion and the costs of the accidents associated to their circulation. The costs of polluting emissions are considered with a matrix model based on an updating of the deliverable 22 of the project MEET. The costs of the noise are associated to the cost of using asphalt noise reducer in the streets with a high daily average intensity. The congestion costs are evaluated starting from the losses of time of the drivers of the commercial vehicles in Barcelona. The costs of accidents are quantified starting from the accident rate studies and mobility in the city of Barcelona.Peer ReviewedPostprint (author's final draft

    cuHinesBatch: solving multiple hines systems on GPUs Human Brain Project

    Get PDF
    The simulation of the behavior of the Human Brain is one of the most important challenges today in computing. The main problem consists of finding efficient ways to manipulate and compute the huge volume of data that this kind of simulations need, using the current technology. In this sense, this work is focused on one of the main steps of such simulation, which consists of computing the Voltage on neurons’ morphology. This is carried out using the Hines Algorithm. Although this algorithm is the optimum method in terms of number of operations, it is in need of non-trivial modifications to be efficiently parallelized on NVIDIA GPUs. We proposed several optimizations to accelerate this algorithm on GPU-based architectures, exploring the limitations of both, method and architecture, to be able to solve efficiently a high number of Hines systems (neurons). Each of the optimizations are deeply analyzed and described. To evaluate the impact of the optimizations on real inputs, we have used 6 different morphologies in terms of size and branches. Our studies have proven that the optimizations proposed in the present work can achieve a high performance on those computations with a high number of neurons, being our GPU implementations about 4× and 8× faster than the OpenMP multicore implementation (16 cores), using one and two K80 NVIDIA GPUs respectively. Also, it is important to highlight that these optimizations can continue scaling even when dealing with number of neurons.This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 720270 (HBP SGA1), from the Spanish Ministry of Economy and Competitiveness under the project Computación de Altas Prestaciones VII (TIN2015-65316-P) and the Departament d’Innovació, Universitats i Empresa de la Generalitat de Catalunya, under project MPEXPAR: Models de Programació i Entorns d’Execució Paral·lels (2014-SGR-1051). We thank the support of NVIDIA through the BSC/UPC NVIDIA GPU Center of Excellence. Antonio J. Peña is cofinanced by the Spanish Ministry of Economy and Competitiveness under Juan de la Cierva fellowship number IJCI-2015-23266.Peer ReviewedPostprint (published version

    The physics potential of a reactor neutrino experiment with Skipper CCDs: Measuring the weak mixing angle

    Get PDF
    We analyze in detail the physics potential of an experiment like the one recently proposed by the vIOLETA collaboration: a kilogram-scale Skipper CCD detector deployed 12 meters away from a commercial nuclear reactor core. This experiment would be able to detect coherent elastic neutrino nucleus scattering from reactor neutrinos, capitalizing on the exceptionally low ionization energy threshold of Skipper CCDs. To estimate the physics reach, we elect the measurement of the weak mixing angle as a case study. We choose a realistic benchmark experimental setup and perform variations on this benchmark to understand the role of quenching factor and its systematic uncertainties,background rate and spectral shape, total exposure, and reactor antineutrino flux uncertainty. We take full advantage of the reactor flux measurement of the Daya Bay collaboration to perform a data driven analysis which is, up to a certain extent, independent of the theoretical uncertainties on the reactor antineutrino flux. We show that, under reasonable assumptions, this experimental setup may provide a competitive measurement of the weak mixing angle at few MeV scale with neutrino-nucleus scattering.Comment: 11 pages, 6 figure

    Variable batched DGEMM

    Get PDF
    Many scientific applications are in need to solve a high number of small-size independent problems. These individual problems do not provide enough parallelism and then, these must be computed as a batch. Today, vendors such as Intel and NVIDIA are developing their own suite of batch routines. Although most of the works focus on computing batches of fixed size, in real applications we can not assume a uniform size for all set of problems. We explore and analyze different strategies based on parallel for, task and taskloop OpenMP pragmas. Although these strategies are straightforward from a programmer's point of view, they have a different impact on performance. We also analyze a new prototype provided by Intel (MKL), which deals with batch operations (cblas dgemm batch). We propose a new approach called grouping. It basically groups a set of problems until filling a limit in terms of memory occupancy or number of operations. In this way, groups composed by different number of problems are distributed on cores, achieving a more balanced distribution in terms of computational cost. This strategy is able to be up to 6× faster than the Intel (MKL) batch routineThis project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 720270 (HBP SGA1), from the Spanish Ministry of Economy and Competitiveness under the project Computacion de Altas Prestaciones VII (TIN2015-65316-P) and the Departament d’Innovacio, Universitats i Empresa de la Generalitat de Catalunya, under project MPEXPAR: Models de Programacio i Entorns d’Execucio Paral·lels (2014-SGR-1051).Peer ReviewedPostprint (author's final draft

    IMPRESS: Improving Engagement in Software Engineering Courses through Gamification

    Get PDF
    Software Engineering courses play an important role for preparing students with the right knowledge and attitude for software development in practice. The implication is far reaching, as the quality of the software that we use ultimately depends on the quality of the people that make them. Educating Software Engineering, however, is quite challenging, as the subject is not considered as most exciting by students, while teachers often have to deal with exploding number of students. The EU project IMPRESS seeks to explore the use of gamification in educating software engineering at the university level to improve students' engagement and hence their appreciation for the taught subjects. This paper presents the project, its objectives, and its current progress

    Diseño e implementación de un sistema de control de vuelo para un vehículo aéreo no tripulado tipo cuadricóptero

    Get PDF
    Context: The aerospace industry had quite a rise and also the development and application to the autonomous systems, favoring important developments in its implementation, and control systems.Method: This work presents the development and implementation of an Unmanned Aerial Vehicle, quad-rotor type. The process begins with the mathematical analysis of the aerial vehicle systems, and finding the dynamic model. The modeling of the prototype is based on the Euler LaGrange equations; the design of the structure and the development of control systems are based on sliding modes. Furthermore, the applied control law is also based on sliding modes in the implemented system, which uses only Pitch, Roll and Elevation informationResults: A prototype of unmanned aerial vehicle was implemented as a quadricopter, and the control system was implemented, where an adequate monitoring of the reference was obtained.Conclusions: The proper selection of the elements for the implementation prototype allows to implement different control strategies, for this case demonstrating the adequate work of the sliding modes for the stabilization in quadricopter two axes.Contexto: La industria aeroespacial ha tenido bastante auge y así mismo el desarrollo y aplicación a los sistemas autónomos, propiciando desarrollos importantes en su implementación, y sistemas de control.Método: En este trabajo se presenta el desarrollo y la implementación de un vehículo aéreo no tripulado, tipo quadricóptero, se inicia con el análisis matemático de los sistemas de vehículos aéreos encontrando el modelo dinámico; el modelado del prototipo se basa en las ecuaciones Euler LaGrange. Posteriormente, se realiza el diseño de la estructura y el desarrollo de los sistemas de control basado en modos deslizantes; se aplica la ley de control basada en modos deslizantes en el sistema implementado que utiliza solamente información de pitch, roll y elevación.Resultados: Se implementó un prototipo de vehículo aéreo no tripulado tipo quadricóptero, y se implementó el sistema de control, donde se obtuvo un adecuado seguimiento de la referencia.Conclusiones: La adecuada selección de los elementos para la implementación del prototipo permite poder implementar diferentes estrategias de control, para este caso demostrando el adecuado trabajo de los modos deslizantes para la estabilización en dos ejes del quadricóptero
    • …
    corecore