1,569 research outputs found

    Toolflows for Mapping Convolutional Neural Networks on FPGAs: A Survey and Future Directions

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    In the past decade, Convolutional Neural Networks (CNNs) have demonstrated state-of-the-art performance in various Artificial Intelligence tasks. To accelerate the experimentation and development of CNNs, several software frameworks have been released, primarily targeting power-hungry CPUs and GPUs. In this context, reconfigurable hardware in the form of FPGAs constitutes a potential alternative platform that can be integrated in the existing deep learning ecosystem to provide a tunable balance between performance, power consumption and programmability. In this paper, a survey of the existing CNN-to-FPGA toolflows is presented, comprising a comparative study of their key characteristics which include the supported applications, architectural choices, design space exploration methods and achieved performance. Moreover, major challenges and objectives introduced by the latest trends in CNN algorithmic research are identified and presented. Finally, a uniform evaluation methodology is proposed, aiming at the comprehensive, complete and in-depth evaluation of CNN-to-FPGA toolflows.Comment: Accepted for publication at the ACM Computing Surveys (CSUR) journal, 201

    Particle creation and non-adiabatic transitions in quantum cosmology

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    The aim of this paper is to compute transitions amplitudes in quantum cosmology, and in particular pair creation amplitudes and radiative transitions. To this end, we apply a double adiabatic development to the solutions of the Wheeler-DeWitt equation restricted to mini-superspace wherein gravity is described by the scale factor aa. The first development consists in working with instantaneous eigenstates, in aa, of the matter Hamiltonian. The second development is applied to the gravitational part of the wave function and generalizes the usual WKB approximation. We then obtain an exact equation which replaces the Wheeler-DeWitt equation and determines the evolution, i.e. the dependence in aa, of the coefficients of this double expansion. When working in the gravitational adiabatic approximation, the simplified equation delivers the unitary evolution of transition amplitudes occurring among instantaneous eigenstates. Upon abandoning this approximation, one finds that there is an additional coupling among matter states living in expanding and contracting universes. Moreover one has to face also the Klein paradox, i.e. the generation of backward waves from an initially forward wave. The interpretation and the consequences of these unusual features are only sketched in the present paper. Finally, the examples of pair creation and radiative transitions are analyzed in detail to establish when and how the above mentioned unitary evolution coincides with the Schr\" odinger evolution.Comment: 27 pages, Late

    Observing dust settling and coagulation in circumstellar discs: Selected constraints from high resolution imaging

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    Circumstellar discs are expected to be the nursery of planets. Grain growth within such discs is the first step in the planet formation process in the core-accretion gas-capture scenario. We aim at providing selected criteria on observational quantities derived from multi-wavelength imaging observations that allow to identify dust grain growth and settling. We define a wide-ranged parameter space of discs in various states of their evolution. Using a parametrised model set-up and radiative transfer techniques we compute multi-wavelength images of discs at different inclinations. Using millimetre and sub-millimetre images we are in the position to constrain the process of dust grain growth and sedimentation. However, the degeneracy between parameters prohibit the same achievement using near- to mid-infrared images. Using face-on observations in the N and Q Band, the sedimentation height can be constrained.Comment: 14 pages, 20 figures, Accepted for publication in A&
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