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PACHA: Low Cost Bare Metal Development for Shared Memory Manycore Accelerators

Alexandre Aminot, Alexandre Guerre, Julien Peeters, Yves Lhuillier
2013 Procedia Computer Science  
Today, efficiently implementing an application on shared memory manycore accelerators is a hard task. Linux eases the development, but is not adapted to exploit the maximum of the platform yet. Bare metal programming environments provided with accelerators give a low-overhead access to the platform. However, they increase the complexity of development, mainly due to 4 gaps: each accelerator has its own specific environment; bare metal environments are only supported on the hardware platform or
more » ... n the proprietary simulator; they have seldom, if ever, execution debugging support; they do not have parallel programming models, and whenever they exist, they are platform-specific. In order to fill the gaps and thus, to lower the barrier to develop on bare metal on shared memory manycore accelerators, we present PACHA. It features two aspects: a low overhead, Platform Agnostic, Close-to-HArdware (PACHA) programming interface, which allows to handle only one version of the application code for all supported accelerators, and an easy-to-use multi-platform development environment, which abstracts the complexity of each accelerator's development environment. With a x86 support and a Linux compatibility, PACHA offers a functional simulator and all the Linux set of debugging tools. Further, based on the programming interface, three parallel execution models have been ported in order to facilitate the development and comparison of applications. PACHA is currently fully supported for x86 platforms, TILEPro64 and STHORM. A case study on a TILEPro64 is presented: the performance gain using PACHA rather than Linux with OpenMP or Pthread is about 1,8x to 4x, without increasing the development cost.
doi:10.1016/j.procs.2013.05.332 fatcat:nycqbhmfjjelddfigpkqnwmnzi

The Couette flow of dense and fluid-saturated granular media

Pierre-Yves Lagrée, Daniel Lhuillier
2006 European journal of mechanics. B, Fluids  
A continuum-mechanical description is proposed for dense granular media submitted to steady shears. By dense granular media we mean high solid fractions in the range between the random loose and the random close packings. The description is based on a modeling of the stresses resulting from free-volume entropic effects, contacts and impacts between particles, and viscosity of the interstitial fluid. The non-homogeneity of the material is taken into account via several transport coefficients
more » ... nding on the solid fraction. When applied to the tangential annular flow in a Couette cell, the model predicts velocity and solid fraction profiles which agree qualitatively with those found experimentally but which also present some conflicting features, possibly due to the difficulties to achieve a true steady profile for the solid fraction. More precisely, we obtain the following predictions: (a) a minimum shear is required for motion, (b) above this minimum the motion is localized and the solid fraction decreases when approaching the inner moving cylinder, (c) the width of the shear band increases with the applied shear stress up to a maximum value above which our description fails because the solid fraction at the inner moving cylinder becomes smaller than the random loose packing, (d) the maximum width of the shear band is proportional to the radius of the inner cylinder, with a proportionality coefficient which increases with the fluid viscosity and decreases with the confining pressure and the grain size, (e) for dry granular media the maximum width of the shear band is approximately half the radius of the inner cylinder so that localization is observed in almost all Couette cells, (f) when a very viscous fluid surrounds the grains the width of the shear band often exceeds the gap of the Couette cell, giving the (wrong) impression that shear localization has disappeared.
doi:10.1016/j.euromechflu.2006.03.003 fatcat:xpydyr2dj5d5xgqojtwspp2b7m

CAPSULE: Hardware-Assisted Parallel Execution of Component-Based Programs

Pierre Palatin, Yves Lhuillier, Olivier Temam
2006 Microarchitecture (MICRO), Proceedings of the Annual International Symposium on  
Since processor performance scalability will now mostly be achieved through thread-level parallelism, there is a strong incentive to parallelize a broad range of applications, including those with complex control flow and data structures. And writing parallel programs is a notoriously difficult task. Beyond processor performance, the architect can help by facilitating the task of the programmer, especially by simplifying the model exposed to the programmer. In this article, among the many
more » ... associated with writing parallel programs, we focus on finding the appropriate parallelism granularity, and efficiently mapping tasks with complex control and data flow to threads. We propose to relieve the user and compiler of both tasks by delegating the parallelization decision to the architecture at run-time, through a combination of hardware and software support and a tight dialogue between both. For the software support, we leverage an increasingly popular approach in software engineering, called component-based programming; the component contract assumes tight encapsulation of code and data for easy manipulation. Previous research works have shown that it is possible to augment components with the ability to split/spawn, providing a simple and fitting approach for programming parallel applications with complex control and data structures. However, such environments still require the programmer to determine the appropriate granularity of parallelism, and spawning incurs significant overheads due to software run-time system management. For that purpose, we provide an environment with the ability to spawn conditionally depending on available hardware resources, and we delegate spawning decisions and actions to the architecture. This conditional spawning is implemented through frequent hardware resource probing by the program. This, in turn, enables rapid adaptation to varying workload conditions, data sets and hardware resources. Furthermore, thanks to appropriate combined hardware and compiler support, the probing has no significant overhead on program performance. We demonstrate this approach on an 8-context SMT, several non-trivial algorithms and re-engineered SPEC CINT2000 benchmarks, written using component syntax processed by our toolchain. We achieve speedups ranging from 1.1 to 3.0 on our test suite.
doi:10.1109/micro.2006.13 dblp:conf/micro/PalatinLT06 fatcat:2e43ekij3zb2hizpllqyiz5u4u

Flow and jamming of a two-dimensional granular bed: Toward a nonlocal rheology?

Lydie Staron, Pierre-Yves Lagrée, Christophe Josserand, Daniel Lhuillier
2010 Physics of Fluids  
In order to test the rheology of granular flows, we performed series of numerical simulations of nearly monodisperse stationary chute flows from rapid to slow and very slow flow regime, namely, close to the jamming transition. We check how existing rheological models ͑i.e., Bagnold's model and the I-model͒ capture the behavior of the numerical flows, and perform an acute characterization of the structure of the flow in terms of grains velocity fluctuations close to the jamming transition. The
more » ... mulations show that both Bagnold's and the I-model fail to describe the data points in the slow regime, namely, when I Յ 2 ϫ 10 −2 . Turning to the analysis of grains velocity fluctuations, we compute the associated correlation length and show its dependence on the inertial number: / d ϰ I −0.32 . The amplitude of the grains velocity fluctuations, namely, the granular temperature, exhibits a power-law dependence on the shear rate and allows for an efficient prediction of the shape of the velocity profiles. The main result consists of a scaling merging all data points for all flow regimes onto the same master curve, and relating granular temperature, shear rate, and the variation of stress between the considered depth and the bottom wall. This scaling can be written as a relation between local stress, local shear rate, and local temperature, provided the introduction of a characteristic length scale = d ͱ ͑H − z͒ / z where both the distance to the surface and the distance to the bottom wall are involved. This scaling strongly suggests a nonlocal behavior, valid in the flow regime and extending close to the jamming transition, and hints at granular temperature as the variable at the origin of the nonlocality. Downloaded 07 Dec 2010 to 134.157.34.241. Redistribution subject to AIP license or copyright; see http://pof.aip.org/about/rights_and_permissions 113303-2 Staron et al. Phys. Fluids 22, 113303 ͑2010͒ Downloaded 07 Dec 2010 to 134.157.34.241. Redistribution subject to AIP license or copyright; see http://pof.aip.org/about/rights_and_permissions 113303-10 Staron et al. Phys. Fluids 22, 113303 ͑2010͒ Downloaded 07 Dec 2010 to 134.157.34.241. Redistribution subject to AIP license or copyright; see http://pof.aip.org/about/rights_and_permissions
doi:10.1063/1.3499353 fatcat:bzauig3jzvdgvg2xygid2zchm4

Interactions Between Topological Defects and Nanoparticles

Syou-P'heng Do, Amine Missaoui, Alessandro Coati, Andrea Resta, Nicolas Goubet, Sébastien Royer, Geraldine Guida, Emrick Briand, Emmanuel Lhuillier, Yves Garreau, David Babonneau, Michel Goldmann (+4 others)
2020 Frontiers in Physics  
Liquid Crystal (LC) topological defects have been shown to trap nanoparticles (NPs) in the defect cores. The LC topological defects may thus be used as a matrix for new kinds of NP organizations templated by the defect geometry. We here study composites of LC smectic dislocations and gold NPs. Straight NP chains parallel to the dislocations are obtained leading to highly anisotropic optical absorption of the NPs controlled by light polarization. Combining Grazing Incidence Small Angle X-ray
more » ... tering (GISAXS), Rutherford Back Scattering (RBS), Spectrophotometry and the development of a model of interacting NPs, we explore the role of the Np size regarding the dislocation core size. We use NPs of diameter D = 6 nm embedded in an array of different kinds of dislocations. For dislocation core larger than the NP size, stable long chains are obtained but made of poorly interacting NPs. For dislocation core smaller than the NP size, the disorder is induced outside the dislocation cores and the NP chains are not equilibrium structures. However we show that at least half of these small dislocations can be filled, leading to chains with strongly enhanced electromagnetic coupling between the NPs. These chains are more probably stabilized by the elastic distortions around the defect cores, the distortion being enhanced by the presence of the grain boundary where the dislocations are embedded.
doi:10.3389/fphy.2019.00234 fatcat:pdtuxut67zht7mq75bupdft3gm

Current practices in the management of respiratory virus infections in lung transplantation

Elodie Lhuillier, Maxime Patout, Philip Marino, Gill Arbane, Patrick B. Murphy, Antoine Roux, Gabriel Thabut, Yves Castier, Hervé Mal, Olivier Brugiere
2019 Transplantation  
doi:10.1097/tp.0000000000003098 pmid:31895338 fatcat:n4hwjqwnkbhfdgdcpgywicssji

Beneficial effects of direct call to emergency medical services on time delays and management of patients with acute myocardial infarction: Real world data from RICO database

Jean-Claude Beer, Gilles Dentan, Luc Janin-Manificat, Marianne Zeller, Yves Laurent, Isabelle Lhuillier, Jacques Ravisy, Yves Cottin, Jean-Eric Wolff
2003 Journal of the American College of Cardiology  
Luc Janin-Manificat, Marianne Zeller, Yves Laurent, lsabelle Lhuillier, Jacques Ravisy Yves Cottin Jean-Eric Wolf, CHU Dijon, Dljon. France 2-1 Background.  ... 
doi:10.1016/s0735-1097(03)81065-3 fatcat:ufevobl2qzf3fdhzvw34utclmq

Coronary heart disease associated with the use of human immunodeficiency virus (HTV)-1 protease inhibitors: Report of four cases and review

Michel Duong, Marielle Buisson, Yves Cottin, Lionel Piroth, Isabelle Lhuillier, Michele Grappin, Pascal Chavanet, Jean-Eric Wolff, Henri Portier
2001 Clinical Cardiology  
Four cases of human immunodeficiency virus (HIV)-infected patients who developed coronary heart disease (CHD) while under treatment with a protease inhibitor (PI) are described, and the epidemiologic and clinical features of 18 cases reported in the literature are analyzed. Cardiac manifestations mostly included myocardial infarctions. Smoking and hyperlipidemia were the most common risk factorsfor CHD, reported in 72 and 8 1 % of the patients, respectively. Hypercholesterolemia was observed in
more » ... 75% of the cases at the time of the cardiovascular event. Ninety percent of the patients with pretreatment normal lipid values experienced a rise in the plasma lipid levels during PI therapy. Although a definite relationship between the development of CHD and HIV PIS can not be made, this analysis suggests that PI-induced hyperlipidemia may play a role in accelerating coronary atherosclerosis in patients with concomitant risk factors. Evaluation and control of risk factors for CHD should be performed in each patient for whom treatment with a PI is indicated.
doi:10.1002/clc.4960241011 pmid:11594416 fatcat:wi3mg5d36zgylnlpupmxl3moqi

A 1-week extension of a ketogenic diet provides a further decrease in myocardial 18F-FDG uptake and a high detectability of myocarditis with FDG-PET

Alexandra Clément, Henri Boutley, Sylvain Poussier, Julien Pierson, Mickael Lhuillier, Allan Kolodziej, Jean-Luc Olivier, Gilles Karcher, Pierre-Yves Marie, Fatiha Maskali
2018 Journal of Nuclear Cardiology  
doi:10.1007/s12350-018-1404-7 pmid:30128917 fatcat:iic73bzyeraq3eumrazt6vcbeu

Page 948 of SMPTE Motion Imaging Journal Vol. 98, Issue 12 [page]

1989 SMPTE Motion Imaging Journal  
.; and Lhuillier, J.  ...  J., Advanced High-Definition 50 to 60-Hz Standards Conversion, June, 420 Roizen, Joseph, and Faroudja, Yves C., A Pro- gress Report on Improved NTSC, Nov., 817 Roufs, Jacques A.  ... 

Marie-Anne Dujarier, Corinne Gaudart, Anne Gillet et Pierre Lénel (dir.), L'activité en théories. Regards croisés sur le travail

Christian Licoppe
2018 Sociologie du travail  
Elle actualise de manière plus ou moins nette un potentiel de développement individuel (l’affect chez Yves Clot) et collectif. 3Dans cette perspective développementale, le travail est à la  ...  Derrière « l’activité empêchée » se profile d’un côté la passivité et la frustration chez le travailleur, mais aussi à un niveau plus collectif des formes de déni et d’invisibilité (Lhuillier, p. 143).  ... 
doi:10.4000/sdt.8406 fatcat:wr6d6euuw5aoncwg34gcpghpoy

In This Issue

2009 Proceedings of the National Academy of Sciences of the United States of America  
''Turning a plant tissue into a living cell froth through isotropic growth '' by Francis Corson, Olivier Hamant, Steffen Bohn, Jan Traas, Arezki Boudaoud, and Yves Couder (see pages 8453-8458) BIOCHEMISTRY  ...  Sophie Lhuillier et al. report the pseudo-atomic structure of the connector of the model tailed phage SPP1, with details that reveal the mechanism that keeps the portal closed.  ... 
doi:10.1073/iti2109106 fatcat:5fsb5fbcozgfpatvfvi2f37o3i

Bibliographie sélective des actes de la journée d'études « Surveillant, un métier en mouvement » (DAP, 2017)

2021 Criminocorpus  
Pied Marie-Laure, Martineau Jean-Pierre, Caer Yves, Les surveillants de prison : un métier à risques , Montpellier, Université de Montpellier I, 2003, 60 p.  ...  Justice au quotidien) Lhuillier Dominique, Aymard Nadia, L’univers pénitentiaire. Du côté des surveillants de prison , Paris, Desclée de Brouwer, 1997, 287 p.  ... 
doi:10.4000/criminocorpus.10169 fatcat:a7ltzo6zhnbdraegsj4mqb5boa

Elevated troponin I is an independent prognostic marker for increased mortality even in patients hospitalized with noncardiac diagnoses

Syed W. Bokhari, Curtiss T. Stinis, Jason A. Zell, Cyril Y. Leung
2003 Journal of the American College of Cardiology  
Luc Janin-Manificat, Marianne Zeller, Yves Laurent, lsabelle Lhuillier, Jacques Ravisy Yves Cottin Jean-Eric Wolf, CHU Dijon, Dljon. France 2-1 Background.  ... 
doi:10.1016/s0735-1097(03)81062-8 fatcat:oqv3fcmm5re4vc2bk2sjit34kq

Predictors of treatment delay in patients with acute myocardial infarction undergoing primary angioplasty: An analysis from the CADILLAC trial

Mark A. Turco, Martin Fahy, Roxana A. Mehran, Alexandra Lansky, Cindy L. Grines, James E. Tcheng, Eulogio Garcia, Giulio Guagliumi, David A. Cox, Thomas D. Stuckey, Dawn E. Shaddinger, Gregg W. Stone
2003 Journal of the American College of Cardiology  
Luc Janin-Manificat, Marianne Zeller, Yves Laurent, lsabelle Lhuillier, Jacques Ravisy Yves Cottin Jean-Eric Wolf, CHU Dijon, Dljon. France 2-1 Background.  ... 
doi:10.1016/s0735-1097(03)81064-1 fatcat:g6kmwijp7benbk7tlqnggdyp2y
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