Transparent and efficient shared-state management for optimistic simulations on multi-core machines

Traditionally, Logical Processes (LPs) forming a simulation model store their execution information into disjoint simulations states, forcing events exchange to communicate data between each other. In this work we propose the design and implementation of an extension to the traditional Time Warp (optimistic) synchronization protocol for parallel/distributed simulation, targeted at shared-memory/multicore machines, allowing LPs to share parts of their simulation states by using global variables. In order to preserve optimism's intrinsic properties, global variables are transparently mapped to multi-version ones, so to avoid any form of safety predicate verification upon updates. Execution's consistency is ensured via the introduction of a new rollback scheme which is triggered upon the detection of an incorrect global variable's read. At the same time, efficiency in the execution is guaranteed by the exploitation of non-blocking algorithms in order to manage the multi-version variables' lists. Furthermore, our proposal is integrated with the simulation model's code through software instrumentation, in order to allow the application-level programmer to avoid using any specific API to mark or to inform the simulation kernel of updates to global variables. Thus we support full transparency. An assessment of our proposal, comparing it with a traditional message-passing implementation of variables' multi-version is provided as well. © 2012 IEEE

TVFS: Topology Voltage Frequency Scaling for Reliable Embedded ConvNets

This brief introduces Topology Voltage Frequency Scaling (TVFS), a performance management technique for embedded Convolutional Neural Networks (ConvNets) deployed on low-power CPUs. Using TVFS, pre-trained ConvNets can be efficiently processed over a continuous stream of data, enabling reliable and predictable multi-inference tasks under latency constraints. Experimental results, collected from an image classification task built with MobileNet-v1 and ported into an ARM Cortex-A15 core, reveal TVFS holds fast and continuous inference (from few runs, up to 2000), ensuring a limited accuracy loss (from 0.9% to 3.1%), and better thermal profiles (average temperature 16.4 °C below the on-chip critical threshold)

REFLEXÕES SOBRE A EDUCAÇÃO AMBIENTAL NO DISTRITO FEDERAL

A presente pesquisa procurou verificar se a educação ambiental oferecida pelo governo no âmbito do distrito federal conduz à participação do cidadão comum na busca de soluções para os problemas ambientais observados nesta unidade da federação. para que o objetivo da pesquisa fosse alcançado foi aplicado um questionário a cidadãos do distrito federal e entorno, além da realização de duas entrevistas com especialistas em educação ambiental com atuação no distrito federal

The winning game in the major football leagues

The new millennium was marked by the epic of the legendary Barcelona of Guardiola, the coach who revolutionized the world of football with his tiki taka. The search for this game made of fast ball exchanges, continuous changes of position and search for free space to occupy, however, has downgraded what is one of the main technical skills of the game of football, the dribbling. Starting with football schools Pedagogical value of the body and physical activity in childhood. 1vs1 has been set aside to favour other technical fundamentals, so we are in a period where fewer and fewer players take responsibility for trying a game in 1vs1, but prefer to pass the ball to their closest partner. This second study has analysed the scorer rankings of the top 4 European championships (Serie A, Premier League, Spanish League, Bundesliga) of the 2009/2010 and 2017/2018 seasons, taking into account not only the total goals, but also the average shots per game and the average dribbling per game

Factors Impacting σ- and π-Hole Regions as Revealed by the Electrostatic Potential and Its Source Function Reconstruction: The Case of 4,4'-Bipyridine Derivatives

Positive electrostatic potential (V) values are often associated with σ- and π-holes, regions of lower electron density which can interact with electron-rich sites to form noncovalent interactions. Factors impacting σ- and π-holes may thus be monitored in terms of the shape and values of the resulting V. Further precious insights into such factors are obtained through a rigorous decomposition of the V values in atomic or atomic group contributions, a task here achieved by extending the Bader–Gatti source function (SF) for the electron density to V. In this article, this general methodology is applied to a series of 4,4'-bipyridine derivatives containing atoms from Groups VI (S, Se) and VII (Cl, Br), and the pentafluorophenyl group acting as a π-hole. As these molecules are characterized by a certain degree of conformational freedom due to the possibility of rotation around the two C–Ch bonds, from two to four conformational motifs could be identified for each structure through conformational search. On this basis, the impact of chemical and conformational features on σ- and π-hole regions could be systematically evaluated by computing the V values on electron density isosurfaces (VS) and by comparing and dissecting in atomic/atomic group contributions the VS maxima (VS,max) values calculated for different molecular patterns. The results of this study confirm that both chemical and conformational features may seriously impact σ- and π-hole regions and provide a clear analysis and a rationale of why and how this influence is realized. Hence, the proposed methodology might offer precious clues for designing changes in the σ- and π-hole regions, aimed at affecting their potential involvement in noncovalent interactions in a desired way

Comparative enantioseparation of planar chiral ferrocenes on polysaccharide-based chiral stationary phases.

Planar chiral ferrocenes are well-known compounds that have attracted interest for application in synthesis, catalysis, material science, and medicinal chemistry for several decades. In spite of the fact that asymmetric synthesis procedures for obtaining enantiomerically enriched ferrocenes are available, sometimes, the accessible enantiomeric excess of the chiral products is unsatisfactory. In such cases and for resolution of racemic planar chiral ferrocenes, enantioselective high-performance liquid chromatography (HPLC) on polysaccharide-based chiral stationary phases (CSPs) has been used in quite a few literature articles. However, although moderate/high enantioselectivities have been obtained for planar chiral ferrocenes bearing polar substituents, the enantioseparation of derivatives containing halogens, or exclusively alkyl groups, remains rather challenging. In this study, the enantioseparation of ten planar chiral 1,2- and 1,3-disubstituted ferrocenes was explored by using five polysaccharide-based CSPs under multimodal elution conditions. Baseline enantioseparations were achieved for nine analytes with separation factors (α) ranging from 1.20 to 2.92. The presence of π-extended systems in the analyte structure was shown to impact affinity of the most retained enantiomer toward amylose-based selectors, observing retention times higher than 80 min with methanol-containing mobile phases (MPs). Electrostatic potential (V) analysis and molecular dynamics (MD) simulations were used in order to study interaction modes at the molecular level

Speculative Client Execution in Deferred Update Replication

ABSTRACT Deferred Update Replication (DUR) is a powerful replication technique that allows parallelism of clients' execution while a global certification phase checks the validity of the transactional execution against workloads running on remote nodes. The well-known favorable scenario of DUR is when remote transactions rarely conflict with each other. In this paper we show that, even in this case, the conflicts happening among local application threads can significantly decrease performance. We address this problem by using speculation. We let local transactions propagate their postexecution snapshot to other local transactions before the outcome of the global certification is notified. This way, in scenarios where accesses are partitioned across nodes, we prevent local transactions from aborting each other. Through experimental study based on well-known transactional benchmarks we assess the effectiveness of the approach, gaining more than 10× using TPC-C benchmark

Cervical dystonia patients display subclinical gait changes

Gait disorders in cervical dystonia (CD) are reported in patients under DBS or in severe cases complicated with spinal deformities