464 research outputs found

    Design and Optimization of Residual Neural Network Accelerators for Low-Power FPGAs Using High-Level Synthesis

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    Residual neural networks are widely used in computer vision tasks. They enable the construction of deeper and more accurate models by mitigating the vanishing gradient problem. Their main innovation is the residual block which allows the output of one layer to bypass one or more intermediate layers and be added to the output of a later layer. Their complex structure and the buffering required by the residual block make them difficult to implement on resource-constrained platforms. We present a novel design flow for implementing deep learning models for field programmable gate arrays optimized for ResNets, using a strategy to reduce their buffering overhead to obtain a resource-efficient implementation of the residual layer. Our high-level synthesis (HLS)-based flow encompasses a thorough set of design principles and optimization strategies, exploiting in novel ways standard techniques such as temporal reuse and loop merging to efficiently map ResNet models, and potentially other skip connection-based NN architectures, into FPGA. The models are quantized to 8-bit integers for both weights and activations, 16-bit for biases, and 32-bit for accumulations. The experimental results are obtained on the CIFAR-10 dataset using ResNet8 and ResNet20 implemented with Xilinx FPGAs using HLS on the Ultra96-V2 and Kria KV260 boards. Compared to the state-of-the-art on the Kria KV260 board, our ResNet20 implementation achieves 2.88X speedup with 0.5% higher accuracy of 91.3%, while ResNet8 accuracy improves by 2.8% to 88.7%. The throughputs of ResNet8 and ResNet20 are 12971 FPS and 3254 FPS on the Ultra96 board, and 30153 FPS and 7601 FPS on the Kria KV26, respectively. They Pareto-dominate state-of-the-art solutions concerning accuracy, throughput, and energy

    Sostenibilit\ue0 ambientale dei biocombustibili legnosi: importanza della filiera corta

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    Il legno \ue8 un materiale disponibile in abbondanza e, se la foresta \ue8 gestita in modo sostenibile, pu\uf2 rappresentare una fonte illimitata di materia prima per diversi settori industriali: dalla costruzione fino alla produzione di energia. Nel settore forestale, come in quello industriale, la domanda di una documentazione relativa alle sue prestazioni ambientali \ue8 in forte crescita. Per esempio, la certificazione ambientale di un prodotto da costruzione diventa necessaria in vista dell\u2019applicazione dei Criteri Ambientali Minimi (CAM) all\u2019edilizia a partire dall\u20191 gennaio 2021 mentre \ue8 gi\ue0 inclusa nella certificazione di qualit\ue0 dei biocombustibili solidi quali pellet (ENplus), bricchetti, cippato e legna da ardere (Biomassplus). Grazie alla competitivit\ue0 del costo della legna da ardere rispetto agli altri combustibili, l\u2019Italia storicamente ha una forte propensione all\u2019utilizzo di questo biocombustibile; tuttavia negli ultimi anni, si \ue8 sempre pi\uf9 sviluppato il mercato di importazione di legna da ardere, in particolar modo proveniente dall\u2019Est-Europa e dai Balcani. Il trasporto su strada della legna da ardere comporta degli input energetici nella filiera e conseguentemente delle emissioni di CO2. Questo studio confronta due diversi approcci di filiera: una filiera corta, in cui la legna da ardere \ue8 prodotta nella regione Veneto e in particolare in Cansiglio, e una filiera lunga, nella quale i tronchi per la produzione della legna da ardere vengono importati da paesi confinanti con l\u2019Italia. I tre obiettivi dello studio sono quelli di (i) valutare l\u2019impatto ambientale delle due filiere utilizzando 4 categorie di impatto, due globali (il potenziale di riscaldamento globale e il potenziale di riduzione dell\u2019ozono) e due locali (la formazione di smog fotochimico e la tossicit\ue0 umana); (ii) eseguire un\u2019analisi di sensitivit\ue0 per determinare la distanza critica del trasporto di legna da ardere e (iii) valutare la compensazione di CO2 in foresta. La metodologia adottata per la valutazione degli impatti ambientali delle due filiere \ue8 l\u2019analisi del ciclo di vita. Lo studio ha evidenziato che, nel caso della filiera corta, la fase critica del ciclo di vita \ue8 la combustione, mentre le operazioni forestali e il trasporto su strada hanno un contributo marginale sull\u2019impatto globale. Passando alla filiera lunga, escludendo le emissioni di CO2 di origine biogenica, il trasporto su strada diventa la fase critica

    Mechanical behavior of a sandwich with corrugated GRP core: numerical modeling and experimental validation

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    In this work the mechanical behaviour of a core reinforced composite sandwich structure isstudied. The sandwich employs a Glass Reinforced Polymer (GRP) orthotropic material for both the twoexternal skins and the inner core web. In particular, the core is designed in order to cooperate with the GRPskins in membrane and flexural properties by means of the addition of a corrugated laminate into the foamcore. An analytical model has been developed to replace a unit cell of this structure with an orthotropicequivalent thick plate that reproduces the in plane and out of plane behaviour of the original geometry.Different validation procedures have been implemented to verify the quality of the proposed method. At first acomparison has been performed between the analytical model and the original unit cell modelled with a FiniteElement mesh. Elementary loading conditions are reproduced and results are compared. Once the reliability ofthe analytical model was assessed, this homogenised model was implemented within the formulation of a shellfinite element. The goal of this step is to simplify the FE analysis of complex structures made of corrugatedcore sandwiches; in fact, by using the homogenised element, the global response of a real structure can beinvestigated only with the discretization of its mid-surface. Advantages are mainly in terms of time to solutionsaving and CAD modelling simplification. Last step is then the comparison between this FE model andexperiments made on sandwich beams and panels whose skins and corrugated cores are made of orthotropiccross-ply GRP laminates. Good agreement between experimental and numerical results confirms the validity ofthe proposed model

    NEMO: A Project for a km3^3 Underwater Detector for Astrophysical Neutrinos in the Mediterranean Sea

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    The status of the project is described: the activity on long term characterization of water optical and oceanographic parameters at the Capo Passero site candidate for the Mediterranean km3^3 neutrino telescope; the feasibility study; the physics performances and underwater technology for the km3^3; the activity on NEMO Phase 1, a technological demonstrator that has been deployed at 2000 m depth 25 km offshore Catania; the realization of an underwater infrastructure at 3500 m depth at the candidate site (NEMO Phase 2).Comment: Proceeding of ISCRA 2006, Erice 20-27 June 200

    De-escalated therapy for HR+/HER2+ breast cancer patients with Ki67 response after 2 weeks letrozole: results of the PerELISA neoadjuvant study

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    BACKGROUND: In HER2+ breast cancers, neoadjuvant trials of chemotherapy plus anti-HER2 treatment consistently showed lower pathologic complete response (pCR) rates in hormone receptor (HR) positive vs negative tumors. The PerELISA study was aimed to evaluate the efficacy of a de-escalated, chemotherapy-free neoadjuvant regimen in HR+/HER2+ breast cancer patients selected on the basis of Ki67 inhibition after 2-weeks letrozole. PATIENTS AND METHODS: PerELISA is a phase II, multicentric study for postmenopausal patients with HR+/HER2+ operable breast cancer. Patients received 2-weeks letrozole, then underwent re-biopsy for Ki67 evaluation. Patients classified as molecular responders (Ki67 relative reduction >20% from baseline) continued letrozole and started trastuzumab-pertuzumab for 5 cycles. Patients classified as molecular non-responders started weekly paclitaxel for 13 weeks combined with trastuzumab-pertuzumab. Primary aim was breast and axillary pCR. According to a 2-stage Simon's design, to reject the null hypothesis, at least 8/43 pCR had to be documented. RESULTS: Sixty-four patients were enrolled, 44 were classified as molecular responders. All these patients completed the assigned treatment with letrozole-trastuzumab-pertuzumab and underwent surgery. A pCR was observed in 9/44 cases (20.5%, 95%CI 11.1%-34.5%). Among molecular non-responders, 16/17 completed treatment and underwent surgery, with pCR observed in 81.3% of the cases. PAM50 intrinsic subtype was significantly associated with Ki67 response and pCR. Among molecular responders, the pCR rate was significantly higher in HER2-enriched vs other subtypes (45.5% vs 13.8%, p=0.042). CONCLUSIONS: The primary endpoint of the study was met, by reaching the pre-specified pCRs. In patients selected using Ki67 reduction after short-term letrozole exposure, a meaningful pCR rate can be achieved without chemotherapy. PAM50 intrinsic subtyping further refines our ability to identify a subset of patients for whom chemotherapy might be spared

    Performance study of GPUs in real-time trigger applications for HEP experiments

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    Graphical Processing Units (GPUs) have evolved into highly parallel, multi-threaded, multicore powerful processors with high memory bandwidth. GPUs are used in a variety of intensive computing applications. The combination of highly parallel architecture and high memory bandwidth makes GPUs a potentially promising technology for effective real-time processing for High Energy Physics (HEP) experiments. However, not much is known of their performance in real-time applications that require low latency, such as the trigger for HEP experiments. We describe an R and D project with the goal to study the performance of GPU technology for possible low latency applications, performing basic operations as well as some more advanced HEP lower-level trigger algorithms (such as fast tracking or jet finding). We present some preliminary results on timing measurements, comparing the performance of a CPU versus a GPU with NVIDIA's CUDA general-purpose parallel computing architecture, carried out at CDF's Level-2 trigger test stand. These studies will provide performance benchmarks for future studies to investigate the potential and limitations of GPUs for real-time applications in HEP experiments

    Measurement of the atmospheric muon flux with the NEMO Phase-1 detector

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    The NEMO Collaboration installed and operated an underwater detector including prototypes of the critical elements of a possible underwater km3 neutrino telescope: a four-floor tower (called Mini-Tower) and a Junction Box. The detector was developed to test some of the main systems of the km3 detector, including the data transmission, the power distribution, the timing calibration and the acoustic positioning systems as well as to verify the capabilities of a single tridimensional detection structure to reconstruct muon tracks. We present results of the analysis of the data collected with the NEMO Mini-Tower. The position of photomultiplier tubes (PMTs) is determined through the acoustic position system. Signals detected with PMTs are used to reconstruct the tracks of atmospheric muons. The angular distribution of atmospheric muons was measured and results compared with Monte Carlo simulations.Comment: Astrop. Phys., accepte

    The effects of theaflavin-enriched black tea extract on muscle soreness, oxidative stress, inflammation, and endocrine responses to acute anaerobic interval training: a randomized, double-blind, crossover study

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    <p>Abstract</p> <p>Background</p> <p>Muscle soreness and decreased performance often follow a bout of high-intensity exercise. By reducing these effects, an athlete can train more frequently and increase long-term performance. The purpose of this study is to examine whether a high-potency, black tea extract (BTE) alters the delayed onset muscle soreness (DOMS), oxidative stress, inflammation, and cortisol (CORT) responses to high-intensity anaerobic exercise.</p> <p>Methods</p> <p>College-age males (N = 18) with 1+ yrs of weight training experience completed a double-blind, placebo-controlled, crossover study. Subjects consumed the BTE (1,760 mg BTE·d<sup>-1</sup>) or placebo (PLA) for 9 days. Each subject completed two testing sessions (T1 & T2), which occurred on day 7 of the intervention. T1 & T2 consisted of a 30 s Wingate Test plus eight 10 s intervals. Blood samples were obtained before, 0, 30 & 60 min following the interval sessions and were used to analyze the total to oxidized glutathione ratio (GSH:GSSG), 8-isoprostane (8-iso), CORT, and interleukin 6 (IL-6) secretion. DOMS was recorded at 24 & 48 h post-test using a visual analog scale while BTE or PLA continued to be administered. Significance was set at <it>P < 0.05</it>.</p> <p>Results</p> <p>Compared to PLA, BTE produced significantly higher average peak power (<it>P = 0.013</it>) and higher average mean power (<it>P = 0.067</it>) across nine WAnT intervals. BTE produced significantly lower DOMS compared to PLA at 24 h post test (<it>P < 0.001</it>) and 48 h post test (<it>P < 0.001</it>). Compared to PLA, BTE had a slightly higher GSH:GSSG ratio at baseline which became significantly higher at 30 and 60 min post test (<it>P < 0.002</it>). AUC analysis revealed BTE to elicit significantly lower GSSG secretion (<it>P = 0.009</it>), significantly higher GSH:GSSG ratio (<it>P = 0.001</it>), and lower CORT secretion (<it>P = 0.078</it>) than PLA. AUC analysis did not reveal a significant difference in total IL-6 response (<it>P = 0.145</it>) between conditions.</p> <p>Conclusions</p> <p>Consumption of theaflavin-enriched black tea extract led to improved recovery and a reduction in oxidative stress and DOMS responses to acute anaerobic intervals. An improved rate of recovery can benefit all individuals engaging in high intensity, anaerobic exercise as it facilitates increased frequency of exercise.</p
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