1,769 research outputs found

    MASCARA (ModulAr Semantic CAching fRAmework) towards FPGA Acceleration for IoT Security Monitoring

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    With the explosive growth of the Internet Of Things (IOTs), emergency security monitoring becomes essential to efficiently manage an enormous amount of information from heterogeneous systems. In concern of increasing the performance for the sequence of online queries on long-term historical data, query caching with semantic organization, called Semantic Query Caching or Semantic Caching (SC), can play a vital role. SC is implemented mostly in software perspective without providing a generic description of modules or cache services in the given context. Hardware acceleration with FPGA opens new research directions to achieve better performance for SC. Hence, our work aims to propose a flexible, adaptable, and tunable ModulAr Semantic CAching fRAmework (MASCARA) towards FPGA acceleration for fast and accurate massive logs processing applications

    Turbulent shear stresses in hydraulic jumps, bores and decelerating surges

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    In an open channel, a sudden rise in water level induces a positive surge, or bore, that may develop as a hydraulic jump in translation. When the surge propagates against an adverse slope, it decelerates until it becomes a stationary hydraulic jump. Both hydraulic jumps and decelerating surges induce some intense turbulent mixing and have some major impact on the sediment transport in natural systems. Herein, a physical investigation was conducted in a relatively large rectangular channel. Hydraulic jumps and surges were generated by the rapid closure of a gate at the channel downstream end. The turbulent shear stresses were measured with high temporal and spatial resolution (200 Hz sampling rate) in the jump flow. A comparison between the stationary hydraulic jump, hydraulic jump in translation and decelerating surge measurements showed some marked differences in terms of turbulent mixing. The results highlighted some intense mixing beneath the jump front and roller for all configurations. The levels of turbulent stresses were one to two orders of magnitude larger than a critical threshold for sediment motion. The findings provide some insights into the hydraulic jump migration processes in mobile bed channels, and the complex transformation from a moving jump into a stationary jump. Copyright (C) 2010 John Wiley & Sons, Ltd

    Direct observation of active material concentration gradients and crystallinity breakdown in LiFePO4 electrodes during charge/discharge cycling of lithium batteries

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    The phase changes that occur during discharge of an electrode comprised of LiFePO4, carbon, and PTFE binder have been studied in lithium half cells by using X-ray diffraction measurements in reflection geometry. Differences in the state of charge between the front and the back of LiFePO4 electrodes have been visualized. By modifying the X-ray incident angle the depth of penetration of the X-ray beam into the electrode was altered, allowing for the examination of any concentration gradients that were present within the electrode. At high rates of discharge the electrode side facing the current collector underwent limited lithium insertion while the electrode as a whole underwent greater than 50% of discharge. This behavior is consistent with depletion at high rate of the lithium content of the electrolyte contained in the electrode pores. Increases in the diffraction peak widths indicated a breakdown of crystallinity within the active material during cycling even during the relatively short duration of these experiments, which can also be linked to cycling at high rate

    Voltage and power-controlled regimes in the progressive unipolar RESET transition of HfO₂-based RRAM

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    Resistive switching (RS) based on the formation and rupture of conductive filament (CF) is promising in novel memory and logic device applications. Understanding the physics of RS and the nature of CF is of utmost importance to control the performance, variability and reliability of resistive switching memory (RRAM). Here, the RESET switching of HfO₂-based RRAM was statistically investigated in terms of the CF conductance evolution. The RESET usually combines an abrupt conductance drop with a progressive phase ending with the complete CF rupture. RESET1 and RESET2 events, corresponding to the initial and final phase of RESET, are found to be controlled by the voltage and power in the CF, respectively. A Monte Carlo simulator based on the thermal dissolution model of unipolar RESET reproduces all of the experimental observations. The results contribute to an improved physics-based understanding on the switching mechanisms and provide additional support to the thermal dissolution model

    Lactose Induces Phenotypic and Functional Changes of Neutrophils and Macrophages to Alleviate Acute Pancreatitis in Mice

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    Publisher's version (Ăștgefin grein)Acute pancreatitis (AP) is one common clinical acute abdominal disease, for which specific pharmacological or nutritional therapies remain elusive. Lactose, a macronutrient and an inducer of host innate immune responses, possesses immune modulatory functions. The current study aimed to investigate potential modulatory effects of lactose and the interplay between the nutrient and pancreatic immunity during experimentally induced AP in mice. We found that either prophylactic or therapeutic treatment of lactose time-dependently reduced the severity of AP, as evidenced by reduced pancreatic edema, serum amylase levels, and pancreatic myeloperoxidase activities, as well as by histological examination of pancreatic damage. Overall, lactose promoted a regulatory cytokine milieu in the pancreas and reduced infiltration of inflammatory neutrophils and macrophages. On acinar cells, lactose was able to suppress caerulein-induced inflammatory signaling pathways and to suppress chemoattractant tumor necrosis factor (TNF)-α and monocyte chemotactic protein-1 production. Additionally, lactose acted on pancreas-infiltrated macrophages, increasing interleukin-10 and decreasing tumor necrosis factor alpha production. Notably, lactose treatment reversed AP-associated infiltration of activated neutrophils. Last, the effect of lactose on neutrophil infiltration was mimicked by a galectin-3 antagonist, suggesting a potential endogenous target of lactose. Together, the current study demonstrates an immune regulatory effect of lactose to alleviate AP and suggests its potential as a convenient, value-added therapeutic macronutrient to control AP, and lower the risk of its systemic complications.This study was supported by funds from the National Natural Science Foundation of China (grant nos. 91642114, 31570915, 81573420, and 31400779, National Young 1000 Talents Plan), Jiangsu Province Recruitment Plan for High-level, Innovative and Entrepreneurial Talents, Fundamental Research Funds for the Central Universities (grant nos. JUSRP51613A and JUSRP11866) and free exploration funding from State Key Laboratory of Food Science and Technology (SKLF-ZZB-201702).Peer Reviewe

    The Fourteenth Data Release of the Sloan Digital Sky Survey: First Spectroscopic Data from the extended Baryon Oscillation Spectroscopic Survey and from the second phase of the Apache Point Observatory Galactic Evolution Experiment

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    The fourth generation of the Sloan Digital Sky Survey (SDSS-IV) has been in operation since July 2014. This paper describes the second data release from this phase, and the fourteenth from SDSS overall (making this, Data Release Fourteen or DR14). This release makes public data taken by SDSS-IV in its first two years of operation (July 2014-2016). Like all previous SDSS releases, DR14 is cumulative, including the most recent reductions and calibrations of all data taken by SDSS since the first phase began operations in 2000. New in DR14 is the first public release of data from the extended Baryon Oscillation Spectroscopic Survey (eBOSS); the first data from the second phase of the Apache Point Observatory (APO) Galactic Evolution Experiment (APOGEE-2), including stellar parameter estimates from an innovative data driven machine learning algorithm known as "The Cannon"; and almost twice as many data cubes from the Mapping Nearby Galaxies at APO (MaNGA) survey as were in the previous release (N = 2812 in total). This paper describes the location and format of the publicly available data from SDSS-IV surveys. We provide references to the important technical papers describing how these data have been taken (both targeting and observation details) and processed for scientific use. The SDSS website (www.sdss.org) has been updated for this release, and provides links to data downloads, as well as tutorials and examples of data use. SDSS-IV is planning to continue to collect astronomical data until 2020, and will be followed by SDSS-V.Comment: SDSS-IV collaboration alphabetical author data release paper. DR14 happened on 31st July 2017. 19 pages, 5 figures. Accepted by ApJS on 28th Nov 2017 (this is the "post-print" and "post-proofs" version; minor corrections only from v1, and most of errors found in proofs corrected

    RÔLE DE L'OCCUPATION DU SOL VIS À VIS DE LA MODÉLISATION DES FLUX ENERGÉTIQUES ET HYDRIQUES EN MILIEU URBAIN ET PÉRIURBAIN

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    National audienceLe projet Rosenhy vise Ă  Ă©tudier l’impact de l’occupation du sol sur la modĂ©lisation mĂ©tĂ©orologique et hydrologique en termes de flux Ă©nergĂ©tiques et hydriques, en milieu urbain et pĂ©riurbain. Trois sites appartenant aux observatoires français OTHU et ONEVU sont au centre de ce projet. Le quartier urbain hĂ©tĂ©rogĂšne du Pin sec (Nantes), impermĂ©abilisĂ© Ă  environ 45%, a fait l’objet d’une campagne expĂ©rimentale durant le mois de juin 2012, visant Ă  estimer les flux de chaleur sensible et latente avec une haute rĂ©solution spatiale et temporelle par rapport aux mesures rĂ©alisĂ©es en continu sur ce site depuis 5 ans. Deux bassins versant pĂ©riurbains (La ChĂ©zine Ă  Nantes et l’Yzeron Ă  Lyon), avec un taux d’impermĂ©abilisation moins important (environ 10%) mais grandissant depuis plusieurs dĂ©cennies, sont aussi Ă©tudiĂ©s. Ces deux derniers sites bĂ©nĂ©ficient d’un suivi hydromĂ©tĂ©orologique depuis 10 ans pour la ChĂ©zine et 15 ans pour l’Yzeron. Sur ces trois sites, diffĂ©rentes sources de donnĂ©es d’occupation du sol Ă  diffĂ©rentes rĂ©solutions sont disponibles :diffĂ©rentes bases de donnĂ©es gĂ©ographiques communĂ©ment utilisĂ©es par la communautĂ© scientifique et les collectivitĂ©s et des donnĂ©es tĂ©lĂ©dĂ©tectĂ©es (multispectrales et hyperspectrales). L’utilisation de ces donnĂ©es en entrĂ©e de diffĂ©rents modĂšles mĂ©tĂ©orologiques et hydrologiques implique un travail d’analyse et de classification pour adapter les informations aux besoins des modĂšles. Dans ce projet, les diffĂ©rents modĂšles adaptĂ©s au milieu urbain ou pĂ©rirubain sont Ă©valuĂ©s et amĂ©liorĂ©s. Ainsi, les modĂšles hydrologiques pĂ©rirubains sont en dĂ©veloppement pour prendre en compte les diffĂ©rentes pratiques de gestion des eaux pluviales existantes (noues, toitures vĂ©gĂ©talisĂ©es, ...). L’utilisation conjointe des donnĂ©es simulĂ©es par les diffĂ©rents modĂšles aidera Ă  dĂ©terminer le rĂŽle de la part des surfaces naturelles et artificielles sur les bilans Ă©nergĂ©tique et hydrique en milieu plus ou moins urbanisĂ©. Le milieu pĂ©riurbain Ă©tant en Ă©volution, le projet s’intĂ©ressera aussi Ă  des scĂ©narios d’urbanisation prospectifs en regardant d’une part l’impact de la densification sur les scĂ©narios construits pour l’Yzeron lors du projet AVuPUR (ANR-VMCS, 2008-2011) et d’autre part, en rĂ©flĂ©chissant conjointement avec Nantes MĂ©tropole, aux possibles voies d’évolution sur le bassin de la ChĂ©zine
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