241 research outputs found

    A Computation Core for Communication Refinement of Digital Signal Processing Algorithms

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    International audienceThe most popular Moore's law formulation, which states the number of transistors on integrated circuits doubles every 18 months, is said to hold for at least another two decades. According to this prediction, if we want to take advantage of technological evolutions, designer's productivity has to increase in the same proportions. To take up this challenge, system level design solutions have been set up, but many efforts have still to be done on system modelling and synthesis. In this paper we propose a computation core synthesis methodology that can be integrated on the communication refinement steps of electronic system level design tools. In the proposed approach, computation cores used for digital signal processing application specifications relying on coarse grain communications and synchronizations (e.g. matrix) can be refined into computation cores which can handle fine grain communications and synchronizations (e.g. scalar). Its originality is its ability to synthesize computation cores which can handle fine grain data consumptions and productions which respect the intrinsic partial orders of the algorithms while preserving their original functionalities. Such cores can be used to model fine grain input output overlapping or iteration pipelining. Our flow is based on the analysis of a fine grain signal flow graph used to extract fine grain synchronizations and algorithmic expressions

    Hardware communication refinement in digital signal processing, modelling issues

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    In this paper we present the different modelling problems which a Digital Signal Processing (DSP) application designer has to tackle while refining an abstract specification relying on coarse grain data (e.g. matrices) toward a hardware implementation model relying on fine grain data (e.g. scalar). To address this problematic, we propose a modelling framework which can be used to refine an algorithm specified with coarse grain interfaces to a form which allow, from the functionnality point of view, to model all its fine grain hardware implmentation

    Buts d'accomplissement de soi et jugement métacognitif des aides en EIAH

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    International audienceLe but de cette étude est d'étudier l'effet des buts d'accomplissement de soi et des jugements métacognitifs de l'individu sur sa recherche d'aide instrumentale ou exécutive au sein d'un site web d'apprentissage en statistique. 49 étudiants ont participé à l'étude. Les résultats montrent que (1) le but de maîtrise est lié positivement à la recherche d'aide instrumentale et positivement à la recherche d'aide exécutive de l'apprenant, (2) le but de performance d'évitement est lié négativement à la recherche d'aide exécutive, (3) la perception d'une menace sur son besoin d'autonomie est lié négativement à la recherche d'aide instrumentale, (4) la perception d'une menace sur ses compétences est reliée négativement à la recherche d'aide exécutive

    Concrush: Understanding fugitive dust production and potential emission at a recycled concrete manufacturing facility

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    The production and emission of fugitive dust is a topic ofconcern that Concrush brought to the MISG, 2020. Concrushis recycled concrete manufacturing company in the Hunterregion of New South Wales. Concrush's operations producefugitive dust, fine particles that can escape the site. Fugitive dust can travel long distances from the site ofemission, and can have negative health impacts includingrespiratory illnesses. Presently, concrete recyclingfacilities are managed by the Environmental ProtectionAgency using guidelines initially developed for the coalindustry. Concrush seeks to understand the appropriatenessof these guidelines, and how they can reduce and managefugitive dust on their Teralba site. Mathematical modellingof dust emission and transport, together with a review ofsimilar processes in the literature, identified a number ofpractical options for Concrush to reduce their dustemissions. In addition, opportunities for improved datacollection are identified

    Granite intrusion in a metamorphic core complex: The example of the Mykonos laccolith (Cyclades, Greece)

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    International audienceThe Aegean domain is a well-suited place to study the formation of metamorphic core complex (MCC) and to investigate the role of syn-tectonic granites on their development. In the northern Cyclades, the Mykonos-Delos-Rhenia MCC is characterised by the intrusion of a kilometer-scale Late Miocene pluton of I-type granitoids within a migmatitic gneiss dome. New combined AMS (Anisotropy of Magnetic Susceptibility) and microstructural studies on the Mykonos granitoids together with recently published thermochronological data allow us to use the granitoids as strain markers. The Mykonos granitoids form a laccolith-like intrusion with a N70°E long axis. The laccolith is strongly asymmetric with an outlying root zone to the SW and a major body mainly developed to the NE. The laccolith construction is due to successive pulses of more or less differentiated magma that intruded the Cycladic Blueschist Unit. The attitude of stretching markers suggests an important (about 60°) vertical-axis local rotation phenomenon in the cycladic upper crust during the exhumation of the Mykonos MCC. Structural data suggest a four-stage evolution of the Mykonos MCC: (i) a first stage characterized by flat shearing toward the N-NE and by the formation of a domal structure in migmatitic paragneisses with multi-scale generation of folds with axes either perpendicular or parallel to the regional stretching, as a result of the interplay between regional N20E°-directed extension and EW shortening; (ii) a second stage marked by the emplacement of the Mykonos laccolith at 13.5 ± 0.3 Ma at the top of the migmatitic paragneisses; (iii) the third stage corresponding to the development of protomylonitic foliations and lineations in the whole laccolith in high to medium temperature conditions; (iv) the late stage marked by an acceleration of the exhumation of the Mykonos MCC. This exhumation was accommodated by important rotations of upper crustal blocks. During the end of the exhumation processes, around 10 Ma, deformation localized at the top of the laccolith in semi-ductile conditions and then in brittle conditions in the major detachment plane. Our study shows that the Cycladic plutonism event had no role on the initiation of the MCC. However, the geometry of the Mykonos intrusion supports that the magmas are "sucked" into the direction of regional extension and that the intrusion of magmas has caused an acceleration of the last stages of the MCC development. This acceleration was marked by a very fast exhumation of the laccolith after its emplacement

    The North Cycladic Detachment System

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    International audienceLow-angle normal faults accommodate a large part of continental post-orogenic extension. Besides the intrinsic rheological characteristics of the continental crust that may lead to the formation of shallow-dipping shear zones at the brittle–ductile transition, the role of pre-existing low-angle structures such as large thrusts has been proposed by several authors. We explore this question with the example of the North Cycladic Detachment System (NCDS) that is composed of a series of distinct detachments cropping out on the islands of Andros, Tinos and Mykonos, separating the Cycladic Blueschists in the footwall from the Upper Cycladic Nappe in the hanging wall. We show that these extensional structures are part of a single large-scale structure (more than 200 km along strike) that reactivates the Vardar suture zone. It extends eastward on Ikaria and westward offshore Evia and Thessalia where it probably connects to recent shallow-dipping normal faults evidenced on published seismic reflection profiles. The NCDS started its activity in the Oligocene concommitantly with the Aegean extension, and was still active in the Late Miocene. It has exhumed a series of metamorphic domes from southern Evia to Mykonos below low-angle detachment systems, made of low-angle normal faults and low-angle ductile shear zones. The ductile shear zones and the faults were created with a low dip and they kept the same attitude throughout their exhumation. We identify three main detachments that are part of a continuum of extension on the NCDS : Tinos detachment, Livada detachment and Mykonos detachment. A fourth detachment (Vari detachment) is the reactivation of an Eocene exhumation-related structure. Deformation in the footwall is characterized by intense stretching and flattening. Using the spatial evolution observed along strike from Andros to Mykonos we construct a history of formation of the NCDS starting with the reactivation of former thrusts leading to the exhumation of high-temperature metamorphic domes. The Aegean example shows that reactivation of earlier shallow-dipping discontinuities can play a fundamental role in continental post-orogenic extension

    Pancreatic Serous Cystadenoma with Compression of the Main Pancreatic Duct: An Unusual Entity

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    Serous cystadenoma is a common benign neoplasm that can be managed without surgery in asymptomatic patients provided that the diagnosis is certain. We describe a patient, whose pancreatic cyst exhibited a radiological appearance distinct from that of typical serous cystadenoma, resulting in diagnostic difficulties. CT and MRI showed a 10 cm-polycystic tumor with upstream dilatation of the main pancreatic duct (MPD), suggestive of intraductal papillary mucinous tumor (IPMT). Ultrasonographic aspect and EUS-guided fine-needle aspiration gave arguments for serous cystadenoma. ERCP showed a communication between cysts and the dilated MPD, compatible with IPMT. The patient underwent left pancreatectomy with splenectomy. Pathological examination concluded in a serous cystadenoma, with only a ductal obstruction causing proximal dilatation

    Changes in urine composition after trauma facilitate bacterial growth.

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    International audienceUNLABELLED: ABSTRACT: BACKGROUND: Critically ill patients including trauma patients are at high risk of urinary tract infection (UTI). The composition of urine in trauma patients may be modified due to inflammation, systemic stress, rhabdomyolysis, life support treatment and/or urinary catheter insertion. METHODS: Prospective, single-centre, observational study conducted in patients with severe trauma and without a history of UTIs or recent antibiotic treatment. The 24-hour urine samples were collected on the first and the fifth days and the growth of Escherichia coli in urine from patients and healthy volunteers was compared. Biochemical and hormonal modifications in urine that could potentially influence bacterial growth were explored. RESULTS: Growth of E. coli in urine from trauma patients was significantly higher on days 1 and 5 than in urine of healthy volunteers. Several significant modifications of urine composition could explain these findings. On days 1 and 5, trauma patients had an increase in glycosuria, in urine iron concentration, and in the concentrations of several amino acids compared to healthy volunteers. On day 1, the urinary osmotic pressure was significantly lower than for healthy volunteers. CONCLUSION: We showed that urine of trauma patients facilitated growth of E. coli when compared to urine from healthy volunteers. This effect was present in the first 24 hours and until at least the fifth day after trauma. This phenomenon may be involved in the pathophysiology of UTIs in trauma patients. Further studies are required to define the exact causes of such modifications
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