1,222 research outputs found

    Explicit F.E. formulation with modified linear tetrahedral elements applied to high speed forming processes

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    International audienceWe will adapt a recent explicit FE formulation with modified linear tetrahedral elements for high speed metal forming simulation. This formulation both enables the use of efficient adaptive non structured meshers, and tackles the locking effect in quasi-incompressible cases. We implement this formulation for the infinitesimal elastic plastic case. The anti-locking modification effect will be underlined on two 3D bench marks: an elastic compression test and an elastic-plastic bar impact test

    Niobate de lithium périodiquement polarisé à courte période et perspectives d'application

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    International audienceLe niobate de lithium périodiquement polarisé (PPLN) sur des périodes courantes de 6 à 22 ”m trouve actuellement de nombreuses applications en optique non linéaire (ONL). La micro-structuration à plus courte période, c'est-à-dire de 2,5 ”m à 300 nm, permettrait de nouvelles fonctionnalités, non seulement en ONL mais aussi en électro-optique. Les problÚmes technologiques posés par ce défi sont présentés, ainsi que quelques exemples d'applications

    Towards Nonlinear Photonic Wires in Z-cut LiNbO3

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    International audienceUsing a modified Proton Exchange process we have realized Photonic Wires in X-cut LiNbO3. They exhibit highly confined mode, low propagation losses, low strain induced polarization coupling and no reduction of the nonlinear properties. We are now transferring this technique to Z-cut LiNbO3 in order to realize very efficient nonlinear devices in PPLN

    Modes Hybrides dans les Fils Quantiques Réalisés sur Niobate de Lithium en Coupe X

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    Dans ce papier, nous nous concentrerons sur l'influence des contraintes induites dans le cristal par le processus de fabrication des fils quantiques. Ces tensions sont responsables d'un couplage fort entre les polarisations qui confĂšre une nature hybride aux modes se propageant et qui doit ĂȘtre prise en considĂ©ration dans la conception des dispositifs

    Tackling the Bottleneck of Delay Tables in 3D Ultrasound Imaging

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    3D ultrasound imaging is quickly becoming a refer- ence technique for high-quality, accurate, expressive diagnostic medical imaging. Unfortunately, its computation requirements are huge and, today, demand expensive, power-hungry, bulky processing resources. A key bottleneck is the receive beamforming operation, which requires the application of many permutations of fine-grained delays among the digitized received echoes. To apply these delays in the digital domain, in principle large tables (billions of coefficients) are needed, and the access bandwidth to these tables can reach multiple TB/s, meaning that their storage both on-chip and off-chip is impractical. However, smarter implementations of the delay generation function, including forgoing the tables altogether, are possible. In this paper we explore efficient strategies to compute the delay function that controls the reconstruction of the image, and present a feasibility analysis for an FPGA platform

    Energy/Reliability Trade-Offs in Low-Voltage ReRAM-Based Non-Volatile Flip-Flop Design

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    The total power budget of Ultra-Low Power (ULP) VLSI Systems-on-Chip (SoCs) is often dominated by the leakage power of embedded memories as well as status registers. On the one hand, supply voltage scaling down to the near-threshold (near-VT) or even to the subthreshold (sub-VT) domain is a commonly used, efficient technique to reduce both leakage power and active energy dissipation. On the other hand, emerging CMOS-compatible device technologies such as Resistive Memories (ReRAMs) enable non-volatile, on-chip data storage and zero-leakage sleep periods. For the first time, we present and compare ReRAM-based Non-Volatile Flip-Flop (NVFF) topologies which are optimized for low-voltage operation (including near-VT and sub-VT operation). Three low-voltage NVFF circuit topologies are proposed and evaluated in terms of energy dissipation and reliability. Using topologies with two complementary programmed ReRAM devices, Monte Carlo simulations accounting for parametric variations confirm reliable data restore operation from the ReRAM devices at a sub- voltage as low as 400 mV. A topology using a single ReRAM device exhibits lower write energy, but requires a near- voltage for robust read. Energy characterization is performed at nominal, near-VT , and sub-VT supply voltages. The minimum energy point is reached for near-VT read operation with a total read+write energy of 735 fJ

    Optimasi Portofolio Resiko Menggunakan Model Markowitz MVO Dikaitkan dengan Keterbatasan Manusia dalam Memprediksi Masa Depan dalam Perspektif Al-Qur`an

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    Risk portfolio on modern finance has become increasingly technical, requiring the use of sophisticated mathematical tools in both research and practice. Since companies cannot insure themselves completely against risk, as human incompetence in predicting the future precisely that written in Al-Quran surah Luqman verse 34, they have to manage it to yield an optimal portfolio. The objective here is to minimize the variance among all portfolios, or alternatively, to maximize expected return among all portfolios that has at least a certain expected return. Furthermore, this study focuses on optimizing risk portfolio so called Markowitz MVO (Mean-Variance Optimization). Some theoretical frameworks for analysis are arithmetic mean, geometric mean, variance, covariance, linear programming, and quadratic programming. Moreover, finding a minimum variance portfolio produces a convex quadratic programming, that is minimizing the objective function ðð„with constraintsð ð ð„ „ ðandðŽð„ = ð. The outcome of this research is the solution of optimal risk portofolio in some investments that could be finished smoothly using MATLAB R2007b software together with its graphic analysis

    Differential cross section measurements for the production of a W boson in association with jets in proton–proton collisions at √s = 7 TeV

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    Measurements are reported of differential cross sections for the production of a W boson, which decays into a muon and a neutrino, in association with jets, as a function of several variables, including the transverse momenta (pT) and pseudorapidities of the four leading jets, the scalar sum of jet transverse momenta (HT), and the difference in azimuthal angle between the directions of each jet and the muon. The data sample of pp collisions at a centre-of-mass energy of 7 TeV was collected with the CMS detector at the LHC and corresponds to an integrated luminosity of 5.0 fb[superscript −1]. The measured cross sections are compared to predictions from Monte Carlo generators, MadGraph + pythia and sherpa, and to next-to-leading-order calculations from BlackHat + sherpa. The differential cross sections are found to be in agreement with the predictions, apart from the pT distributions of the leading jets at high pT values, the distributions of the HT at high-HT and low jet multiplicity, and the distribution of the difference in azimuthal angle between the leading jet and the muon at low values.United States. Dept. of EnergyNational Science Foundation (U.S.)Alfred P. Sloan Foundatio

    Penilaian Kinerja Keuangan Koperasi di Kabupaten Pelalawan

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    This paper describe development and financial performance of cooperative in District Pelalawan among 2007 - 2008. Studies on primary and secondary cooperative in 12 sub-districts. Method in this stady use performance measuring of productivity, efficiency, growth, liquidity, and solvability of cooperative. Productivity of cooperative in Pelalawan was highly but efficiency still low. Profit and income were highly, even liquidity of cooperative very high, and solvability was good

    Juxtaposing BTE and ATE – on the role of the European insurance industry in funding civil litigation

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    One of the ways in which legal services are financed, and indeed shaped, is through private insurance arrangement. Two contrasting types of legal expenses insurance contracts (LEI) seem to dominate in Europe: before the event (BTE) and after the event (ATE) legal expenses insurance. Notwithstanding institutional differences between different legal systems, BTE and ATE insurance arrangements may be instrumental if government policy is geared towards strengthening a market-oriented system of financing access to justice for individuals and business. At the same time, emphasizing the role of a private industry as a keeper of the gates to justice raises issues of accountability and transparency, not readily reconcilable with demands of competition. Moreover, multiple actors (clients, lawyers, courts, insurers) are involved, causing behavioural dynamics which are not easily predicted or influenced. Against this background, this paper looks into BTE and ATE arrangements by analysing the particularities of BTE and ATE arrangements currently available in some European jurisdictions and by painting a picture of their respective markets and legal contexts. This allows for some reflection on the performance of BTE and ATE providers as both financiers and keepers. Two issues emerge from the analysis that are worthy of some further reflection. Firstly, there is the problematic long-term sustainability of some ATE products. Secondly, the challenges faced by policymakers that would like to nudge consumers into voluntarily taking out BTE LEI
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