541 research outputs found
LISACode : A scientific simulator of LISA
A new LISA simulator (LISACode) is presented. Its ambition is to achieve a
new degree of sophistication allowing to map, as closely as possible, the
impact of the different sub-systems on the measurements. LISACode is not a
detailed simulator at the engineering level but rather a tool whose purpose is
to bridge the gap between the basic principles of LISA and a future,
sophisticated end-to-end simulator. This is achieved by introducing, in a
realistic manner, most of the ingredients that will influence LISA's
sensitivity as well as the application of TDI combinations. Many user-defined
parameters allow the code to study different configurations of LISA thus
helping to finalize the definition of the detector. Another important use of
LISACode is in generating time series for data analysis developments
Reluplex: An Efficient SMT Solver for Verifying Deep Neural Networks
Deep neural networks have emerged as a widely used and effective means for
tackling complex, real-world problems. However, a major obstacle in applying
them to safety-critical systems is the great difficulty in providing formal
guarantees about their behavior. We present a novel, scalable, and efficient
technique for verifying properties of deep neural networks (or providing
counter-examples). The technique is based on the simplex method, extended to
handle the non-convex Rectified Linear Unit (ReLU) activation function, which
is a crucial ingredient in many modern neural networks. The verification
procedure tackles neural networks as a whole, without making any simplifying
assumptions. We evaluated our technique on a prototype deep neural network
implementation of the next-generation airborne collision avoidance system for
unmanned aircraft (ACAS Xu). Results show that our technique can successfully
prove properties of networks that are an order of magnitude larger than the
largest networks verified using existing methods.Comment: This is the extended version of a paper with the same title that
appeared at CAV 201
Apport des tests de quantification de la libĂ©ration dâinterfĂ©ron gamma par les lymphocytes T sensibilisĂ©s pour le diagnostic des infections tuberculeuses
RĂ©sumĂ©LâintradermorĂ©action cutanĂ©e Ă la tuberculine, couramment utilisĂ©e depuis un siĂšcle pour le diagnostic dâinfection tuberculeuse, prĂ©sente de nombreux inconvĂ©nients. De nouveaux tests diagnostiques ont Ă©tĂ© rĂ©cemment introduits. Ils mesurent soit la production dâinterfĂ©ron-Îł dans le sang total, soit le nombre de lymphocytes T producteurs dâinterfĂ©ron-Îł aprĂšs stimulation in vitro par des protĂ©ines spĂ©cifiques de M. tuberculosis, absentes du BCG et de la plupart des mycobactĂ©ries atypiques. Le gain en spĂ©cificitĂ© permet de rĂ©duire les rĂ©sultats faux positifs chez les sujets vaccinĂ©s, Ă©vitant ainsi le coĂ»t de chimioprophylaxies inutiles et potentiellement toxiques. Le gain en sensibilitĂ©, identifiant les infections tuberculeuses latentes parmi les sujets ayant une IDR faussement nĂ©gative, permet dâaccroĂźtre les performances diagnostiques dans les populations les plus Ă risques de progresser vers la tuberculose maladie, Ă savoir les patients immunodĂ©primĂ©s. LâĂ©valuation de ces tests doit dĂ©sormais se focaliser sur certains points qui restent Ă prĂ©ciser : leur sensibilitĂ© chez lâenfant et le sujet immunodĂ©primĂ©, leurs valeurs prĂ©dictives positive et nĂ©gative et lâinterprĂ©tation de leur variation Ă©ventuelle au cours du temps, que les patients soient traitĂ©s ou non
Quasi-static and propagating modes in three-dimensional THz circuits
We provide an analysis of the electromagnetic modes of three-dimensional metamaterial resonators in the THz frequency range. The fundamental resonance of the structures is fully described by an analytical circuit model, which not only reproduces the resonant frequencies but also the coupling of the metamaterial with an incident THz radiation. We also demonstrate the contribution of the propagation effects, and show how they can be reduced by design. In the optimized design, the electric field energy is lumped into ultra-subwavelength (λ/100) capacitors, where we insert a semiconductor absorber based on the collective electronic excitation in a two dimensional electron gas. The optimized electric field confinement is exhibited by the observation of the ultra-strong light-matter coupling regime, and opens many possible applications for these structures in detectors, modulators and sources of THz radiation
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