11,916 research outputs found

    Typing Quantum Superpositions and Measurement

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    We propose a way to unify two approaches of non-cloning in quantum lambda-calculi. The first approach is to forbid duplicating variables, while the second is to consider all lambda-terms as algebraic-linear functions. We illustrate this idea by defining a quantum extension of first-order simply-typed lambda-calculus, where the type is linear on superposition, while allows cloning base vectors. In addition, we provide an interpretation of the calculus where superposed types are interpreted as vector spaces and non-superposed types as their basis.Fil: Díaz Caro, Alejandro. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Dowek, Gilles. Institut National de Recherche en Informatique et en Automatique; Franci

    Dynamics of active membranes with internal noise

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    We study the time-dependent height fluctuations of an active membrane containing energy-dissipating pumps that drive the membrane out of equilibrium. Unlike previous investigations based on models that neglect either curvature couplings or random fluctuations in pump activities, our formulation explores two new models that take both of these effects into account. In the first model, the magnitude of the nonequilibrium forces generated by the pumps is allowed to fluctuate temporally. In the second model, the pumps are allowed to switch between "on" and "off" states. We compute the mean squared displacement of a membrane point for both models, and show that they exhibit distinct dynamical behaviors from previous models, and in particular, a superdiffusive regime specifically arising from the shot noise.Comment: 7 pages, 4 figure

    Minimizing Test Power in SRAM through Reduction of Pre-charge Activity

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    In this paper we analyze the test power of SRAM memories and demonstrate that the full functional pre-charge activity is not necessary during test mode because of the predictable addressing sequence. We exploit this observation in order to minimize power dissipation during test by eliminating the unnecessary power consumption associated with the pre-charge activity. This is achieved through a modified pre-charge control circuitry, exploiting the first degree of freedom of March tests, which allows choosing a specific addressing sequence. The efficiency of the proposed solution is validated through extensive Spice simulations

    Central Proper-Motion Kinematics of NGC 6752

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    We present proper motions derived from WFPC2 imaging for stars in the core of the peculiar globular cluster NGC 6752. The central velocity dispersion in both components of the proper motion is 12 km/s. We discuss the implications of this result as well as the intrinsic difficulties in making such measurements. We also give an alternative correction for the 34-row problem in the WFPC2 CCDs.Comment: 25 pages, 7 figures, 1 table included. Accepted for publication in A

    KMOS LENsing Survey (KLENS) : morpho-kinematic analysis of star-forming galaxies at z2z \sim 2

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    We present results from the KMOS lensing survey-KLENS which is exploiting gravitational lensing to study the kinematics of 24 star forming galaxies at 1.4<z<3.51.4<z<3.5 with a median mass of log(M/M)=9.6\rm log(M_\star/M_\odot)=9.6 and median star formation rate (SFR) of 7.5Myr1\rm 7.5\,M_\odot\,yr^{-1}. We find that 25% of these low-mass/low-SFR galaxies are rotation dominated, while the majority of our sample shows no velocity gradient. When combining our data with other surveys, we find that the fraction of rotation dominated galaxies increases with the stellar mass, and decreases for galaxies with a positive offset from the main sequence. We also investigate the evolution of the intrinsic velocity dispersion, σ0\sigma_0, as a function of the redshift, zz, and stellar mass, M\rm M_\star, assuming galaxies in quasi-equilibrium (Toomre Q parameter equal to 1). From the zσ0z-\sigma_0 relation, we find that the redshift evolution of the velocity dispersion is mostly expected for massive galaxies (log(M/M)>10\rm log(M_\star/M_\odot)>10). We derive a Mσ0\rm M_\star-\sigma_0 relation, using the Tully-Fisher relation, which highlights that a different evolution of the velocity dispersion is expected depending on the stellar mass, with lower velocity dispersions for lower masses, and an increase for higher masses, stronger at higher redshift. The observed velocity dispersions from this work and from comparison samples spanning 0<z<3.50<z<3.5 appear to follow this relation, except at higher redshift (z>2z>2), where we observe higher velocity dispersions for low masses (log(M/M)9.6\rm log(M_\star/M_\odot)\sim 9.6) and lower velocity dispersions for high masses (log(M/M)10.9\rm log(M_\star/M_\odot)\sim 10.9) than expected. This discrepancy could, for instance, suggest that galaxies at high-zz do not satisfy the stability criterion, or that the adopted parametrisation of the specific star formation rate and molecular properties fail at high redshift.Comment: Accepted for publication in A&A, 21 pages, 10 figure

    Resource-driven Substructural Defeasible Logic

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    Linear Logic and Defeasible Logic have been adopted to formalise different features relevant to agents: consumption of resources, and reasoning with exceptions. We propose a framework to combine sub-structural features, corresponding to the consumption of resources, with defeasibility aspects, and we discuss the design choices for the framework

    Call-by-value non-determinism in a linear logic type discipline

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    We consider the call-by-value lambda-calculus extended with a may-convergent non-deterministic choice and a must-convergent parallel composition. Inspired by recent works on the relational semantics of linear logic and non-idempotent intersection types, we endow this calculus with a type system based on the so-called Girard's second translation of intuitionistic logic into linear logic. We prove that a term is typable if and only if it is converging, and that its typing tree carries enough information to give a bound on the length of its lazy call-by-value reduction. Moreover, when the typing tree is minimal, such a bound becomes the exact length of the reduction

    Confirmation of the planet around HD 95086 by direct imaging

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    VLT/NaCo angular differential imaging at L' (3.8 microns) revealed a probable giant planet comoving with the young and early-type HD 95086 also known to harbor an extended debris disk. The discovery was based on the proper motion analysis of two datasets spanning 15 months. However, the second dataset suffered from bad atmospheric conditions, which limited the significance of the redetection at the 3 sigma level. In this Letter, we report new VLT/NaCo observations of HD 95086 obtained on 2013 June 26-27 at L' to recover the planet candidate. We unambiguously redetect the companion HD 95086 b with multiple independent pipelines at a signal-to-noise ratio greater than or equal to 5. Combined with previously reported measurements, our astrometry decisively shows that the planet is comoving with HD 95086 and inconsistent with a background object. With a revised mass of 5 pm 2 Jupiter masses, estimated from its L' photometry and "hot-start" models at 17 pm 4 Myr, HD 95086 b becomes a new benchmark for further physical and orbital characterization of young giant planets.Comment: accepted for publication to AP
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