Dynamics of Spontaneous Magnetization Reversal in Exchange Biased Heterostructures

The dependence of thermally induced spontaneous magnetization reversal on time-dependent cooling protocols was studied. Slower cooling and longer waiting close to the N\`{e}el temperature of the antiferromagnet ($T_N$) enhances the magnetization reversal. Cycling the temperature around $T_N$ leads to a thermal training effect under which the reversal magnitude increases with each cycle. These results suggest that spontaneous magnetization reversal is energetically favored, contrary to our present understanding of positive exchange bias

Preserving differential privacy under finite-precision semantics

International audienceThe approximation introduced by finite-precision representation of continuous data can induce arbitrarily large information leaks even when the computation using exact semantics is secure. Such leakage can thus undermine design efforts aimed at protecting sensitive information. We focus here on differential privacy, an approach to privacy that emerged from the area of statistical databases and is now widely applied also in other domains. In this approach, privacy is protected by adding noise to the values correlated to the private data. The typical mechanisms used to achieve differential privacy have been proved correct in the ideal case in which computations are made using infinite-precision semantics. In this paper, we analyze the situation at the implementation level, where the semantics is necessarily limited by finite precision, i.e., the representation of real numbers and the operations on them are rounded according to some level of precision. We show that in general there are violations of the differential privacy property, and we study the conditions under which we can still guarantee a limited (but, arguably, acceptable) variant of the property, under only a minor degradation of the privacy level. Finally, we illustrate our results on two examples: the standard Laplacian mechanism commonly used in differential privacy, and a bivariate version of it recently introduced in the setting of privacy-aware geolocation

Une analyse lexicaliste des affixes pronominaux en français

Cet article considère comme acquis que les pronoms faibles du français sont des affixes flexionnels morphologiquement attachés à une base verbale et introduit le terme affixe pronominal pour les désigner. Nous proposons une analyse syntaxique strictement lexicaliste, dans le cadre HPSG, des formes verbales fléchies pour des affixes pronominaux objets. Cette analyse explique les propriétés spécifiques de ces formes verbales au niveau de la syntaxe de la phrase, notamment (i) l’impossibilité d’un complément plein si la forme verbale est fléchie pour l’affixe correspondant; (ii) le phénomène des affixes pronominaux « non locaux », c’est-à-dire les cas où les affixes pronominaux n’apparaissent pas sur la base verbale dont ils sont des arguments sémantiques; (iii) les corrélations entre la syntaxe des dépendances qu- et des affixes pronominaux, notamment au niveau du flottement des quantificateurs. Nous faisons crucialement appel à une forme de composition de fonctions, qui permet à une tête exigeant normalement un complément saturé de se combiner avec un complément non saturé et avec les compléments exigés par celui-ci.This paper takes as its premise the idea that French weak pronouns are in fact morphologically attached inflectional affixes, and introduces the term pronominal affix for them. We propose a strictly lexicalist syntactic analysis for verbs inflected for object pronominal affixes, couched in the framework of HPSG. This analysis explains the special syntactic properties of these verb forms, especially (i) the impossibility of a full complement in the presence of the corresponding affix on the verb; (ii) the phenomenon of "non local" pronominal affixes, i.e. cases where the affixes do not appear on the verb of which they are semantic arguments; (iii) the correlations between the syntax of wh- dependencies and that of pronominal affixes specifically with respect to quantifier floating. We crucially rely on a form of function composition that allows a head which normally requires a saturated complement to combine with a non-saturated complemement and with those complements which the latter normally requires

Detecting and Intervening on Suicidality in Emergency Departments: The ED-SAFE Study [English and Spanish versions]

A Spanish translation of this publication is available to download under Additional Files. In 2016, there were 44,695 deaths by suicide in the United States. Suicide accounts for 1.6% of all deaths and is the tenth leading cause of death in the United States. Suicide attempts are much more common, with more than 1 million people per year attempting suicide. In response to this critical need in 2009, the National Institute for Mental Health funded ED Safety Assessment and Follow-up Evaluation (ED-SAFE). ED-SAFE was a large, three-phase suicide intervention trial designed to determine if an ED-initiated intervention could reduce subsequent suicidal behavior. Read more about the how the ED-SAFE study developed and tested a feasible approach to universal emergency department-based screening for suicide risk, as well as effective interventions that can be initiated at the emergency department visit

LCF Life of NiCr-Y Coated Disk Alloys After Shot Peening, Oxidation and Hot Corrosion

In a prior companion study (Ref. 1), three different Ni-Cr coating compositions (29, 35.5, 45 wt% Cr) were applied at two thicknesses by Plasma Enhanced Magnetron Sputtering (PEMS) to two similar Ni-based disk alloys. One coating also received a thin ZrO2 overcoat. The low cycle fatigue (LCF) life of each coating was determined at 760 C and was less than that of the uncoated specimens. In this followon effort, shot peening was examined as a means to improve the as-deposited coating morphology as well as impart a residual compressive stress in the near-surface region. After evaluating the effect of the shot peening on the LCF life, the effectiveness of the shot-peened coating in protecting the disk alloy from oxidation and hot corrosion attack was evaluated. This evaluation was accomplished by exposing coated and shot-peened specimens to 500 h of oxidation followed by 50 h of hot corrosion, both at 760 C in air. These exposed specimens were then tested in fatigue and compared to similarly treated and exposed uncoated specimens. For all cases, shot peening improved the LCF life of the coated specimens. More specifically, the highest Cr coating showed the best LCF life of the coated specimens after shot peening, as well as after the environmental exposures. Characterization of the coatings after shot peening, oxidation, hot corrosion and LCF testing is presented and discussed

Dynamic Spin-Polarized Resonant Tunneling in Magnetic Tunnel Junctions

Precisely engineered tunnel junctions exhibit a long sought effect that occurs when the energy of the electron is comparable to the potential energy of the tunneling barrier. The resistance of metal-insulator-metal tunnel junctions oscillates with an applied voltage when electrons that tunnel directly into the barrier's conduction band interfere upon reflection at the classical turning points: the insulator-metal interface, and the dynamic point where the incident electron energy equals the potential barrier inside the insulator. A model of tunneling between free electron bands using the exact solution of the Schroedinger equation for a trapezoidal tunnel barrier qualitatively agrees with experiment.Comment: 4pgs, 3 fig

Family business growth around the world

Growth is important for the long-term success of a business. Regrettably, the impact of family influence on firm growth is largely neglected. We examine whether family firms have a higher growth rate than their nonfamily counterparts. Based on a large sample of firms across 43 countries over a 10-year period, we show that family firms on average have higher growth rates than nonfamily firms, and this positive effect is greater for family firms operating in strong national institutional environments which are less corrupt, more democratic, more subject to rule of law, and have effective government policies. We also find that the positive effect of family influence on firm growth varies significantly across different types of family firms and different business cycles. These findings show that family control has an economically significant impact on growth rates and important implications for both family firm theory and practice

Nucleon Generalized Parton Distributions and Holographic Models

Using ideas from Light Front Holography, we discuss the calculation of the nucleon helicity-independent generalized parton distributions of quarks in the zero skewness case.Comment: Prepared for LIGHTCONE 2011, 23 - 27 May, 2011, Dalla