Transonic aeroelastic analyses

In this paper, means are investigated whereby the effects on loading of the shock-wave patterns and non-linearities associated with transonic flow may be included in an aeroelastic analysis. These effects if present on a rigid wing would also exist, although in a modified form, for a flexible wing of the same planform under the same flight conditions. Three methods are described for adjusting linearised theoretical aerodynamic influence coefficients so that the predicted aerodynamic load distribution on a rigid wing at incidence and at the required Mach number agrees with the measured distribution. Thereafter, it is assumed that these modified influence coefficients, which are possibly dependent on Incidence, may be applied to the prediction of the load distribution on the same wing planform at the same Mach number but with an arbitrary spanwise twist variation. It is proposed that the methods be applicable throughout the entire speed range but are pursued in detail only for transonic speeds for which the linearised theories break down. Two methods are tested by applying them to wind-tunnel data measured at Mach numbers of 0.30 and 0,94 for a series of flexible wings with different geometrical spanwise twist distributions. The elastic twist distribution for each wing under aerodynamic loading is known or can be calculated. The wings are of aspect ratio 4, quarter-chord sweep of 4

Exploring the Challenges of Reentry Among Female Former Offenders

AbstractThe incarceration rate of female in the United States is growing faster than the rate of male ex-offenders. This purpose of this generic qualitative study was to understand female ex-offenders’ perceptions of reentry programs. The ecological system theory was used to explore how family support, federal and state financial support, and the economic conditions of the neighborhood ex-offenders were returning to influenced their return to society. Data were collected via semistructured interviews with female ex-offenders who had completed a reentry program and had not recidivated for 1 year. The use of Yin’s 5-step process for data analysis provided the following structured approach: (a) compile the data, (b) dissemble the data, (c) reassemble the data, (d) interpret the meaning of the data, and (e) conclude the data. Data were coded to develop 8 common themes: family support, support of probation and parole officer, employment, reentry programs, faith, determination, accountability, and education. The results of this study can lead to positive social change by providing human service workers with information about female ex-offenders and what is needed to assist them with returning to society. When human service workers and providers understand the challenges faced by female exoffenders they will be able to provide programs that meet the needs of the population

Stochastic Invariants for Probabilistic Termination

Termination is one of the basic liveness properties, and we study the termination problem for probabilistic programs with real-valued variables. Previous works focused on the qualitative problem that asks whether an input program terminates with probability~1 (almost-sure termination). A powerful approach for this qualitative problem is the notion of ranking supermartingales with respect to a given set of invariants. The quantitative problem (probabilistic termination) asks for bounds on the termination probability. A fundamental and conceptual drawback of the existing approaches to address probabilistic termination is that even though the supermartingales consider the probabilistic behavior of the programs, the invariants are obtained completely ignoring the probabilistic aspect. In this work we address the probabilistic termination problem for linear-arithmetic probabilistic programs with nondeterminism. We define the notion of {\em stochastic invariants}, which are constraints along with a probability bound that the constraints hold. We introduce a concept of {\em repulsing supermartingales}. First, we show that repulsing supermartingales can be used to obtain bounds on the probability of the stochastic invariants. Second, we show the effectiveness of repulsing supermartingales in the following three ways: (1)~With a combination of ranking and repulsing supermartingales we can compute lower bounds on the probability of termination; (2)~repulsing supermartingales provide witnesses for refutation of almost-sure termination; and (3)~with a combination of ranking and repulsing supermartingales we can establish persistence properties of probabilistic programs. We also present results on related computational problems and an experimental evaluation of our approach on academic examples.Comment: Full version of a paper published at POPL 2017. 20 page

On the relation between Differential Privacy and Quantitative Information Flow

Differential privacy is a notion that has emerged in the community of statistical databases, as a response to the problem of protecting the privacy of the database's participants when performing statistical queries. The idea is that a randomized query satisfies differential privacy if the likelihood of obtaining a certain answer for a database $x$ is not too different from the likelihood of obtaining the same answer on adjacent databases, i.e. databases which differ from $x$ for only one individual. Information flow is an area of Security concerned with the problem of controlling the leakage of confidential information in programs and protocols. Nowadays, one of the most established approaches to quantify and to reason about leakage is based on the R\'enyi min entropy version of information theory. In this paper, we analyze critically the notion of differential privacy in light of the conceptual framework provided by the R\'enyi min information theory. We show that there is a close relation between differential privacy and leakage, due to the graph symmetries induced by the adjacency relation. Furthermore, we consider the utility of the randomized answer, which measures its expected degree of accuracy. We focus on certain kinds of utility functions called "binary", which have a close correspondence with the R\'enyi min mutual information. Again, it turns out that there can be a tight correspondence between differential privacy and utility, depending on the symmetries induced by the adjacency relation and by the query. Depending on these symmetries we can also build an optimal-utility randomization mechanism while preserving the required level of differential privacy. Our main contribution is a study of the kind of structures that can be induced by the adjacency relation and the query, and how to use them to derive bounds on the leakage and achieve the optimal utility

Microscopic theory for the light-induced anomalous Hall effect in graphene

We employ a quantum Liouville equation with relaxation to model the recently observed anomalous Hall effect in graphene irradiated by an ultrafast pulse of circularly polarized light. In the weak-field regime, we demonstrate that the Hall effect originates from an asymmetric population of photocarriers in the Dirac bands. By contrast, in the strong-field regime, the system is driven into a non-equilibrium steady state that is well-described by topologically non-trivial Floquet-Bloch bands. Here, the anomalous Hall current originates from the combination of a population imbalance in these dressed bands together with a smaller anomalous velocity contribution arising from their Berry curvature. This robust and general finding enables the simulation of electrical transport from light-induced Floquet-Bloch bands in an experimentally relevant parameter regime and creates a pathway to designing ultrafast quantum devices with Floquet-engineered transport properties

Parametric and sensitivity analysis for a proposed filtered tailings storage facility in challenging topography

Parametric and sensitivity analyses were performed for a proposed filtered tail- ings storage facility in challenging topography from the Southern Peru region. The purpose was to identify elements which are likely to dictate performance and stability, and to understand the risk profile for the facility. The analyses were performed varying: foundation material physical and hydraulic properties, tailings physical and hydraulic properties, foundation configuration, seismicity, and staged construction. The physical properties of the foundation material were varied by changing the Mohr-Coulomb strength parameters c’ and φ’, whereas the hydraulic properties were varied by moving the groundwater table upwards or saturating a larger amount of the foundation material. A similar approach was adopted in order to vary the physical and hydraulic properties of the tailings. The foundation configuration was varied by hypothetically moving the starter buttress closer to the edge of steep slopes further downhill from the facility. Staged construction stability analyses were simulated by analyzing filtered tailings fill configurations, which followed the overall design slope but varied in height. All analyses presented herein were conducted for the most critical failure mode for each scenario. The results from these parametric analyses showed that the design of the facility was highly sensitive to tailings potential saturation. In the simulation scenarios, saturation of the tailings caused instability in both static and seismic conditions. This sensitivity to moisture conditions highlighted the importance of properly defining the unsaturated filtered tailings parameters and simulating water infiltration processes through the vadose zone.Fil: Preciado, H. F. AMEC S.A; Perú.Fil: Ale, J. AMEC S.A; Perú.Fil: Byler, B. AMEC Englewood; USA.Fil: Perez, F. AMEC S.A; Perú.Fil: Mejía, V. AMEC S.A; Perú.Fil: McIver, D. Minera IRL SA; Perú.Otras Ingeniería Civi

Nonlocality of Two-Mode Squeezing with Internal Noise

We examine the quantum states produced through parametric amplification with internal quantum noise. The internal diffusion arises by coupling both modes of light to a reservoir for the duration of the interaction time. The Wigner function for the diffused two-mode squeezed state is calculated. The nonlocality, separability, and purity of these quantum states of light are discussed. In addition, we conclude by studying the nonlocality of two other continuous variable states: the Werner state and the phase-diffused state for two light modes.Comment: 7 pages, 5 figures, submitted to PR

Noninvasive Biomarkers for Cardiovascular Dysfunction Programmed in Male Offspring of Adverse Pregnancy.

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Constraining Unmodeled Physics with Compact Binary Mergers from GWTC-1

We present a flexible model to describe the effects of generic deviations of observed gravitational wave signals from modeled waveforms in the LIGO and Virgo gravitational wave detectors. With the detection of 11 gravitational wave events from the GWTC-1 catalog, we are able to constrain possible deviations from our modeled waveforms. In this paper we present our coherent spline model that describes the deviations, then choose to validate our model on an example phenomenological and astrophysically motivated departure in waveforms based on extreme spontaneous scalarization. We find that the model is capable of recovering the simulated deviations. By performing model comparisons we observe that the spline model effectively describes the simulated departures better than a normal compact binary coalescence (CBC) model. We analyze the entire GWTC-1 catalog of events with our model and compare it to a normal CBC model, finding that there are no significant departures from the modeled template gravitational waveforms used