10,392 research outputs found

    The Influence of Mental Workload in Causes of System Degradation in Air Traffic Control

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    System safety and resilience is a critical concern in the air traffic domain. An important element of maintaining system safety and resilience is the ability of systems to degrade gracefully. However, previous research on the causes of system degradation in the air traffic domain are sporadic, and the potential interaction between the causes of degradation, and the resulting possible compound effect on the entire system, has been under-researched. An interview study was conducted with 12 retired controllers as participants. The results of a thematic analysis revealed the key causes of system degradation, and the associated impact on the ability of the controllers to prevent system degradation or recover the system. Findings have direct implications for identifying and mitigating potential risks of increasingly automated air traffic control systems

    SALSA : SAving Lives Staying Active to Promote Physical Activity and Healthy Eating

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    Physical inactivity, poor dietary habits, and obesity are vexing problems among minorities. SAving Lives, Staying Active (SALSA) was an 8-week randomized controlled crossover design, pilot study to promote regular physical activity (PA) and fruit and vegetable (FV) consumption as a means to preventing weight gain among women of color. Participants completed measures of demographics, PA, and dietary habits. Women (N = 50; M = 42 years) who participated were overweight (MBMI = 29.7 kg/m2; Mbody fat = 38.5%) and reported low levels of leisure time PA (M = 10.7 MET-min/wk) and FV consumption (M = 4.2 servings/day). All were randomized to a four-week (1) semiweekly Latin dance group or (2) internet-based dietary education group. All participants reported a significant increase in weekly leisure time PA from baseline (M = 10.7 MET-min/wk) to follow up (M = 34.0 MET-min/wk, P < .001), and FV consumption increased over time by group (P = .02). Data suggest that Latin dance interventions to improve PA and web-based interventions to improve dietary habits show promise for improving health among women of color

    Parametrization of the Driven Betatron Oscillation

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    An AC dipole is a magnet which produces a sinusoidally oscillating dipole field and excites coherent transverse beam motion in a synchrotron. By observing this coherent motion, the optical parameters can be directly measured at the beam position monitor locations. The driven oscillation induced by an AC dipole will generate a phase space ellipse which differs from that of the free oscillation. If not properly accounted for, this difference can lead to a misinterpretation of the actual optical parameters, for instance, of 6% or more in the cases of the Tevatron, RHIC, or LHC. The effect of an AC dipole on the linear optics parameters is identical to that of a thin lens quadrupole. By introducing a new amplitude function to describe this new phase space ellipse, the motion produced by an AC dipole becomes easier to interpret. Beam position data taken under the influence of an AC dipole, with this new interpretation in mind, can lead to more precise measurements of the normal Courant-Snyder parameters. This new parameterization of the driven motion is presented and is used to interpret data taken in the FNAL Tevatron using an AC dipole.Comment: 8 pages, 8 figures, and 1 tabl

    Excited states of a dilute Bose-Einstein condensate in a harmonic trap

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    The low-lying hydrodynamic normal modes of a dilute Bose-Einstein gas in an isotropic harmonic trap determine the corresponding Bogoliubov amplitudes. In the Thomas-Fermi limit, these modes have large low-temperature occupation numbers, and they permit an explicit construction of the dynamic structure function S(q,ω)S(q,\omega). The total noncondensate number N(0)N'(0) at zero temperature increases like R6R^6, where RR is the condensate radius measured in units of the oscillator length. The lowest dipole modes are constructed explicitly in the Bogoliubov approximation.Comment: 15 pages, REVTE

    Photons as a 21st century reagent

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    A pharmaceutical industry viewpoint on how the fundamental laws of photochemistry are used to identify the parameters required to implement photochemistry from lab to scale. Parameters such as photon stoichiometry and light intensity are highlighted within to inform future publications

    The Importance of Time Congruity in the Organisation.

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    In 1991 Kaufman, Lane, and Lindquist proposed that time congruity in terms of an individual's time preferences and the time use methods of an organisation would lead to satisfactory performance and enhancement of quality of work and general life. The research reported here presents a study which uses commensurate person and job measures of time personality in an organisational setting to assess the effects of time congruity on one aspect of work life, job-related affective well-being. Results show that time personality and time congruity were found to have direct effects on well-being and the influence of time congruity was found to be mediated through time personality, thus contributing to the person–job (P–J) fit literature which suggests that direct effects are often more important than indirect effects. The study also provides some practical examples of ways to address some of the previously cited methodological issues in P–J fit research

    Path Integrals in Polar Field Variables in QFT

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    We show how to transform a dd-dimensional Euclidean path integral in terms of two (Cartesian) fields to a path integral in terms of polar field variables. First we present a conjecture that states how this transformation should be done. Then we show that this conjecture is correct in the case of two toy models. Finally the conjecture will be proven for a general QFT model with two fields
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