15,431 research outputs found

    Forecasting Equicorrelation

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    We study the out-of-sample forecasting performance of several time-series models of equicorrelation, which is the average pairwise correlation between a number of assets. Building on the existing Dynamic Conditional Correlation and Linear Dynamic Equicorrelation models, we propose a model that uses proxies for equicorrelation based on high-frequency intraday data, and the level of equicorrelation implied by options prices. Using state-of-the-art statistical evaluation technology, we find that the use of both realized and implied equicorrelations outperform models that use daily data alone. However, the out-of-sample forecasting benefits of implied equicorrelation disappear when used in conjunction with the realized measures.Equicorrelation, Implied Correlation, Multivariate GARCH, DCC

    Opportunities and Challenges Around a Tool for Social and Public Web Activity Tracking

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    While the web contains many social websites, people are generally left in the dark about the activities of other people traversing the web as a whole. In this paper, we explore the potential benefits and privacy considerations around generating a real-time, publicly accessible stream of web activity where users can publish chosen parts of their web browsing data. Taking inspiration from social media systems, we describe individual benefits that can be unlocked by such sharing and that may incentivize users to publish aspects of their browsing. We ask whether and how these benefits outweigh potential costs in lost privacy. We conduct our study of public web activity sharing through scenario-based interviews and a field deployment of a tool for web activity sharing

    Performance of the Components of the XJ34-WE-32 Turbojet Engine over a Range of Engine and Flight Conditions

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    Performance of the compressor, combustor, and turbine operating as integral parts of the XJ34-WE-32 turbojet engine was determined in the Lewis altitude wind tunnel over a range of altitudes from 5000 to 55,000 feet and flight Mach numbers from 0.28 to 1.05. Data were obtained for each of four exhaust-nozzle areas and are presented in graphical and tabular form

    Studies of the large-scale structure in adiabatic and moderately-wall-heated subsonic boundary layers

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    Simultaneous velocity-optical measurements in subsonic boundary layers were conducted in order to investigate the relationship between the instantaneous 2-D wavefronts, measured by different optical sensors, the Malley probe and 2-D Shack-Hartmann sensors, and the instantaneous large-scale structure along a wall-normal plane, using PIV in both incompressible and compressible subsonic boundary layers. These systematic studies of the instantaneous relation between the large-scale boundary layer structure and its aero-optical signature provide additional understanding of the instantaneous dynamics of the large-scale structure at subsonic and transonic speeds

    Exploring newly qualified doctors' workplace stressors:an interview study from Australia

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    Purpose Postgraduate year 1 (PGY1) doctors suffer from high levels of psychological distress, yet the contributory factors are poorly understood. This study used an existing model of workplace stress to explore the elements most pertinent to PGY1 doctors. In turn, the data were used to amend and refine the conceptual model to better reflect the unique experiences of PGY1 doctors. Method Focus groups were undertaken with PGY1 doctors working at four different health services in Victoria, Australia. Transcripts were coded using Michie's model of workplace stress as the initial coding template. Remaining text was coded inductively and the supplementary codes were used to modify and amplify Michie's framework. Results There were 37 participants in total. Key themes included stressors intrinsic to the job, such as work overload and long hours, as well as those related to the context of work such as lack of role clarity and relationships with colleagues. The main modification to Michie's framework was the addition of the theme of uncertainty. This concept related to most of the pre-existing themes in complex ways, culminating in an overall sense of anxiety. Conclusions Michie's model of workplace stress can be effectively used to explore the stressors experienced by PGY1 doctors. Pervasive uncertainty may help to explain the high levels of psychological morbidity in this group. While some uncertainty will always remain, the medical education community must seek ways to improve role clarity and promote mutual respect.</p
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