NASA/RAE collaboration on nonlinear control using the F-8C digital fly-by-wire aircraft

Design procedures are reviewed for variable integral control to optimize response (VICTOR) algorithms and results of preliminary flight tests are presented. The F-8C aircraft is operated in the remotely augmented vehicle (RAV) mode, with the control laws implemented as FORTRAN programs on a ground-based computer. Pilot commands and sensor information are telemetered to the ground, where the data are processed to form surface commands which are then telemetered back to the aircraft. The RAV mode represents a singlestring (simplex) system and is therefore vulnerable to a hardover since comparison monitoring is not possible. Hence, extensive error checking is conducted on both the ground and airborne computers to prevent the development of potentially hazardous situations. Experience with the RAV monitoring and validation procedures is described

Semi-classical limit and minimum decoherence in the Conditional Probability Interpretation of Quantum Mechanics

The Conditional Probability Interpretation of Quantum Mechanics replaces the abstract notion of time used in standard Quantum Mechanics by the time that can be read off from a physical clock. The use of physical clocks leads to apparent non-unitary and decoherence. Here we show that a close approximation to standard Quantum Mechanics can be recovered from conditional Quantum Mechanics for semi-classical clocks, and we use these clocks to compute the minimum decoherence predicted by the Conditional Probability Interpretation.Comment: 8 pages, references adde

Poststroke Trajectories: The Process of Recovery Over the Longer Term Following Stroke

We adopted a grounded theory approach to explore the process of recovery experienced by stroke survivors over the longer term who were living in the community in the United Kingdom, and the interacting factors that are understood to have shaped their recovery trajectories. We used a combination of qualitative methods. From the accounts of 22 purposively sampled stroke survivors, four different recovery trajectories were evident: (a) meaningful recovery, (b) cycles of recovery and decline, (c) ongoing disruption, (d) gradual, ongoing decline. Building on the concept of the illness trajectory, our findings demonstrate how multiple, interacting factors shape the process and meaning of recovery over time. Such factors included conception of recovery and meanings given to the changing self, the meanings and consequences of health and illness experiences across the life course, loss, sense of agency, and enacting relationships. Awareness of the process of recovery will help professionals better support stroke survivors

Search for antiproton decay at the Fermilab Antiproton Accumulator

A search for antiproton decay has been made at the Fermilab Antiproton Accumulator. Limits are placed on thirteen antiproton decay modes. The results include the first explicit experimental limits on the muonic decay modes of the antiproton, and the first limits on the decay modes e- gamma gamma, and e- omega. The most stringent limit is for the decay mode pbar-> e- gamma. At 90% C.L. we find that tau/B(pbar-> e- gamma) > 7 x 10^5 yr. The most stringent limit for decay modes with a muon in the final state is for the decay pbar-> mu- gamma. At 90% C.L. we find that tau/B(pbar-> mu- gamma) > 5 x 10^4 yr.Comment: 20 pages, 8 figures. Submitted to Phys. Rev. D. Final results on 13 channels (was 15) are presente

Hydrologic Modeling of Urban Development Scenarios and Low-Impact Design Systems on an Undisturbed Coastal Forested Watershed under Extreme Rainfall-Runoff Events and Hydro-Meteorological Conditions in a Changing Climate

Watershed 80 (WS80), a reference watershed located in the USDA Forest Service Santee Experimental Forest, has been undisturbed since 1937, including from the silviculture that has historically characterized the region. Therefore, the results from this study are assumed to serve as a baseline of the developmental behavior for similar watersheds along the Southeastern Coastal Plain. The purpose of this study was first to analyze and compare the outputs of two rainfall-runoff models, the NRCS program WinTR-55 and the USGS Regional Regression Equations (RREs), with historical data gathered from WS80 to examine which model most accurately fits existing peak flow data. An accurate sense of peak flows is crucial in both the conservation and planning of sites, as proper stormwater management and infrastructure preserve the integrity of both natural resources and humanmade structures. Second, the study sought to analyze the impact of hypothetical development on design peak flow rate with up to 15% watershed imperviousness using each model. Additionally, two hypothetical scenarios of low-impact design (LID) practices such as vegetative rooftops and permeable pavements on development within the watershed were examined using the Purdue University software L-THIA. The USGS RREs overpredicted peak flows by 84% at a 5-yr return period to 12% at a 100-yr return period. WinTR-55 underpredicted peak flows by 31% at a 5-yr return period to 52% at a 100-yr return period. Increases in impervious surfaces led to subsequent increases in modeled design peak flows, with the greatest post-development change in design peak flow rate occurring within the USGS model. Although results showed that neither the USGS nor WinTR-55 models accurately predicted the design peak flow data from the watershed, USGS predictions were closer to the observed values for 50-yr or higher return periods than that from WinTR-55. Though LID practices were only applied up to a hypothetical 15% of the watershed, when fully implemented they were estimated to exert a 98% reduction in runoff which translated to a total reduction in volume by 20% and depth by 16% as compared to traditional design counterparts. This hypothesized evidence indicates the merit for using LID practices for runoff management even in situations of low imperviousness

Production of Gravitational Waves in the nMSSM

During a strongly first-order phase transition gravitational waves are produced by bubble collisions and turbulent plasma motion. We analyze the relevant characteristics of the electroweak phase transition in the nMSSM to determine the generated gravitational wave signal. Additionally, we comment on correlations between the production of gravitational waves and baryogenesis. We conclude that the gravitational wave relic density in this model is generically too small to be detected in the near future by the LISA experiment. We also consider the case of a "Standard Model" with dimension-six Higgs potential, which leads to a slightly stronger signal of gravitational waves.Comment: 29 pages, 7 figures; published version, some comments adde

Blaming Bill Gates AGAIN! Misuse, overuse and misunderstanding of performance data in sport

Recently in Sport, Education and Society, Williams and Manley (2014) argued against the heavy reliance on technology in professional Rugby Union and elite sport in general. In summary, technology is presented as an elitist, ‘gold standard’ villain that management and coaches use to exert control and by which players lose autonomy, identity, motivation, social interactions and expertise. In this article we suggest that the sociological interpretations and implications offered by Williams and Manley may be somewhat limited when viewed in isolation. In doing so, we identify some core methodological issues in Williams and Manley’s study and critically consider important arguments for utilising technology; notably, to inform coach decision making and generate player empowerment. Secondly, we present a different, yet perhaps equally concerning, practice-oriented interpretation of the same results but from alternative coaching and expertise literature. Accordingly, we suggest that Williams and Manley have perhaps raised their alarm prematurely, inappropriately and on somewhat shaky foundations. We also hope to stimulate others to consider contrary positions, or at least to think about this topic in greater detail. More specifically, we encourage coaches and academics to think carefully about what technology is employed, how and why, and then the means by which these decisions are discussed with and, preferably, sold to players. Certainly, technology can significantly enhance coach decision making and practice, while also helping players to optimise their focus, empowerment and independence in knowing how to achieve their personal and collective goals