20,371 research outputs found
Genetics and insurance in the United Kingdom 1995-2010: the rise and fall of scientific discrimination
Around the millennium there was extensive debate in the United Kingdom of the possible use of predictive genetic tests by insurance companies. Many insurance experts, geneticists and public policymakers appeared to believe that genetic test results would soon become widely used by the insurance industry. This expectation has not been borne out. This article outlines the history of exaggerated perceptions of the significance of genetic test results to insurance, with particular reference to the United Kingdom, suggesting reasons why they arose and also why they have declined. The article concludes with some speculation about how policy on genetics and insurance might develop in future
The Supernova Legacy Survey 3-year sample: Type Ia supernovae photometric distances and cosmological constraints
Aims. We present photometric properties and distance measurements of 252 high redshift Type Ia supernovae (0.15 < z < 1.1)
discovered during the first three years of the Supernova Legacy Survey (SNLS). These events were detected and their multi-colour
light curves measured using the MegaPrime/MegaCam instrument at the Canada-France-Hawaii Telescope (CFHT), by repeatedly
imaging four one-square degree fields in four bands. Follow-up spectroscopy was performed at the VLT, Gemini and Keck telescopes
to confirm the nature of the supernovae and to measure their redshifts.
Methods. Systematic uncertainties arising from light curve modeling are studied, making use of two techniques to derive the peak
magnitude, shape and colour of the supernovae, and taking advantage of a precise calibration of the SNLS fields.
Results. A flat ΛCDM cosmological fit to 231 SNLS high redshift type Ia supernovae alone gives Ω_M = 0.211 ± 0.034(stat) ±
0.069(sys). The dominant systematic uncertainty comes from uncertainties in the photometric calibration. Systematic uncertainties
from light curve fitters come next with a total contribution of ± 0.026 on Ω_M. No clear evidence is found for a possible evolution of
the slope (β) of the colour-luminosity relation with redshift
Challenges of physiological monitoring in a Navy operational setting
Challenges to physiological monitoring in the Navy include environmental extremes, acceptance of use by test subjects, data transfer, data interpretation, and capability of relating collected data to valid operational relevant criterion measures. These problems are discussed with respect to diving, electrophysiological monitoring, in-flight monitoring, aircrew fatigue, in-flight cardiac stress, and in-flight monitoring devices
Error bounds for monotone approximation schemes for parabolic Hamilton-Jacobi-Bellman equations
We obtain non-symmetric upper and lower bounds on the rate of convergence of
general monotone approximation/numerical schemes for parabolic Hamilton Jacobi
Bellman Equations by introducing a new notion of consistency. We apply our
general results to various schemes including finite difference schemes,
splitting methods and the classical approximation by piecewise constant
controls
Olympic Coast National Marine Sanctuary Habitat Mapping: Survey report and classification of side scan sonar data from surveys HMPR-114-2004-02 and HMPR-116-2005-01.
The Olympic Coast National Marine Sanctuary (OCNMS) continues to invest significant resources into seafloor mapping activities along Washington’s outer coast (Intelmann and Cochrane 2006; Intelmann et al. 2006; Intelmann 2006). Results from these annual mapping efforts offer a snapshot of current ground conditions, help to guide research and management activities, and provide a baseline for assessing the impacts of various threats
to important habitat. During the months of August 2004 and May and July 2005, we used side scan sonar to image several regions of the sea floor in the northern OCNMS, and the
data were mosaicked at 1-meter pixel resolution. Video from a towed camera sled, bathymetry data, sedimentary samples and side scan sonar mapping were integrated to describe geological and biological aspects of habitat. Polygon features were created and attributed with a hierarchical deep-water marine benthic classification scheme (Greene et
al. 1999). For three small areas that were mapped with both side scan sonar and multibeam echosounder, we made a comparison of output from the classified images indicating little difference in results between the two methods. With these considerations, backscatter derived from multibeam bathymetry is currently a costefficient and safe method for seabed imaging in the shallow (<30 meters) rocky waters of
OCNMS. The image quality is sufficient for classification purposes, the associated depths provide further descriptive value and risks to gear are minimized. In shallow waters (<30 meters) which do not have a high incidence of dangerous rock pinnacles, a towed multi-beam side scan sonar could provide a better option for obtaining seafloor
imagery due to the high rate of acquisition speed and high image quality, however the high probability of losing or damaging such a costly system when deployed as a towed
configuration in the extremely rugose nearshore zones within OCNMS is a financially risky proposition. The development of newer technologies such as intereferometric
multibeam systems and bathymetric side scan systems could also provide great potential for mapping these nearshore rocky areas as they allow for high speed data acquisition,
produce precisely geo-referenced side scan imagery to bathymetry, and do not experience the angular depth dependency associated with multibeam echosounders allowing larger range scales to be used in shallower water. As such, further investigation of these systems is needed to assess their efficiency and utility in these environments compared to traditional side scan sonar and multibeam bathymetry. (PDF contains 43 pages.
Expanded operational capabilities of the Langley Mach 7 Scramjet test facility
An experimental research program conducted to expand the operational capabilities of the NASA Langley Mach 7 Scramjet Test Facility is described. Previous scramjet testing in this facility was limited to a single simulated flight condition of Mach 6.9 at an altitude of 115,300 ft. The arc heater research demonstrates the potential of the facility for scramjet testing at simulated flight conditions from Mach 4 (at altitudes from 77,000 to 114,000 ft) to Mach 7 (at latitudes from 108,000 to 149,000 ft). Arc heater electrical characteristics, operational problems, measurements of nitrogen oxide contaminants, and total-temperature profiles are discussed
Position-Based Multi-Agent Dynamics for Real-Time Crowd Simulation (MiG paper)
Exploiting the efficiency and stability of Position-Based Dynamics (PBD), we
introduce a novel crowd simulation method that runs at interactive rates for
hundreds of thousands of agents. Our method enables the detailed modeling of
per-agent behavior in a Lagrangian formulation. We model short-range and
long-range collision avoidance to simulate both sparse and dense crowds. On the
particles representing agents, we formulate a set of positional constraints
that can be readily integrated into a standard PBD solver. We augment the
tentative particle motions with planning velocities to determine the preferred
velocities of agents, and project the positions onto the constraint manifold to
eliminate colliding configurations. The local short-range interaction is
represented with collision and frictional contact between agents, as in the
discrete simulation of granular materials. We incorporate a cohesion model for
modeling collective behaviors and propose a new constraint for dealing with
potential future collisions. Our new method is suitable for use in interactive
games.Comment: 9 page
A class of N-body problems with nearest- and next-to-nearest neighbour interactions
We obtain the exact ground state and a part of the excitation spectrum in one
dimension on a line and the exact ground state on a circle in a case where N
particles are interacting via nearest- and next-to-nearest neighbour
interactions. Further, using the exact ground-state, we establish a mapping
between these N-body problems and the short-range Dyson models introduced
recently to model intermediate spectral statistics. Using this mapping we
compute the one- and two-point functions of a related many-body theory and show
that there is no long-range order in the thermodynamic limit. However, quite
remarkably, we prove the existence of an off-diagonal long-range order in the
symmetrised version of the related many-body theory. Generalisation of the
models to other root systems is also considered. Besides, we also generalize
the model on the full line to higher dimensions. Finally, we consider a model
in two dimensions in which all the states exhibit novel correlations.Comment: LaTeX2e, 40 pages, 2 figures, submitted to Nucl. Phys. B [FS
Notes On Some Common Misconceptions In Input-Output Impact Methodology
The methodology in many studies involving input-output analysis appears to be often misunderstood, particularly in the way multipliers are used. The preoccupation with multipliers has led in many cases to incorrect analytical procedures; for example, there is a temptation to first derive a multiplier and then use this multiplier to calculate the total impact on the economy. This paper demonstrates that this approach is often erroneous and can result in significant errors. In addition, the importance of determining how imports are treated when using input-output in empirical situations is discussed. This is particularly relevant when using input-output tables in developing countries. Other issues which are clarified include the use of output multipliers, state versus regional multipliers and impacts, expenditure switching and table balancing.
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