Local energy decay for scalar fields on time dependent non-trapping backgrounds

We consider local energy decay estimates for solutions to scalar wave equations on nontrapping asymptotically flat space-times. Our goals are two-fold. First we consider the stationary case, where we can provide a full spectral characterization of local energy decay bounds; this characterization simplifies in the stationary symmetric case. Then we consider the almost stationary, almost symmetric case. There we establish two main results: The first is a “two point” local energy decay estimate which is valid for a general class of (non-symmetric) almost stationary wave equations which satisfy a certain nonresonance property at zero frequency. The second result, which also requires the almost symmetry condition, is to establish an exponential trichotomy in the energy space via finite dimensional time dependent stable and unstable sub-spaces, with an infinite dimensional complement on which solutions disperse via the usual local energy decay estimate

The sensitivity of willingness to pay to an economic downturn

Stated preference (SP) studies are typically undertaken at one point in time, while the results may be relied on in decision-making several months or even years later. This reliance is only justified if values are stable over time, an assumption which is doubtable given the onset of an economic downturn. We assess the reliability of values taken before an economic downturn for application during the downturn, via analysis of responses to two near identical surveys conducted respectively before and during the 2008-2010 economic recession. The surveys were valuing near identical sets of permanent water sector service and environmental improvements. Each survey employed a dichotomous choice and a payment card contingent valuation question. Our main result is that the economic downturn led to lower payment card responses but had no effect on the values elicited via a dichotomous choice (ie referendum-type) contingent valuation question. We explore potential explanations for this finding in light of the literature on closed-ended versus open-ended elicitation method comparisons

The direct numerical simulations of the turbulent wakes of axisymmetric bodies

Results of direct numerical simulations of turbulence are compared with both laboratory data and self-similarity theory for the case of the turbulent wakes of towed, axisymmetric bodies. In general, the agreement of the simulation results with both the laboratory data and the self-similarity theory is good, although the comparisons are hampered by inadequate procedures for initializing the numerical simulations

Microbial Effects on Repository Performance

This report presents a critical review of the international literature on microbial effects in and around a deep geological repository for higher activity wastes. It is aimed at those who are familiar with the nuclear industry and radioactive waste disposal, but who are not experts in microbiology; they may have a limited knowledge of how microbiology may be integrated into and impact upon radioactive waste disposal safety cases and associated performance assessments (PA)

Feeling of knowing and restudy choices

Feeling-of-knowing judgments (FOK-Js) reflect people’s confidence that they would be able to recognize a currently unrecallable item. Although much research has been devoted to the factors determining the magnitude and accuracy of FOK-Js, much less work has addressed the issue of whether FOK-Js are related to any form of metacognitive control over memory processes. In the present study, we tested the hypothesis that FOK-Js are related to participants’ choices of which unrecallable items should be restudied. In three experiments, we showed that participants tend to choose for restudy items with high FOK-Js, both when they are explicitly asked to choose for restudy items that can be mastered in the restudy session (Exps. 1a and 2) and when such specific instructions are omitted (Exp. 1b). The study further demonstrated that increasing FOK-Js via priming cues affects restudy choices, even though it does not affect recall directly. Finally, Experiment 2 showed the strategy of restudying unrecalled items with high FOK-Js to be adaptive, because the efficacy of restudy is greater for these items than for items with low FOK-Js. Altogether, the present findings underscore an important role of FOK-Js for the metacognitive control of study operations

Is subjective social status a more important determinant of health than objective social status? Evidence from a prospective observational study of Scottish men

Both subjective and objective measures of lower social position have been shown to be associated with poorer health. A psychosocial, as opposed to material, aetiology of health inequalities predicts that subjective social status should be a stronger determinant of health than objective social position. In a workplace based prospective study of 5232 Scottish men recruited in the early 1970s and followed up for 25 years we examined the association between objective and subjective indices of social position, perceived psychological stress, cardiovascular disease risk factors and subsequent health. Lower social position, whether indexed by more objective or more subjective measures, was consistently associated with an adverse profile of established disease risk factors. Perceived stress showed the opposite association. The main subjective social position measure used was based on individual perceptions of workplace status (as well as their actual occupation, men were asked whether they saw themselves as “employees”, “foremen”, or “managers”). Compared to foremen, employees had a small and imprecisely estimated increased risk of all cause mortality, whereas managers had a more marked decreased risk. The strongest predictors of increased mortality were father's manual as opposed to non-manual occupation; lack of car access and shorter stature, (an indicator of material deprivation in childhood). In the fully adjusted analyses, perceived work-place status was only weakly associated with mortality. In this population it appears that objective material circumstances, particularly in early life, are a more important determinant of health than perceptions of relative status. Conversely, higher perceived stress was not associated with poorer health, presumably because, in this population, higher stress was not associated with material disadvantage. Together these findings suggest that, rather than targeting perceptions of disadvantage and associated negative emotions, interventions to reduce health inequalities should aim to reduce objective material disadvantage, particularly that experienced in early life

A survey of electric and hybrid vehicle simulation programs, volume 1

Development and capabilities of automotive performance simulation programs suitable for electric and hybrid vehicle studies are considered

Reducing Crop Nutrient Applications: The Yield Reserve Program

A proposed Yield Reserve Program designed to compensate farmers for any reduced yields resulting from reduced nitrogen (N) application rates below recommended rates is evaluated. Assuming that farmers currently follow extension recommendations for applying N, Yield Reserve Program participation reduces expected net revenue by $10 to$13/ha. The Yield Reserve Program reduces expected net revenue by $17 to$20/ha for farmers who apply N to maximize expected net revenue. Farmers costs of participation increase with lower probabilities of inadequate rainfall and higher corn prices and decline with higher N prices. The Yield Reserve Program can significantly reduce N applications to cropland, which may reduce N content of surface waters, but the costs to taxpayers and farmers will depend on how the program is implemented.compliance cost, nitrogen fertilizer, nonpoint source pollution, policy, yield response function, Crop Production/Industries,

A survey of electric and hybrid vehicle simulation programs

Results of a survey conducted within the United States to determine the extent of development and capabilities of automotive performance simulation programs suitable for electric and hybrid vehicle studies are summarized. Altogether, 111 programs were identified as being in a usable state. The complexity of the existing programs spans a range from a page of simple desktop calculator instructions to 300,000 lines of a high-level programming language. The capability to simulate electric vehicles was most common, heat-engines second, and hybrid vehicles least common. Batch-operated programs are slightly more common than interactive ones, and one-third can be operated in either mode. The most commonly used language was FORTRAN, the language typically used by engineers. The higher-level simulation languages (e.g. SIMSCRIPT, GPSS, SIMULA) used by "model builders" were conspicuously lacking