5,774 research outputs found
Prime diagnosticity in short-term repetition priming: Is primed evidence discounted, even when it reliably indicates the correct answer?
The authors conducted 4 repetition priming experiments that manipulated prime duration and prime diagnosticity in a visual forced-choice perceptual identification task. The strength and direction of prime diagnosticity produced marked effects on identification accuracy, but those effects were resistant to subsequent changes of diagnosticity. Participants learned to associate different diagnosticities with primes of different durations but not with primes presented in different colors. Regardless of prime diagnosticity, preference for a primed alternative covaried negatively with prime duration, suggesting that even for diagnostic primes, evidence discounting remains an important factor. A computational model, with the assumption that adaptation to the statistics of the experiment modulates the level of evidence discounting, accounted for these results
Quantum gates and multipartite entanglement resonances realized by non-uniform cavity motion
We demonstrate the presence of genuine multipartite entanglement between the
modes of quantum fields in non-uniformly moving cavities. The transformations
generated by the cavity motion can be considered as multipartite quantum gates.
We present two setups for which multi-mode entanglement can be generated for
bosons and fermions. As a highlight we show that the bosonic genuine
multipartite correlations can be resonantly enhanced. Our results provide
fundamental insights into the structure of Bogoliubov transformations and
suggest strong links between quantum information, quantum fields in curved
spacetimes and gravitational analogs by way of the equivalence principle.Comment: v2: extended to 9 pages, 2 figures, appendix with explicit witness
inequalities added; to appear in Phys. Rev. D; Ivette Fuentes previously
published as Ivette Fuentes-Guridi and Ivette Fuentes-Schulle
The Use of Various Failure Criteria as Applied to High Speed Wear
This research has been aimed at developing methods to predict mechanical wear of sliding bodies at high velocities. Specifically, wear of test sled slippers at the Holloman High Speed Test Track at Holloman AFB, NM, is being considered. Developing a numerical model to represent the velocity range achieved at the test track is infeasible, so numerical modeling techniques must be adopted. Previous research has made use of finite element codes to simulate the high velocity sliding event. However, the extreme velocities at the test track can create numerical errors in the finite element codes. To avoid the numerical errors, an Eulerian-Lagrangian hydrocode called CTH has been used to allow for a velocity range of 200 to 1,500 meters per second. The CTH model used in this research performs plane strain analysis of a slipper colliding with a 6 ÎĽm radius semi-circular surface asperity. The slipper-asperity collision event creates pressure waves in the slipper which leads to failed cells and worn material. Equations have been derived to represent the onset of plasticity and elastic wave speed through a material under plane strain conditions. These equations were validated using the CTH model. Several failure criteria were evaluated as possible methods to estimate damaged material from the sliding body. The Johnson and Cook constitutive model was selected because of its ability to handle high strains, strain rates, and temperatures. The model developed in this thesis calculates total mechanical wear between 49.31% and 80.87% of the experimental wear from the HHSTT January 2008 test mission
Effects of Great Plains Irrigation on Regional Climate
Irrigation provides a much needed source of water in regions of low precipitation such as the western Great Plains. However, adding water to a region that would otherwise see little natural precipitation has ramifications for the partitioning of radiative and turbulent fluxes, the development of the planetary boundary layer, and the transport of water vapor from the regions of irrigation. The first two effects have the potential to drastically alter the climate of irrigated regions of the Great Plains, while the transport mechanism can alter precipitation processes of regions far downstream of the irrigated areas. These effects are investigated in this thesis through the employment of the Advanced Research (ARW) implementation of the Weather Research and Forecasting Model (WRF) version 3.1.1 using a pair of simulations representing an irrigated and non-irrigated Great Plains. It will be shown that the introduction of irrigation in the Great Plains alters the radiation budget by increasing latent heat flux and cooling the surface temperatures. These effects, in turn, provide additional moisture to the atmosphere and increases the net radiation at the surface, thus increasing moist static energy in the boundary layer and providing downstream convective systems with additional energy and moisture. The increase in atmospheric moisture nearly doubles precipitation accumulations downstream without producing any new precipitation events
Re-evaluating effects of water quality changes on soil hydraulic properties
2011 Summer.Includes bibliographical references.Elevated soil salinity has long been an agricultural concern, causing reductions in infiltration and crop yields, and in extreme cases loss of agricultural land. This study reexamines how salinity affects soil hydraulic properties in order to address deficiencies in prediction methods and management of salinity's impacts on soils. This research project explores the effects of both changing irrigation water electrical conductivity (EC) and sodium adsorption ratio (SAR) on soil hydraulic conductivity, K, and soil moisture retention, θ, over a range of soil water tensions. The Results show that a decrease in EC from 20 to 0.25 dS m-1, with SAR held constant at low to moderate levels, causes changes in K(θ) only after dropping below 1.5 dS m-1 for soils at this particular site. The initial K(θ) could not be recovered by increasing the EC to its original level, indicating that irreversible clay dispersion had taken place. Increasing SAR from approximately 4 to 25 with EC held at 0.5 dS m-1 caused slight reductions in K(θ). In contrast to the EC treatment, K(θ) partially recovered after the SAR was reduced to its initial condition. The mechanism for the SAR effect is clay swelling and is reversible with changing soil water chemistry. The results from both EC and SAR treatments are consistent with other research reports. However, in contrast to previous studies and of particular interest is the magnitude of change in K with changing EC or SAR and decreasing θ. Unlike current models that assume the decline in K due to solution chemistry is constant over the entire K(θ) range, equal to the change at Ksat, this study observes an exponential increase in the solution chemistry's effect on K with decreasing θ. These findings suggest that current models that ignore solution chemistry, or models that assume a constant K reduction for the entire K(θ) function, are over-estimating the drainage in these systems. Adoption of a more characteristic solution chemistry model, similar to the one presented here, could help better manage irrigation water quality, reduce salt accumulation, and improve crop yields
Is new spread of the European beaver in Pannonian basin an evidence of the species recovery?
Abstract: During fieldwork from 6 June to 20 July 2016, the first records of the European beaver (Castor fiber) in south-eastern Slovakia were made. Beavers are mainly nocturnal animals, and as such, they are rarely observed; therefore, our observations were based on searching for beaver presence signs: damaged trees, dams, signs of food consumption (chewed/felled trees) and footprints in the mud. The southern part of the Košická kotlina basin, from the city of Košice down to the state border and the surrounding villages in Hungary, was checked. We found two beaver locations via feeding signs in the vicinity of the Slovakia–Hungary state border, at the villages of Milhosť (Miglécnémeti) and Buzica (Buzita), in Slovakia. According to our calculations, the present total beaver population in Hungary is between 4,000 and 5,000 and 14,600–18,300 beavers with potential support. For Slovakia, we estimated the potential population size to be 7,700–9,600. Our findings in northern Pannonian lowland (Slovakia–Hungary border) are an important evidence of beaver expansion. Although we don’t know the exact origin of investigated population, these new records indicate the possibility of merging the populations of different origin, which could enable gene flow and increase the genetic diversity. This could lead to improved recovery of species and its stabilisation in nature. However, it is necessary to carry out a detailed investigation of the presence of beaver in these regions in future
Machine learning with screens for detecting bid-rigging cartels
We combine machine learning techniques with statistical screens computed from the distribution of bids in tenders within the Swiss construction sector to predict collusion through bid-rigging cartels. We assess the out of sample performance of this approach and find it to correctly classify more than 80% of the total of bidding processes as collusive or non-collusive. As the correct classification rate, however, differs across truly non-collusive and collusive processes, we also investigate tradeoffs in reducing false positive vs. false negative predictions. Finally, we discuss policy implications of our method for competition agencies aiming at detecting bid- rigging cartel
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