Encouraging better hand drying hygiene

Electric hand driers have the potential to improve sanitation when using public toilets; if used properly, electric driers can dry hands more thoroughly than towels, and users do not come into physical contact with potentially contaminated objects. But electric driers are frequently used for just a few seconds--and so the potential advantage is lost. This paper describes the prototyping and evaluation of a system intended to encourage longer hand drying times in public toilets. The challenges are: to develop hygienic interfaces for use in toilet areas; to design simple to use software that is engaging enough to be used several times a day; and to conduct usability and system acceptance tests in an environment in which users are highly sensitive about privacy issues

Learning to generate one-sentence biographies from Wikidata

We investigate the generation of one-sentence Wikipedia biographies from facts derived from Wikidata slot-value pairs. We train a recurrent neural network sequence-to-sequence model with attention to select facts and generate textual summaries. Our model incorporates a novel secondary objective that helps ensure it generates sentences that contain the input facts. The model achieves a BLEU score of 41, improving significantly upon the vanilla sequence-to-sequence model and scoring roughly twice that of a simple template baseline. Human preference evaluation suggests the model is nearly as good as the Wikipedia reference. Manual analysis explores content selection, suggesting the model can trade the ability to infer knowledge against the risk of hallucinating incorrect information

A high-order spectral deferred correction strategy for low Mach number flow with complex chemistry

We present a fourth-order finite-volume algorithm in space and time for low Mach number reacting flow with detailed kinetics and transport. Our temporal integration scheme is based on a multi-implicit spectral deferred correction (MISDC) strategy that iteratively couples advection, diffusion, and reactions evolving subject to a constraint. Our new approach overcomes a stability limitation of our previous second-order method encountered when trying to incorporate higher-order polynomial representations of the solution in time to increase accuracy. We have developed a new iterative scheme that naturally fits within our MISDC framework that allows us to simultaneously conserve mass and energy while satisfying on the equation of state. We analyse the conditions for which the iterative schemes are guaranteed to converge to the fixed point solution. We present numerical examples illustrating the performance of the new method on premixed hydrogen, methane, and dimethyl ether flames.Comment: 27 pages, 5 figure

House-Swapping with Objective Indifferences

We study the classic house-swapping problem of Shapley and Scarf (1974) in a setting where agents may have "objective" indifferences, i.e., indifferences that are shared by all agents. In other words, if any one agent is indifferent between two houses, then all agents are indifferent between those two houses. The most direct interpretation is the presence of multiple copies of the same object. Our setting is a special case of the house-swapping problem with general indifferences. We derive a simple, easily interpretable algorithm that produces the unique strict core allocation of the house-swapping market, if it exists. Our algorithm runs in square polynomial time, a substantial improvement over the cubed time methods for the more general problem.Comment: 9 page

Symmetron Cosmology

The symmetron is a scalar field associated with the dark sector whose coupling to matter depends on the ambient matter density. The symmetron is decoupled and screened in regions of high density, thereby satisfying local constraints from tests of gravity, but couples with gravitational strength in regions of low density, such as the cosmos. In this paper we derive the cosmological expansion history in the presence of a symmetron field, tracking the evolution through the inflationary, radiation- and matter-dominated epochs, using a combination of analytical approximations and numerical integration. For a broad range of initial conditions at the onset of inflation, the scalar field reaches its symmetry-breaking vacuum by the present epoch, as assumed in the local analysis of spherically-symmetric solutions and tests of gravity. For the simplest form of the potential, the energy scale is too small for the symmetron to act as dark energy, hence we must add a cosmological constant to drive late-time cosmic acceleration. We briefly discuss a class of generalized, non-renormalizable potentials that can have a greater impact on the late-time cosmology, though cosmic acceleration requires a delicate tuning of parameters in this case.Comment: 42 page

Suitability Layers for Mesonet Stations in Tennessee

Mesonet stations are environmental monitoring systems used to examine environmental features such as Precipitation, Temperature, Insolation, Soil Moisture, and Localized Hazards. network of Mesonet stations is an integral part of weather and climate monitoring and the data produced are essential for agriculture, planning, transportation, and other industries. Tennessee is one of the few states without a Mesonet; a bill currently before the state assembly includes funding for such a system. Therefore, this research describes development of a Mesonet suitability layer for Tennessee that can be used to guide placement of individual Mesonet stations across the state, taking into account spacing, terrain, land use, construction suitability, and other factors. Land cover, road centerline, roughness, elevation, flood zone, building footprint, and soil type data were obtained from USGS, FEMA, NLCD, and the Tennessee state database to create each layer. Using ArcGIS Pro, each data layer was converted to a raster and then masked to the state of Tennessee at 30-meter resolution to ensure proper alignment of data overlays. The combined overlay map will identify zones that meet suitability criteria, and it is expected that multiple areas in each county will meet the such that a complete Mesonet network can be sited across the state. This study provides important information needed for final placement of Tennessee’s future Mesonet stations, which will provide essential weather and environmental monitoring data important for Tennessee