Using Insights from Psychology and Language to Improve How People Reason with Description Logics

Inspired by insights from theories of human reasoning and language, we propose additions to the Manchester OWL Syntax to improve comprehensibility. These additions cover: functional and inverse functional properties, negated conjunction, the definition of exceptions, and existential and universal restrictions. By means of an empirical study, we demonstrate the effectiveness of a number of these additions, in particular: the use of solely to clarify the uniqueness of the object in a functional property; the replacement of and with intersection in conjunction, which was particularly beneficial in negated conjunction; the use of except as a substitute for and not; and the replacement of some with including and only with noneOrOnly, which helped in certain situations to clarify the nature of these restrictions

Upper and lower bounds for the eigenvalues of vibrating beams with linearly varying axial load

Upper and lower bounds for eigenvalues of vibrating beams and flat plates with varying axial loa

The X-ray luminosity function of AGN at z~3

We combine Lyman-break colour selection with ultradeep (> 200 ks) Chandra X-ray imaging over a survey area of ~0.35 deg^2 to select high redshift AGN. Applying careful corrections for both the optical and X-ray selection functions, the data allow us to make the most accurate determination to date of the faint end of the X-ray luminosity function (XLF) at z~3. Our methodology recovers a number density of X-ray sources at this redshift which is at least as high as previous surveys, demonstrating that it is an effective way of selecting high z AGN. Comparing to results at z=1, we find no evidence that the faint slope of the XLF flattens at high z, but we do find significant (factor ~3.6) negative evolution of the space density of low luminosity AGN. Combining with bright end data from very wide surveys we also see marginal evidence for continued positive evolution of the characteristic break luminosity L*. Our data therefore support models of luminosity-dependent density evolution between z=1 and z=3. A sharp upturn in the the XLF is seen at the very lowest luminosities (Lx < 10^42.5 erg s^-1), most likely due to the contribution of pure X-ray starburst galaxies at very faint fluxes.Comment: 16 pages, 9 figures, accepted for publication in MNRA

Providing Self-Aware Systems with Reflexivity

We propose a new type of self-aware systems inspired by ideas from higher-order theories of consciousness. First, we discussed the crucial distinction between introspection and reflexion. Then, we focus on computational reflexion as a mechanism by which a computer program can inspect its own code at every stage of the computation. Finally, we provide a formal definition and a proof-of-concept implementation of computational reflexion, viewed as an enriched form of program interpretation and a way to dynamically "augment" a computational process.Comment: 12 pages plus bibliography, appendices with code description, code of the proof-of-concept implementation, and examples of executio

Design and Construction of a Soil Bentonite Slurry Wall Around an Operating Facility Superfund Site

A soil bentonite slurry wall was designed for an NPL site to stop further migration of chemicals in a complex aquifer system, and to facilitate the removal of possible chemical sources from saturated zones beneath the site. Pumping from within the slurry wall will maintain inward and upward hydraulic gradients and thus stop further lateral or vertical migration of chemicals from the contained area. The slurry wall was constructed under an exceptionally detailed Quality Assurance; Quality Control review by the Contractor and two independent consulting firms. Ground movements, vibration levels and opacity of dust produced during construction were monitored for compliance with design specifications. It was made a condition of the contract that no hazardous material could leave the site. Federal regulations required all persons involved in site work to have health and safety training. Careful planning and close liaison between the Owner, Engineer and Contractor has enabled the slurry wall to be constructed in a business park environment around an operating manufacturing facility without disruption to production

A Modified Field Infiltrometer Test for Clay Liners

Regulatory agencies are looking more frequently to in situ field hydraulic conductivity tests for the assessment of a liner\u27s compliance to a specified hydraulic conductivity. Most field tests have evaluated hydraulic conductivity by measuring the infiltration rate of the liner. The infiltration rate can be used to arrive at a hydraulic conductivity value if the hydraulic boundary conditions of the test can be identified or if the head loss at different depths can be measured. A test fill of a clay liner was evaluated for its saturated vertical hydraulic conductivity. This paper discusses the use of eight tensiometers to measure soil suction at four depths beneath a double ring infiltrometer. The hydraulic conductivity results using the tensiometer data displayed good consistency and agreed well with laboratory test results

Has the Earth been exposed to numerous supernovae within the last 300 kyr?

Firestone (2014) asserted evidence for numerous (23) nearby (d<300 pc) supernovae within the Middle and Late Pleistocene. If true, this would have strong implications for the irradiation of the Earth; at this rate, mass extinction level events due to supernovae would be more frequent than 100 Myr. However, there are numerous errors in the application of past research. The paper overestimates likely nitrate and 14C production from moderately nearby supernovae by about four orders of magnitude. Moreover, the results are based on wrongly selected (obsolete) nitrate and 14C datasets. The use of correct and up-to-date datasets does not confirm the claimed results. The claims in the paper are invalidated.Comment: 8 pages, 1 figure. to be published in the Interenational Journal of Astrobiolog

Weighted-density approximation for general nonuniform fluid mixtures

In order to construct a general density-functional theory for nonuniform fluid mixtures, we propose an extension to multicomponent systems of the weighted-density approximation (WDA) of Curtin and Ashcroft [Phys. Rev. A 32, 2909 (1985)]. This extension corrects a deficiency in a similar extension proposed earlier by Denton and Ashcroft [Phys. Rev. A 42, 7312 (1990)], in that that functional cannot be applied to the multi-component nonuniform fluid systems with spatially varying composition, such as solid-fluid interfaces. As a test of the accuracy of our new functional, we apply it to the calculation of the freezing phase diagram of a binary hard-sphere fluid, and compare the results to simulation and the Denton-Ashcroft extension.Comment: 4 pages, 4 figures, to appear in Phys. Rev. E as Brief Repor

A New Spectroscopic and Photometric Analysis of the Transiting Planet Systems TrES-3 and TrES-4

We report new spectroscopic and photometric observations of the parent stars of the recently discovered transiting planets TrES-3 and TrES-4. A detailed abundance analysis based on high-resolution spectra yields [Fe/H] $= -0.19\pm 0.08$, $T_\mathrm{eff} = 5650\pm 75$ K, and $\log g = 4.4\pm 0.1$ for TrES-3, and [Fe/H] $= +0.14\pm 0.09$, $T_\mathrm{eff} = 6200\pm 75$ K, and $\log g = 4.0\pm0.1$ for TrES-4. The accuracy of the effective temperatures is supported by a number of independent consistency checks. The spectroscopic orbital solution for TrES-3 is improved with our new radial-velocity measurements of that system, as are the light-curve parameters for both systems based on newly acquired photometry for TrES-3 and a reanalysis of existing photometry for TrES-4. We have redetermined the stellar parameters taking advantage of the strong constraint provided by the light curves in the form of the normalized separation $a/R_\star$ (related to the stellar density) in conjunction with our new temperatures and metallicities. The masses and radii we derive are M_\star=0.928_{-0.048}^{+0.028} M_{\sun},R_\star = 0.829_{-0.022}^{+0.015} R_{\sun}, and M_\star = 1.404_{-0.134}^{+0.066} M_{\sun}, R_\star=1.846_{-0.087}^{+0.096} R_{\sun} for TrES-3 and TrES-4, respectively. With these revised stellar parameters we obtain improved values for the planetary masses and radii. We find $M_p = 1.910_{-0.080}^{+0.075} M_\mathrm{Jup}$, $R_p=1.336_{-0.036}^{+0.031} R_\mathrm{Jup}$ for TrES-3, and $M_p=0.925 \pm 0.082 M_\mathrm{Jup}$, $R_p=1.783_{-0.086}^{+0.093} R_\mathrm{Jup}$ for TrES-4. We confirm TrES-4 as the planet with the largest radius among the currently known transiting hot Jupiters.Comment: 42 pages, 10 tables, 8 figures. Accepted for publication in the Astrophysical Journa