Data-graph repairs: the preferred approach

Repairing inconsistent knowledge bases is a task that has been assessed, with great advances over several decades, from within the knowledge representation and reasoning and the database theory communities. As information becomes more complex and interconnected, new types of repositories, representation languages and semantics are developed in order to be able to query and reason about it. Graph databases provide an effective way to represent relationships among data, and allow processing and querying these connections efficiently. In this work, we focus on the problem of computing preferred (subset and superset) repairs for graph databases with data values, using a notion of consistency based on a set of Reg-GXPath expressions as integrity constraints. Specifically, we study the problem of computing preferred repairs based on two different preference criteria, one based on weights and the other based on multisets, showing that in some cases it is possible to retain the same computational complexity as in the case where no preference criterion is available for exploitation

Sensitivity plots for WIMP direct detection using the annual modulation signature

Annual modulation due to the Earth's motion around the Sun is a well known signature of the expected WIMP signal induced in a solid state underground detector. In the present letter we discuss the prospects of this technique on statistical grounds, introducing annual-modulation sensitivity plots for the WIMP-nucleon scalar cross section for different materials and experimental conditions. The highest sensitivity to modulation is found in the WIMP mass interval 10 GeV< m_W < 130 GeV, the actual upper limit depending from the choice of the astrophysical parameters, while the lowest values of the explorable WIMP-nucleon elastic cross-sections fall in most cases within one order of magnitude of the sensitivities of present direct detection WIMP searches.Comment: 24 pages, ReVTeX, 9 figures, submitted to Astroparticle Physic

Complexity Bounds for Ordinal-Based Termination

`What more than its truth do we know if we have a proof of a theorem in a given formal system?' We examine Kreisel's question in the particular context of program termination proofs, with an eye to deriving complexity bounds on program running times. Our main tool for this are length function theorems, which provide complexity bounds on the use of well quasi orders. We illustrate how to prove such theorems in the simple yet until now untreated case of ordinals. We show how to apply this new theorem to derive complexity bounds on programs when they are proven to terminate thanks to a ranking function into some ordinal.Comment: Invited talk at the 8th International Workshop on Reachability Problems (RP 2014, 22-24 September 2014, Oxford

Phenomenological models for transient NAPL-water mass-transfer processes

A phenomenological model for transient NAPL dissolution, referred to as the "sphere" model, is developed. In this model, the mass-transfer coefficient and specific surface areas are quantified independently. The unique aspect of this work is the assumption that the complex distribution of NAPL blob shapes and sizes can be represented by a set of spheres with a range of diameters. The sphere diameter distributions are determined through the entrapment, polymerization and characterization of styrene blobs in sandy media. Mass-transfer coefficients are estimated from experimental measurements of the dissolution of naphthalene emplaced as solid spheres within sandy media.The phenomenological model describing NAPL dissolution rates is incorporated into a solute transport equation and solved with a numerical simulator. Simulations show that the sphere model can be calibrated to experimental NAPL dissolution data from column studies presented previously. The inclusion of a range of sphere sizes resulted in a model which represents experimental data better than a model based on mono-size spheres. The sphere model also adequately predicts dissolution for NAPL's with a range of solubilities provided the NAPL blob size distributions can be adequately estimated.The primary limitation of the sphere model is the qiantity of input data required to describe the distribution of effective sphere sizes. While these data requirements are extensive, the ability to define the NAPL blob distribution within the model makes the sphere model much more versatile for extrapolation to heterogeneous systems than other available dissolution models.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/31587/1/0000516.pd

Investigation of the reaction mechanisms for 10 B + 197 Au at near-barrier energies

The 10 B + 197 Au reaction has been investigated through cross-section measurements for different channels, such as quasielastic and elastic scattering, inelastic excitation of low-lying 197 Au states, and one-neutron pickup and one-proton stripping transfer reactions. Experimental angular distributions were obtained for 20 bombardment energies around the Coulomb barrier: 38 ≤ E l a b ≤ 61 MeV . Coupled reaction channels calculations have been performed in the context of the double-folding São Paulo potential, and details of the data analysis are discussed along the paper. In general, the theoretical calculations provide a satisfactory description of the data.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) 2018/09998-8 y 2017/05660-0,Conselho Nacional de Desenvolvimento Científico e Tecnológico de Brasil (CNPq) 407096/2017-5 y 306433/2017-6Instituto Nacional de Ciência e Tecnologia: Física Nuclear de Brasil (INCT-FNA) 464898/2014-5Ministerio de Ciencia, Innovación y Universidades de España. PGC2018-096994-B-C21Ministerio de Economía y Competitividad de España, Fondo de Desarrollo Regional de la Unión Europea (FEDER) FIS2017-88410-PPrograma de investigación e innovación Horizonte 2020 de la Unión Europea.654002Consejo Nacional de Investigaciones Científicas y Técnicas de Argentina (CONICET) PIP00786COFondo para la Investigación Científica y Tecnológica de Argentina (FONCYT) PICT-2017-408

Experimental Search for Solar Axions

A new technique has been used to search for solar axions using a single crystal germanium detector. It exploits the coherent conversion of axions into photons when their angle of incidence satisfies a Bragg condition with a crystalline plane. The analysis of approximately 1.94 kg.yr of data from the 1-kg DEMOS detector in Sierra Grande, Argentina, yields a new laboratory bound on axion-photon coupling of g_{a,\gamma\gamma}<2.7\times 10^{-9} GeV^{-1} independent of axion mass up to \sim 1 keV

Experimental Search for Solar Axions via Coherent Primakoff Conversion in a Germanium Spectrometer

Results are reported of an experimental search for the unique, rapidly varying temporal pattern of solar axions coherently converting into photons via the Primakoff effect in a single crystal germanium detector. This conversion is predicted when axions are incident at a Bragg angle with a crystalline plane. The analysis of approximately 1.94 kg.yr of data from the 1 kg DEMOS detector in Sierra Grande, Argentina, yields a new laboratory bound on axion-photon coupling of $g_{a\gamma \gamma} < 2.7\cdot 10^{-9}$ GeV$^{-1}$, independent of axion mass up to ~ 1 keV.Comment: RevTeX, 11 pages, figures can be obtained by fax from [email protected]. Submitted to Phys. Lett.