1,653 research outputs found

    Application transfer activity in Missouri

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    Experimental demonstrations and workshop instructional courses were conducted to transfer the technology of satellite remote sensing to a wide audience of resource managers. This audience included planning commissions, state agencies, federal agencies, and special councils of the Governor. Some of the experiments and workshops are outlined

    The Right Mutation Strength for Multi-Valued Decision Variables

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    The most common representation in evolutionary computation are bit strings. This is ideal to model binary decision variables, but less useful for variables taking more values. With very little theoretical work existing on how to use evolutionary algorithms for such optimization problems, we study the run time of simple evolutionary algorithms on some OneMax-like functions defined over Ω={0,1,,r1}n\Omega = \{0, 1, \dots, r-1\}^n. More precisely, we regard a variety of problem classes requesting the component-wise minimization of the distance to an unknown target vector zΩz \in \Omega. For such problems we see a crucial difference in how we extend the standard-bit mutation operator to these multi-valued domains. While it is natural to select each position of the solution vector to be changed independently with probability 1/n1/n, there are various ways to then change such a position. If we change each selected position to a random value different from the original one, we obtain an expected run time of Θ(nrlogn)\Theta(nr \log n). If we change each selected position by either +1+1 or 1-1 (random choice), the optimization time reduces to Θ(nr+nlogn)\Theta(nr + n\log n). If we use a random mutation strength i{0,1,,r1}ni \in \{0,1,\ldots,r-1\}^n with probability inversely proportional to ii and change the selected position by either +i+i or i-i (random choice), then the optimization time becomes Θ(nlog(r)(log(n)+log(r)))\Theta(n \log(r)(\log(n)+\log(r))), bringing down the dependence on rr from linear to polylogarithmic. One of our results depends on a new variant of the lower bounding multiplicative drift theorem.Comment: an extended abstract of this work is to appear at GECCO 201

    Applying remote sensing and GIS techniques in solving rural county information needs

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    The project designed was to acquaint county government officials and their clientele with remote sensing and GIS products that contain information about land conditions and land use. Other users determined through the course of this project were federal agencies working at the county level, agricultural businesses and others in need of spatial information. The specific project objectives were: (1) to investigate the feasibility of using remotely sensed data to identify and quantify specific land cover categories and conditions for purposes of tax assessment, cropland area measurements and land use evaluation; (2) to investigate the use of satellite remote sensing data as an aid in assessing soil management practices; and (3) to evaluate the use of remotely sensed data to assess soil resources and conditions which affect productivity

    Mapping land cover from satellite images: A basic, low cost approach

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    Simple, inexpensive methodologies developed for mapping general land cover and land use categories from LANDSAT images are reported. One methodology, a stepwise, interpretive, direct tracing technique was developed through working with university students from different disciplines with no previous experience in satellite image interpretation. The technique results in maps that are very accurate in relation to actual land cover and relative to the small investment in skill, time, and money needed to produce the products

    Optimal Tableaux Method for Constructive Satisfiability Testing and Model Synthesis in the Alternating-time Temporal Logic ATL+

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    We develop a sound, complete and practically implementable tableaux-based decision method for constructive satisfiability testing and model synthesis in the fragment ATL+ of the full Alternating time temporal logic ATL*. The method extends in an essential way a previously developed tableaux-based decision method for ATL and works in 2EXPTIME, which is the optimal worst case complexity of the satisfiability problem for ATL+ . We also discuss how suitable parametrizations and syntactic restrictions on the class of input ATL+ formulae can reduce the complexity of the satisfiability problem.Comment: 45 page

    NASA applications project in Miami County, Indiana

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    The study site selection is intended to serve all of the different research areas within the project, i.e., soil conditions, soil management, etc. There are seven major soil associations or soils formed on similar landscapes in the Miami Co., and over 38 soil series that were mapped. Soil sampling was conducted in some sites because of its variability in soils and cover types, variable topography, and presence of erosion problems. Results from analysis of these soil data is presented

    A Metric for Rapidly Spinning Black Holes Suitable for Strong-Field Tests of the No-Hair Theorem

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    According to the no-hair theorem, astrophysical black holes are uniquely characterized by their masses and spins and are described by the Kerr metric. Several parametric deviations from the Kerr metric have been suggested to study observational signatures in both the electromagnetic and gravitational-wave spectra that differ from the expected Kerr signals. Due to the no-hair theorem, however, such spacetimes cannot be regular everywhere outside the event horizons, if they are solutions to the Einstein field equations; they are often characterized by naked singularities or closed time-like loops in the regions of the spacetime that are accessible to an external observer. For observational tests of the no-hair theorem that involve phenomena in the vicinity of the circular photon orbit or the innermost stable circular orbit around a black hole, these pathologies limit the applicability of the metrics only to compact objects that do not spin rapidly. In this paper, we construct a Kerr-like metric which depends on a set of free parameters in addition to its mass and spin and which is regular everywhere outside of the event horizon. We derive expressions for the energy and angular momentum of a particle on a circular equatorial orbit around the black hole and compute the locations of the innermost stable circular orbit and the circular photon orbit. We demonstrate that these orbits change significantly for even moderate deviations from the Kerr metric. The properties of our metric make it an ideally suited spacetime to carry out strong-field tests of the no-hair theorem in the electromagnetic spectrum using the properties of accretion flows around astrophysical black holes of arbitrary spin.Comment: 11 pages, 7 figures, accepted for publication in PR

    Earth observational research using multistage EOS-like data

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    This grant is funded as a part of a program in which both research and educational impact are intended. Research work under this grant is directed at the understanding and use of future hyperspectral data such as that from imaging spectrometers. Specifically, the objectives of the work are (1) to prepare suitable means for analyzing data from sensors which have large numbers of spectral bands, (2) to advance the fundamental understanding of the manner in which soils and vegetative materials reflect high spectral resolution optical wavelength radiation, and (3) to maximize the impact of the results on the educational community. Over the life of the grant, the work has thus involved basic Earth science research and information system technique understanding and development in a mutually supportive way, however, more recently it has become necessary to focus the work primarily on areas (1) and (3). During the last year, the level of effort on this grant has been reduced to half its previous value. We have also been advised that this grant will end with the current year, thus this will be the penultimate semiannual progress summary

    Foreign aid, exports and development in Euromed

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    This paper investigates the link between foreign aid and exports between the two shores of the Mediterranean. The main hypothesis is that the Euro-Mediterranean Process should promote not only trade but also stronger links between the European Union (EU) and the Middle East and North Africa (MENA). Hence, we expect development aid to have a positive impact on exports, which could also intensify the aid-trade relationship. In particular, we expect to find higher trade volumes in both directions after the process started in 1995 and intensified in the late 1990s and early 2000s, when several bilateral free trade agreements were signed. A gravity model augmented with bilateral and multilateral aid and trade regime variables is estimated for exports and imports from recipient countries to donor countries for the period 1988 to 2007 using advanced panel data techniques. Our method addresses the endogeneity bias of the trade regime/economic integration agreement (EIA) variable, assuming that decisions to form or enlarge EIAs are slow-moving relative to trade flows

    Modeling Seven Years of Event Horizon Telescope Observations with Radiatively Inefficient Accretion Flow Models

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    An initial three-station version of the Event Horizon Telescope, a millimeter-wavelength very-long baseline interferometer, has observed Sagittarius A* (Sgr A*) repeatedly from 2007 to 2013, resulting in the measurement of a variety of interferometric quantities. Of particular importance, there is now a large set of closure phases, measured over a number of independent observing epochs. We analyze these observations within the context of a realization of semi-analytic radiatively inefficient disk models, implicated by the low luminosity of Sgr A*. We find a broad consistency among the various observing epochs and between different interferometric data types, with the latter providing significant support for this class of models of Sgr A*. The new data significantly tighten existing constraints on the spin magnitude and its orientation within this model context, finding a spin magnitude of a=0.100.100.10+0.30+0.56a=0.10^{+0.30+0.56}_{-0.10-0.10}, an inclination with respect to the line of sight of θ=60813+5+10\theta={60^\circ}^{+5^\circ+10^\circ}_{-8^\circ-13^\circ}, and a position angle of ξ=1561727+10+14\xi={156^\circ}^{+10^\circ+14^\circ}_{-17^\circ-27^\circ} east of north. These are in good agreement with previous analyses. Notably, the previous 180180^\circ degeneracy in the position angle has now been conclusively broken by the inclusion of the closure phase measurements. A reflection degeneracy in the inclination remains, permitting two localizations of the spin vector orientation, one of which is in agreement with the orbital angular momentum of the infrared gas cloud G2 and the clockwise disk of young stars. This possibly supports a relationship between Sgr A*'s accretion flow and these larger-scale features.Comment: 16 pages, 11 figures, accepted to Ap
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