2,227 research outputs found

    Semantic correlation of behavior for the interoperability of heterogeneous simulations

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    A desirable goal of military simulation training is to provide large scale or joint exercises to train personnel at higher echelons. To help meet this goal, many of the lower echelon combatants must consist of computer generated forces with some of these echelons composed of units from different simulations. The object of the research described is to correlate the behaviors of entities in different simulations so that they can interoperate with one another to support simulation training. Specific source behaviors can be translated to a form in terms of general behaviors which can then be correlated to any desired specific destination simulation behavior without prior knowledge of the pairing. The correlation, however, does not result in 100% effectiveness because most simulations have different semantics and were designed for different training needs. An ontology of general behaviors and behavior parameters, a database of source behaviors written in terms of these general behaviors with a database of destination behaviors. This comparison is based upon the similarity of sub-behaviors and the behavior parameters. Source behaviors/parameters may be deemed similar based upon their sub-behaviors or sub-parameters and their relationship (more specific or more general) to destination behaviors/parameters. As an additional constraint for correlation, a conversion path from all required destination parameters to a source parameter must be found in order for the behavior to be correlated and thus executed. The length of this conversion path often determines the similarity for behavior parameters, both source and destination. This research has shown, through a set of experiments, that heuristic metrics, in conjunction with a corresponding behavior and parameter ontology, are sufficient for the correlation of heterogeneous simulation behavior. These metrics successfully correlated known pairings provided by experts and provided reasonable correlations for behaviors that have no corresponding destination behavior. For different simulations, these metrics serve as a foundation for more complex methods of behavior correlation

    Core Services in the Architecture of the National Digital Library for Science Education (NSDL)

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    We describe the core components of the architecture for the (NSDL) National Science, Mathematics, Engineering, and Technology Education Digital Library. Over time the NSDL will include heterogeneous users, content, and services. To accommodate this, a design for a technical and organization infrastructure has been formulated based on the notion of a spectrum of interoperability. This paper describes the first phase of the interoperability infrastructure including the metadata repository, search and discovery services, rights management services, and user interface portal facilities

    Aerosol Optical Hygroscopicity Measurements during the 2010 CARES Campaign

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    Measurements of the effect of water uptake on particulate light extinction or scattering made at two locations during the 2010 CARES study around Sacramento, CA are reported. The observed influence of water uptake, characterized through the dimensionless optical hygroscopicity parameter Ī³, is compared with calculations constrained by observed particle size distributions and size-dependent particle composition. A closure assessment has been carried out that allowed for determination of the average hygroscopic growth factors (GF) at 85% relative humidity and the dimensionless hygroscopicity parameter Īŗ for oxygenated organic aerosol (OA) and for supermicron particles, yielding Īŗ = 0.1ā€“0.15 and 0.9ā€“1.0, respectively. The derived range of oxygenated OA Īŗ values are in line with previous observations. The relatively large values for supermicron particles is consistent with substantial contributions of sea salt-containing particles in this size range. Analysis of time-dependent variations in the supermicron particle hygroscopicity suggest that atmospheric processing, specifically chloride displacement by nitrate and the accumulation of secondary organics on supermicron particles, can lead to substantial depression of the observed GF

    Quantitative analysis of high-resolution computed tomography scans in severe asthma subphenotypes

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    BACKGROUND: Severe asthma is a heterogeneous condition. Airway remodelling is a feature of severe asthma and can be determined by the assessment of high-resolution computed tomography (HRCT) scans. The aim of this study was to assess whether airway remodelling is restricted to specific subphenotypes of severe asthma. METHODS: A retrospective analysis was performed of HRCT scans from subjects who had attended a single-centre severe asthma clinic between 2003 and 2008. The right upper lobe apical segmental bronchus (RB1) dimensions were measured and the clinical and sputum inflammatory characteristics associated with RB1 geometry were assessed by univariate and multivariate regression analyses. Longitudinal sputum data were available and were described as area under the time curve (AUC). Comparisons were made in RB1 geometry across subjects in four subphenotypes determined by cluster analysis, smokers and non-smokers, and subjects with and without persistent airflow obstruction. RESULTS: Ninety-nine subjects with severe asthma and 16 healthy controls were recruited. In the subjects with severe asthma the RB1 percentage wall area (%WA) was increased (p=0.009) and lumen area (LA)/body surface area (BSA) was decreased (p=0.008) compared with controls but was not different across the four subphenotypes. Airway geometry was not different between smokers and non-smokers and RB1 %WA was increased in those with persistent airflow obstruction. RB1 %WA in severe asthma was best associated with airflow limitation and persistent neutrophilic airway inflammation (model R(2)=0.27, p=0.001). CONCLUSIONS: Airway remodelling of proximal airways occurs in severe asthma and is associated with impaired lung function and neutrophilic airway inflammation

    O/IR Polarimetry for the 2010 Decade (GAN): Science at the Edge, Sharp Tools for All

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    Science opportunities and recommendations concerning optical/infrared polarimetry for the upcoming decade in the field of Galactic science. Community-based White Paper to Astro2010 in response to the call for such papers.Comment: White Paper to the Galactic Neighborhood (GAN) Science Frontiers Panel of the Astro2010 Decadal Surve

    The ANZUS Treaty during the Cold War: a reinterpretation of U.S. diplomacy in the Southwest Pacific

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    This article explains the origins of the Australiaā€“New Zealandā€“United States (ANZUS) Treaty by highlighting U.S. ambitions in the Pacific region after World War II. Three clarifications to the historiography merit attention. First, an alliance with Australia and New Zealand reflected the pursuit of U.S. interests rather than the skill of antipodean diplomacy. Despite initial reservations in Washington, geostrategic anxiety and economic ambition ultimately spurred cooperation. The U.S. government's eventual recourse to coercive diplomacy against the other ANZUS members, and the exclusion of Britain from the alliance, substantiate claims of self-interest. Second, the historiography neglects the economic rationale underlying the U.S. commitment to Pacific security. Regional cooperation ensured the revival of Japan, the avoidance of discriminatory trade policies, and the stability of the Bretton Woods monetary system. Third, scholars have unduly played down and misunderstood the concept of race. U.S. foreign policy elites invoked ideas about a ā€œWhite Man's Clubā€ in Asia to obscure the pursuit of U.S. interests in the region and to ensure British exclusion from the treaty

    On the exchange of momentum over the open ocean

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    Author Posting. Ā© American Meteorological Society, 2013. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Physical Oceanography 43 (2013): 1589ā€“1610, doi:10.1175/JPO-D-12-0173.1.This study investigates the exchange of momentum between the atmosphere and ocean using data collected from four oceanic field experiments. Direct covariance estimates of momentum fluxes were collected in all four experiments and wind profiles were collected during three of them. The objective of the investigation is to improve parameterizations of the surface roughness and drag coefficient used to estimate the surface stress from bulk formulas. Specifically, the Coupled Oceanā€“Atmosphere Response Experiment (COARE) 3.0 bulk flux algorithm is refined to create COARE 3.5. Oversea measurements of dimensionless shear are used to investigate the stability function under stable and convective conditions. The behavior of surface roughness is then investigated over a wider range of wind speeds (up to 25 m sāˆ’1) and wave conditions than have been available from previous oversea field studies. The wind speed dependence of the Charnock coefficient Ī± in the COARE algorithm is modified to , where m = 0.017 māˆ’1 s and b = āˆ’0.005. When combined with a parameterization for smooth flow, this formulation gives better agreement with the stress estimates from all of the field programs at all winds speeds with significant improvement for wind speeds over 13 m sāˆ’1. Wave ageā€“ and wave slopeā€“dependent parameterizations of the surface roughness are also investigated, but the COARE 3.5 wind speedā€“dependent formulation matches the observations well without any wave information. The available data provide a simple reason for why wind speedā€“, wave ageā€“, and wave slopeā€“dependent formulations give similar resultsā€”the inverse wave age varies nearly linearly with wind speed in long-fetch conditions for wind speeds up to 25 m sāˆ’1.This work was funded by the National Science Foundation Grant OCE04-24536 as part of the CLIVAR Mode Water Dynamics Experiment (CLIMODE) and the Office of Naval Research Grant N00014-05-1-0139 as part of the CBLAST-LOW program.2014-02-0
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