1,201 research outputs found

    Birkhoff Coordinates for the Focusing NLS Equation

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    In this paper we construct Birkhoff coordinates for the focusing nonlinear Schrödinger equation near the zero solutio

    Mammography Social Support for Women Living in a Midwestern City: Toward Screening Promotion via Social Interactions

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    Notwithstanding recommendations and interventions, the percentage of 50 – 74-year-old U.S. women who reported having had a mammography in the past two years remained below target coverage. Social interactions may influence mammography rates. To measure characteristics of social interactions in a Midwestern city as they relate to social support for mammography received by women older than 40 years of age. A cross-sectional study was conducted in Bloomington, Indiana, sending mail surveys to 3,000 telephone directory addresses selected by simple random sampling. An anonymous, self-administered, closed-ended, questionnaire with eight checklist items (for demographics) and six multipart semantic differential scale items (for social support), derived from validated instruments, was used. Social support for mammography in women who had undergone regular screening was analyzed using chi-square test and logistic regression. Of 450 respondents with valid responses, 91% were white; 47% were older than 80; 92% had good health insurance coverage; and 82% had undergone regular mammography. Healthcare workers provided the highest support, followed by children, siblings, and relatives. Friends, neighbors, and co-workers were least supportive. In social interactions, emotional support was the most prominent, followed by informational, appraisal, and instrumental supports. Having higher income and being married were associated with receiving greater support. Although mammography provides limited benefits after age 74, women older than 80 years of age received the highest support. Identifying the structural and functional characteristics of social interactions is important for: 1) designing interventions that enhance social support, and 2) expanding breast cancer screening via personalized approaches using existing social interactions

    Development of a cost-effective optical sensor for continuous monitoring of turbidity and suspended particulate matter in marine environment

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    A cost-effective optical sensor for continuous in-situ monitoring of turbidity and suspended particulate matter concentration (SPM), with a production cost in raw materials less than 20 €, is presented for marine or fluvial applications. The sensor uses an infrared LED and three photodetectors with three different positions related to the light source-135º, 90º and 0º-resulting in three different types of light detection: backscattering, nephelometry and transmitted light, respectively. This design allows monitoring in any type of environment, offering a wide dynamic range and accuracy for low and high turbidity or SPM values. An ultraviolet emitter-receiver pair is also used to differentiate organic and inorganic matter through the differences in absorption at different wavelengths. The optical transducers are built in a watertight structure with a radial configuration where a printed circuit board with the electronic signal coupling is assembled. An in-lab calibration of the sensor was made to establish a relation between suspended particulate matter (SPM) or the turbidity (NTU) to the photodetectors' electrical output value in Volts. Two different sizes of seashore sand were used (180 µm and 350 µm) to evaluate the particle size susceptibility. The sensor was tested in a fluvial environment to evaluate SPM change during sediment transport caused by rain, and a real test of 22 days continuous in-situ monitoring was realized to evaluate its performance in a tidal area. The monitoring results were analysed, showing the SPM change during tidal cycles as well as the influence of the external light and biofouling problems.Funding Agency Programa Operacional Regional do Norte (NORTE2020), through Fundo Europeu de Desenvolvimento Regional (FEDER) NORTE-01-0145-FEDER-000032 European Union through the European Regional Development Fund, based on COMPETE 2020 (Programa Operacional da Competitividade e Internacionalizacao), project ICT UID/GEO/04683/2013 POCI-01-0145-FEDER-007690 Fundacao para a Ciencia e a Tecnologia (FCT)info:eu-repo/semantics/publishedVersio

    Efficacy-aware Business Process Modeling

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    In business process design, business objective models can fulfill the role of formal requirement definitions. Matching process models against objective models would, for instance, enable sound comparison of implementation alternatives. For that purpose, objective models should be available independently of their concrete implementation in a business process. This issue is not addressed by common business process management concepts yet. Moreover, process models are currently not sufficiently expressive to determine business process efficacy in the sense of fulfilling a business objective. Therefore, this paper develops and integrates constructs required for efficacy-aware process modeling and apt to extend common modeling approaches. The concept is illustrated with a sample scenario. Overall, it serves as an enabler for progressive applications like automated process optimization

    Charged-Particle Multiplicity in Proton-Proton Collisions

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    This article summarizes and critically reviews measurements of charged-particle multiplicity distributions and pseudorapidity densities in p+p(pbar) collisions between sqrt(s) = 23.6 GeV and sqrt(s) = 1.8 TeV. Related theoretical concepts are briefly introduced. Moments of multiplicity distributions are presented as a function of sqrt(s). Feynman scaling, KNO scaling, as well as the description of multiplicity distributions with a single negative binomial distribution and with combinations of two or more negative binomial distributions are discussed. Moreover, similarities between the energy dependence of charged-particle multiplicities in p+p(pbar) and e+e- collisions are studied. Finally, various predictions for pseudorapidity densities, average multiplicities in full phase space, and multiplicity distributions of charged particles in p+p(pbar) collisions at the LHC energies of sqrt(s) = 7 TeV, 10 TeV, and 14 TeV are summarized and compared.Comment: Invited review for Journal of Physics G -- version 2: version after referee's comment

    Bremsstrahlung Suppression due to the LPM and Dielectric Effects in a Variety of Materials

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    The cross section for bremsstrahlung from highly relativistic particles is suppressed due to interference caused by multiple scattering in dense media, and due to photon interactions with the electrons in all materials. We present here a detailed study of bremsstrahlung production of 200 keV to 500 MeV photons from 8 and 25 GeV electrons traversing a variety of target materials. For most targets, we observe the expected suppressions to a good accuracy. We observe that finite thickness effects are important for thin targets.Comment: 52 pages, 13 figures (incorporated in the revtex LaTeX file

    Calculating Reynolds stresses from ADCP measurements in the presence of surface gravity waves using the cospectra-fit method

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    Author Posting. © American Meteorological Society, 2010. 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 Atmospheric and Oceanic Technology 27 (2010): 889-907, doi:10.1175/2009JTECHO682.1.Recently, the velocity observations of acoustic Doppler current profilers (ADCPs) have been successfully used to estimate turbulent Reynolds stresses in estuaries and tidal channels. However, the presence of surface gravity waves can significantly bias stress estimates, limiting application of the technique in the coastal ocean. This work describes a new approach to estimate Reynolds stresses from ADCP velocities obtained in the presence of waves. The method fits an established semiempirical model of boundary layer turbulence to the measured turbulent cospectra at frequencies below those of surface gravity waves to estimate the stress. Applied to ADCP observations made in weakly stratified waters and variable significant wave heights, estimated near-bottom and near-surface stresses using this method compared well with independent estimates of the boundary stresses in contrast to previous methods. Additionally, the vertical structure of tidal stress estimated using the new approach matched that inferred from a linear momentum balance at stress levels below the estimated stress uncertainties. Because the method makes an estimate of the horizontal turbulent length scales present as part of the model fit, these results can also enable a direct correction for the mean bias errors resulting from instrument tilt, if these scales are long relative to the beam separation.AK acknowledges support from the WHOI Coastal Ocean Institute, and SL acknowledges support from NSF Ocean Science Grant OCE-0548961

    Top quark physics in hadron collisions

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    The top quark is the heaviest elementary particle observed to date. Its large mass makes the top quark an ideal laboratory to test predictions of perturbation theory concerning heavy quark production at hadron colliders. The top quark is also a powerful probe for new phenomena beyond the Standard Model of particle physics. In addition, the top quark mass is a crucial parameter for scrutinizing the Standard Model in electroweak precision tests and for predicting the mass of the yet unobserved Higgs boson. Ten years after the discovery of the top quark at the Fermilab Tevatron top quark physics has entered an era where detailed measurements of top quark properties are undertaken. In this review article an introduction to the phenomenology of top quark production in hadron collisions is given, the lessons learned in Tevatron Run I are summarized, and first Run II results are discussed. A brief outlook to the possibilities of top quark research a the Large Hadron Collider, currently under construction at CERN, is included.Comment: 84 pages, 32 figures, accepted for publication by Reports on Progress in Physic
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