18,765 research outputs found

    Evolving Health Care Systems and Approaches to Maintenance of Certification

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/102239/1/21207_ftp.pd

    Generalization of the density-matrix method to a non-orthogonal basis

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    We present a generalization of the Li, Nunes and Vanderbilt density-matrix method to the case of a non-orthogonal set of basis functions. A representation of the real-space density matrix is chosen in such a way that only the overlap matrix, and not its inverse, appears in the energy functional. The generalized energy functional is shown to be variational with respect to the elements of the density matrix, which typically remains well localized.Comment: 11 pages + 2 postcript figures at the end (search for -cut here

    Systems-based framework for continuing medical education and improvements in translating new knowledge into physicians' practices

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    Concerns about health care costs and quality are focusing increasing attention on physicians and their continuing medical education (CME). These concerns have produced several calls for “a new definition,” “a new vision,” “repositioning,” “reinventing,” and “transforming” CME. However, differences in conceptualizations and vocabularies have introduced appreciable confusion in recommending changes. This article uses a systems-based approach to describe and analyze the processes involved in translating new information into physicians' practices. The article (1) introduces a conceptual framework that links physician learning and performance to systems for information, education, implementation, and regulation in the context of the larger health care system; (2) uses the framework to identify concerns and opportunities for the major types of systems immediately relevant to CME: and (3) uses the framework to suggest broader implications for CME, including the nature of process for changing physicians' practices, needed improvements, priorities in performing research, and implications for CME professionals.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/35027/1/1340240508_ftp.pd

    Modeling Multi-Wavelength Stellar Astrometry. I. SIM Lite Observations of Interacting Binaries

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    Interacting binaries consist of a secondary star which fills or is very close to filling its Roche lobe, resulting in accretion onto the primary star, which is often, but not always, a compact object. In many cases, the primary star, secondary star, and the accretion disk can all be significant sources of luminosity. SIM Lite will only measure the photocenter of an astrometric target, and thus determining the true astrometric orbits of such systems will be difficult. We have modified the Eclipsing Light Curve code (Orosz & Hauschildt 2000) to allow us to model the flux-weighted reflex motions of interacting binaries, in a code we call REFLUX. This code gives us sufficient flexibility to investigate nearly every configuration of interacting binary. We find that SIM Lite will be able to determine astrometric orbits for all sufficiently bright interacting binaries where the primary or secondary star dominates the luminosity. For systems where there are multiple components that comprise the spectrum in the optical bandpass accessible to SIM Lite, we find it is possible to obtain absolute masses for both components, although multi-wavelength photometry will be required to disentangle the multiple components. In all cases, SIM Lite will at least yield accurate inclinations, and provide valuable information that will allow us to begin to understand the complex evolution of mass-transferring binaries. It is critical that SIM Lite maintains a multi-wavelength capability to allow for the proper deconvolution of the astrometric orbits in multi-component systems.Comment: 12 pages, 6 figures, 6 tables. Accepted for publication in the Astrophysical Journa

    A framework of web-based conceptual design

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    A web-based conceptual design prototype system is presented. The system consists of four parts which interpret on-line sketches as 2D and 3D geometry, extract 3D hierarchical configurations, allow editing of component behaviours, and produce VRML-based behavioural simulations for design verification and web-based application. In the first part, on-line freehand sketched input is interpreted as 2D and 3D geometry, which geometrically represents conceptual design. The system then infers 3D configuration by analysing 3D modelling history. The configuration is described by a parent–child hierarchical relationship and relative positions between two geometric components. The positioning information is computed with respect to the VRML97 specification. In order to verify the conceptual design of a product, the behaviours can be specified interactively on different components. Finally, the system creates VRML97 formatted files for behavioural simulation and collaborative design application over the Internet. The paper gives examples of web-based applications. This work forms a part of a research project into the design and establishing of modular machines for automation manufacture. A consortium of leading automotive companies is collaborating on the research project

    SYMPOSIUM ON RECENT DEVELOPMENTS IN DATA ANALYSIS

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    The purpose of this symposium is to present recent developments in biomechanical data analyses in two areas. First, current methods used in a dynamical systems approach will be described. Second, two statistical approaches, Principal Components Analysis and Functional Data Analysis, will be presented. The emphasis in this symposium will be on how to use each of these recent analysis techniques

    Spitzer Space Telescope Observations of Circumbinary Dust Disks around Polars

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    We present Spitzer Space Telescope IRAC photometry of the magnetic cataclysmic variables EF Eri, MR Ser, VV Pup, V834 Cen, GG Leo and V347 Pav. When we combine our results with the 2MASS data, we find that at least five of the polars have flux densities in the mid-IR in excess of the emission expected from the stellar components alone. We are unable to model this mid-IR excess with cyclotron emission, but we can recreate the observed spectral energy distributions with the inclusion of a simple circumbinary dust disk model. Importantly, we find that the masses of our modelled disks are approximately 12 orders of magnitude lower than required to significantly affect CV evolution. The accretion disk-less polars are ideal places to search for these disks, since the luminous accretion disk in most CVs would drown out the faint IR signature of the cooler, dimmer circumbinary disks

    Fermi Surface Properties of Low Concentration Cex_{x}La1x_{1-x}B6_{6}: dHvA

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    The de Haas-van Alphen effect is used to study angular dependent extremal areas of the Fermi Surfaces (FS) and effective masses of Cex_{x}La1x_{1-x}B6% _{6} alloys for xx between 0 and 0.05. The FS of these alloys was previously observed to be spin polarized at low Ce concentration (xx = 0.05). This work gives the details of the initial development of the topology and spin polarization of the FS from that of unpolarized metallic LaB6_{6} to that of spin polarized heavy Fermion CeB6_{6} .Comment: 7 pages, 9 figures, submitted to PR

    What Brown saw and you can too

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    A discussion is given of Robert Brown's original observations of particles ejected by pollen of the plant \textit{Clarkia pulchella} undergoing what is now called Brownian motion. We consider the nature of those particles, and how he misinterpreted the Airy disc of the smallest particles to be universal organic building blocks. Relevant qualitative and quantitative investigations with a modern microscope and with a "homemade" single lens microscope similar to Brown's, are presented.Comment: 14.1 pages, 11 figures, to be published in the American Journal of Physics. This differs from the previous version only in the web site referred to in reference 3. Today, this Brownian motion web site was launched, and http://physerver.hamilton.edu/Research/Brownian/index.html, is now correc
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