13,746 research outputs found

    The Veterans Health Administration: Taking Home Telehealth Services to Scale Nationally

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    Since the 1990s, the Veterans Health Administration (VHA) has used information and communications technologies to provide high-quality, coordinated, and comprehensive primary and specialist care services to its veteran population. Within the VHA, the Office of Telehealth Services offers veterans a program called Care Coordination/Home Telehealth (CCHT) to provide routine noninstitutional care and targeted care management and case management services to veterans with diabetes, congestive heart failure, hypertension, post-traumatic stress disorder, and other conditions. The program uses remote monitoring devices in veterans' homes to communicate health status and to capture and transmit biometric data that are monitored remotely by care coordinators. CCHT has shown promising results: fewer bed days of care, reduced hospital admissions, and high rates of patient satisfaction. This issue brief highlights factors critical to the VHA's success -- like the organization's leadership, culture, and existing information technology infrastructure -- as well as opportunities and challenges

    Bipolar Lawson Tau-Surfaces and Generalized Lawson Tau-Surfaces

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    Recently Penskoi [J. Geom. Anal. 25 (2015), 2645-2666, arXiv:1308.1628] generalized the well known two-parametric family of Lawson tau-surfaces τr,m\tau_{r,m} minimally immersed in spheres to a three-parametric family Ta,b,cT_{a,b,c} of tori and Klein bottles minimally immersed in spheres. It was remarked that this family includes surfaces carrying all extremal metrics for the first non-trivial eigenvalue of the Laplace-Beltrami operator on the torus and on the Klein bottle: the Clifford torus, the equilateral torus and surprisingly the bipolar Lawson Klein bottle τ~3,1\tilde{\tau}_{3,1}. In the present paper we show in Theorem 1 that this three-parametric family Ta,b,cT_{a,b,c} includes in fact all bipolar Lawson tau-surfaces τ~r,m\tilde{\tau}_{r,m}. In Theorem 3 we show that no metric on generalized Lawson surfaces is maximal except for τ~3,1\tilde{\tau}_{3,1} and the equilateral torus.Comment: arXiv admin note: text overlap with arXiv:1308.1628 by other author

    The Event Horizon of Sagittarius A*

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    Black hole event horizons, causally separating the external universe from compact regions of spacetime, are one of the most exotic predictions of General Relativity (GR). Until recently, their compact size has prevented efforts to study them directly. Here we show that recent millimeter and infrared observations of Sagittarius A* (Sgr A*), the supermassive black hole at the center of the Milky Way, all but requires the existence of a horizon. Specifically, we show that these observations limit the luminosity of any putative visible compact emitting region to below 0.4% of Sgr A*'s accretion luminosity. Equivalently, this requires the efficiency of converting the gravitational binding energy liberated during accretion into radiation and kinetic outflows to be greater than 99.6%, considerably larger than those implicated in Sgr A*, and therefore inconsistent with the existence of such a visible region. Finally, since we are able to frame this argument entirely in terms of observable quantities, our results apply to all geometric theories of gravity that admit stationary solutions, including the commonly discussed f(R) class of theories.Comment: 11 pages, 6 figures, submitted to Ap

    Signal ratio system utilizing voltage controlled oscillators Patent

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    Voltage controlled oscillators and pulse amplitude modulation for signal ratio syste

    Radiative Transfer Along Rays in Curved Spacetimes

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    Radiative transfer in curved spacetimes has become increasingly important to understanding high-energy astrophysical phenomena and testing general relativity in the strong field limit. The equations of radiative transfer are physically equivalent to the Boltzmann equation, where the latter has the virtue of being covariant. We show that by a judicious choice of the basis of the phase space, it is generally possible to make the momentum derivatives in the Boltzmann equation vanish along an arbitrary (including nongeodesic) path, thus reducing the problem of radiative transfer along a ray to a path integral in coordinate space.Comment: To be published in MNRAS Letter

    An interferometer tracking radar system

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    Fine tuning acquisition and tracking interferometer radar system uses a first antenna array of at least three receiving antennas. Array includes a reference antenna, a coarse tuning antenna, and a fine tuning antenna aligned on a receiving axis. Short range rendezvous system provides increased position accuracy

    Ni-cd Battery Life Expectancy in Geosynchronous Orbit

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    The feasibility of using nickel cadmium batteries as an alternate if flight qualified NiH2 batteries are not available is explored. Battery life expectancy data being a key element of power system design, an attempt is made to review the literature, life test data and in orbit performance data to develop an up to date estimate of life expectancy for NiCd batteries in a geosynchronous orbit

    The Roles of a Consultant in a Cooperative System Headquarters

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