13,865 research outputs found
The Veterans Health Administration: Taking Home Telehealth Services to Scale Nationally
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
Recently Penskoi [J. Geom. Anal. 25 (2015), 2645-2666, arXiv:1308.1628]
generalized the well known two-parametric family of Lawson tau-surfaces
minimally immersed in spheres to a three-parametric family
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 . In the
present paper we show in Theorem 1 that this three-parametric family
includes in fact all bipolar Lawson tau-surfaces
. In Theorem 3 we show that no metric on generalized Lawson
surfaces is maximal except for and the equilateral torus.Comment: arXiv admin note: text overlap with arXiv:1308.1628 by other author
The Event Horizon of Sagittarius A*
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
Voltage controlled oscillators and pulse amplitude modulation for signal ratio syste
Radiative Transfer Along Rays in Curved Spacetimes
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
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
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
published or submitted for publicatio
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