4,471 research outputs found
A Mobile Geo-Communication Dataset for Physiology-Aware DASH in Rural Ambulance Transport
Use of telecommunication technologies for remote, continuous monitoring of
patients can enhance effectiveness of emergency ambulance care during transport
from rural areas to a regional center hospital. However, the communication
along the various routes in rural areas may have wide bandwidth ranges from 2G
to 4G; some regions may have only lower satellite bandwidth available.
Bandwidth fluctuation together with real-time communication of various clinical
multimedia pose a major challenge during rural patient ambulance transport.;
AB@The availability of a pre-transport route-dependent communication bandwidth
database is an important resource in remote monitoring and clinical multimedia
transmission in rural ambulance transport. Here, we present a geo-communication
dataset from extensive profiling of 4 major US mobile carriers in Illinois,
from the rural location of Hoopeston to the central referral hospital center at
Urbana. In collaboration with Carle Foundation Hospital, we developed a
profiler, and collected various geographical and communication traces for
realistic emergency rural ambulance transport scenarios. Our dataset is to
support our ongoing work of proposing "physiology-aware DASH", which is
particularly useful for adaptive remote monitoring of critically ill patients
in emergency rural ambulance transport. It provides insights on ensuring higher
Quality of Service (QoS) for most critical clinical multimedia in response to
changes in patients' physiological states and bandwidth conditions. Our dataset
is available online for research community.Comment: Proceedings of the 8th ACM on Multimedia Systems Conference
(MMSys'17), Pages 158-163, Taipei, Taiwan, June 20 - 23, 201
Thermal effects on lattice strain in hcp Fe under pressure
We compute the c/a lattice strain versus temperature for nonmagnetic hcp iron
at high pressures using both first-principles linear response quasiharmonic
calculations based on the full potential linear-muffin-tin-orbital (LMTO)
method and the particle-in-cell (PIC) model for the vibrational partition
function using a tight-binding total-energy method. The tight-binding model
shows excellent agreement with the all-electron LMTO method. When hcp structure
is stable, the calculated geometric mean frequency and Helmholtz free energy of
hcp Fe from PIC and linear response lattice dynamics agree very well, as does
the axial ratio as a function of temperature and pressure. On-site
anharmonicity proves to be small up to the melting temperature, and PIC gives a
good estimate of its sign and magnitude. At low pressures, hcp Fe becomes
dynamically unstable at large c/a ratios, and the PIC model might fail where
the structure approaches lattice instability. The PIC approximation describes
well the vibrational behavior away from the instability, and thus is a
reasonable approach to compute high temperature properties of materials. Our
results show significant differences from earlier PIC studies, which gave much
larger axial ratio increases with increasing temperature, or reported large
differences between PIC and lattice dynamics results.Comment: 9 figure
Hydrodynamic Design of Integrated Bulbous Bowlsonar Dome for Naval Ships
Recently, the idea of bulbous bow has been extended from the commercial ships to the design of an integrated bow that houses a sonar dome for naval ships. In the present study, a design method for a particular set of requirements consisting of a narrow range of input parameters is presented. The method uses an approximate linear theory with sheltering effect for resistance estimation and pressure distribution, and correlation with statistical analysis from the existing literature and the tank-test results available in the public domain. Though the optimisation of design parameters has been done for the design speed, but the resistance performance over the entire speed range has been incorporated in the design. The bulb behaviourhas been discussed using the principle of minimisation of resistance and analysis of flow pattern over the bulb and near the sonar dome. It also explores the possible benefits arising out of new design from the production, acoustic, and hydrodynamic point of view. The results of this study are presented in the form of design parameters (for the bulbous bow) related tothe main hull parameters for a set of input data in a narrow range. Finally, the method has been used to design the bulbous bow for a surface combatant vessel
Casimir Force for Arbitrary Objects Using the Argument Principle and Boundary Element Methods
Recent progress in the simulation of Casimir forces between various objects
has allowed traditional computational electromagnetic solvers to be used to
find Casimir forces in arbitrary three-dimensional objects. The underlying
theory to these approaches requires knowledge and manipulation of quantum field
theory and statistical physics. We present a calculation of the Casimir force
using the method of moments via the argument principle. This simplified
derivation allows greater freedom in the moment matrix where the argument
principle can be used to calculate Casimir forces for arbitrary geometries and
materials with the use of various computational electromagnetic techniques.Comment: 6 pages, 2 figure
First-principles thermoelasticity of bcc iron under pressure
We investigate the elastic and isotropic aggregate properties of
ferromagnetic bcc iron as a function of temperature and pressure by computing
the Helmholtz free energies for the volume-conserving strained structures using
the first-principles linear response linear-muffin-tin-orbital method and the
generalized-gradient approximation. We include the electronic excitation
contributions to the free energy from the band structures, and phonon
contributions from quasi-harmonic lattice dynamics. We make detailed
comparisons between our calculated elastic moduli and their temperature and
pressure dependences with available experimental and theoretical data.Comment: 5 figures, 2 table
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