204 research outputs found
Reporting an Experience on Design and Implementation of e-Health Systems on Azure Cloud
Electronic Health (e-Health) technology has brought the world with
significant transformation from traditional paper-based medical practice to
Information and Communication Technologies (ICT)-based systems for automatic
management (storage, processing, and archiving) of information. Traditionally
e-Health systems have been designed to operate within stovepipes on dedicated
networks, physical computers, and locally managed software platforms that make
it susceptible to many serious limitations including: 1) lack of on-demand
scalability during critical situations; 2) high administrative overheads and
costs; and 3) in-efficient resource utilization and energy consumption due to
lack of automation. In this paper, we present an approach to migrate the ICT
systems in the e-Health sector from traditional in-house Client/Server (C/S)
architecture to the virtualised cloud computing environment. To this end, we
developed two cloud-based e-Health applications (Medical Practice Management
System and Telemedicine Practice System) for demonstrating how cloud services
can be leveraged for developing and deploying such applications. The Windows
Azure cloud computing platform is selected as an example public cloud platform
for our study. We conducted several performance evaluation experiments to
understand the Quality Service (QoS) tradeoffs of our applications under
variable workload on Azure.Comment: Submitted to third IEEE International Conference on Cloud and Green
Computing (CGC 2013
Study the impact of ketamine, clonidine and combination of ketamine-clonidine on cardiovascular system during pre and postoperatively: A double blind, placebo controlled study
Background: The use of ketamine as a sole anesthetic induces marked central sympathetic stimulation, causing increased heart rate, blood pressure (BP), and oxygen consumption (VO2). Both alpha 2-agonists and benzodiazepines have been used to attenuate these potentially harmful ketamine-induced responses. Materials and Methods: After approval from institutional ethical committee and written informed consent, 120 adult patients, ASA physical status I and II, undergoing elective surgeries e.g. Open abdominal surgery, laparoscopic surgery, open urological surgery were included in this controlled, prospective, randomized, double-blind study. Patients were randomly (envelop randomization) allocated in 4 groups (n=30): Group K received IV ketamine (0.5mg/kg), Group C received IV clonidine (1.5μg/kg), Group KC received combination of IV ketamine (0.25mg/kg) and IV clonidine (0.75μg/kg) and Group P received IV normal saline (placebo). One envelop at a time was chosen by an anaesthesiologist, who was blinded to the preparation of study agents and administered the study drugs in the envelope one after the other, intravenously approximately 20 minutes before extubation. Results: Pre operative haemodynamic parameters like mean arterial pressure (MAP) and heart rate are comparable across the groups. There was statistically significant (two tailed p value < 0.001) rise in intra operative heart rate following intubation in groups K, KC and P. There was statistically significant increase in systolic blood pressure (SBP) in groups K and P (two tailed p value < 0.001). In group C and KC, there were significant fall in SBP, from the baseline values, following induction. Conclusion: The unwanted effects of the individual drugs like, haemodynamic alteration, hallucination or lower incidences of nausea and vomiting could be achieved by using half of the dose of each of the drugs in combination
Synthetic Turbulence, Fractal Interpolation and Large-Eddy Simulation
Fractal Interpolation has been proposed in the literature as an efficient way
to construct closure models for the numerical solution of coarse-grained
Navier-Stokes equations. It is based on synthetically generating a
scale-invariant subgrid-scale field and analytically evaluating its effects on
large resolved scales. In this paper, we propose an extension of previous work
by developing a multiaffine fractal interpolation scheme and demonstrate that
it preserves not only the fractal dimension but also the higher-order structure
functions and the non-Gaussian probability density function of the velocity
increments. Extensive a-priori analyses of atmospheric boundary layer
measurements further reveal that this Multiaffine closure model has the
potential for satisfactory performance in large-eddy simulations. The
pertinence of this newly proposed methodology in the case of passive scalars is
also discussed
Solving the Graceful Exit Problem in Superstring Cosmology
We briefly review the status of the ``graceful exit'' problem in superstring
cosmology and present a possible resolution. It is shown that there exists a
solution to this problem in two-dimensional dilaton gravity provided quantum
corrections are incorporated. This is similar to the recently proposed solution
of Rey. However, unlike in his case, in our one-loop corrected model the
graceful exit problem is solved for any finite number of massless scalar matter
fields present in the theory.Comment: 8 pages, RevTex. Based on talk given at Conference on Big Bang and
Alternative Cosmologies: A Critical Appraisal, Bangalore, India, January,
199
Prospects for GMRT to Observe Radio Waves from UHE Particles Interacting with the Moon
Ultra high energy (UHE) particles of cosmic origin impact the lunar regolith
and produce radio signals through Askaryan effect, signals that can be detected
by Earth based radio telescopes. We calculate the expected sensitivity for
observation of such events at the Giant Metrewave Radio Telescope (GMRT), both
for UHE cosmic rays (CR) and UHE neutrino interactions. We find that for 30
days of observation time a significant number of detectable events is expected
above eV for UHECR or neutrino fluxes close to the current limits.
Null detection over a period of 30 days will lower the experimental bounds on
UHE particle fluxes by magnitudes competitive to both present and future
experiments at the very highest energies.Comment: 21 pages, 9 figure
Exact solutions in two-dimensional string cosmology with back reaction
We present analytic cosmological solutions in a model of two-dimensional
dilaton gravity with back reaction. One of these solutions exhibits a graceful
exit from the inflationary to the FRW phase and is nonsingular everywhere. A
duality related second solution is found to exist only in the ``pre-big-bang''
epoch and is singular at . In either case back reaction is shown to
play a crucial role in determining the specific nature of these geometries.Comment: Shortened slightly, references added, to appear in Physical Review D
(Rapid Communications). 16 pages, RevTex, 3 PostScript figure
Gravitational wave radiometry: Mapping a stochastic gravitational wave background
The problem of the detection and mapping of a stochastic gravitational wave
background (SGWB), either of cosmological or astrophysical origin, bears a
strong semblance to the analysis of CMB anisotropy and polarization. The basic
statistic we use is the cross-correlation between the data from a pair of
detectors. In order to `point' the pair of detectors at different locations one
must suitably delay the signal by the amount it takes for the gravitational
waves (GW) to travel to both detectors corresponding to a source direction.
Then the raw (observed) sky map of the SGWB is the signal convolved with a beam
response function that varies with location in the sky. We first present a
thorough analytic understanding of the structure of the beam response function
using an analytic approach employing the stationary phase approximation. The
true sky map is obtained by numerically deconvolving the beam function in the
integral (convolution) equation. We adopt the maximum likelihood framework to
estimate the true sky map that has been successfully used in the broadly
similar, well-studied CMB map making problem. We numerically implement and
demonstrate the method on simulated (unpolarized) SGWB for the radiometer
consisting of the LIGO pair of detectors at Hanford and Livingston. We include
`realistic' additive Gaussian noise in each data stream based on the LIGO-I
noise power spectral density. The extension of the method to multiple baselines
and polarized GWB is outlined. In the near future the network of GW detectors,
including the Advanced LIGO and Virgo detectors that will be sensitive to
sources within a thousand times larger spatial volume, could provide promising
data sets for GW radiometry.Comment: 24 pages, 19 figures, pdflatex. Matched version published in Phys.
Rev. D - minor change
Behavior of Quasilocal Mass Under Conformal Transformations
We show that in a generic scalar-tensor theory of gravity, the ``referenced''
quasilocal mass of a spatially bounded region in a classical solution is
invariant under conformal transformations of the spacetime metric. We first
extend the Brown-York quasilocal formalism to such theories to obtain the
``unreferenced'' quasilocal mass and prove it to be conformally invariant. The
appropriate reference term in this case is defined by generalizing the
Hawking-Horowitz prescription, which was originally proposed for general
relativity. For such a choice of reference term, the referenced quasilocal mass
for a general spacetime solution is obtained. This expression is shown to be a
conformal invariant provided the conformal factor is a monotonic function of
the scalar field. We apply this expression to the case of static spherically
symmetric solutions with arbitrary asymptotics to obtain the referenced
quasilocal mass of such solutions. Finally, we demonstrate the conformal
invariance of our quasilocal mass formula by applying it to specific cases of
four-dimensional charged black hole spacetimes, of both the asymptotically flat
and non-flat kinds, in conformally related theories.Comment: LaTeX, 31 pages, one ps figur
Stau detection at neutrino telescopes in scenarios with supersymmetric dark matter
We have studied the detection of long-lived staus at the IceCube neutrino
telescope, after their production inside the Earth through the inelastic
scattering of high energy neutrinos. The theoretical predictions for the stau
flux are calculated in two scenarios in which the presence of long-lived staus
is naturally associated to viable supersymmetric dark matter. Namely, we
consider the cases with superWIMP (gravitino or axino) and neutralino dark
matter (along the coannihilation region). In both scenarios the maximum value
of the stau flux turns out to be about 1 event/yr in regions with a light stau.
This is consistent with light gravitinos, with masses constrained by an upper
limit which ranges from 0.2 to 15 GeV, depending on the stau mass. Likewise, it
is compatible with axinos with a mass of about 1 GeV and a very low reheating
temperature of order 100 GeV. In the case of the neutralino dark matter this
favours regions with a low value of tan(beta), for which the neutralino-stau
coannihilation region occurs for smaller values of the stau mass. Finally, we
study the case of a general supergravity theory and show how for specific
choices of non-universal soft parameters the predicted stau flux can increase
moderately.Comment: 26 pages, 7 figures. References added and minor changes. Final
version to appear in JCA
Hamiltonian thermodynamics of two-dimensional vacuum dilatonic black holes
We consider the Hamiltonian dynamics and thermodynamics of the
two-dimensional vacuum dilatonic black hole in the presence of a timelike
boundary with a fixed value of the dilaton field. A~canonical transformation,
previously developed by Varadarajan and Lau, allows a reduction of the
classical dynamics into an unconstrained Hamiltonian system with one canonical
pair of degrees of freedom. The reduced theory is quantized, and a partition
function of a canonical ensemble is obtained as the trace of the analytically
continued time evolution operator. The partition function exists for any values
of the dilaton field and the temperature at the boundary, and the heat capacity
is always positive. For temperatures higher than , the partition function is dominated by a classical black
hole solution, and the dominant contribution to the entropy is the
two-dimensional Bekenstein-Hawking entropy. For temperatures lower
than~, the partition function remains well-behaved and the heat
capacity is positive in the asymptotically flat space limit, in contrast to the
corresponding limit in four-dimensional spherically symmetric Einstein gravity;
however, in this limit, the partition function is not dominated by a classical
black hole solution.Comment: 20 pages, REVTEX. Added a discussion on the boundary action and
boundary terms in Sec. IIIA. Minor changes in Acknowledgements and Reference
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