657 research outputs found
PS-Sim: A Framework for Scalable Simulation of Participatory Sensing Data
Emergence of smartphone and the participatory sensing (PS) paradigm have
paved the way for a new variant of pervasive computing. In PS, human user
performs sensing tasks and generates notifications, typically in lieu of
incentives. These notifications are real-time, large-volume, and multi-modal,
which are eventually fused by the PS platform to generate a summary. One major
limitation with PS is the sparsity of notifications owing to lack of active
participation, thus inhibiting large scale real-life experiments for the
research community. On the flip side, research community always needs ground
truth to validate the efficacy of the proposed models and algorithms. Most of
the PS applications involve human mobility and report generation following
sensing of any event of interest in the adjacent environment. This work is an
attempt to study and empirically model human participation behavior and event
occurrence distributions through development of a location-sensitive data
simulation framework, called PS-Sim. From extensive experiments it has been
observed that the synthetic data generated by PS-Sim replicates real
participation and event occurrence behaviors in PS applications, which may be
considered for validation purpose in absence of the groundtruth. As a
proof-of-concept, we have used real-life dataset from a vehicular traffic
management application to train the models in PS-Sim and cross-validated the
simulated data with other parts of the same dataset.Comment: Published and Appeared in Proceedings of IEEE International
Conference on Smart Computing (SMARTCOMP-2018
-Expansion in the Gross-Neveu Model from Conformal Field Theory
We compute the anomalous dimensions of a class of operators of the form
and to leading order in in
the Gross-Neveu model in dimensions. We use the techniques
developed in arXiv: 1505.00963.Comment: 16 pages, some explanations in section 2 improved, references added
and typos correcte
Transition from radiatively inefficient to cooling dominated phase in two temperature accretion discs around black holes
We investigate the transition of a radiatively inefficient phase of a viscous
two temperature accreting flow to a cooling dominated phase and vice versa
around black holes. Based on a global sub-Keplerian accretion disc model in
steady state, including explicit cooling processes self-consistently, we show
that general advective accretion flow passes through various phases during its
infall towards a black hole. Bremsstrahlung, synchrotron and inverse
Comptonization of soft photons are considered as possible cooling mechanisms.
Hence the flow governs a much lower electron temperature ~10^8 - 10^{9.5}K
compared to the hot protons of temperature ~10^{10.2} - 10^{11.8}K in the range
of the accretion rate in Eddington units 0.01 - 100. Therefore, the solutions
may potentially explain the hard X-rays and the gamma-rays emitted from AGNs
and X-ray binaries. We finally compare the solutions for two different regimes
of viscosity and conclude that a weakly viscous flow is expected to be cooling
dominated compared to its highly viscous counterpart which is radiatively
inefficient. The flow is successfully able to reproduce the observed
luminosities of the under-fed AGNs and quasars (e.g. Sgr A*), ultra-luminous
X-ray sources (e.g. SS433), as well as the highly luminous AGNs and
ultra-luminous quasars (e.g. PKS 0743-67) at different combinations of the mass
accretion rate and ratio of specific heats.Comment: 13 pages including 8 figures; couple of typos corrected; to appear in
Research in Astronomy and Astrophysic
Variation of the gas and radiation content in the sub-Keplerian accretion disk around black holes and its impact to the solutions
We investigate the variation of the gas and the radiation pressure in
accretion disks during the infall of matter to the black hole and its effect to
the flow. While the flow far away from the black hole might be
non-relativistic, in the vicinity of the black hole it is expected to be
relativistic behaving more like radiation. Therefore, the ratio of gas pressure
to total pressure (beta) and the underlying polytropic index (gamma) should not
be constant throughout the flow. We obtain that accretion flows exhibit
significant variation of beta and then gamma, which affects solutions described
in the standard literature based on constant beta. Certain solutions for a
particular set of initial parameters with a constant beta do not exist when the
variation of beta is incorporated appropriately. We model the viscous
sub-Keplerian accretion disk with a nonzero component of advection and pressure
gradient around black holes by preserving the conservations of mass, momentum,
energy, supplemented by the evolution of beta. By solving the set of five
coupled differential equations, we obtain the thermo-hydrodynamical properties
of the flow. We show that during infall, beta of the flow could vary upto
~300%, while gamma upto ~20%. This might have a significant impact to the disk
solutions in explaining observed data, e.g. super-luminal jets from disks,
luminosity, and then extracting fundamental properties from them. Hence any
conclusion based on constant gamma and beta should be taken with caution and
corrected.Comment: 22 pages including 8 figures; published in New Astronom
Andrographis paniculata transcriptome provides molecular insights into tissue-specific accumulation of medicinal diterpenes
A summary of SSRs identified in leaf and root transcriptomes. (DOCX 11 kb
Stochastic model of transcription factor-regulated gene expression
We consider a stochastic model of transcription factor (TF)-regulated gene
expression. The model describes two genes: Gene A and Gene B which synthesize
the TFs and the target gene proteins respectively. We show through analytic
calculations that the TF fluctuations have a significant effect on the
distribution of the target gene protein levels when the mean TF level falls in
the highest sensitive region of the dose-response curve. We further study the
effect of reducing the copy number of Gene A from two to one. The enhanced TF
fluctuations yield results different from those in the deterministic case. The
probability that the target gene protein level exceeds a threshold value is
calculated with a knowledge of the probability density functions associated
with the TF and target gene protein levels. Numerical simulation results for a
more detailed stochastic model are shown to be in agreement with those obtained
through analytic calculations. The relevance of these results in the context of
the genetic disorder haploinsufficiency is pointed out. Some experimental
observations on the haploinsufficiency of the tumour suppressor gene, Nkx3.1,
are explained with the help of the stochastic model of TF-regulated gene
expression.Comment: 17 pages, 11 figures. Accepted for publication in Physical Biolog
Solving relativistic hydrodynamic equation in presence of magnetic field for phase transition in a neutron star
Hadronic to quark matter phase transition may occur inside neutron stars (NS)
having central densities of the order of 3-10 times normal nuclear matter
saturation density (). The transition is expected to be a two-step
process; transition from hadronic to 2-flavour matter and two-flavour to
equilibrated charge neutral three-flavour matter. In this paper we
concentrate on the first step process and solve the relativistic hydrodynamic
equations for the conversion front in presence of high magnetic field. Lorentz
force due to magnetic field is included in the energy momentum tensor by
averaging over the polar angles. We find that for an initial dipole
configuration of the magnetic field with a sufficiently high value at the
surface, velocity of the front increases considerably.Comment: 16 pages, 4 figures, same as published version of JPG, J. Phys. G:
Nucl. Part. Phys. 39 (2012) 09520
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