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Secure Anonymous Routing for MANETs Using Distributed Dynamic Random Path Selection
Most of the MANET security research has so far focused on providing routing security and confidentiality to the data packets, but less has been done to ensure privacy and anonymity of the communicating entities. In this paper, we propose a routing protocol which ensures anonymity, privacy of the user. This is achieved by randomly selecting next hop at each intermediate. This protocol also provides data security using public key ciphers. The protocol is simulated using in-house simulator written in C with OpenSSL crypto APIs. The robustness of our protocol is evaluated against known security attacks
Inside-Out Planet Formation. V. Structure of the Inner Disk as Implied by the MRI
The large population of Earth to super-Earth sized planets found very close
to their host stars has motivated consideration of formation
models. In particular, Inside-Out Planet Formation is a scenario in which
planets coalesce sequentially in the disk, at the local gas pressure maximum
near the inner boundary of the dead zone. The pressure maximum arises from a
decline in viscosity, going from the active innermost disk (where thermal
ionization of alkalis yields high viscosities via the magneto-rotational
instability (MRI)) to the adjacent dead zone (where the MRI is quenched).
Previous studies of the pressure maximum, based on -disk models, have
assumed ad hoc values for the viscosity parameter in the active zone,
ignoring the detailed physics of the MRI. Here we explicitly couple the MRI
criteria to the -disk equations, to find steady-state (constant
accretion rate) solutions for the disk structure. We consider the effects of
both Ohmic and ambipolar resistivities, and find solutions for a range of disk
accretion rates ( = - /yr),
stellar masses ( = 0.1 - 1 ), and fiducial values of
the -MRI -viscosity in the dead zone ( - ). We find that: (1) A midplane pressure maximum forms
radially the inner boundary of the dead zone; (2) Hall resistivity
dominates near the midplane in the inner disk, which may explain why close-in
planets do form in 50% of systems; (3) X-ray ionization can be
competitive with thermal ionization in the inner disk, because of the low
surface density there in steady-state; and (4) our inner disk solutions are
viscously unstable to surface density perturbations.Comment: 34 pages, 28 figures, 3 appendices. Accepted by the Astrophysical
Journa
Mean Scattering Cross-Section of Radiation During Diffusion
In this paper,a general discussion for mean scattering cross-section for radiation during diffusion is presented. Necessary general formulas are derived for mean number of scatterings and application is made to one dimensional medium in which radiation of constant frequency undergoes diffusion
Acceptance Dependence of Fluctuation in Particle Multiplicity
The effect of limiting the acceptance in rapidity on event-by-event
multiplicity fluctuations in nucleus-nucleus collisions has been investigated.
Our analysis shows that the multiplicity fluctuations decrease when the
rapidity acceptance is decreased. We explain this trend by assuming that the
probability distribution of the particles in the smaller acceptance window
follows binomial distribution. Following a simple statistical analysis we
conclude that the event-by-event multiplicity fluctuations for full acceptance
are likely to be larger than those observed in the experiments, since the
experiments usually have detectors with limited acceptance. We discuss the
application of our model to simulated data generated using VENUS, a widely used
event generator in heavy-ion collisions. We also discuss the results from our
calculations in presence of dynamical fluctuations and possible observation of
these in the actual data.Comment: To appear in Int. J. Mod. Phys.
Data analysis of continuous gravitational wave: All sky search and study of templates
We have studied the problem of all sky search in reference to continuous
gravitational wave particularly for such sources whose wave-form are known in
advance. We have made an analysis of the number of templates required for
matched filter analysis as applicable to these sources. We have employed the
concept of {\it fitting factor} {\it (FF)}; treating the source location as the
parameters of the signal manifold and have studied the matching of the signal
with templates corresponding to different source locations. We have
investigated the variation of FF with source location and have noticed a
symmetry in template parameters, and . It has been found
that the two different template values in source location, each in
and , have same {\it FF}. We have also computed the number of templates
required assuming the noise power spectral density to be flat. It is
observed that higher {\it FF} requires exponentially increasing large number of
templates.Comment: Accepted in MNRAS, 14 pages, 5 figure
Radial Flow from Electromagnetic Probes and Signal of Quark Gluon Plasma
A first attempt has been made to extract the evolution of radial flow from
the analysis of the experimental data on electromagnetic probes experimentally
measured at SPS and RHIC energies. The spectra of photons and dileptons
measured by WA98 and NA60 collaborations respectively at CERN-SPS and the
photon spectra obtained by PHENIX collaboration at BNL-RHIC have been used to
constrain the theoretical models, rendering the outcome of the analysis largely
model independent. We argue that the variation of the radial velocity with
invariant mass is indicative of a phase transition from initially produced
partons to hadrons at SPS and RHIC energies.Comment: One LaTeX and 9 eps files, to appear in Phys. Rev.
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