10,826 research outputs found
A Session based Multiple Image Hiding Technique using DWT and DCT
This work proposes Steganographic technique for hiding multiple images in a
color image based on DWT and DCT. The cover image is decomposed into three
separate color planes namely R, G and B. Individual planes are decomposed into
subbands using DWT. DCT is applied in HH component of each plane. Secret images
are dispersed among the selected DCT coefficients using a pseudo random
sequence and a Session key. Secret images are extracted using the session key
and the size of the images from the planer decomposed stego image. In this
approach the stego image generated is of acceptable level of imperceptibility
and distortion compared to the cover image and the overall security is high.Comment: 4 pages,16 figures, "Published with International Journal of Computer
Applications (IJCA)
Mean field baryon magnetic moments and sumrules
New developments have spurred interest in magnetic moments (-s) of
baryons. The measurement of some of the decuplet -s and the findings of
new sumrules from various methods are partly responsible for this renewed
interest. Our model, inspired by large colour approximation, is a relativistic
self consistent mean field description with a modified Richardson potential and
is used to describe the -s and masses of all baryons with up (u), down (d)
and strange (s) quarks. We have also checked the validity of the Franklin
sumrule (referred to as CGSR in the literature) and sumrules of Luty,
March-Russell and White. We found that our result for sumrules matches better
with experiment than the non-relativistic quark model prediction. We have also
seen that quark magnetic moments depend on the baryon in which they belong
while the naive quark model expects them to be constant.Comment: 7 pages, no figure, uses epl.cl
Maximum mass of a cold compact star
We calculate the maximum mass of the class of compact stars described by
Vaidya-Tikekar \cite{VT01} model. The model permits a simple method of
systematically fixing bounds on the maximum possible mass of cold compact stars
with a given value of radius or central density or surface density. The
relevant equations of state are also determined. Although simple, the model is
capable of describing the general features of the recently observed very
compact stars. For the calculation, no prior knowledge of the equation of state
(EOS) is required. This is in contrast to the earlier calculations for maximum
mass which were done by choosing first the relevant EOSs and using those to
solve the TOV equation with appropriate boundary conditions. The bounds
obtained by us are comparable and, in some cases, more restrictive than the
earlier results.Comment: 18 pages including 4 *.eps figures. Submitted for publicatio
Randall-Sundrum with Kalb-Ramond field: return of the hierarchy problem?
We show that when the antisymmetric Kalb-Ramond field is included in the
Randall-Sundrum scenario, although the hierarchy problem can be solved, it
requires an extreme fine tuning of the Kalb-Ramond field (about 1 part in
). We interpret this as the return of the problem in disguise.
Further, we show that the Kalb-Ramond field induces a small negative
cosmological constant on the visible brane.Comment: 8 pages, latex, 4 figures. Contributed talk at `Recent Developments
in Gravity' (NEB XII), Nafplion, Greece, 29 June 200
Surface latent heat flux as an earthquake precursor
International audienceThe analysis of surface latent heat flux (SLHF) from the epicentral regions of five recent earthquakes that occurred in close proximity to the oceans has been found to show anomalous behavior. The maximum increase of SLHF is found 2?7 days prior to the main earthquake event. This increase is likely due to an ocean-land-atmosphere interaction. The increase of SLHF prior to the main earthquake event is attributed to the increase in infrared thermal (IR) temperature in the epicentral and surrounding region. The anomalous increase in SLHF shows great potential in providing early warning of a disastrous earthquake, provided that there is a better understanding of the background noise due to the tides and monsoon in surface latent heat flux. Efforts have been made to understand the level of background noise in the epicentral regions of the five earthquakes considered in the present paper. A comparison of SLHF from the epicentral regions over the coastal earthquakes and the earthquakes that occurred far away from the coast has been made and it has been found that the anomalous behavior of SLHF prior to the main earthquake event is only associated with the coastal earthquakes
Radiating spherical collapse with heat flow
We present here a simple model of radiative gravitational collapse with
radial heat flux which describes qualitatively the stages close to the
formation of a superdense cold star. Starting with a static general solution
for a cold star, the model can generate solutions for the earlier evolutionary
stages. The temporal evolution of the model is specified by solving the
junction conditions appropriate for radiating gravitational collapse.Comment: 13 pages, including 3 figures, submitted to IJMP-
Study of Dissipative Collisions of Ne (7-11 MeV/nucleon) + Al
The inclusive energy distributions of complex fragments (3 Z 9)
emitted in the reactions Ne (145, 158, 200, 218 MeV) + Al have
been measured in the angular range 10 - 50. The fusion-fission and
the deep-inelastic components of the fragment yield have been extracted using
multiple Gaussian functions from the experimental fragment energy spectra. The
elemental yields of the fusion-fission component have been found to be fairly
well exlained in the framework of standard statistical model. It is found that
there is strong competition between the fusion-fission and the deep-inelastic
processes at these energies. The time scale of the deep-inelastic process was
estimated to be typically in the range of 10 - 10 sec.,
and it was found to decrease with increasing fragment mass. The angular
momentum dissipations in fully energy damped deep-inelastic process have been
estimated from the average energies of the deep-inelastic components of the
fragment energy spectra. It has been found that, the estimated angular momentum
dissipations, for lighter fragments in particular, are more than those
predicted by the empirical sticking limit.Comment: 16 pages, 9 figure
Behaviour of Cyclically Loaded Model Piles in Soft Clay
Instability studies on offshore piles has been carried out to a very limited extent. Cyclic loading resulting from wave action is a very common phenomenon for such piles. Continuous cycling {both vertical and lateral) presumably leads to substantial degradation in pile-soil response, the ultimate result of which could be disastrous. Over the last decade and a half, some work has been done to study the pile-soil interaction behaviour under repeated cyclic loading. This paper aims to highlight and discuss the salient features and the important observations of extensive model tests on piles subjected to vertical cyclic load. The degradation of pile-soil behaviour with different parameters have been studied, rationally analysed and a set of definite conclusions drawn therefrom
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