4,847 research outputs found

    Improvements in Blind Image Restoration

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    We present a revisal of blind image deconvolution technique for the restoration of linearly degraded images, without the explicit knowledge of either original image or the psf- the point spread function. Even the scenes which consist of finite support object over a uniformly black, white or grey background, this technique works fine. Occurrence includes certain types of medical imaging, astronomical imaging, and (1-D) gamma ray spectra processing. The only information that is required are the nonnegativity of the true image and the support size of the original object. The restoration procedure involves recursive filtering of the blurred image to minimize a convex cost function. The new approach is experimentally shown to be more reliable and to have faster convergence than existing nonparametric ¯nite support blind deconvolution methods, for situations in which the exact object support is known. This thesis covers the basic implementation of NAS-RIF method, using steepest descent, followed by implementation of swarm optimization technique- ACO, to optimize the results

    Brackish water culture fisheries: A comment

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    Based on the papers and proceedings of The National Workshop on Development of Inland Fishery Resources, sponsored by the Ministry of Agriculture, Govemment of India, and held during November 1-3, 1983 at Ahmedabad under the joint auspices of the Centre for Management in Agriculture, Indian Institute of Management, Ahmedabad, and the Indian Society of Agricultural Economics, Bomba

    Velocity of sound in relativistic heavy-ion collisions

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    We have studied the rapidity distribution of secondary hadrons produced in nucleus-nucleus collisions at ultra-relativistic energies within the ambit of the Landau's hydrodynamical model. A reasonable description of the data can also be obtained by using the Bjorken's hydrodynamical model if the boost invariance is restricted to a finite rapidity range. The sensitivity of the hadronic spectra on the equation of state vis- a -vis the velocity of sound has been discussed. The correlation between the velocity of sound and the freeze-out temperature has been indicated. The effects of the non-zero widths of various mesonic and baryonic degrees of freedom up to the mass value ~ 2.5 GeV is seen to be small.Comment: 9 pages and 11 figures. Major changes. To appear in Physical Review

    Nutrient Management for Higher Productivity of Swarna Sub1 Under Flash Floods Areas

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    Two field experiments were conducted at Regional Agricultural Research Station, Tarahara, Nepal during 2012 and 2013 to determine the effect of agronomic management on growth and yield of Swarna Sub1 under flash floods. The first experiment was laid out in a split plot design with three replications; and four different nutrient combinations at nursery as main plots and three age groups of rice seedlings as sub plots. The second experiment was laid out in a randomized complete block design and replicated thrice; with three post flood nutrient doses at six and 12 days after de-submergence (dad). The experiments were complete submerged at 10 days after transplanting for 12 days. The survival percentage, at 21 dad, was significantly higher in plots planted with 35 (90.25%) and 40 (91.58%) days-old seedlings compared to 30 days-old seedlings (81.75%). Plots with 35 days-old seedlings produced 5.15 t ha-1 with advantage of 18.83% over 30 days-old seedlings. Plots with 100-50-50 kg N-P2O5-K2O/ha at nursery recorded the highest grain filling of 79.41% and grain yield of 5.068 t/ha with more benefit. Post flood application of 20-20 N-K20kg/ha at 6 dad resulted in higher plant survival and taller plants, leading to significantly higher grain yield of 5.183 t/ha and straw yield of 5.315 t/ha. Hence, 35-40 days old seedlings raised with 100-50-50 kg N-P2O5-K2O /ha in nursery and the additional application of20-20 kg N-K2O /ha at 6 dad improved plant survival and enhanced yield of Swarna Sub1 under flash flood conditions. The practice has prospects of saving crop loss with getting rice yield above national average yield leading to enhanced food security in the flood prone areas of Nepal

    Droplet size distribution in homogeneous isotropic turbulence

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    We study the physics of droplet breakup in a statistically stationary homogeneous and isotropic turbulent flow by means of high resolution numerical investigations based on the multicomponent lattice Boltzmann method. We verified the validity of the criterion proposed by Hinze (1955) for droplet breakup and we measured the full probability distribution function (pdf) of droplets radii at different Reynolds numbers and for different volume fraction. By means of a Lagrangian tracking we could follow individual droplets along their trajectories, define a local Weber number based on the velocity gradients and study its cross-correlation with droplet deformation.Comment: 10 pages, 6 figure

    Cosmic Evolution with Early and Late Acceleration Inspired by Dual Nature of the Ricci Scalar Curvature

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    In the present paper, it is found that dark energy emerges spontaneously from the modified gravity. According to cosmological scenario, obtained here, the universe inflates for 1037\sim 10^{-37} sec. in the beginning and late universe accelerates after 8.58 Gyrs. During the long intermediate period, it decelerates driven by radiation and subsequently by matter. Emerged gravitational dark energy mimics quintessence and its density falls by 115 orders from its initial value 2.58×1068GeV42.58\times 10^{68} {\rm GeV}^4 to its current value 2.19×1047GeV42.19\times 10^{-47} {\rm GeV}^4 .Comment: 40 pages. To appearin Int. J. Mod. Phys.

    Spin-charge and spin-orbital coupling effects on spin dynamics in ferromagnetic manganites

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    Correlation-induced spin-charge and spin-orbital coupling effects on spin dynamics in ferromagnetic manganites are calculated with realistic parameters in order to provide a quantitative comparison with experimental results for spin stiffness, magnon dispersion, magnon damping, anomalous zone-boundary magnon softening, and Curie temperature. The role of orbital degeneracy, orbital ordering, and orbital correlations on spin dynamics in different doping regimes is highlighted.Comment: 19 pages, 9 figure

    Empirical determination of charm quark energy loss and its consequences for azimuthal anisotropy

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    We propose an empirical model to determine the form of energy loss of charm quarks due to multiple scatterings in quark gluon plasma by demanding a good description of production of D mesons and non-photonic electrons in relativistic collision of heavy nuclei at RHIC and LHC energies. Best results are obtained when we approximate the momentum loss per collision ΔpTαpT\Delta p_T \propto \alpha \, p_T, where α\alpha is a constant depending on the centrality and the centre of mass energy. Comparing our results with those obtained earlier for drag coefficients estimated using Langevin equation for heavy quarks we find that up to half of the energy loss of charm quarks at top RHIC energy could be due to collisions while that at LHC energy at 2760 GeV/A the collisional energy loss could be about one third of the total. Estimates are obtained for azimuthal anisotropy in momentum spectra of heavy mesons, due to this energy loss. We further suggest that energy loss of charm quarks may lead to an enhanced production of D-mesons and single electrons at low pTp_T in AA collisions.Comment: 11 pages, 3 figures, Typographical errors corrected, Key-words and PACS indices added, sequence of figures corrected, references added in section 3, discussions expande

    X-Ray K Absorptou Edges of Some Niobium Complexes

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