Noise in optical synthesis images. I. Ideal Michelson interferometer

We study the distribution of noise in optical images produced by the aperture synthesis technique, in which the principal source of noise is the intrinsic shot noise of photoelectric detection. The results of our analysis are directly applicable to any space-based optical interferometer. We show that the signal-to-noise ratio of images synthesized by such an ideal interferometric array is essentially independent of the details of the beam-combination geometry, the degree of array redundancy, and whether zero-spatial-frequency components are included in image synthesis. However, the distribution of noise does depend on the beam-combination geometry. A highly desirable distribution, one of uniform noise across the entire image, is obtained only when the beams from the n primary apertures are subdivided and combined pairwise on n(n - 1)/2 detectors

Noise in optical synthesis images. II. Sensitivity of an ^nC_2 interferometer with bispectrum imaging

We study the imaging sensitivity of a ground-based optical array of n apertures in which the beams are combined pairwise, as in radio-interferometric arrays, onto n(n - 1)/2 detectors, the so-called ^nC_2 interferometer. Groundbased operation forces the use of the fringe power and the bispectrum phasor as the primary observables rather than the simpler and superior observable, the Michelson fringe phasor. At high photon rates we find that bispectral imaging suffers no loss of sensitivity compared with an ideal array (space based) that directly uses the Michelson fringe phasor. In the opposite limit, when the number of photons per spatial coherence area per coherence time drops below unity, the sensitivity of the array drops rapidly relative to an ideal array. In this regime the sensitivity is independent of n, and hence it may be efficient to have many smaller arrays, each operating separately and simultaneously

Prospects of inflation with perturbed throat geometry

We study brane inflation in a warped deformed conifold background that includes general possible corrections to the throat geometry sourced by coupling to the bulk of a compact Calabi-Yau space. We focus specifically, on the perturbation by chiral operator of dimension 3/2 in the CFT. We find that the effective potential in this case can give rise to required number of e-foldings and the spectral index $n_S$ consistent with observation. The tensor to scalar ratio of perturbations is generally very low in this scenario. The COBE normalization, however, poses certain difficulties which can be circumvented provided model parameters are properly fine tuned. We find the numerical values of parameters which can give rise to enough inflation, observationally consistent values of density perturbations, scalar to tensor ratio of perturbations and the spectral index $n_S$.Comment: 7 pages and nine figures; typos corrected, minor comments and clarifications added, revised version to appear in PL

A Novel Design of Multi-Chambered Biomass Battery

In this paper, a novel design of biomass battery has been introduced for providing electricity to meet the lighting requirements of rural household using biomass. A biomass battery is designed, developed and tested using cow dung as the raw material. This is done via anaerobic digestion of the cow dung, and power generation driven by the ions produced henceforth. The voltage and power output is estimated for the proposed system. It is for the first time that such a high voltage is obtained from cow dung fed biomass battery. The output characteristics of this novel battery design have also been compared with the previously designed battery

Prediction of Success or Failure of Software Projects based on Reusability Metrics using Support Vector Machine

In the field of computer science & engineering and software industry the term reusability means usage of existing software assets or previously developed code in the software development process. The assets of the software are products and by-products of the product development life cycle which includes code, test cases, software designs and code documentation. The process of modifying the existing assets as per the need and specific requirements is called leveraging. But the reusability process creates a new version of the existing assets. So always reusability is preferred rather than leveraging. To identify the quality of the reusability of the software components various software metrics are available. But the framework or model that can predict the reusability of the software assets are needed to be developed. The reusability metrics must be identified during the design or coding phase and that can be used to reduce the rework needed develop a similar software module. This can much improve the productivity due to the probabilistic increase in the reuse level. In this study various software metrics representing the software reusability nature of the software components are collected in relation with a particular software project to form a database. The database is divided in to training and test set and Support Vector Machine is trained using the Radial Basis Function (RBF) to predict whether the software component can be reused or not

Stage-dependent changes in localization of a germ cell-specific lamin during mammalian spermatogenesis

We had earlier identified a 110/120-kDa protein specific to nuclear matrix of rat pachytene spermatocytes (Behal, A., Prakash, K., and Rao, M.R.S. (1987) J. Biol. Chem. 262, 10898-10902). This protein is now shown to be a disulfide-linked homodimer of a 60-kDa polypeptide. Indirect immunofluorescence and Western blot analyses using anti-120-kDa polyclonal antibodies have shown that this protein is a component of the pore-complex lamina structure of spermatogonia. As germ cells enter meiotic prophase and the lamina structure disassembles, this polypeptide is redistributed in the nucleus and can be isolated as a component of synaptonemal complexes. Following meiotic division, this 60-kDa protein is relocalized in the lamina, then representing the sole major component of the lamina structure of round spermatids. The identity of the 60-kDa protein in the pore-complex lamina fraction and synaptonemal complexes was further confirmed by two-dimensional analysis of iodinated tryptic peptides. Such an analysis has also shown that the germ cell-specific 60-kDa protein is related but not identical to somatic lamin B

A Low Complexity Near-Optimal MIMO Antenna Subset Selection Algorithm for Capacity Maximisation

Multiple input multiple output (MIMO) wireless systems employ a scheme called antenna subset selection for maximising the data rate or reliability for the prevailing channel conditions with the available or affordable number of radio frequency (RF) chains. In this paper, a low-complexity, and near-optimal performance fast algorithm is formulated and the detailed algorithm statements are stated with the exact complexity involved for capacity-maximising receive-only selection. The complexities of other receive-only selection comparable algorithms are calculated. Complexities have been stated in terms of both complex-complex flops and real-real flops. Significantly, all the algorithms are seen in the perspective of linear increase of capacity with the number of selected antennas up to one less than the total number of receive antennas. It is shown that our algorithm will be a good choice in terms of both performance and complexity for systems, which look for linear increase in capacity with the number of selected antennas up to one less than the total receive antennas. Our algorithm complexity is much less dependent on the number of transmit antennas and is not dependent on the number of selected antennas and it strikes a good tradeoff between performance and speed, which is very important for practical implementations

Free vibration of higher-order sandwich and composite arches, Part I: formulation

A higher-order refined model with seven degrees of freedom per node is presented in this paper for the free vibration analysis of composite and sandwich arches. The strain field is modeled through cubic axial, cubic transverse shear and linear transverse normal strain components. As the cross-sectional warping is accurately modeled by this theory, it does not require any shear correction factor. The stress-strain relationship is derived from an orthotropic lamina in a three-dimensional state of stress. The proposed higher-order formulation is validated, in this first part, through arches with various curvatures, aspect ratios, boundary conditions and materials

Pharmaceutico-Analytical study of Karanjadi Taila and its conversion into cream

Karanjadi Taila is medicated oil used in Ayurveda for Indralupta (Alopecia). Indralupta comes under Kshudra Roga which is characterized by loss of hair it can be correlated with Alopecia areata which is having chief complaint of hair loss on body especially on scalp. The aim of the present study is to do physic-chemical standards for the above Taila and its conversion into Karanjadi Taila cream. These two formulations have a special importance from pharmaceutical point of view when compared to usual Tailas or cream. In present article, we are trying to study analytical results of Karanjadi Taila w.s.r. to Karanjadi Taila cream