An improved magnetic field simulator - MAGFLD.

An improved two-dimensional simulator MAGFLD has been developed which is useful for the design and simulation of periodic permanent magnet (PPM) focusing system for linear beam tubes. At present, input is possible only through the input file, which is very simple and user friendly. A complete PPM circuit is generated using the coordinates of first pole piece, first magnet, gun adapter (if the structure is a-periodic) and the region of computation. Small mesh units of either square or rectangular shapes can be used with mesh refinement capability in one or more regions in any or both directions for better accuracy of the solution. Materials with different magnetic permeability can be modeled by defining a characteristic value for each mesh point of the geometry. The effective potential value at each point in the region of interest is calculated based on the vector potential model by using the 5-point finite difference method and the solution is achieved by over relaxation technique for faster convergence. This package has an interface with EGUN to model the electron gun and collector under the influence of magnetic field. Versatile color graphics are capable of plotting both axial magnetic field and flux lines along with the magnetic circuit. MAGFLD has been validated against some published data and experimental results

Microcontroller Based Application in Electronics & Communication

This paper is showing the various applications of electronics and communication which are working paralleled to each other that makes our life easy and wonder fool. In our life style from morning to evening there are various devices which we are using, and there may be much more possibilities to innovate devices. Such as smart gadgets which are capable to measure rate of change of humidity, temperature, sun light as according to weather and then system should control fan and light. There are also need of electricity consumption analysis, which keep intelligent eyes on every instrument. Here we want to develop a smart system that can analyze vehicle maintenance cycle, losses of electricity, uses of water in home or offices. In this paper we will discuss about innovative research in electronics and communications and their future scope

Semi-analytical approach for the Vaidya metric in double-null coordinates

We reexamine here a problem considered in detail before by Waugh and Lake: the solutions of spherically symmetric Einstein's equations with a radial flow of unpolarized radiation (the Vaidya metric) in double-null coordinates. This problem is known to be not analytically solvable, the only known explicit solutions correspond to the constant mass case (Schwarzschild solution in Kruskal-Szekeres form) and the linear and exponential mass functions originally discovered by Waugh and Lake. We present here a semi-analytical approach that can be used to discuss some qualitative and quantitative aspects of the Vaidya metric in double-null coordinates for generic mass functions. We present also a new analytical solution corresponding to $(1/v)$-mass function.Comment: 5 pages, 6 figure

A novel low complexity local hybrid pseudo-SSIM-SATD distortion metric towards perceptual rate control

The front-end block-based video encoder applies an Image Quality Assessment (IQA) as part of the distortion metric. Typically, the distortion metric applies uniform weighting for the absolute differences within a Sub-Macroblock (Sub-MB) at any given time. As video is predominately designed for Humans, the distortion metric should reflect the Human Visual System (HVS). Thus, a perceptual distortion metric (PDM), will lower the convex hull of the Rate-Distortion (R-D) curve towards the origin, by removing perceptual redundancy and retaining perceptual clues. Structured Similarity (SSIM), a perceptual IQA, has been adapted via logarithmic functions to measure distortion, however, it is restricted to the Group of Picture level and hence unable to adapt to the local Sub-MB changes. This paper proposes a Local Hybrid Pseudo-SSIM-SATD (LHPSS) Distortion Metric, operating at the Sub-MB level and satisfying the Triangle Equality Rule (≤). A detailed discussion of LHPSS's Psuedo-SSIM model will illustrate how SSIM can be perceptually scaled within the distortion metric space of SATD using non-logarithmic functions. Results of HD video encoded across different QPs will be presented showing the competitive bit usage under IbBbBbBbP prediction structure for similar image quality. Finally, the mode decision choices superimposed on the Intra frame will illustrate that LHPSS lowers the R-D curve as homogeneous regions are represented with larger block size

Review of standard traditional distortion metrics and a need for perceptual distortion metric at a (sub) macroblock level

Within a video encoder the distortion metric performs an Image Quality Assessment (IQA). However, to exploit perceptual redundancy to lower the convex hull of the Rate- Distortion (R-D) curve, a Perceptual Distortion Metric (PDM) modelling of the Human Visual System (HVS) should be used. Since block-based video encoders like H.264/AVC operate at the Sub-Macroblock (Sub-MB) level, there exists a need to produce a locally operating PDM. A locally operating PDM must meet the requirements of Standard Traditional Distortion Metrics (STDMs), in that it must satisfy the Triangle Equality Rule. Hence, this paper presents a review of STDMs of SSE, SAD and SATD against the perceptual IQA of Structural Similarity (SSIM) at the Sub-MB level. Furthermore, this paper illustrates the Universal Bounded Region (UBR) by block size that supports the triangle equality rule within the Sub-MB level, between SSIM and STDMs like SATD at the prediction stage

Gravitational Collapse in Constant Potential Bath

We analyse here the gravitational collapse of directed null radiation in a background with a constant potential such as one produced by a star system like galaxy in which the collapsing object is immersed. Both naked singularities and black holes are shown to be developing as the final outcome of the collapse. An interesting feature that emerges is that a part of the naked singularity spectrum in collapsing Vaidya region gets covered in the corresponding dual-Vaidya region, which corresponds to the Vaidya directed null radiation sitting in constant potential bath. The implications of such a result towards the issue of stability of naked singularities are discussed.Comment: LaTex 12 Pages, 2 figures. To appear in Physical Review

Thermal and Transport Behavior of Single Crystalline R2CoGa8 (R = Gd, Tb, Dy, Ho, Er, Tm, Lu and Y) Compounds

The anisotropy in electrical transport and thermal behavior of single crystalline R$_{2}$CoGa$_{8}$ series of compounds is presented. These compounds crystallize in a tetragonal structure with space gropup P4/mmm. The nonmagnetic counterparts of the series namely Y$_{2}$CoGa$_{8}$ and Lu$_{2}$CoGa$_{8}$show a behavior consistent with the low density of states at the fermi level. In Y$_{2}$CoGa$_{8}$, a possibility of charge density wave transition is observed at $\approx$ 30 K. Gd$_{2}$CoGa$_{8}$ and Er$_{2}$CoGa$_{8}$ show a presence of short range correlation above the magnetic ordering temperature of the compound. In case of Gd$_{2}$CoGa$_{8}$, the magnetoresistance exhibits a significant anisotropy for current parallel to {[}100{]} and {[}001{]} directions. Compounds with other magnetic rare earths (R = Tb, Dy, Ho and Tm) show the normal expected magnetic behavior whereas Dy$_{2}$CoGa$_{8}$ exhibits the possibility of charge density wave (CDW) transition at approximately same temperature as that of Y$_{2}$CoGa$_{8}$. The thermal property of these compounds is analysed on the basis of crystalline electric field (CEF) calculations.Comment: 10 Pages 14 Figures. Submitted to PR