7,292 research outputs found

    EMEEDP: Enhanced Multi-hop Energy Efficient Distributed Protocol for Heterogeneous Wireless Sensor Network

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    In WSN (Wireless Sensor Network) every sensor node sensed the data and transmit it to the CH (Cluster head) or BS (Base Station). Sensors are randomly deployed in unreachable areas, where battery replacement or battery charge is not possible. For this reason, Energy conservation is the important design goal while developing a routing and distributed protocol to increase the lifetime of WSN. In this paper, an enhanced energy efficient distributed protocol for heterogeneous WSN have been reported. EMEEDP is proposed for heterogeneous WSN to increase the lifetime of the network. An efficient algorithm is proposed in the form of flowchart and based on various clustering equation proved that the proposed work accomplishes longer lifetime with improved QOS parameters parallel to MEEP. A WSN implemented and tested using Raspberry Pi devices as a base station, temperature sensors as a node and xively.com as a cloud. Users use data for decision purpose or business purposes from xively.com using internet.Comment: 6 pages, 4 figures. arXiv admin note: substantial text overlap with arXiv:1409.1412 by other author

    Shape-changing Collisions of Coupled Bright Solitons in Birefringent Optical Fibers

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    Wecritically review the recent progress in understanding soliton propagation in birefringent optical fibers.By constructing the most general bright two-soliton solution of the integrable coupled nonlinear Schroedinger equation (Manakov model) we point out that solitons in birefringent fibers can in general change their shape after interaction due to a change in the intensity distribution among the modes even though the total energy is conserved. However, the standard shape-preserving collision (elastic collision) property of the (1+1)-dimensional solitons is recovered when restrictions are imposed on some of the soliton parameters. As a consequence the following further properties can be deduced using this shape-changing collision. (i) The exciting possibility of switching of solitons between orthogonally polarized modes of the birefringent fiber exists. (ii) When additional effects due to periodic rotation of birefringence axes are considered, the shape changing collision can be used as a switch to suppress or to enhance the periodic intensity exchange between the orthogonally polarized modes. (iii) For ultra short optical soliton pulse propagation in non-Kerr media, from the governing equation an integrable system of coupled nonlinear Schroedinger equation with cubic-quintic terms is identified. It admits a nonlocal Poisson bracket structure. (iv) If we take the higher-order terms in the coupled nonlinear Schroedinger equation into account then their effect on the shape-changing collision of solitons, during optical pulse propagation, can be studied by using a direct perturbational approach.Comment: 14 pages, ROMP31, 4 EPS figure

    A Ray-Tracing Model of the Vela Pulsar

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    In the relativistic plasma surrounding a pulsar, a subluminal ordinary-mode electromagnetic wave will propagate along a magnetic field line. After some distance, it can break free of the field line and escape the magnetosphere to reach an observer. We describe a simple model of pulsar radio emission based on this scenario and find that applying this model to the case of the Vela pulsar reproduces qualitative characteristics of the observed Vela pulse profile.Comment: 23 pages, 9 figures, accepted for publication in Ap

    Impact of Tandem Repeats on the Scaling of Nucleotide Sequences

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    Techniques such as detrended fluctuation analysis (DFA) and its extensions have been widely used to determine the nature of scaling in nucleotide sequences. In this brief communication we show that tandem repeats which are ubiquitous in nucleotide sequences can prevent reliable estimation of possible long-range correlations. Therefore, it is important to investigate the presence of tandem repeats prior to scaling exponent estimation.Comment: 14 Pages, 3 Figure

    The observational evidence pertinent to possible kick mechanisms in neutron stars

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    We examine available observations on pulsars for evidence pertaining to mechanisms proposed to explain the origin of their velocities. We find that mechanisms predicting a correlation between the rotation axis and the pulsar velocity are ruled out. Also, that there is no significant correlation between pulsar magnetic field strengths and velocities. With respect to recent suggestions postulating asymmetric impulses at birth being solely responsible for both the spins and velocities of pulsars, single impulses of any duration and multiple extended duration impulses appear ruled out.Comment: 7 pages. Accepted for publication in Astronomy & Astrophysic

    Nutritive value of the crab Podophthalmus vigil (Fabricius)

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    Among the edible crabs, Podophthalmus vigil occupies a distinct position in Porto Novo coast. Though the fishery is seasonal, P. vigil supports an additional crab fishery from august to october. An attempt has been made to evaluate the nutritional status of different size groups of P. vigil. It has been observed that protein and moisture values are more in smaller crabs, corresponding with a drop in carbohydrate and fat. In bigger size groups, the values of fat and carbohydrate are found to be higher, while protein and moisture contents decreased slightly. The total meat content varies in different crabs of the same size group and the average value of the total consumable part is found to be only less than 30% of the total weight of the animal

    Fishery and ecology of the spiny lobster Panulirus homarus (Linnaeus, 1758) at Khadiyapatanam in the southwest coast of India

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    Commercial exploitation of palinurid lobsters has been on the increase due to high demand and lucrative price for live lobsters in the international market. The spiny lobster Panulirus homarus caught generally by traps and bottom-set gillnets support significant commercial catches along the southern Indian coast. Fishery along the southwest coast is seasonal, extending from September to March and peak landings are during October to December. The catch gradually declines from January and the landing is negligible in April and May. The paper presents results of a field study carried out on the ecology of the lobster fishing ground at Khadiyapatanam, on the southwest coast of India. Hydrographical parameters were used to correlate the lobster catch from the coastal fishing grounds during the fishing (October-November) and the non-fishing season (April-May) for which lobster catch and the entangled associated fauna and flora from 8 bottom-set-gillnets operated at different depth zones were monitored. Mean catch in the bottom-set- gillnet varied from 1.6 to 0.68 kg/net/day during October-January and 0.1 kg/net/day during April-May. Negative correlation between bottom sea water temperature and the catch of P. homarus was observed. The environmental and ecological conditions, widespread beds of the brown mussel Perna indica are likely to be impacting the abundance of P. homarus at Khadiyapatanam fishing ground. The major groups of organisms in the fishing ground were echinoderms, fishes, sponges, crustaceans and molluscs. The paper discusses the probable influence of environmental and ecological factors that impact the distribution and fishery of P. homarus in the fishing grounds of Khadiyapatanam
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