848 research outputs found

    Multicast Conventions to Improve Obstacle Detection and Collusion Avoidance in MANET

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    As of late, it got to be obvious that gathering focused administrations are one of the essential application classes focused by MANETs. In spite of the fact that these conventions perform well under particular versatility situations, movement loads, and system conditions, no single convention has been appeared to be ideal in all situations. The objective of this paper is to describe the execution of multicast conventions over an extensive variety of MANET situations. To this end, we assess the execution of lattice and tree-based multicast steering plans in respect to flooding and prescribe conventions most reasonable for particular MANET situations. In view of the investigation and reproduction results, we likewise propose two varieties of flooding, Perused flooding and hyper flooding, as a way to diminish overhead and expansion unwavering quality, separately. Another commitment of the paper is a recreation based relative investigation of the proposed flooding varieties against plain flooding, work, and tree-based MANET directing. In this paper we researched about various sending technique for GPSR in remote system furthermore discover the issues and their answers. The principle point of our study was to distinguish which directing strategy has better execution in very versatile environment of VANET. In MANET, this depletion of vitality will be more because of its infrastructure less nature and versatility. Because of this, the topology get shifted. This may definitely influence the execution of steering convention furthermore influence the system lifetime. To address this issue another calculation has been created which uses the system parameters identifying with element nature of hubs viz. vitality channel rate, relative versatility estimation to foresee the hub lifetime and connection lifetime. At that point execute this calculation in the DYMO convention environment. This will expand the system lifetime and adaptability. Further enhance the execution, we have actualized another calculation by incorporating course lifetime expectation calculation alongside the molecule swarm enhancement (PSO) calculation

    Phosphorus Mobilizers from Mangrove Ecosystem and their Role in Desalination of Agricultural Lands

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    Globally the agricultural activities are having shrinkage in terms of area and salinization of agricultural lands is one of the most serious environmental problems. Nationally our land is affected by salinity and alkalinity, and thus results in decreased production. Phosphorus being one of the essential mineral nutrients limits the plant growth and is unavailable to plants due to its low solubility and high fixation in the soil. Hence, this is rectified with additional supply of as phosphatic fertilizers. However, major portion of soluble inorganic phosphate in form of chemical fertilizer applied to soil is immobilized rapidly and occurs in oxidised form as phosphates bounded to aluminium, calcium or iron and becomes unavailable to plants. Hence, the use of phosphorus-mobilizing bacteria can provide a solution to the problem of limited phosphorus availability in salt-affected soils. The application of phosphorus-mobilizing bacteria as biofertilizer can not only improves the growth and quality of produce, but also drastically reduces the usage of chemical fertilizers. Hence, phosphorus-mobilizing bacteria can be used as environment friendly bio-fertilizers help to reduce the requirement of phosphatic fertilizer

    Bringing "The Moth" to Light: A Planet-Sculpting Scenario for the HD 61005 Debris Disk

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    The HD 61005 debris disk ("The Moth") stands out from the growing collection of spatially resolved circumstellar disks by virtue of its unusual swept-back morphology, brightness asymmetries, and dust ring offset. Despite several suggestions for the physical mechanisms creating these features, no definitive answer has been found. In this work, we demonstrate the plausibility of a scenario in which the disk material is shaped dynamically by an eccentric, inclined planet. We present new Keck NIRC2 scattered-light angular differential imaging of the disk at 1.2-2.3 microns that further constrains its outer morphology (projected separations of 27-135 AU). We also present complementary Gemini Planet Imager 1.6 micron total intensity and polarized light detections that probe down to projected separations less than 10 AU. To test our planet-sculpting hypothesis, we employed secular perturbation theory to construct parent body and dust distributions that informed scattered-light models. We found that this method produced models with morphological and photometric features similar to those seen in the data, supporting the premise of a planet-perturbed disk. Briefly, our results indicate a disk parent body population with a semimajor axis of 40-52 AU and an interior planet with an eccentricity of at least 0.2. Many permutations of planet mass and semimajor axis are allowed, ranging from an Earth mass at 35 AU to a Jupiter mass at 5 AU.Comment: Accepted to AJ; added Figure 5 and minor text edit

    Gemini Planet Imager Observational Calibrations VI: Photometric and Spectroscopic Calibration for the Integral Field Spectrograph

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    The Gemini Planet Imager (GPI) is a new facility instrument for the Gemini Observatory designed to provide direct detection and characterization of planets and debris disks around stars in the solar neighborhood. In addition to its extreme adaptive optics and corona graphic systems which give access to high angular resolution and high-contrast imaging capabilities, GPI contains an integral field spectrograph providing low resolution spectroscopy across five bands between 0.95 and 2.5 μ\mum. This paper describes the sequence of processing steps required for the spectro-photometric calibration of GPI science data, and the necessary calibration files. Based on calibration observations of the white dwarf HD 8049B we estimate that the systematic error in spectra extracted from GPI observations is less than 5%. The flux ratio of the occulted star and fiducial satellite spots within coronagraphic GPI observations, required to estimate the magnitude difference between a target and any resolved companions, was measured in the HH-band to be Δm=9.23±0.06\Delta m = 9.23\pm0.06 in laboratory measurements and Δm=9.39±0.11\Delta m = 9.39\pm 0.11 using on-sky observations. Laboratory measurements for the YY, JJ, K1K1 and K2K2 filters are also presented. The total throughput of GPI, Gemini South and the atmosphere of the Earth was also measured in each photometric passband, with a typical throughput in HH-band of 18% in the non-coronagraphic mode, with some variation observed over the six-month period for which observations were available. We also report ongoing development and improvement of the data cube extraction algorithm.Comment: 15 pages, 6 figures. Proceedings of the SPIE, 9147-30

    Parameters and Predictions for the Long-Period Transiting Planet HD 17156b

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    We report high-cadence time-series photometry of the recently-discovered transiting exoplanet system HD 17156, spanning the time of transit on UT 2007 October 1, from three separate observatories. We present a joint analysis of our photometry, previously published radial velocity measurements, and times of transit center for 3 additional events. Adopting the spectroscopically-determined values and uncertainties for the stellar mass and radius, we estimate a planet radius of Rp = 1.01 +/- 0.09 RJup and an inclination of i = 86.5 +1.1 -0.7 degrees. We find a time of transit center of Tc = 2454374.8338 +/- 0.0020 HJD and an orbital period of P = 21.21691 +/- 0.00071 days, and note that the 4 transits reported to date show no sign of timing variations that would indicate the presence of a third body in the system. Our results do not preclude the existence of a secondary eclipse, but imply there is only a 9.2% chance for this to be present, and an even lower probability (6.9%) that the secondary eclipse would be a non-grazing event. Due to its eccentric orbit and long period, HD 17156b is a fascinating object for the study of the dynamics of exoplanet atmospheres. To aid such future studies, we present theoretical light curves for the variable infrared emission from the visible hemisphere of the planet throughout its orbit.Comment: 8 pages, 4 figures, 1 table, emulateapj format. v2: accepted for publication in ApJ, minor changes. Changed to emulateapj to save the rainforest

    Accumulator pricing

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    Accumulator is a highly path dependant derivative structure that has been introduced as a retail financial product in recent years and becomes very popular in some Asian cities with its speculative nature. Despite its popularity, its pricing formula is not well known especially when there is a barrier structure. When the barrier in an accumulator contract is applied continuously, this paper obtains exact analytic pricing formulae for immediate settlement and for delay settlement. For discrete barrier, we also obtain analytic formulae which can approximate the fair price of an accumulator under both settlement methods. Through Monte Carlo simulation, we show that the approximation is highly satisfactory. With price formulae in close forms, this paper further explains how to price the product fairly to fit into its zero-cost structure. The analytic formulae also help in computing the Greeks of an accumulator which are documented in this paper. An asymmetry can be observed here that when the buyer is suffering a loss, risk characteristics like delta and vega are substantially larger than when the buyer is enjoying a profit. This means that losing buyers will be more vulnerable to price changes and volatility changes than winning buyers. This is consistent with another observation in the paper that the value at risk for the buyer can be several times larger than that of the seller. © 2009 IEEE.published_or_final_versionThe IEEE Symposium on Computational Intelligence for Financial Engineering (CIFEr) 2009, Nashville, TN., 30 March-2 April 2009. In Proceedings of the CIFEr, 2009, p. 72-7

    Prospective nutritional, therapeutic, and dietary benefits of camel milk making it a viable option for human consumption: Current state of scientific knowledge

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    For over five thousand years, people in Asia and Africa have known about the health benefits of camel milk. Thus, it is used not only as a food source but also as a medicine. The similarities between camel milk and human milk have been scientifically proven. Camel milk is unique among ruminant milk because it is high in vitamins C and E and low in sugar and cholesterol. Still, it contains a wide variety of beneficial minerals (including sodium, potassium, iron, copper, zinc, and magnesium), besides being rich in several nutrients, including monounsaturated and polyunsaturated fatty acids, serum albumin, lactoferrin, immunoglobulins, lysozyme and the hormone insulin. Because of these components, many medical professionals now recommend camel milk as a treatment for various human ailments. It has been demonstrated to be effective in treating gastrointestinal issues, Type 1 diabetes, and food allergies. As a bonus, camel milk has been utilized to cure autism, lower cholesterol, prevent psoriasis, heal inflammation, aid tuberculosis patients, boost the body's natural defences, and impede the spread of cancer cells. Those who have problems digesting lactose may still be able to tolerate it. Conversely, camel milk can also help reduce an excessively high bilirubin, globulin, and granulocyte count. Drinking camel milk does not affect the erythrocyte sedimentation rate, hemoglobin concentration, and leukocyte count. The proteins in camel milk have an adequate ratio of critical amino acids. Immunoglobulins, which fight disease, are contained inside, and their small size allows antigens to penetrate and boosts the immune system's efficacy. This article highlights the health benefits and medicinal uses of camel milk

    Dynamical Mass Measurement of the Young Spectroscopic Binary V343 Normae AaAb Resolved With the Gemini Planet Imager

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    We present new spatially resolved astrometry and photometry from the Gemini Planet Imager of the inner binary of the young multiple star system V343 Normae, which is a member of the beta Pictoris moving group. V343 Normae comprises a K0 and mid-M star in a ~4.5 year orbit (AaAb) and a wide 10" M5 companion (B). By combining these data with archival astrometry and radial velocities we fit the orbit and measure individual masses for both components of M_Aa = 1.10 +/- 0.10 M_sun and M_Ab = 0.290 +/- 0.018 M_sun. Comparing to theoretical isochrones, we find good agreement for the measured masses and JHK band magnitudes of the two components consistent with the age of the beta Pic moving group. We derive a model-dependent age for the beta Pic moving group of 26 +/- 3 Myr by combining our results for V343 Normae with literature measurements for GJ 3305, which is another group member with resolved binary components and dynamical masses.Comment: 12 pages, 7 figures. Accepted to A
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